Unanswered Questions in Physics and Math: A Challenging Quiz

  • Thread starter Thread starter K.J.Healey
  • Start date Start date
AI Thread Summary
The discussion revolves around a series of challenging physics and math questions presented in a trivia format, with some questions remaining unanswered. Key topics include the concept of an isotropic universe, where the detectability of scatterers is debated, suggesting that a random distribution would yield equal probabilities of deflection, making detection difficult. Another point discusses the softness of pillows, attributing it to the properties of materials like feathers, which allow for spring-like behavior and durability over time. Additionally, the effects of turbulence on temperature changes in inviscid liquids are examined, raising questions about energy loss due to heat generation in a closed system. Participants are encouraged to engage with these questions and share their insights.
K.J.Healey
Messages
622
Reaction score
0
These are some challenging physics and math based questions, sort of like trivia though a few haven't been answered. You should all give them a shot.
http://star.tau.ac.il/QUIZ/

Ill put in white what I think of some of the unanswered ones.


01/04 - Isotropic Universe
I do not think the S would ever be detectable if it had a random distribution
of scatterers that had random orientation. From a probability standpoint, there is a finite probability of deflecting toward O, P(DT); a probability of deflecting away P(DA). The problem is, assuming a random distribution, you have an equal chance of deflecting away as you do toward (P(DT) = P(DA)). So the net difference would be 0. The only thing I can think that would make this difficult is the fact that though its random orientation, there is not an infinite number of scatterers, thus over time you may see a trend. So If you were told "in this region of space there may or may not be Scatteres" and you compared the distribution over time to that of the rest of your input, you could see a difference. But if you were trying to locate if there was one anywhere there would be no way to tell where it actually was. Though you may be able to tell that there is an uneven distribution of where particles are coming from. This is also assuming you don't know its size.

08/03 - Why is a pillow soft?
Seems like I'm missing something here. If by "soft" they mean something that has an exponential damping curve that, then it is due to 1. Restriction of displacement of air thru the material. 2. The feathers create enough of a "spring" to displace the material when there is no load on it, thus its equillibrium is a larger volume than when its flat. 3. Feathers, due to their geometry, are very durable when being compressed. They can stay soft for many uses. Though over time they can break and trear, thus resulting in a pillow that is no longer soft.

11/02 - Inviscid Motion
My question is a thermodynamics one. Can turbulence (changes in pressure) cause changes in Temperature in inciscid liquids? If so, then there will be loss of Total Energy of the motion of the sphere due to this turbulent generation of heat. I am assuming the sphere is in a box that has this liquid filled to its max volume, and there is no way for volume to change or to lose liquid. Though I do assume you can have temperature, such as a heatsink attached to the box.





What do you guys think of some of the unanswered ones?
 
Last edited by a moderator:
Physics news on Phys.org
cool thanks for the suggestion
 
Hey, you're not really Bill Nye, the science guy...are you ? :wink:
 
Similar to the 2024 thread, here I start the 2025 thread. As always it is getting increasingly difficult to predict, so I will make a list based on other article predictions. You can also leave your prediction here. Here are the predictions of 2024 that did not make it: Peter Shor, David Deutsch and all the rest of the quantum computing community (various sources) Pablo Jarrillo Herrero, Allan McDonald and Rafi Bistritzer for magic angle in twisted graphene (various sources) Christoph...
Thread 'My experience as a hostage'
I believe it was the summer of 2001 that I made a trip to Peru for my work. I was a private contractor doing automation engineering and programming for various companies, including Frito Lay. Frito had purchased a snack food plant near Lima, Peru, and sent me down to oversee the upgrades to the systems and the startup. Peru was still suffering the ills of a recent civil war and I knew it was dicey, but the money was too good to pass up. It was a long trip to Lima; about 14 hours of airtime...

Similar threads

Replies
25
Views
4K
3
Replies
114
Views
10K
2
Replies
61
Views
11K
2
Replies
60
Views
11K
Replies
46
Views
8K
4
Replies
150
Views
19K
2
Replies
77
Views
15K
Replies
43
Views
12K
2
Replies
98
Views
14K
Replies
3
Views
1K
Back
Top