raphael at Wed, 6 Nov 2024 00:50:03 UTC No. 16464292

>>16464278
physics

one side is heavier

Anonymous at Wed, 6 Nov 2024 01:27:28 UTC No. 16464318

>>16464278
So, make a coin/disk that is just different colors or has a slight ink mark or something, have a robot hand flip it exactly the same weights and pressures 1000 times from 1 inch high, 1000 times from 1.1 inch, 1000 times from 1.2 inch....etc.
Oh I geuss it would need 1000 flips starting on side A, 1000 flips starting on side B, then we may have some convincing poll data by which we might solve the truth of probability

Anonymous at Wed, 6 Nov 2024 02:03:04 UTC No. 16464337

>>16464278
Every single coin from every currency has a heavier head side? Seems like the details are missing but I already knew that but for another reason: the side that is facing up when you flip the coin is more likely to come up.

Anonymous at Wed, 6 Nov 2024 02:14:47 UTC No. 16464342

>>16464278
Flip the coin twice.
One person gets HT, other person gets TH.
HH and TT are rerolls.

Anonymous at Wed, 6 Nov 2024 03:12:33 UTC No. 16464373

Kelly Criterion

Anonymous at Wed, 6 Nov 2024 03:34:07 UTC No. 16464385

>>16464278
Did you get this from ChatGPT or something? Last I heard Persi found that coin flips are slightly biased toward whatever side of the coin was face-up to begin with, and this effect is caused by precession.
https://www.stat.berkeley.edu/users/aldous/157/Papers/diaconis_coinbias.pdf
https://arxiv.org/abs/2310.04153

Anonymous at Fri, 8 Nov 2024 00:40:59 UTC No. 16466629

>>16464292
from the article the other anon posted

Anonymous at Fri, 8 Nov 2024 00:44:18 UTC No. 16466632

>>16464385
Wasn't that demonstrated to be a bias from their orientation with the Earth's rotation?

Anonymous at Fri, 8 Nov 2024 01:16:01 UTC No. 16466652

>>16466629
What is the science behind inhomogeneous coins landing heavy-side up? At first I would think that they should go heavy side down, since if you just have an object standing still with one side heavier than the other, then it will fall toward the heavier side. But maybe when spinning that effect is somehow cancelled out by the heavier side having greater inertia?

Anonymous at Fri, 8 Nov 2024 01:29:30 UTC No. 16466658

>>16466652
*when spun on a table, not when flipped, for clarification, since the image says inhomogeneity has no noticeable effect on the result when flipped

Anonymous at Fri, 8 Nov 2024 01:35:33 UTC No. 16466662

>>16464278
Why would the heavier side land facing up more often? Also, if you have a perfectly balanced coin and flipped it perfectly the exact same way every time, wouldn't it land on the same side every time?

Anonymous at Fri, 8 Nov 2024 02:18:01 UTC No. 16466689

>>16466629
Googling this brings up contradictory claims, but I tested it out by spinning a jam jar lid and at least that does seem to fit with the claim in the excerpt. If I simply hold the lid as straight as I can and let it fall, it invariably falls toward the top of the lid so the interior is face up. But if I spin it, it invariably lands the other way around with the top side face up. Very mysterious.

Anonymous at Fri, 8 Nov 2024 06:36:23 UTC No. 16466862

>>16466689
Will scientists ever explain the famous jam jar lid paradox?

Anonymous at Fri, 8 Nov 2024 19:57:15 UTC No. 16467494

>>16466862
Further update even though I seem to be the only person interested in this: I tried taping a penny to one side of a quarter and it does the same thing—obviously falls toward the penny side when simply stood on its side and let go, but lands the other way around most often by far when spun.

Interestingly as said different some articles claim the opposite should happen, even including the smithsonianmag: https://www.smithsonianmag.com/science-nature/gamblers-take-note-the-odds-in-a-coin-flip-arent-quite-5050-145465423/ which suggests that pre-2010 pennies should most often land tails side up when spun specifically because the heads side is heavier.

But on the other hand I found a blog elsewhere: https://mathtourist.blogspot.com/2011/02/penny-bias.html?m=1 which suggests that pre-2010 pennies should most often land tails side up when spun because in fact the tails side is heavier side, as they claim can be detected by standing a bunch of pennies on their side and then banging the table and watching which side they fall toward. So that person's finding agrees with the jam jar lid paradox.

I grabbed a few pre-2010 pennies to try this myself, but what I found was that, by the table-banging test although each penny seemed to be strongly biased toward one side, different coins seemed to be biased toward different sides. And by the spinning test, the pennies seemed to tend to land on the same side they were biased to fall toward, disagreeing with the jam jar lid paradox. So idk what's up with that.

🗑️ Anonymous at Fri, 8 Nov 2024 20:27:15 UTC No. 16467521

>>16467494
Wait, nevermind, I'm an idiot. Taping the penny to the quarter moved its center of mass, making the penny side lighter.

Anonymous at Fri, 8 Nov 2024 21:00:37 UTC No. 16467547

>>16467494
Ah, I think I finally understand it at least in an intuitive way (I am very slow and my physics education is poor). When spinning, the coin/lid wants its center of mass to be at the center of the rotation, and the only way that can happen is if it tilts so that the heavy side is facing more up. If it tilts the other way then the center of mass has to move in even wider circles than if the coin just stays straight.