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## John Baez

I'm trying to get mathematicians and physicists to help save the planet.

Occupation: I'm a mathematical physicist. (Centre for Quantum Technologies)

Location: Riverside, California

His ProfilesRankThis is the rank of 'John Baez' out of all Google+ Profiles (individuals).: 2,523 (GenderRankFor the gender 'Men'.: 1,170)

His ProfilesRankThis is the rank of 'John Baez' out of all Google+ Profiles (individuals). in United States: 708 (GenderRankFor the gender 'Men'.: 413)

Followers: 53,707

Following: -

Views: 30,383,181

Cream of the Crop: 11/05/2011

Added to CircleCount.com: 07/21/2011That's the date, where John Baez has been indexed by CircleCount.com.

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### John Baez has been shared in 324 public circles

You can see here the 50 latest shared circles.

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Author | Followers | Date | Users in Circle | Comments | Reshares | +1 | Links | |
---|---|---|---|---|---|---|---|---|

Becky Collins | 16,609 | Science Circle :Circle of very #social #engagerspeople and companiesTo be included in my shares (#sharedcircle), be so kind to:1 - Do +1 t the post2 - Comment the post and specify your "category" (job or interest) Ex: Fashion, SEO, Companies, Social Media Marketing, Sailing, Photography, Bloggers/Writers, Web graphics and design, Italy, Artists, Sport, Finance/Economy ...3 - include the circle among your circles4 - share the circle (include yourself)Improve your popularity, be social be cool !Keep yourself updated, enjoy the Shared Circles Hellenic Alliance, you can share your shared circles inside the upcoming Community:https://plus.google.com/communities/112552559573595396104 #socialmedia #media #circles #circleshare #circlesharing #circlecircle #beckyscircle #sharedcircles #sharedpubliccircles #sharedcircleoftheday +Becky Collins ? | 2014-09-16 05:24:00 | 459 | 1 | 0 | 2 | |

Richard Green | 81,215 | Engagers Showcase Circle, September 14, 2014If I sent you a notification, it means that you are included in my Engagers Showcase Circle. “Showcase” means that you are invited to leave a comment (on the original post) with a link to one of your own posts, which ideally should be one of your best recent posts.This circle consists of people who have engaged with one of my recent posts in the form of +1s, comments and reshares. I skipped over one post because it received too much engagement, but I'm including a link to it for completeness.Everyone mentioned below is also included in the circle.Do nuclear physicists have half life crises?https://plus.google.com/101584889282878921052/posts/ayw6WPGGaFESt Peter's Church, Heyshamhttps://plus.google.com/101584889282878921052/posts/9DEtmbdz15zSmiling cow?https://plus.google.com/101584889282878921052/posts/9NuqPpsgtBkThe look-and-say sequence and Conway's Cosmological Theoremhttps://plus.google.com/101584889282878921052/posts/jEQ7zxFpJt4Cordyline australis, the “cabbage tree”https://plus.google.com/101584889282878921052/posts/hktDAgyo6mA“Maurits, stop picking at it. You'll only make it worse.” by David Swarthttps://plus.google.com/101584889282878921052/posts/gj327Ywh33T“Phyllotactic Portrait of Fibonacci” by Robert Boschhttps://plus.google.com/101584889282878921052/posts/8LykdvHpRvPFountain in Williamson Parkhttps://plus.google.com/101584889282878921052/posts/HzZTLQaQ9RT“Youth” by Silvia Cordeddahttps://plus.google.com/101584889282878921052/posts/T2Lo3c2zLxvThe arithmetic derivative, the Goldbach conjecture, and the twin prime conjecturehttps://plus.google.com/101584889282878921052/posts/9nY35Ma1pbUGlobe Thistlehttps://plus.google.com/101584889282878921052/posts/i8mtiyVikWhTallinn (reshared from +Paul Harper)https://plus.google.com/101584889282878921052/posts/U4DAQxK5fkxCubes passing in the night (reshared from +Sean Walker)https://plus.google.com/101584889282878921052/posts/32JKvAFqP9SThe graph of arctanhttps://plus.google.com/101584889282878921052/posts/FLvyDupud1z“Hopf Knott” by Peter Sittner | 2014-09-14 15:25:57 | 463 | 212 | 113 | 212 | |

Cableicous | 2,882 | Thanks for all teh cablezThanks muchly to all those who have contributed their #Cableicous imagery for this 14th circle of 99 people who have contributed their cableicous grandeur - your continued support of my cable fetish is much enjoyed.And a new circle of 99 begins...#photography #cables #cableicous #circleshare #2014 #cableriacirculus | 2014-09-10 10:47:19 | 99 | 12 | 4 | 42 | |

Becky Collins | 15,950 | Dance Related Circle :Circle of very #social #engagerspeople and companiesTo be included in my shares (#sharedcircle), be so kind to:1 - Do +1 t the post2 - Comment the post and specify your "category" (job or interest) Ex: Fashion, SEO, Companies, Social Media Marketing, Sailing, Photography, Bloggers/Writers, Web graphics and design, Italy, Artists, Sport, Finance/Economy ...3 - include the circle among your circles4 - share the circle (include yourself)Improve your popularity, be social be cool !Keep yourself updated, enjoy the Shared Circles Hellenic Alliance, you can share your shared circles inside the upcoming Community:https://plus.google.com/communities/112552559573595396104 #socialmedia #media #circles #circleshare #circlesharing #circlecircle #beckyscircle #sharedcircles #sharedpubliccircles #sharedcircleoftheday +Becky Collins ? | 2014-09-02 05:00:43 | 471 | 30 | 9 | 35 | |

EDZUL FREDY KRISNAWAN | 0 | Meet the People who WILL...Take This Circle To The TopLet 'er Rip! You guys and gals are SUPERSTARS!!!Want to be added to the #hyperadd?1) Add me to your circles.2) Share, +1, and Comment This Share3) Reshare anything that interests you on my stream (profile) from today or the rest of this week.#circlesharing #sharedcircles #circles #circlemaster | 2014-08-29 11:28:10 | 485 | 11 | 4 | 13 | |

Wendy Thanh Hồng | 43 | GOOGLE FRIENDS! - RESHARE if you want to be included *'"*:•:••:*:•-:¦:* *SHARE AND BE SHARED* *:¦:-•:*:••-:•:''''* This is a super Circle and in it I put together a group of really interesting and active people on Google Plus to add in your circles.I'm talking about the top Google + users that share unique and original contents.Follow this advice and grow your G+ community with people that share amazing content that will surprise you:boost visibility on Google+ - Share the circle!If you want to be added to the next Circle you have to do these simple steps:1 - Include me in your circles 3 - Share the circle (Publicly) 4 - Add +1 to the post 5 - Follow your dreams and smile to life.More you share More you get! :)I will thankful if you plus and share this circle!#circles #shared #share #add #friends #circle #share #sharecircle #circleshare | 2014-08-25 05:58:23 | 486 | 11 | 3 | 15 | |

Kieu Trinh | 0 | GOOGLE FRIENDS! - RESHARE if you want to be included *'"*:•:••:*:•-:¦:* *SHARE AND BE SHARED* *:¦:-•:*:••-:•:''''* This is a super Circle and in it I put together a group of really interesting and active people on Google Plus to add in your circles.I'm talking about the top Google + users that share unique and original contents.Follow this advice and grow your G+ community with people that share amazing content that will surprise you:boost visibility on Google+ - Share the circle!If you want to be added to the next Circle you have to do these simple steps:1 - Include me in your circles 3 - Share the circle (Publicly) 4 - Add +1 to the post 5 - Follow your dreams and smile to life.More you share More you get! :)I will thankful if you plus and share this circle!#circles #shared #share #add #friends #circle #share #sharecircle #circleshare | 2014-08-25 05:34:03 | 486 | 13 | 6 | 19 | |

Cableicous | 2,902 | Thanks for all teh cablezThanks muchly to all those who have contributed their #Cableicous imagery for another grand week of beautaliciousness.And a new week begins...#photography #cables #cableicous #circleshare #2014 #cableriacirculus | 2014-08-09 22:10:58 | 40 | 6 | 1 | 19 | |

Richard Green | 77,832 | Engagers Showcase Circle, August 7, 2014If I sent you a notification, it means that you are included in my Engagers Showcase Circle. “Showcase” means that you are invited to leave a comment (on the original post) with a link to one of your own posts, which ideally should be one of your best recent posts.This circle consists of people who have engaged with one of my recent posts in the form of +1s, comments and reshares.Everyone mentioned below is also included in the circle.Our cat, Chesterhttps://plus.google.com/101584889282878921052/posts/ToxRHsMHytsFibonacci numbers and corridors of width 4https://plus.google.com/101584889282878921052/posts/gCTyaSV4ugzWalk in the rainhttps://plus.google.com/101584889282878921052/posts/gVPzuv7aKHALenticular cloud (reshared from +Sean R. Heavey)https://plus.google.com/101584889282878921052/posts/giTgt4PUd1GGlass Paperweight by Paul Stankardhttps://plus.google.com/101584889282878921052/posts/fLfKWxFj3f2“Mathematistan” by Martin Kuppehttps://plus.google.com/101584889282878921052/posts/AcUBb8Y9uBjCat's back on the menu, boys!https://plus.google.com/101584889282878921052/posts/aP3cZEnaqquWaterfall (reshared from +Keith Boone)https://plus.google.com/101584889282878921052/posts/S2pmsTTyiZzOak tree at “The Pig”https://plus.google.com/101584889282878921052/posts/cv8pi2ffX1NThe Bargate, Southamptonhttps://plus.google.com/101584889282878921052/posts/LsYSEpUS1bLCosmos flowerhttps://plus.google.com/101584889282878921052/posts/KqvLW32KyXfThe Ashton Memorialhttps://plus.google.com/101584889282878921052/posts/aK1E3XqWWSSThrough the castle windowhttps://plus.google.com/101584889282878921052/posts/MT7uBM2SUt7Friedman numbershttps://plus.google.com/101584889282878921052/posts/32tzjfB8NnMThe Norfolk Knifehttps://plus.google.com/101584889282878921052/posts/DHf4jfSkUKKThe lake at Wyresdale Parkhttps://plus.google.com/101584889282878921052/posts/3xFACaympiNCastle of the Clouds | 2014-08-07 21:46:51 | 451 | 213 | 123 | 238 | |

Nick Warner | 645 | Check out these awesome Crowdfunders | 2014-08-07 16:05:31 | 470 | 0 | 0 | 1 | |

Refurio Anachro | 4,492 | This july engagers circle comes packed with curiosity, brought to life by questions and answers, and people sharing their enthusiasm. Take your chance, get acquainted to this party of very nice people and deep thinkers, add it now!+John Baez had asked for an inside view of a mirror ellipsoid i was happy to provide. The result's actually a spheroid because it has a symmetry axis. Since then, i did quite some staring at ellipsoids, see below... https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/5zcrptKx3C3This reshare of +Xah Lee's "math is programing" rant got me into ugly. Gracefully handling distractions would be nice to have more of. If you must know, i heard one can retrieve deleted comments using the search...https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/TZpAUuQfzSn“Mathematistan” by Martin Kuppe offers innocuous glances aside from the popular maths mainstream. Thanks +Richard Green for sharing and noting similarities to the all time favorite "Hitchikers guide to the galaxy"!https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/UnXikyENJo1A raytraced perspective down a mirror cylinder showing quite a lot about billiard trajectories on a bunch of elliptic tables. Learn what Birkhoff, Poincare, and Poncelet had to do with it...https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/Vmrx7GMRe2iReshare of 6d toroid animations, thanks +Owen Maresh and +Cornus Ammonis for sharing!https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/gSma1ksKFeiThis ellipsoid glossary and coordinate system came with puzzles! Special thanks to +Bruce Elliott for taking part in the fun. Apparently i didn't add a clean solution putting everything together at the end... More to come, stay tuned!https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/L6C4Kob2bNeLast june's engagers circlehtt | 2014-08-03 23:22:23 | 113 | 14 | 3 | 10 | |

Marius Kiupelis | 279 | If you received this notification you are in this circle♚♚ If you want to be shared in this circle ♚♚♚♚♚♚♚ Then just keep sharing! ♚♚♚♚♚ | 2014-08-03 19:05:53 | 201 | 0 | 3 | 6 | |

Lynda Chervil | 890 | Add this circle of excellent engagers, thinkers, innovators, and future tech leaders. My ++Solar Power++ Circle will provide you with the latest and greatest from the world of tech innovations, especially in the renewable energy sector. Simply add this circle and then share it!If you'd like to be added to this circle, please comment below, share and add the circle. Only those who qualify with content and expertise will be added. Thanks! #Tesla #nikolatesla #elonmusk #solarenergy #innovation #technology #solarpower #hydroelectric #science #STEM #research #education #futuretech #futuretechnology | 2014-07-31 14:24:32 | 343 | 1 | 2 | 5 | |

Peter Edenist | 31,015 | 2014 Super Sci-FI Circle : No, the Sky is not Falling!!! Also the Gravity is not sucking you in... please +1 this post to support it or you may have to take a trip in Snowpiercer, no need to thank me. Please reshare if you think this is a worthwhile circle. If you have been notified, you are in the circle!All the people in this circle are linked to our community (see link further down). As usual, please tag and recommend anyone who you think should be in this circle. Live long and prosper!Sci-FI Community here: http://goo.gl/s1NVd Science Fiction Pics: http://goo.gl/sOSPK5Mighty Shiny Browncoats : http://goo.gl/9osg1tDoctor Who : http://goo.gl/z3uWX3Ultimate Star Wars : http://goo.gl/Wu8bv6Ultimate Star Trek : http://goo.gl/JJPql9Science on G+ community here: http://goo.gl/46uFH #sciencefiction #sf #scifi | 2014-07-24 12:58:07 | 462 | 119 | 60 | 145 | |

Becky Collins | 13,434 | Mobile Operator Circle:Circle of very #social #engagerspeople and companiesTo be included in my shares (#sharedcircle), be so kind to:1 - Do +1 t the post2 - Comment the post and specify your "category" (job or interest) Ex: Fashion, SEO, Companies, Social Media Marketing, Sailing, Photography, Bloggers/Writers, Web graphics and design, Italy, Artists, Sport, Finance/Economy ...3 - include the circle among your circles4 - share the circle (include yourself)Improve your popularity, be social be cool !Keep yourself updated, enjoy the Shared Circles Hellenic Alliance, you can share your shared circles inside the upcoming Community:https://plus.google.com/communities/112552559573595396104 #socialmedia #media #circles #circleshare #circlesharing #circlecircle #beckyscircle #sharedcircles #sharedpubliccircles #sharedcircleoftheday +Becky Collins ? | 2014-07-24 05:16:12 | 476 | 3 | 1 | 12 | |

Able Lawrence | 100,166 | 100K Engagers Celebration Circle Thank you all those who have followed me and engaged with my posts and taking me to the milestone of 100,000 followers. Goolge+ has been an exhilarating journey of 3 years and I would like to thank all those who have followed me and engaged on my posts whether they were on Science or Birds or Technology. The circle has been created using * +Circloscope * which is the work of +Ehsan Ahmadi Gharacheh All of you are free to share your favorite posts in the comments and also reshare this circle. If you are included in the circle, you will get a notification. | 2014-07-17 17:22:18 | 340 | 49 | 17 | 87 | |

Doug Hyatt | 5,196 | THIS IS MEGA CIRCLE 5 #DOUGHYATTCIRCLESHARING IT ADDED 1,000+ FOLLOWERS FOR ME IN A WEEK.1) ADD THE CIRCLE2) RESHARE THE CIRCLE AND BE SURE TO REMEMBER TO CHECK THE BOX WHICH INCLUDES YOURSELF.3)RESHARE TO PUBLIC EVERY DAY!BE SURE TO COPY THE HASHTAG LIST AND ADD IN YOUR COMMENTS LIKE I HAVE! IT WILL GIVE YOU MAXIMUM RESULTS#doughyattcirclesharing#circles #circlemania #circletoday #circleplus #circleshare #circlesharing #CircleSharing #sharecircle #sharecirclethis #worldsharecircle #pleasecircleaddme #circleoftheday #newgenerationcircle #monstercircle #usacircle #bestofthecircle #shareofthecircle #pleasecircle #newbestcircl add circle add circle * best share circle * share please pleaseplease add circle * best share circle * share please please#add #circle #addcircle #pleasecircle #bestcircle #mostcircle #bestsharecircle #newcircle #top100circle #best500circle #top500circle | 2014-07-16 15:49:10 | 477 | 15 | 14 | 21 | |

Richard Green | 74,896 | Engagers Showcase Circle, July 12, 2014If I sent you a notification, it means that you are included in my Engagers Showcase Circle. “Showcase” means that you are invited to leave a comment (on the original post) with a link to one of your own posts, which ideally should be one of your best recent posts.This circle consists of people who have engaged with one of my recent posts in the form of +1s, comments and reshares.Everyone mentioned below is also included in the circle.Thistlehttps://plus.google.com/101584889282878921052/posts/CKB7ks1VWZ3“Star Gate” by +Gary Matthews https://plus.google.com/101584889282878921052/posts/ean83YFix7sBubble (reshared from +Ann-Marie Jurek)https://plus.google.com/101584889282878921052/posts/PkybKJfXv14Gabriel's Hornhttps://plus.google.com/101584889282878921052/posts/MXNTuq8ZEBPHibiscus flowerhttps://plus.google.com/101584889282878921052/posts/Xsmw62v98CHStackable 12-sided dicehttps://plus.google.com/101584889282878921052/posts/5mLoukdZAA5Astronomical book priceshttps://plus.google.com/101584889282878921052/posts/S15LTNxJA9GPyritohedral symmetryhttps://plus.google.com/101584889282878921052/posts/XQUYMrKGiAQSt Stephen's Basilica (reshared from +Laura Orange)https://plus.google.com/101584889282878921052/posts/ApnSMBsUWFeCircular Pascal Arrays and Fibonacci numbershttps://plus.google.com/101584889282878921052/posts/NVqYKoRVnHg“Fungi tree” by +Tom Beddardhttps://plus.google.com/101584889282878921052/posts/J6S4bDc6QwQAs always, reshares of this circle are appreciated, and I look forward to seeing everyone's links. Thanks for reading my posts! | 2014-07-12 05:31:36 | 476 | 209 | 126 | 225 | |

Refurio Anachro | 4,312 | June engagers circle: Say hello to almost 200 nice people who joined in to participate in math topics. If you're intelligent, curious, like well written posts and engaged discussion - these people will not dissappoint. Go on and add them now!Last month's posts:Spin story continues (part 3): Angular velocity and tilings in spin space. While i locked myself in a cycle, struggling to follow, +wendy krieger blew the bubble and lifted the party up to dimension 4! I couldn't resist but to guest post this gem. Next time i'll find a picture first, promised!:https://plus.google.com/115434895453136495635/posts/6F9sxQxiqEaClifford Algebra (part 1): Into Clifford algebra. Because with those one can easily describe spin in any dimension.https://plus.google.com/115434895453136495635/posts/1CtiDXou6RqUnicode math cheat sheet: ⁵√7+x² – ℵ₀ – ℝⁿ – x̅ ≟ x*⊕x⁎ – αβ ≺ ∇ϕhttps://plus.google.com/115434895453136495635/posts/GNoCEmBxSWSClifford Algebra (part 2): Multiplication in geometric algebra.https://plus.google.com/115434895453136495635/posts/NKqs5BwsCqqCardioid gears, a reshare of +Rob Kook's very unexpected video find:https://plus.google.com/115434895453136495635/posts/UMBXJihPgcaCan we get anything faster than light that way? While arguing below +John Baez' cool post i suddenly started hearing vikings...https://plus.google.com/115434895453136495635/posts/jjYu4KhHaCTClifford Algebra (part 3): Cayley graphs and a strange clock. My first attempt to quickly put my thoughts down for you to see. I guess i'll have to practice a bit to make it more appealing on shorter glance, so more people can benefit.https://plus.google.com/115434895453136495635/posts/bkHQAZLzpt8Last may's engagers circle:https://plus.google.com/115434895453136495635/posts/hGPebLWRcU2You're in this circle because you reshared, plussed or commented on one of my posts (possibly via +Spherical Reflections), or got into a discussion with me. Thank you!#engagers #engagerscircle #engagersshowcasecircle #circleshare #circlesharing #circl | 2014-07-02 13:23:15 | 194 | 6 | 5 | 9 | |

Peter Edenist | 30,747 | TESLA Super Science Circle 2014 - June Edition!!!! : A quality circle curated carefully and tended since 2011. Who is in this circle? people who are either involved in science, love science or are active on the Science on G+ community. Community link is here http://goo.gl/46uFH and the Page is +Science on G+!Have you wondered where one can meet with like-minded people who love science and like to read about the real stuff? This is the ultimate SUL on science.... add and share to keep it alive.--------------------------------------------------------------------------------------------------Want to nominate someone? Please do so in comments. If you want to recommend something let us know. People who are notified are part of the circle.#science #tesla #scienceongplus #scienceeveryday | 2014-06-19 13:39:49 | 342 | 75 | 56 | 93 | |

David Wees | 4,496 | This is a circle of 346 math educators. If you are interested in following the work of innovative mathematics educators, this circle is for you.If you are a mathematics educator, and I have not included you in this circle, let me know. | 2014-06-11 16:24:03 | 346 | 0 | 1 | 0 | |

Dina Tika | 0 | Here is a group of Active Engagers, Circle Sharers, Awesome Plus Oners, and Cool People on Google Plus! Circle Sharing is an awesome way to increase your followers and active engagers on your profile. Some of my favorite people that I've met here on Google + through Circle Sharing. Want to be in the next Circle of Awesomeness? Follow the Steps Below! ☛ Add the circle ☛ Share in the Public ☛ Plus 1 the Post. ☛ Comment. | 2014-06-10 05:53:52 | 479 | 0 | 0 | 1 | |

Refurio Anachro | 4,141 | May engagers circle: Meet the people who made the fabulous cheer of this week's spin party. Many curious people, all of them worth to add!Diagram 18: rotations and spinorshttps://plus.google.com/b/115434895453136495635/115434895453136495635/posts/dpPMfoH6zc5This is actually part two, but got posted earlier (see below). You just made my first +100, thank you! Stay tuned for more on spinning and spinors.https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/TLkA6tCNwEeIf you want to know what an earlier stage of Diagram 18 looked like, see here. I posted 2/3rd of the final post with a question marking my progess. Also note the discussion below, thanks to everybody who helped me out!https://plus.google.com/b/115434895453136495635/115434895453136495635/posts/THePbpcPnqDYou're in this circle because you reshared, plussed or commented on one of my posts (possibly via +Spherical Reflections), or got into a discussion with me. Thank you!Last april's engagers circlehttps://plus.google.com/b/115434895453136495635/115434895453136495635/posts/RFMY2aYscJJ#engagers #engagerscircle #engagersshowcasecircle #circleshare #circlesharing #circle #circleoftheday #addcircle #findcircles #publicsharedcircles #addpeople #plussers #awesomepeople #sciencecircle #commenterscircle #mathematicians #friends | 2014-06-02 11:57:02 | 158 | 4 | 4 | 7 | |

John Nuntiatio | 37,493 | 30k+ Circle - A circle worth adding and followingThe people from this circle have more than 30,000 followers. | 2014-06-02 08:54:46 | 140 | 4 | 9 | 6 | |

Becky Collins | 10,282 | Mobile Circle :Circle of very #social #engagerspeople and companiesTo be included in my shares (#sharedcircle), be so kind to:1 - Do +1 t the post2 - Comment the post and specify your "category" (job or interest) Ex: Fashion, SEO, Companies, Social Media Marketing, Sailing, Photography, Bloggers/Writers, Web graphics and design, Italy, Artists, Sport, Finance/Economy ...3 - include the circle among your circles4 - share the circle (include yourself)Improve your popularity, be social be cool !Keep yourself updated, enjoy the Shared Circles Hellenic Alliance, you can share your shared circles inside the upcoming Community:https://plus.google.com/communities/112552559573595396104 #socialmedia #media #circles #circleshare #circlesharing #circlecircle #beckyscircle #sharedcircles #sharedpubliccircles #sharedcircleoftheday +Becky Collins ? | 2014-05-28 05:03:17 | 477 | 7 | 2 | 19 | |

Jasmina Brozović | 53,426 | Notification CircleThis is a circle of people I don't wanna miss any new posts from!Great Circle idea by +Zvonimir FrasRead more :https://plus.google.com/u/0/+ZvonimirFras/posts/VsZjS7H7vJf#circles #circlethis #circleyoushare #sharedcircles #addcircle #sharedpubliccircles #circleshare #publicsharedcircles #circleoftheweek #circlesharing #publiccircle #sharedcircle #circleshare #circle #motivateme | 2014-05-20 16:26:14 | 179 | 27 | 10 | 31 | |

Daniel Zawadzki | 7,897 | This #circle is #great, #amazing, #wonderful,Boost your visibility on Google+ - Share the circle!#1 - Click add people and create your circle#2 - share the circle (include yourself)#3 - add +1 to the post#circle #circleshare #circlesharing #circleoftheday #circleoftheweek #share #sharedcircles #sharedpubliccircles #sharedcircleoftheday #engagers #engagerscircle #engagerspeople | 2014-05-19 20:33:55 | 470 | 94 | 46 | 123 | |

Refurio Anachro | 4,070 | April engagers circle, a ball of intelligent, nice, and responsive people. Have a look!You're in this circle because you reshared, plussed or commented on one of my posts (possibly via +Spherical Reflections), or got into a discussion with me. Thank you!The following has been classic april fool's, of course. Works best on kids %-]https://plus.google.com/115434895453136495635/posts/SA2aNCZPrQkNot being a big fan of synchronous communication, i will try and challenge you in case you do want to hang out. That's a rather new ploy of my character, and it seems i still have to learn a lot on how to do this nicely...https://plus.google.com/115434895453136495635/posts/fM8DtSPKL2MI have been seen spreading rumours with +David Roberts, speculating that this year's Fields medal might go to Manjul Bhargava. Here for the fullest explanation, thanks again David:https://plus.google.com/115434895453136495635/posts/KUbagU2C7C7A raytraced landscape featuring two spherical mirrors. It's about dynamical billiards (chaos theory).https://plus.google.com/115434895453136495635/posts/BCduuGFS75LWhen i saw +Richard Green's post about Coxeter-Conway friezes i couldn't resist to divert my readers to have fun counting paths with +DrJamesTanton. Fibonacci inside:https://plus.google.com/115434895453136495635/posts/gKBcK1HNdMvEverybody should have played at least once with an interactive IFS demo! If you haven't, or want to try again - here's a nice one by +Felix Woitzel:https://plus.google.com/115434895453136495635/posts/N9HeysDgTzi #engagers #engagerscircle #engagersshowcasecircle #circleshare #circlesharing #circle #circleoftheday #addcircle | 2014-05-16 11:46:12 | 81 | 8 | 6 | 7 | |

Richard Green | 68,138 | Engagers Showcase Circle, May 12, 2014If you received a notification, it means that you are included in my Engagers Showcase Circle. “Showcase” means that you are invited to leave a comment (on the original post) with a link to one of your own posts, which ideally should be one of your best recent posts.This circle consists of people who have engaged with one of my recent posts in the form of +1s, comments and reshares.Everyone mentioned below is also included in the circle.Peruvian glacier (reshared from +Irina Tcherednichenko)https://plus.google.com/101584889282878921052/posts/Z6NR7zaZa5qGrape hyacinthshttps://plus.google.com/101584889282878921052/posts/GZoHH2bnRUiSymmetries of a regular octagonhttps://plus.google.com/101584889282878921052/posts/bFcGcsurF5HHappy Easter!https://plus.google.com/101584889282878921052/posts/YkWFA9WmxVAPerfect Squared Squareshttps://plus.google.com/101584889282878921052/posts/HDU4mWD3wptOur dog Rexhttps://plus.google.com/101584889282878921052/posts/5JtEcnt5MpPPerrott's Follyhttps://plus.google.com/101584889282878921052/posts/8DzXHLn6fe4The Lonely Runner Conjecturehttps://plus.google.com/101584889282878921052/posts/YHJkEdKg3jz“Owl” by Andrea Mininihttps://plus.google.com/101584889282878921052/posts/12uh9J9MjMXPenrose nanotileshttps://plus.google.com/101584889282878921052/posts/7PZPSLaFkAx“Interlaced Stars” by Magnenauthttps://plus.google.com/101584889282878921052/posts/5vNjv1yjVMqBlack Forest View (reshared from +Ralph Reichert)https://plus.google.com/101584889282878921052/posts/YKPsvCFDyUv“Hippie Bus Apartments” by +Richie Montgomeryhttps://plus.google.com/101584889282878921052/posts/iCMXCBVzjd2Not crazy enoughhttps://plus.google.com/101584889282878921052/posts/d5EeDSoHe5u“Impossible Sphere” by Alexey Ermushevhttps://plus.google.com/101584889282878921052/posts/J2yUMw6YASqBeethoven, high on | 2014-05-12 05:07:06 | 489 | 214 | 129 | 231 | |

Cindy Wilson | 0 | 2014-05-10 14:34:25 | 371 | 7 | 0 | 0 | ||

Pamela Baskett | 0 | 2014-05-10 13:35:43 | 371 | 15 | 0 | 5 | ||

DRESS | 3,901 | If you want to be added to the next Circle you have to do these simple steps:1 - Include me in your circles 2 - Share this post3 - Add +1 to the post 4 - Leave a comment if you have done the 3 steps above#circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare #circle #circleshare | 2014-05-05 12:20:41 | 372 | 3 | 4 | 11 | |

Graeme McRae | 24,994 | Graeme's Circle of Active GooglePlussers! . . . This is a curated circle of active people on Google+* If you add this circle, you will see hundreds of new posts per day in your stream from this circle alone. It's a circle of people I started following a few months ago, and who have consistently posted something at least once a week during all of weeks since then. If you want an interesting stream, you should add this circle. If you're interested in how I curated this circle, and why I think it makes for a really great stream, read on. . .How did these people get in the circle?. . . They must have posted something interesting, at least once, because I don't follow people unless they post something interesting. By now, you're probably not surprised by the number of people on G+ whose pages are full of repeated posts, videos without comments, "what's up" and other uninteresting things. I don't follow those people.How did they stay in the circle since they were added?. . . After I add someone, I keep them in the circle of people I added around the same time. Then, several times a week, I go through all my circles and delete people who haven't posted (something visible to me) in the last 7 days. So the people who are left in the circle are consistent posters. That says something important about them, because consistency is a proxy for quality.Wait. What? Why is consistency is a proxy for quality?. . . I'll admit it: I don't have the science to back up that wild statement, but I'll tell you why I believe it to be true. People who post crap don't get a lot of followers, and the few followers they have don't bother to engage. After a while, the crappy-posting people start to think G+ is a ghost town, and they lose interest. On the other hand, the people who share (or re-share) interesting things get followers and engagement, slowly at first, but ever increasing, and this outpouring of love is what keeps them going. That's what I think anyway, and I'm sticking to it.People who share interesting things get lots of followers. . . This is another half-baked theory of mine, but hear me out. You might think this makes sense: Google+ offers suggestions of people to follow, especially to new users. Google+'s only source of names to suggest are other G+ers like yourself. The G+ers who have the most engagement are the ones Google+ knows will be good to follow, so these people get put out as suggestions more often, and some percentage of those suggestions are taken up. So the more engagement you have, the more Google+ will suggest you as a person to follow, and so the more followers you'll get. Completing the theory: the more interesting the stuff you share (or reshare), the more engagement you'll get, and hence the more followers you'll get.How can I get in your circle?. . . Don't bother trying to "get into" this circle. This circle isn't for you to get into. Think of it the other way around. This circle is for you to add, so you can follow a bunch of interesting and consistent people. The stream from this one circle will be chock-full of fascinating content for you to reshare. People will start to notice your reshares, and they will engage with you, and then Google+ will "notice" (it's a computer, but let's anthropomorphise, shall we?) you and suggest you to others, who will then follow you.No, really. How can I get in your circle?. . . First, unfollow me, then wait, oh, about a week. Spend that week posting a shitload of interesting things. Then follow me. Since you're so interesting, Google+ will notify me that you followed me (G+ doesn't notify me about every follower). I'll look at your posts, find one interestin | 2014-05-04 21:03:52 | 371 | 11 | 13 | 19 | |

nicholas syahputra | 82 | 1. Plus The Post2. Comment3. Add People To Circles4. Share The Circle!#circlesharing #circleshare #circles #circle #googleplustips #googleplus #indonesia #artists #artist #artistphotographeramateurorprofessional | 2014-04-30 07:03:15 | 485 | 31 | 8 | 42 | |

Ryan Johnson | 3,346 | My new some cool, fun & interesting people CirclePlease reshare it#circles #circlescirclescircles #circleshare #circleshare | 2014-04-25 06:14:36 | 235 | 7 | 8 | 20 | |

Becky Collins | 8,289 | Engagers Showcase Circle :Circle of very #social #engagerspeople and companiesTo be included in my shares (#sharedcircle), be so kind to:1 - Do +1 t the post2 - Comment the post and specify your "category" (job or interest) Ex: Fashion, SEO, Companies, Social Media Marketing, Sailing, Photography, Bloggers/Writers, Web graphics and design, Italy, Artists, Sport, Finance/Economy ...3 - include the circle among your circles4 - share the circle (include yourself)Improve your popularity, be social be cool !Keep yourself updated, enjoy the Shared Circles Hellenic Alliance, you can share your shared circles inside the upcoming Community:https://plus.google.com/communities/112552559573595396104 #socialmedia #media #circles #circleshare #circlesharing #circlecircle #beckyscircle #sharedcircles #sharedpubliccircles #sharedcircleoftheday +Becky Collins ? | 2014-04-23 05:59:02 | 400 | 20 | 15 | 26 | |

Circlemania !!! | 2,173 | in this circle you can find people keen to publish, share, track and unr to good communities. see and discover new friends and circles that may interest you. Do not forget to follow me as: +Andres Aguilar #circle #circleshare #circlemaina #circlemeup | 2014-04-19 15:48:55 | 498 | 26 | 19 | 34 | |

Richard Green | 64,997 | Engagers Showcase Circle, April 17, 2014If you received a notification, it means that you are included in my Engagers Showcase Circle. “Showcase” means that you are invited to leave a comment (on the original post) with a link to one of your own posts, which ideally should be one of your best recent posts.This circle consists of people who have engaged with one of my recent posts in the form of +1s, comments and reshares. Two of the posts below attracted too much engagement to be usable for the circle, but I am including links to them for completeness.Everyone mentioned below is also included in the circle.Adding cubeshttps://plus.google.com/101584889282878921052/posts/WqimoVTZWL3Flower and snail shell (reshared from +Ralph Reichert)https://plus.google.com/101584889282878921052/posts/5st1n4VBMh5April Fools' Dayhttps://plus.google.com/101584889282878921052/posts/Mxa1TNjYo4r“Trinity” by Jen Starkhttps://plus.google.com/101584889282878921052/posts/gfRheBovSZUHyperbolic honeycombs (reshared from +Roice Nelson)https://plus.google.com/101584889282878921052/posts/59yPx8yoFbuCoxeter—Conway friezeshttps://plus.google.com/101584889282878921052/posts/4XvYb9biaLpTriple helix staircase (reshared from +Romain Brasselet)https://plus.google.com/101584889282878921052/posts/SRJ7CqGNrtLWhich airport is closest to you?https://plus.google.com/101584889282878921052/posts/FxxdDb6orPy“Spinning Cosmos” by Paul Friedlanderhttps://plus.google.com/101584889282878921052/posts/RjnVfRhBPmZStrč prst skrz krkhttps://plus.google.com/101584889282878921052/posts/h87PZWs2MSbMersenne primes and perfect numbershttps://plus.google.com/101584889282878921052/posts/cLWBTddiSyy“Urge to fly” by Hermin Abramovitchhttps://plus.google.com/101584889282878921052/posts/j2K97AvLvAoKeeper of Time (reshared from +Michael Quinn)https://plus.google.com/101584889282878921052/posts/QnaHrgKjsUUSeven mutual | 2014-04-17 04:49:32 | 487 | 185 | 132 | 233 | |

Ryan Johnson | 2,352 | sharedcircle #publiccircleshare #circleshare #circleoftheday #circleshares #circlesharing #circlesshare #publicsharedcircle #publicsharedcircles #sharedcircleoftheday #sharedcircleoftheweek #sharedcircles #sharedpubliccircle #todayspublicsharedcircle #todayssharedcircle #publiccircle #circle #circles #awesome #awesomeness #awesomepeople #shareyourcircle #bestengagers #followers #followback #awesomecircles #topsharedcircle #topsharedcircle #myseoissocial #besocial #socializethesocial #trust #circles #sharedcircle #followers #social #socialnetworking | 2014-04-16 05:12:35 | 262 | 9 | 2 | 12 | |

Adam Black | 6,732 | Transhumans CircleBy popular Demand, I am sharing some of my Circles. This is +Mark Bruce Transhumans Circle Plus Others Ive been adding.If you are tagged, you are in it.Web Link for Mobile https://plus.google.com/u/0/+AdamBlack/posts/6iQmLpEj1Zm #sharedcircles #GeekCulture #ScienceSunday #Transhumans #Transhumanism #HumanPlus | 2014-04-13 06:25:04 | 245 | 22 | 7 | 33 | |

John Nuntiatio | 33,101 | #circles #sharedcircles #circlesharing #circle #circleoftheday #bestofcircles #bestcircleshare #share #tech #business #sport #health #tennis #europe #asia #america #africa #australia #football #golf #basketball #news | 2014-04-09 06:25:56 | 329 | 6 | 12 | 13 | |

Refurio Anachro | 3,603 | You're in this march engagers circle because you reshared, plussed or commented on one of my posts (possibly via +Spherical Reflections), or got into a discussion with me. It's been fun being with you and i'm looking forward to more of it soon! Thank you!Mar 4, 2014 - links a couple of my favorite videos featuring John Conway on the occasion of +Numberphile posting a new one:https://plus.google.com/115434895453136495635/posts/AHpMJ79biC3Mar 12, 2014 - reshared an excellent post by +Gerald Stuhrberg about Richard Couranthttps://plus.google.com/115434895453136495635/posts/CzMomxKK2HzMar 18, 2014 - Diagram 17: Bratteli diagram about C★ algebrashttps://plus.google.com/115434895453136495635/posts/6EiftoFjkxmMar 19, 2014 - reshared a four dimensional platonic covered with gears by Greg Egan, thanks +John Baezhttps://plus.google.com/115434895453136495635/posts/NeaNS4XDBXNMar 22, 2014 - linked a blog post by keegan, an animated quiascrystal with a simple recipe to get one. Don't miss the link to Roger Penroses latest public lecture video in the commentshttps://plus.google.com/115434895453136495635/posts/8RUh6oQzMdpMar 31 - a link to +Vladimir Voevodsky's latest public lecture, and to an implementation of the addictive 2048 game in Coq!https://plus.google.com/115434895453136495635/posts/9bnhXDeH1UXIf you're looking for even more, please have a look at my trusty +Spherical Reflections's page. I reshare interesting circles there, and occasionally post mandelbrot beach pictures. #engagers #circle , #circles #circleshare #circlesharing #sharedcircles #publiccircle | 2014-04-03 11:25:39 | 78 | 1 | 6 | 5 | |

John Nuntiatio | 32,205 | #circles #sharedcircles #circlesharing #circle #circleoftheday #bestofcircles #bestcircleshare #share #tech #business #sport #health | 2014-04-03 06:40:30 | 128 | 1 | 6 | 4 | |

Jean-Marc Luna | 36,938 | My buddies (432/1)of the G+ villageI am happy to share (finally) my first big circles (432/1 and 432/2) with you. It is also a way to thank you and to inform you of my consideration.You will find in these two circles all the people I follow regularly since my first steps on Google+ and which accompany me for soon two years in this beautiful adventure, bringing every day, by their sympathy, their humor, their knowledge, their generosity and their open-mindedness, a bit extra to my everyday life.I do not know everybody, I have crossed the path with some, I communicate more with some and many people became friends, thing which I did not expect by landing here.When I began, I was lucky enough to discover new interesting people, thanks to the system of circles sharing, and I hope that these both will be for you of the same utility.If you add a “plus”, maybe it will have an impact on climate change,if you share this circle, maybe Putin is going to get married with an ukrainian women in 2014,if you include me in your circles, maybe it will solve the problem of hunger in the world,Maybe ... but in fact, nothing is sure ;)A good day to all :)With a special thought for #dirktalamasca #sharedcircles #circles #circlesharing | 2014-03-31 15:25:36 | 432 | 62 | 26 | 58 | |

Daniel Zawadzki | 6,461 | Very soccial Circle#specialcircle #topengagers #circleoftheday #saturdaycircle #weekendcircleHi friends! This is very imoprtant circle, most of top g+ pplif you want to add this circle:1 - include all circle in your circles 3 - shared the circle (include yourself) 4 - add +1 to the post More you share more you are great. | 2014-03-22 09:41:38 | 472 | 57 | 15 | 72 | |

Enrico Altavilla | 5,522 | I'm sharing with you my Science circle. It's focused mainly on physics, astrophysics and math but it also contains subjects (both people and pages) who share news about other scientific fields. Enjoy! | 2014-03-21 06:45:03 | 103 | 10 | 1 | 5 | |

Richard Green | 61,119 | Engagers Showcase Circle, March 20, 2014If you received a notification, it means that you are included in my Engagers Showcase Circle. “Showcase” means that you are invited to leave a comment (on the original post) with a link to one of your own posts, which ideally should be one of your best recent posts.This circle consists of people who have engaged with one of my recent posts in the form of +1s, comments and reshares. I ran out of room, so my most recent posts will be included next time instead.Everyone mentioned below is also included in the circle.Michelangelo and the Jordan curve theoremhttps://plus.google.com/101584889282878921052/posts/UN8TetdX48VThe Kelpieshttps://plus.google.com/101584889282878921052/posts/M6aWXwu6zESAntoine's necklacehttps://plus.google.com/101584889282878921052/posts/4anPfBNTyjXThe Farey-Ford tessellationhttps://plus.google.com/101584889282878921052/posts/GrZP3ajnRGUAlien Garden (reshared from +Kevin Clift)https://plus.google.com/101584889282878921052/posts/j55RpNfocNABetween a rock and a hard placehttps://plus.google.com/101584889282878921052/posts/WGNdNFneW1uAlan Turing: a universal Turing machine?https://plus.google.com/101584889282878921052/posts/MUjAnVtL7hbVisual artist Aliza Razellhttps://plus.google.com/101584889282878921052/posts/hbd3e6U1fhSBeet it (reshared from +Laura Ockel)https://plus.google.com/101584889282878921052/posts/U7RjV31mM7WChess played on a sphere... and other animalshttps://plus.google.com/101584889282878921052/posts/LGXUE73Z3MoPass 'Em Onhttps://plus.google.com/101584889282878921052/posts/iFCQcXfhNdDArizona sunset (reshared from +Debashish Samaddar)https://plus.google.com/101584889282878921052/posts/CR1yJ48g8CWThe inside of my fridge, through Glasshttps://plus.google.com/101584889282878921052/posts/SQK6KoFL2rmBatmobile 1?https://plus.google.com/101584889282878921052/posts/aV43AZenAd9Mary O'Malley ceramics (reshared from | 2014-03-20 19:09:36 | 469 | 199 | 157 | 230 | |

John Nuntiatio | 30,154 | #circles #sharedcircles #circlesharing #circle #circleoftheday #bestofcircles #bestcircleshare #share #tech #business #sport | 2014-03-18 08:53:47 | 471 | 0 | 2 | 5 | |

John Nuntiatio | 30,154 | #circles #sharedcircles #circlesharing #circle #circleoftheday #bestofcircles #bestcircleshare #share #tech #business #sport | 2014-03-18 08:53:18 | 471 | 0 | 0 | 1 | |

John Nuntiatio | 30,154 | #circles #sharedcircles #circlesharing #circle #circleoftheday #bestofcircles #bestcircleshare #share #tech #business #sport | 2014-03-18 08:52:50 | 471 | 1 | 2 | 5 |

### Activity

#### Average numbers for the latest posts (max. 50 posts, posted within the last 4 weeks)

comments per post

reshares per post

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characters per posting

Top posts in the last 50 posts

### Most comments: 219

2014-08-03 09:59:26 (219 comments, 70 reshares, 244 +1s)

My last post on the NASA "quantum vacuum plasma thruster" was mainly about the shoddy theory behind it - like how there's no such thing as a "quantum vacuum plasma".

But you could argue: hey, if the gizmo actually works, isn't that good enough?

Unfortunately, the experiment has problems too. In brief:

1. They tested a device that was designed to work and one that was designed not to work. They both worked.

2. They tested the devices in a "vacuum chamber", but they didn't take the air out.

3. They didn't carefully study all possible causes of experimental error... like their devices heating the air.

In a bit more detail:

1. Their device, called the **Cannae drive**, was invented by a guy named Guido Fetta. You can see a picture below. It's not complicated! It's a... more »

### Most reshares: 682

2014-08-10 02:51:19 (169 comments, 682 reshares, 554 +1s)

**Both rectangles are moving at constant speed**

At least that's what the creator of this illusion says! It looks like the yellow and blue rectangles are taking turns going forward - one step at a time.

This is an illusion that's so good it's hard to believe it's an illusion. When the black and white lines disappear, it's easy to see the rectangles are moving at constant speed. But before that they seem to be taking turns, and pausing when they reach each new line.

Could the creator of this illusion be cheating - fooling you into thinking there's an illusion? How can you tell, except by making your own version of this animated gif?

Hide one rectangle with your hand. Then look closely at the other. Try not to look at the black and white lines. I think you'll see the rectangle is moving at constant speed.

Butif you... more »

### Most plusones: 599

2014-08-13 03:16:36 (57 comments, 250 reshares, 599 +1s)

Maryam Mirzakhani won the Fields medal yesterday.

As a child in Tehran, she didn't intend to become a mathematician - she just wanted to read every book she could find! She also watched television biographies of famous women like Marie Curie and Helen Keller. She started wanting to do something great... maybe become a writer.

She finished elementary school while the Iran-Iraq war was ending, and took a test that got her into a special middle school for girls. She did poorly in math her first year, and it undermined her confidence. “I lost my interest in math," she said.

But the next year she had a better teacher, and she fell in love with the subject. She and a friend became the first women on Iranian math Olympiad team. She won a gold medal the first year, and got a perfect score the next year.

After getting finishing her undergraduate workat Shar... more »

Latest 50 posts

2014-09-18 04:11:22 (36 comments, 30 reshares, 133 +1s)

**Packing tetrahedra**

What's the densest way to pack regular tetrahedra? Aristotle, after staying up too late grading Alexander the Great's homework, once claimed they could fill space completely. But that's clearly false.

Here's the story. To save space, I'll use **tet** to mean 'regular tetrahedron'.

In 1976, a guy named Hoylman showed that if you have tets centered at points in a lattice, all pointing the same way, the best density you can get is

18/49 ≈ 36.73%

That's lousy - spheres can do 74.05%. But Hoylman's work was good, because he corrected an earlier false claim by Minkowski, who was a genius when it came to lattices.

In 2006, Conway and Torquato made a big breakthrough. First they packed 20 tets into an icosahedron - there's a beautiful easy way to do this, since anicosahed... more »

2014-09-17 02:58:44 (42 comments, 41 reshares, 130 +1s)

**Packing spheres**

What's the densest way to pack spheres? Here are two equally good ways.

In fact there are infinitely many equally good ways! We start by laying spheres on the plane in a hexagonal arrangement, as tightly as we can. Then we put a second layer like this on top, with the new spheres resting in the gaps between the old ones. Then we put on a third layer. But now there are 2 really different ways to do it!

The spheres in the third layer can be directly above the spheres in the first layer - that's the picture at right. Or they can be not directly above - shown at left.

As we continue, we keep getting more choices.

One systematic choice is to make the layers alternate like ABABAB..... That's called the **hexagonal close packing**, and that's how crystals of magnesium work.

Anothersystemati... more »

2014-09-16 01:40:24 (76 comments, 82 reshares, 285 +1s)

**Bézier curves**

Say you have some dots and you want to draw a smooth curve that sorta almost goes through these dots. Then you can use a **Bézier curve**. Some drawing programs use this trick... and lots of fonts are drawn with the help of Bézier curves.

The math behind these curves had been known since 1912, but they were popularized by Pierre Bézier, an engineer who used them to design automobile bodies at Renault.

Can you figure out how they work just by looking at the movie? An explanation in words sounds complicated... but it's really easy as pie.

It's like you've got 3 guys running along straight racetracks. The 2 guys in back have rabbits that each chase the next guy, always heading straight toward that next guy. And the guy at the very back also has a dog that chases straight after the next guy's rabbit. Everyonestarts at ... more »

2014-09-15 02:17:43 (43 comments, 15 reshares, 120 +1s)

**Cremation in Bali**

This is a cremation ceremony in the town of Bedulu, in Bali. The remains of 18 people were set on fire.

In Bali most people are Hindu, so cremation is preferred to burial. They build a big paper model of a buffalo - you can see part of one at left - and put the corpse inside, and pay for a priest called a pandit to come and do a ritual, and then set the buffalo on fire. But this is expensive. So, poor families will bury the body until they save up enough money for the ceremony.

I've been to a cemetery that's holding area for bodies - or bones - waiting to be cremated. It's near the temple to Kali in the Monkey Forest in Ubud. People look on the graves with a touch of shame.

But there seems to be a kind of 'bulk discount' for cremations. So when a well-off old auntie in Bedulu died, 17 othersfrom this tow... more »

2014-09-13 06:34:55 (159 comments, 26 reshares, 171 +1s)

**Crackpot emails**

I save crackpot emails, but I just decided to delete all 41 with attachments bigger than 1 megabyte. Here are some choice quotes, taken from ones that were sent as mass emails to many scientists.

------------------------------

Here's a typical example of someone who feels they've made an earthshaking discovery and needs to get the news out. He's waited 2 days and he's getting impatient. If he follows the standard pattern, he will later become embittered and angry.

I solved what's known as ToE, The Theory of Everything, but most simply I've shown how 0 approximates 1. I did so in a completely valid, simple mathematical way, yet due to the current structuring of the University system, I can't get to anyone that specializes in ToE!!!

And the University of Miami has black balled me because they haveno... more »

2014-09-13 02:19:58 (9 comments, 34 reshares, 111 +1s)

**Falling through an infinity of gears**

Greg Egan has done it again! This is an infinite cubic lattice of rotating gears in 3-dimensional space... seen by someone who is falling through it and also rotating!

It's a bit bewildering. One reason is that after you turn 180 degrees, the view looks exactly the same.

He's been developing techniques for studying 'higher-dimensional gears', like 3d ball bearings that turn while touching each other, arranged on the surface of a hypersphere in 4d space:

http://www.gregegan.net/SCIENCE/Bearings/Bearings.html

The hard part is figuring out how the bearings can turn without slipping against each other. This involves solving large systems of linear equations.

His real tour de force was to get a setup with a ball bearing at each of the 600 vertices and 1200 edge-centres of a4-dim... more »

2014-09-12 01:06:13 (22 comments, 38 reshares, 98 +1s)

**A quantum thriller**

A cop finds a suitcase. A mysterious caller says it's been rigged so that if you look inside - if even one photon gets inside - a bomb will explode!

But maybe he's bluffing.

Can you tell if he's bluffing, without blowing up the bomb if he's not? How can you see something without actually looking at it?

You'd better call in +Vlatko Vedral from the Centre for Quantum Technologies!

This short film was made in Singapore by +Dag Dogg, another physicist here at the CQT. I like the local scenery and the cinematic touches. For example, there are black lines and glitches in the first part that make it look like an old 8mm film.

It's an entry in the Foundational Questions Institute Video Contest:

http://fqxi.org/community/forum/topic/2190

The amazing physicsbehind th... more »

2014-09-11 01:19:00 (66 comments, 38 reshares, 169 +1s)

**The logic of real and complex numbers**

When you read pop books about Gödel's theorems and other mind-blowing achievements of early 20th-century logic, they focus on arithmetic. This is the simplest form of math, dealing with the numbers

0, 1, 2, 3, 4, ...

For example, you learn that no matter what axioms you choose to describe these numbers, there are a lot of true facts you can't prove about them... as long as some computer program can list those axioms. This is called **Gödel's first incompleteness theorem**.

Why the fine print about computer programs? Without that you could choose all true facts as axioms! But Gödel showed no program can list these - that's called **undecidability**.

If you read a bit more about logic, you'll learn that thanks to Gödel's first incompleteness theorem, there are weird**nons... more »**

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2014-09-10 00:27:13 (14 comments, 3 reshares, 113 +1s)

**Hiking in Bali**

Lisa and I enjoyed the deep, calm gardens of the Wayang Cafe in Ubud so much that we went there two days in a row. We got to know a waiter, and he invited us to visit his home in a nearby village called Bedulu. He also took us on a hike.

We started by walking through his property. The Balinese use cassava for starch - it's a low-growing vine that looks a bit like morning glory. We also saw fruit trees: cacao, jackfruit, mangosteen, and more.

Then we followed a trail through a fern-covered forest, shown here.

This trail led to the terraced rice fields of his village. We walked through those, balancing on narrow walkways, trying not to fall into the mud. There is a disease affecting some villagers' rice paddies - I don't know what it is, and I'd like to find out. Due to the unreliability of rice, more and morepeople ... more »

2014-09-09 01:12:11 (38 comments, 52 reshares, 161 +1s)

**Science, models, and machine learning****Machine learning** is the art of getting computers to learn, so you don't have to explicitly tell them what to do. People use it in spam filters, search engines that guess what you're trying to find, optical character recognition, cars that drive themselves, and many other things. But how does it work?

There are many different approaches, but here +David Tweed explains some of the main ideas:

http://johncarlosbaez.wordpress.com/2014/09/03/science-models-and-machine-learning/

The picture shows one. Say we're trying to classify dots into two kinds - the kind on the left of the red curve, and the kind on the right. There are lots of choices of where you could put this red curve. For the data so far, anything between the dashed curves will work. Which choice is best? You'd like amachine ... more »

2014-09-08 01:17:04 (14 comments, 10 reshares, 82 +1s)

**Gamelan and dance**

Every Thursday in Ubud Palace there's a concert of gamelan and dance by the best troupe in town.

Here you see a guy in a fancy getup showing off: juggling drumsticks and playing a big percussive instrument while the rest of the musicians play as usual. The androgynous look of this guy - eye shadow, lipstick, and so on - is common for male performers in traditional Balinese dances.

Both for women and men, exaggerated eye motions and complicated hand gestures are a big part of dancing. I imagine they have some significance, so I feel I'm watching signals in a code I haven't cracked. Even when the dance tells a story I know - like the story of Rama and Sita from the Ramayana - I have trouble seeing the story in the dance. It's beautiful but cryptic, and thus a bit boring at times. Sort of like how most people feel aboutmath. ... more »

2014-09-07 01:20:06 (14 comments, 1 reshares, 62 +1s)

**Bali**

Ubud is the 'cultural capital' of Bali, up in the hill, far from the beaches - a good place to see dances and hear gamelan music. In the heart of Ubud, on Monkey Forest Road, you'll see a sign for Igna Used Books. It's next to an alley. If you walk down that alley, you'll come to a small rice field on your left, and Alit's Warung on your right: a warung is a restaurant. Turn right down an even smaller alley, and at the end is Hotel Okawati.

It's one of my favorite places: you can fall asleep to the sound of crickets and frogs, and wake up to the sound of roosters and ducks. Lisa and I wanted a peaceful little vacation, and we decided to come back here. This is a view from the balcony.

We stayed here 5 days, but we're leaving today. Back to Singapore. Back to work!

You shouldn't come here looking for abeautif... more »

2014-09-04 02:21:49 (34 comments, 38 reshares, 107 +1s)

**Stochastic resonance on your browser****Stochastic resonance** is a way that noise can amplify a signal. It sounds paradoxical, but crickets actually use it to hear better.

It might also help explain how ice ages work.

The idea is that you've got a system that can hop between two stable states. Your signal might not be strong enough to make the hop occur. So, add some noise! This gives an extra push, which sometimes helps your system make the jump from one state to another. It ain't pretty - but it really does work.

Here we see the green signal getting amplified by some noise to give the red output. The red output jumps between high and low values. If there were less noise, this wouldn't work! You can see why here:

http://johncarlosbaez.wordpress.com/2014/08/28/the-stochastic-resonance-program-part-2/

Thishas a l... more »

2014-09-03 00:11:59 (18 comments, 26 reshares, 239 +1s)

**A cool cat from Central Asia: the manul**

The **manul** lives in the grasslands and high steppes of Central Asia: Mongolia, Tajikistan, Kyrgyzstan, Pakistan, Kazakhstan, Kashmir, and western China. It's the size of a house cat, but its stocky build and long, dense fur makes it look stout and plush. It has a shorter jaw with fewer teeth than most cats.

Mamuls spend most of the day in caves, cracks in the rock, or marmot burrows. In the late afternoon they come out and hunt. They can't run fast, so they mainly hunt by ambush or stalking. They feed largely on prey that are active during the day: gerbils, pikas, voles, partridges, and sometimes young marmots.

They're most closely related to the **leopard cat**, a small cat of southeast Asia which is sometimes crossbred with house cats to give beautiful cats called 'Bengals' that enjoy gettingwe... more »

2014-09-02 00:41:09 (118 comments, 86 reshares, 282 +1s)

**Hyperreal numbers: infinities and infinitesimals**

When Leibniz invented calculus, he also invented **infinitesimals** - numbers that are bigger than zero but smaller than 1/2, 1/3, 1/4, ... and so on. Many people were uncomfortable with these, so they figured out how to do calculus without infinitesimals. That's how it's usually taught now.

But it turns out you can do calculus with infinitesimals in a perfectly rigorous way... and in some ways, it's easier! Here's a free online textbook that teaches calculus this way:

• H. Jerome Keisler, Elementary Calculus, http://www.vias.org/calculus/ or for a PDF version, https://www.math.wisc.edu/~keisler/calc.html.

The picture here is from this book. There's a tiny little infinitesimal number **ε**, pronounced **epsilon**. And 1/ε is infinitely big! These aren't'real nu... more »

2014-09-01 04:02:12 (12 comments, 49 reshares, 177 +1s)

**A sunflower at infinity**

This picture by +Roice Nelson shows the 'view at infinity' of a honeycomb in hyperbolic space.

A **honeycomb** is a way of chopping space into polyhedra. For example, we can chop ordinary 3d space into cubes. This is called the **{4,3,4} honeycomb**. Why?

• a square has 4 sides so its symbol is {4}

• a cube has 3 squares meeting at each corner so its symbol is {4,3}

• the cubical honeycomb has 4 cubes meeting at each edge so its symbol is {4,3,4}

The picture here is a view of the **{3,3,7} honeycomb**. This is defined in the same sort of way, but it doesn't fit into ordinary Euclidean space. It fits into a curved space called hyperbolic space! The honeycomb extends forever, and it forms this pattern where it meets the 'plane at infinity' of hyperbolic space.

For ... more »

2014-08-30 06:59:03 (34 comments, 64 reshares, 180 +1s)

The **Klein bottle** has just one side! **A mathematician named Klein****Thought the Möbius strip was divine****Said he, "If you glue****The edges of two****You get a weird bottle like mine."**

The Möbius strip has just one side and one edge. So if you glue the edges of two, you get a surface with one side and no edge... which happens to be a Klein bottle!

But here's an even cooler way to get a Klein bottle. Consider black-and-white images that are 3×3 pixels in size. It takes 9 numbers to describe such an image. So, the set of all possible images like this is a 9-dimensional cube.

But if you go through actual black-and-white photos and keep track of the 3×3-pixel images that show up, you'll find they aren't evenly distributed in this 9-dimensional cube! Most of them lie near acertain sur... more »

2014-08-27 06:01:31 (74 comments, 76 reshares, 230 +1s)

Did you ever feel your brain is about to break? It happens not just to beginners in math, but to everyone!

So, in case you feel frustrated with math, let me share one of my own frustrations. You'll see you're not alone!

Right now I'd love to understand something a logician tried to explain to me at lunch a while back. His name is Boris Zilber. He's studying what he calls 'logically perfect' theories - that is, lists of axioms that almost completely determine the structure they're trying to describe. He thinks that we could understand physics better if we thought harder about these logically perfect theories.

Now, Gödel's incompleteness theorem means our usual theory of natural numbers

0, 1, 2, 3, ...

together with addition and multiplication is far from 'logically perfect' in this sense. In fact,only fi... more »

2014-08-26 02:52:51 (74 comments, 11 reshares, 93 +1s)

The latest news is getting people upset. +David Brin writes:**This is what we had all feared. The possible tipping point. Methane plumes are emanating from at least 570 seafloor cold seeps on the outer continental shelf and the continental slope, Mississippi State University reported. A potential disaster that I warned about in EARTH (1989), accelerating ocean acidification and turning the greenhouse into a runaway.**

http://www.hngn.com/articles/40189/20140825/methane-leaking-from-sea-floor-could-change-ocean-acidity-oxygen-content.htm**"Warming of ocean temperatures on seasonal, decadal or much longer time scales can cause gas hydrate to release its methane, which may then be emitted at seep sites," said Carolyn Ruppel, study co-author and chief of the USGS Gas Hydrates Project. "Such continental slope seeps have previously been recognized inthe... more »**

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**2014-08-25 04:56:35 (37 comments, 71 reshares, 194 +1s)

**Why do we have these particles in our Universe?**

We understand a lot about physics - and that makes the remaining mysteries even more tantalizing! For example: why are quarks so much like leptons?

Elementary particles come in two main kinds: the ones that carry forces (**gauge bosons**) and the ones that make up matter (**quarks** and **leptons**). There's also at least one more... but never mind! Today's puzzle is about quarks and leptons. You'll see from the chart that they look sort of similar. But why?

Maybe a lightning review of particle physics will help, in case you skipped that class in high school. Most of the matter you see is made of electrons, protons and neutrons. Protons and neutrons are made of up and down quarks, held together by the strong force. But electrons are 'leptons', which means they don'tfeel the s... more »

2014-08-24 01:08:06 (52 comments, 87 reshares, 403 +1s)

**Head on**

Wolves run through the air, hit a glass wall and fall down. Then they pick themselves up, go back and do it again.

This is just one of the remarkable and unsettling pieces by Chinese artist **Cai Guo-Qiang**.

He recently made the news by creating a kind of Noah's ark with endangered animals and floating it down the river past the main financial district of Shanghai. The animals aren't real - but they look pretty real, like these wolves.

The boat is now on display in Shanghai, in an exhibit that's become very popular. You can see more of it here:

http://www.npr.org/blogs/parallels/2014/08/21/342189261/chinas-pollution-crisis-inspires-an-unsettling-art-exhibit

and here:

http://www.emptykingdom.com/featured/cai-guo-qiang/

A piece called 'Silent Ink' features a waterfall of inkplu... more »

2014-08-23 03:45:54 (85 comments, 10 reshares, 96 +1s)

**Sub-Roman Britain**

I've been a fan of the legends of King Arthur for a long time. I love how they continue to inspire new versions, from Marion Zimmer Bradley's Tales of Avalon (where Morgaine is recast as a hero in the doomed struggle of the Druids against encroaching Christians) to the goofy but fun TV series Merlin (where a black Guinevere starts as a serving-girl and winds up ruling Camelot).

But I'm only just now poking into the mysterious centuries from 400 to 600 AD in Britain, after the collapse of Roman rule, when Arthur would have lived... if he existed.

It's really cool to imagine life in former Roman towns and villas during these 'dark ages'. We have some archaeological evidence, but very little written history: mainly just the writings of Saint Patrick and a book called On the Ruin and Conquest of Britain, written by a guyca... more »

2014-08-22 02:42:17 (69 comments, 79 reshares, 183 +1s)

**The ostrich effect**

Why do people think ostriches stick their heads under the sand when they're scared? A Roman named Pliny the Elder might be to blame. He wrote that ostriches "imagine, when they have thrust their head and neck into a bush, that the whole of their body is concealed."

That would be silly - birds aren't that dumb. But people will actually pay to avoid learning unpleasant facts. It seems irrational to avoid information that can help us survive. But people do it. It's called **information aversion**.

Here's a new experiment:**In order to gauge how information aversion affects health care, one group of researchers decided to look at how college students react to being tested for a sexually transmitted disease.****That's a subject a lot of students worry about, according to JoshTasoff,... more »**

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**2014-08-21 02:43:20 (24 comments, 16 reshares, 71 +1s)

**A mix of bosonic and fermionic superfluids**

Two different kinds of gas, each completely frictionless, can pass through each other as they wiggle back and forth in a magnetic field!

One gas is made of lithium with an even number of electrons, protons and neutrons, so it's called a **boson**. The other is made of lithium with an odd number of these particles, so it's a **fermion**. They act very different.

If you cool down a gas of bosons enough, it can become a completely frictionless fluid - a **superfluid**. It's a lot harder to do this trick for fermions. This is the first time anyone has made a mixture of bosonic and fermionic superfluids.

Christophe Salomon gave a talk about this here at the +Centre for Quantum Technologies. He said nobody has been able to make such a mixture with helium.

Helium-4 is the mostcomm... more »

2014-08-20 00:11:31 (51 comments, 5 reshares, 80 +1s)

**What caption should this picture have?**

And who took it?

I found this picture at the New York Daily News, which says it's an alligator on top of its mother. It's part of a series of cute pictures of animals and their mothers:

http://www.nydailynews.com/life-style/baby-animals-mothers-gallery-1.1076585?pmSlide=1.1340672

But they don't credit anyone!**[EDIT: yes they do! As ****+Ralf Haring**** noted, it's by Clayton Bonds.]**

2014-08-19 02:00:21 (47 comments, 95 reshares, 339 +1s)

**How to turn space into time - in the lab**

Wouldn't it be cool if we could turn one dimension of space into an extra dimension of time? We can't - but we can fake it!

Einstein showed the only difference between space and time is a minus sign. So: make a material where light obeys equations with an extra minus sign!

How? Just take lots of microscopic metal wires and put them in transparent stuff that doesn't conduct electricity. Line them all up. You'll get something that conducts electricity like a metal in one direction but not the other two directions!

It's called a **hyperbolic metamaterial**. The video explains why.

But why is this like converting a dimension of space into a dimension of time?

Einstein showed that if you have a photon - a particle of light - in a vacuum, it obeys

X² + Y² ... more »

2014-08-18 02:54:41 (40 comments, 158 reshares, 365 +1s)

**Opal: a photonic crystal**

This opal from South Australia is beautiful... but why does it look like this? It's actually a photonic crystal!**Opal** is made of small spheres of silicon dioxide, the same stuff as quartz. These spheres are between 150 to 300 nanometers in diameter, and they're arranged in a regular pattern.

When light waves pass through an opal, funny stuff happens when the distance between these spheres is half the wavelength of the light. Imagine water waves trying to fight their way through a regular pattern of round logs standing in the water and you'll get the picture. The waves start to bounce back and interfere with themselves.

So, light of certain wavelengths winds up bouncing back off the opal instead of going through! Since the opal is not perfectly the same everywhere, different parts reflect differentcolors... more »

2014-08-17 02:06:16 (10 comments, 8 reshares, 25 +1s)

**The only thing savin' your life****is that I don't look good in orange and I hate stripes**

If you like songs with catchy lyrics and a dark sense of humor, you've got to listen to... Cole Porter. But he's dead. For new stuff, try Brandy Clark.

She's been working as a song writer for about 16 years, but she just came out with an album of her own, 12 Stories. It's about life in small-town America, with all its hilarious and tragic craziness. I recommend this song here, and also:

"Stripes" - by Brandy Clark

Brandy Clark Get High

Pray To Jesus - Brandy Clark

and

Brandy Clark - Take A Little Pill

which is about the epidemic of prescription painkiller abuse:

Fella down the road

Walks with a limp

He's a decorated soldier

And a pain pillpimp... more »

2014-08-16 01:04:37 (15 comments, 8 reshares, 114 +1s)

**Reflections at Keppel Bay**

There's a big network of trails and parks in Singapore. You can climb up a huge wooden bridge and suddenly see this futuristic apartment complex amid the jungle.

My friend +Jamie Vicary is visiting the Centre for Quantum Technologies. He showed Lisa and me how to walk through park land to Vivocity, a fancy shopping mall by the sea. There are some elevated walkways through the jungle, that really let you see the trees and vines. There's a World War II museum that shows how the Japanese invaded, and the battles fought around here. It was open for free because it was National Day - the 49th anniversary of the birth of Singapore as an independent country. It's weird to be in a country that's younger than I am.

Walking across the Henderson Wave Bridge, we spotted these buildings, called **Reflections at KeppelBaymore »**

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**2014-08-15 01:28:39 (39 comments, 46 reshares, 153 +1s)

**{7,3,3} meets the plane at infinity**

Maryam Mirzakhani won the Fields medal largely for her work on hyperbolic geometry. The **hyperbolic plane** is something we can all enjoy: it's not flat, but curved like a saddle, and triangles have angles that add up to less than 180 degrees. We can draw it crushed down to a disk, as in this picture by +Roice Nelson. All the light blue circles should really be the same size - but the ones near the edge have been squashed.

Instead of learning Euclidean geometry in school, you could have learned hyperbolic geometry - it's almost the same, with some big differences. The main thing is that the **parallel postulate** is false in hyperbolic geometry: there are many ways to draw a line through a point parallel to another line! This is how Lobachevsky discovered hyperbolic geometry in 1823: by seeing what would happen ifyou c... more »

2014-08-14 03:06:45 (19 comments, 95 reshares, 245 +1s)

**The 290 theorem**

Manjul Bhargava is another of this year's Fields medalists. He works on **number theory**, which in its simplest form is the study of integers:

..., -3, -2, -1, 0, 1, 2, 3, ...

So when I say 'number' in this post, I'll always mean one of these!

When Bhargava was a grad student at Princeton, he read a book on number theory by the famous mathematician Gauss. Gauss was interested in **quadratic forms**, which are things like this:

x² + 3xy + y²

or this

-3x² + y² + 4xz + yz - 7z²

Gauss was mainly interested in quadratic forms with two variables, but it's also fun to think about more variables.

I can hand you a quadratic form and ask: what numbers can you get if you plug in any numbers you want for the variables?

Start with something reallyeasy. ... more »

2014-08-13 03:16:36 (57 comments, 250 reshares, 599 +1s)

Maryam Mirzakhani won the Fields medal yesterday.

As a child in Tehran, she didn't intend to become a mathematician - she just wanted to read every book she could find! She also watched television biographies of famous women like Marie Curie and Helen Keller. She started wanting to do something great... maybe become a writer.

She finished elementary school while the Iran-Iraq war was ending, and took a test that got her into a special middle school for girls. She did poorly in math her first year, and it undermined her confidence. “I lost my interest in math," she said.

But the next year she had a better teacher, and she fell in love with the subject. She and a friend became the first women on Iranian math Olympiad team. She won a gold medal the first year, and got a perfect score the next year.

After getting finishing her undergraduate workat Shar... more »

2014-08-12 08:27:22 (26 comments, 25 reshares, 112 +1s)

**The Picture of Dorian Gray****"...the face appeared to him to be a little changed. The expression looked different. One would have said that there was a touch of cruelty in the mouth. It was certainly strange."** - Oscar Wilde

Sadly, I haven't read this story yet - I've just seen a movie version. And I've read some quotes. Since Wilde was a master of the epigram, you can enjoy these like popping down peanuts until you get sick to your stomach:**Nowadays people know the price of everything and the value of nothing.****He was always late on principle, his principle being that punctuality is the thief of time.****I never talk during music - at least, during good music. If one hears bad music, it is one's duty to drown it in conversation.****The basis of optimism is sheer terror.**

more »

2014-08-11 03:56:02 (45 comments, 40 reshares, 155 +1s)

**What is quantum entanglement good for?**

Here's a headline from the New York Times in 1935. Einstein had already done his best work: photons, special relativity and general relativity. But this year he had 2 good ideas about spooky ways that distant objects could be connected. He wrote about them in 2 papers with a guy named Rosen.

One introduced the idea of a 'wormhole': a kind of tunnel connecting distant regions of space. Another, written with a third guy named Podolsky, argued that quantum theory was 'incomplete'. Einstein later complained that it allowed 'spooky action at a distance'.

Why? Because you can't always fully describe a quantum system by fully describing each piece of it. In fact sometimes you can know as much as possible about the whole system while still knowing nothing about the state of each piece.

2014-08-10 02:51:19 (169 comments, 682 reshares, 554 +1s)

**Both rectangles are moving at constant speed**

At least that's what the creator of this illusion says! It looks like the yellow and blue rectangles are taking turns going forward - one step at a time.

This is an illusion that's so good it's hard to believe it's an illusion. When the black and white lines disappear, it's easy to see the rectangles are moving at constant speed. But before that they seem to be taking turns, and pausing when they reach each new line.

Could the creator of this illusion be cheating - fooling you into thinking there's an illusion? How can you tell, except by making your own version of this animated gif?

Hide one rectangle with your hand. Then look closely at the other. Try not to look at the black and white lines. I think you'll see the rectangle is moving at constant speed.

Butif you... more »

2014-08-08 07:52:41 (61 comments, 34 reshares, 186 +1s)

**Time to panic yet? Too soon to tell...**

You know that mysterious crater that suddenly opened up in the Yamal Peninsula in northwest Siberia? Now an article in Nature blames it on melting permafrost:

http://www.nature.com/news/mysterious-siberian-crater-attributed-to-methane-1.15649

A Russian archaeologist named Andrei Plekhanov led an expedition there. He and his team think it could be caused by melting permafrost due to abnormally hot summers in 2012 and 2013 - about 5°C warmer than usual. Air in the crater had up to 9.6% methane. The normal amount is closer to 0.0002%

Some scientists are already worrying about methane released from melting permafrost. Methane is a potent greenhouse gas: 90 times worse than carbon dioxide by weight, at least for the first 20 years. (It goes away faster.) Could we be in for a nasty feedback loop, where awarming c... more »

2014-08-07 02:42:37 (30 comments, 42 reshares, 167 +1s)

**Harpooning a comet**

After a decade-long chase, the **Rosetta** spacecraft has now reached a comet! This photo was taken from just 285 kilometers away. The comet's gravity is very weak, so Rosetta will move in a triangular orbit under its own power before moving closer.

On November 11th, Rosetta will send in a probe called **Philae**, which will harpoon the comet and land on it! The picture at bottom right shows what that should look like. Philae will drill into the comet and carry out lots of experiments.

As the comet approaches the Sun, it will heat up. Gas will start to boil up from the surface, earthquakes will shake it, and I suppose Philae may even be destroyed. I haven't read any details about what to expect! But they will try to land Philae far away from places where jets of gas will erupt. The comet will makes its closestapproach... more »

2014-08-05 00:52:07 (6 comments, 33 reshares, 122 +1s)

**Lost in space**

Physicists often use a 'Cartesian coordinate system' - an imaginary grid, like 3d graph paper, that lets us name any point in space with 3 numbers. But what if it were real? You could climb around on it!

That's the idea of this art project by **Numen/For Use**, the guys who made that expanding and shrinking glowing cube with an infinity of reflections inside.

It's an inflatable structure. Ropes inside get stretched tight when it inflates. They form a 3d grid that's strong enough to climb around on. The inside walls are white, so it seems to go on infinitely. They tested it out in countryside near Vienna at the end of December 2013.

For more photos, try this:

http://www.numen.eu/installations/string/prototype/

If you didn't see that glowing cube, you missed some fun. Here itis:

more »

2014-08-03 09:59:26 (219 comments, 70 reshares, 244 +1s)

My last post on the NASA "quantum vacuum plasma thruster" was mainly about the shoddy theory behind it - like how there's no such thing as a "quantum vacuum plasma".

But you could argue: hey, if the gizmo actually works, isn't that good enough?

Unfortunately, the experiment has problems too. In brief:

1. They tested a device that was designed to work and one that was designed not to work. They both worked.

2. They tested the devices in a "vacuum chamber", but they didn't take the air out.

3. They didn't carefully study all possible causes of experimental error... like their devices heating the air.

In a bit more detail:

1. Their device, called the **Cannae drive**, was invented by a guy named Guido Fetta. You can see a picture below. It's not complicated! It's a... more »

2014-08-03 07:07:41 (31 comments, 2 reshares, 13 +1s)

**Puzzle:** what are these sciences?

People who can read Chinese will have a huge advantage. I don't think googling these words in English will help you much! Some websites use **coppology** to mean the study of film-maker Francis Ford Coppola, but that's not what it means here. Another website says:**Domain Misspelling for: coptology****coppology; copqology; coprology; copsology; coptology; copuology; copvology; copwology; copxology; copyology; copzology; coptalogy; coptblogy; coptclogy...**

In case you're wondering, **coptology** is the study of the native Christians of Egypt, called **Copts**. But that's not relevant either.

Since you read down this far I'll give you a big hint: I saw this sign on a local shop in Singapore.

There are lots of interesting signs around here. For example,there&... more »

2014-08-02 09:33:16 (75 comments, 218 reshares, 470 +1s)

**The incredible shrinking force**

Around 2000, a guy named Roger Shawyer claimed he could bounce microwaves inside a fancy-shaped can and get them to push the can forwards, without anything leaving the can.

This would violate conservation of momentum. It's like sitting inside a car and making it roll forwards by pushing on the steering wheel. Standard physics doesn't allow this. He didn't claim to be using anything other than standard physics.

So: ho hum, just another guy with a really bad idea. I get emails like this all the time.

But in 2001, his company got a £45,000 grant from the British government to study this idea. He built his machine and claimed that with 850 watts of power he could get a force of 0.016 newtons. That's a bit less than the force of gravity from a penny pushing down on your hand. It could easilybe an exper... more »

2014-08-02 02:14:22 (11 comments, 14 reshares, 106 +1s)

**Fractal madness with heptagons**

This picture drawn by +Danny Calegari shows the '{7,3,3} honeycomb' in hyperbolic space. Hyperbolic space is an infinite space where triangles have angles that add up to less than 180 degrees. But the mathematician Poincaré figured out how compress it down to a ball so we can see it from the outside, and that's what we see here.

The {7,3,3} honeycomb is built of regular 7-sided shapes - **heptagons** - in hyperbolic space. But what does {7,3,3} mean?

The heptagons lie on infinite sheets, which show up as holes here. If you look at these holes, you'll see they have three heptagons meeting at each corner. So, each one is a copy of the **{7,3} tiling** of the hyperbolic plane. 7 stands for heptagon, 3 stands for three meeting at each corner.

It's impossible to see, but 3 of these {7,3}tilings... more »

2014-08-01 02:04:52 (4 comments, 20 reshares, 76 +1s)

**Citizen Science**

The Azimuth Code Project is a friendly gang of hackers and geeks. We're studying a new method of El Niño prediction that uses a "climate network". We replicated the software used in a paper about this method, and we made it open-source. Then a statistician named Steven Wenner jumped in and examined the results! Check it out here:

http://johncarlosbaez.wordpress.com/2014/07/23/el-nino-project-part-6/

Very roughly, when the red curve goes over the horizontal line, the method predicts an El Niño in the following year - a blue spike. But sometimes it doesn't work, and there are weird borderline cases.

Wenner ran some statistical tests on this method, and then +Jan Galkowski jumped in and ran a bunch more, using sophisticated Bayesian ideas. You can read about that in the comments.

There's a lot ofbuzz ab... more »

2014-07-31 00:12:17 (48 comments, 515 reshares, 389 +1s)

**The one you're not looking at turns clockwise**

Look at either the red dot or the yellow dot. The circles near that dot will turn counterclockwise. The others turn clockwise!

Or: let your eyes bounce back and forth between the two.

Or: look away from both of them.**Puzzle 1:** how does it work?**Puzzle 2:** who first made this gif? I can't find the original source.

#illusions

2014-07-30 01:44:38 (32 comments, 11 reshares, 111 +1s)

**There's a monster in the kitchen!**

Not really. This is a baby **aye-aye** being weighed at the the Duke Lemur Centre in North Carolina.

Aye-ayes live in Madagascar. They're the world's largest nocturnal primate. They find grubs to eat by tapping on trees. When an aye-aye finds a good spot, it chews a hole in the wood. Then it sticks its narrow middle finger in the hole to pull the grubs out.

Since it was founded in 1966, the Duke Lemur Center has collected data on 3600 animals from more than 40 species of prosimians - the group of primates that includes lemurs, lorises, galagos, bushbabies, and tarsiers. Now they've released the data to the world! It's available online, for free:

http://lemur.duke.edu/duke-lemur-center-database/

Almost all these animals only live in Madagascar, and most of them are rare,threaten... more »

2014-07-29 02:47:39 (31 comments, 10 reshares, 55 +1s)

**Mansion of Wind and Waves**

Last night Lisa and I ate at **Feng Bo Zhuang** on Temple Street in Singapore. We went there since it had good spicy food from Hunan and Dongbei, a crowd of happy customers, and nice wood decor... but it turned out to have a **jiang-hu** theme: that's what Chinese call the world of wandering martial artists and swordsmen.

See that sword on the wall there?

The name of this restaurant means 'Mansion of Wind and Waves' - but 'wind and waves' means the turbulence and fighting that that goes on in the jiang-hu. There's a poem by the entrance that says "in the jiang-hu you have no choice, you either fight back or die". This tough world is romanticized in **wuxia** fiction and movies:**Typically, the heroes in wuxia fiction do not serve a lord, wield military power or belong to theari... more »**

**
**2014-07-28 01:57:54 (27 comments, 13 reshares, 100 +1s)

**Cracked moon**

Jupiter's moon **Europa** is about as big as ours... but its crust is made of water ice, and underneath there seems to be a salty ocean!

The surface has red cracks. Spectrographs suggest these are rich in salts like magnesium sulfate left by evaporating water that comes from within. But why are they red? Nobody knows. Maybe it's sulfur.

Why are there cracks? That's an interesting story.

Europa orbits Jupiter every three and a half days... but it's tidally locked to Jupiter, so there's a place on Europa's surface where Jupiter always hangs directly overhead. If you looked up, it would be about 24 times as big across as the Sun viewed from Earth.

But all is not calm! Europa is in resonance with two other moons of Jupiter. It goes around exactly half as often as the moon Io, and twice asoften as G... more »

2014-07-27 02:26:25 (10 comments, 13 reshares, 112 +1s)

**As if millions of voices cried out in terror and were suddenly silenced**

The first report of a **fast radio burst** appeared in 2007. An astronomer named Duncan Lorimer found a signal buried in recordings made at the Parkes radio telescope in Australia. It lasted for less than 5 milliseconds and it seemed to come from outside our galaxy. It didn't match anything we'd seen in visible light, X-rays or anything else. A complete mystery!

Last year people found 4 more. But all at the Parkes telescope. Maybe there was an error of some sort?

But now they've seen one at Arecibo, the famous radio telescope in Puerto Rico. Duncan Lorimer says several more confirmations will soon be announced.

So what causes these fast radio bursts?

We don't know. But here's one theory: a 'blitzar'.

When a supernovablasts t... more »

2014-07-26 02:38:12 (45 comments, 245 reshares, 248 +1s)

**The hypersnake versus the moiré eel**

This animated gif is cool, but here's something much cooler:

http://wry.me/hacking/moire-eel.html

It starts out intense... and then keeps getting more so.

You can control the shape of the little rectangles by moving your cursor over the screen. Try to keep your eye on just one little rectangle! It moves up and down, not very fast... but sometimes it's impossible to keep your eye on it, because all the rectangles together produce patterns that grab your attention. These are called **moiré** patterns.

I think the 'hypersnake' here is attention-grabbing because your brain has parts that are good at detecting snakes even before you are conscious of it. Your **amygdala** is one of these parts:**Information from an external stimulus reaches the amygdala in twodiffere... more »**

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