In mathematics, a holyhedron is a type of 3-dimensional geometric body: a polyhedron each of whose faces contains at least one polygon-shaped hole, and whose holes' boundaries share no point with each other or the face's boundary.
The concept was first introduced by John H. Conway; the term "holyhedron" was coined by David W. Wilson in 1997 as a pun involving polyhedra and holes. Conway also offered a prize of 10,000 USD, divided by the number of faces, for finding an example, asking:
Is there a polyhedron in Euclidean three-dimensional space that has only finitely many plane faces, each of which is a closed connected subset of the appropriate plane whose relative interior in that plane is multiply connected?
No actual holyhedron was constructed until 1999, when Jade P. Vinson presented an example of a holyhedron with a total of 78,585,627 faces;[3] another example was subsequently given by Don Hatch, who presented a holyhedron with 492 faces in 2003, worth about 20.33 USD prize money.
Bookmarks
Interesting Links/bookmarks for personal use or sharing with others
🔖 Gilbreath’s conjecture | Wikipedia
Gilbreath's conjecture is a conjecture in number theory regarding the sequences generated by applying the forward difference operator to consecutive prime numbers and leaving the results unsigned, and then repeating this process on consecutive terms in the resulting sequence, and so forth. The statement is named after mathematician Norman L. Gilbreath who, in 1958, presented it to the mathematical community after observing the pattern by chance while doing arithmetic on a napkin. In 1878, eighty years before Gilbreath's discovery, François Proth had, however, published the same observations along with an attempted proof, which was later shown to be false.
🔖 The Formula: The Universal Laws of Success by Albert-László Barabási
In the bestselling tradition of Malcom Gladwell, James Gleick, and Nate Silver, prominent professor László Barabási gives us a trailblazing book that promises to transform the very foundations of how our success-obsessed society approaches their professional careers, life pursuits and long-term goals.
Too often, accomplishment does not equal success. We did the work but didn't get the promotion; we played hard but weren't recognized; we had the idea but didn't get the credit. We convince ourselves that talent combined with a strong work ethic is the key to getting ahead, but also realize that combination often fails to yield results, without any deeper understanding as to why. Recognizing this striking disconnect, the author, along with a team of renowned researchers and some of the most advanced data-crunching systems on the planet, dedicated themselves to one goal: uncovering that ever-elusive link between performance and success.
Now, based on years of academic research, The Formula finally unveils the groundbreaking discoveries of their pioneering study, not only highlighting the scientific and mathematic principles that underpin success, but also revolutionizing our understanding of:
Why performance is necessary but not adequate
Why "Experts" are often wrong
How to assemble a creative team primed for success
How to most effectively engage our networks
And much more.
Caught an interesting reference to this in an episode of Human Current, but I’ve also recently finished his prior book Linked. I’ll likely read it, but I’ll probably wish I had read the relevant papers instead.
Syndicated copies to:🔖 SLOWLY
SLOWLY lets you meet pen friends from your smartphone! Match with someone that shares your passion, write a letter and collect stamps from around the world. Speak your mind – one letter at a time!
SLOWLY is not your typical networking or dating app - we’re bringing the traditional pen friend experience to your smartphone.
The app is created for those who yearns for meaningful conversations with people in the era of instant messaging. We hope to connect people around the world at a slower but better pace – one letter at a time.
Meet a new pen friend, seal your letter & place a stamp - start connecting with the world on SLOWLY!
Features:
- Mailing time depends on where you & your pen friend live.
- A nickname & an avatar is all you need. Speak your mind & connect freely to the world.
- Matches based on common interests & languages.
- Collect & unlock hidden stamps!
👓 NetNewsWire is a free and open source feed reader for macOS. | Ranchero
NetNewsWire is a free and open source feed reader for macOS.
It’s at a very early stage — we use it, but we don’t expect other people to use it yet. It’s not actually shipping.
🔖 FlowReader: A modern reader with a social twist.
FlowReader is a faster way to manage your online content! Combine your favorite sources & networks to get the news the matters most - all in one place.
A feed reader I hadn’t heard about before. Looks vaguely interesting, but the UI doesn’t make me want to throw my current feed reader set up overboard.
Syndicated copies to:🔖 Current Pricing for Our Grass-Fed Beef | Coyote Creek Farm
Our steers are raised and grazed on 100% USDA certified organic pasture.
Our grass-fed beef price for this year is $3.70 per pound (same price as last year) hanging weight for the beef, your total cost with slaughter and processing is explained below. All figures are approximate since we won’t know the exact weights until time of processing.
Slaughter is $50.00 and cut and wrap is $.75 per pound based on hanging weight. The wrapping is in cryovac, which will keep your beef for up to two years.
Assume 1,000 lbs. on the hoof for figuring purposes, it may weight up to 1,200 lbs. or as little as 900 lbs.
55% of live weight on rail = 550 lbs. x $3.70 = $2035 + (.75 x 550) $412 = $2447 + $50 = $2,497
Cut and wrapped meat = 75% x 550 = 412 lbs. (plus soup bones & sausage) (sausage is optional)
$2,497 / 412 lbs. = $6.06 (This average will run from $6.50 to $6.75) per pound for your organic pasture grazed, grass-fed beef. This is about the price of one pound of ground grass-fed beef at a Farmer’s Market or at Whole Foods Market. This is clearly the most economical way to feed your family with all the health benefits of grass-fed beef.
For half a beef the cost is just that, one half of the above cost of a whole beef.
We like to dry age our beef in the cold storage from 14-21 days, so add this time to the slaughter date to determine your pickup date. We deliver your steer to the locker plant and you pick it up, unless other arrangements are made with us in advance.
Taking a peek at this for comparison to the cow party earlier today.
Syndicated copies to:🔖 View and export Hypothesis annotations
Click HTML, CSV, or JSON to search for matching Hypothesis annotations and display them in one of those formats. Fill in one or more facets to filter results. The facets are username, url (or wildcard_uri), tag, and any. If you need more than 400 results, set max to a larger number. If you just click a button without specifying any facets other than the default group Public, you'll get the most recent 400 Hypothesis annotations in the Public group.
🔖 Rename Hypothesis tags
This tool lists your Hypothesis tags, and enables you to rename one or more of them.
Please do make a safe copy your annotations first. And proceed with care. There's a kind of information loss that's possible unrelated to any technical malfunction. Suppose you are using three tags, A, B, and C, to classify annotations into three buckets. Then you rename B to C. Now bucket B is gone. There is only A, unchanged. and C, which includes what was in B. You can't reverse the arrow of entropy and reconstitute the set of annotations that were in B!
👓 Books of the year: economics | Economist Espresso
Radical Markets: Uprooting Capitalism and Democracy for a Just Society. By Eric Posner and E. Glen Weyl. Princeton University Press; 368 pages
Do the rich world’s problems stem from an overdose of liberal principles, or their insufficiently bold application? Glen Weyl and Eric Posner argue that the ideals of thinkers such as Adam Smith, John Stuart Mill and Henry George can still inspire radical change. Such luminaries were unafraid of challenging the status quo. Following suit, the pair suggest expanding and refining markets, putting them to work for society as a whole. Property may not be theft, for example, but it is monopoly. Every individual should put a value on each item she owns, down to the last pencil, and be taxed on her total declared wealth. The twist: she must stand ready to sell any item at its declared value, should a buyer emerge. Such policies are so radical that they are unlikely ever to be adopted. But they may help jolt liberals out of their hand-wringing.
This is certainly an intriguing way of doing taxes. Reminiscent of the way that claiming races are done in horse racing.
Syndicated copies to:🔖 Talk Like a Pirate, Me Hearties | Adactio.com
Simply, you put in a URL and this tool will return a web page that “translates” the page into pirate speech. The UI is so sparse here you can’t do much but put in a URL (though without knowing exactly what is going to happen).
Ideal for your talk-like-a-pirate-day browsing every September 19th. Maybe a bookmarklet that does this would be cool? Come to think of it, maybe having a browser extension that does this for you automatically on every page you visit on September 19th would be a fun little toy!
Syndicated copies to:🔖 La Première partie des subtiles et plaisantes inventions, comprenant plusieurs jeux de récréation et traicts de soupplesse, par le discours desquels les impostures des bateleurs sont descouvertes. par Jean Prévost | Gallica
The earliest known important book on conjuring or magic, printed in French in Lyons in 1584.
hat tip: Ricky Jay’s Magical Secrets (The New Yorker)
Syndicated copies to:🔖 Newspaper Club – Make and print your own newspapers
Make and print your own newspapers
🔖 Google Custom Search for IndieWeb
A custom search for IndieWeb sites via IndieMap
Syndicated copies to:🔖 Computational Complexity Conference 2019: Call for Papers
Submission Deadline: Tuesday, February 19, 2019, 5:00pm EST
The conference seeks original research papers in all areas of computational complexity theory, studying the absolute and relative power of computational models under resource constraints. We also encourage contributions from other areas of computer science and mathematics motivated by questions in complexity theory.