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Dec
31
comment What will a glass look like in 500 years?
I'm not an expert (maybe there's someone here who is) but I believe it's debatable whether glass is really a "slow liquid" rather than a solid. But even if it is a liquid, I think it will takes a lot more than 500 years for it to flow appreciably.
Dec
22
comment Is simulating the entire universe possible?
@KyleKanos I think it's entirely clear that it's asking about whether there are physical limitations that would prevent it, not about what humans can conceive. (I've edited to change the wording.)
Dec
22
revised Is simulating the entire universe possible?
added 8 characters in body; edited tags
Dec
19
revised Is there a way for an astronaut to rotate?
added 155 characters in body
Dec
17
comment Is it possible that a person with myopia will see a blurry picture as normal?
@DarioP it seems you're right - I had assumed that convolution (as a mathematical operation) was non-invertible, but it seems the difficulty of doing deconvolution in practical applications actually stems from not knowing the kernel exactly. But since convolution is linear and its inverse must also be linear, that seems to imply that you can sharpen an image such that it will return to its original appearance when later blurred, as long as you know the exact kernel for the blurring convolution. This might mean my answer is technically wrong.
Dec
16
awarded  Nice Answer
Dec
16
answered Is it possible that a person with myopia will see a blurry picture as normal?
Dec
11
answered Is there a spin glass version of Prince Rupert's Drop?
Dec
6
comment Is it possible to learn about an event that occurred outside of your observable universe?
@brucesmitherson that was edited into the question shortly after I answered it. It makes it a more interesting question, but I don't know the answer in that case. (Logically, the resolution has to be that the bound observer has the same cosmic horizon as us, but I don't immediately know how to show that it does. It probably has to do with the fact that you can no longer consider space flat and homogeneous on the scale of interest.)
Dec
5
answered Is it possible to learn about an event that occurred outside of your observable universe?
Dec
1
awarded  Generalist
Nov
30
awarded  Popular Question
Nov
30
awarded  Nice Answer
Nov
30
answered Can sugar be affected by a magnetic field?
Nov
30
comment Temperature loss of a moving object
@WhatRoughBeast it's both - first the heat conducts into the air, and then the air convects away. But you're right, "convective" is a better term here.
Nov
18
comment Why is temperature constant during melting?
@user3932000 I guess that can happen - depending on how you heat the system, some of the heat will go into the ice rather than the liquid water part. That portion of the incoming energy will not increase the temperature either, simply because it goes directly into melting the ice.
Nov
13
comment Could gravity accelerate light?
Just to clear up any doubt: the statements preceded by "I'm not a physicist" in the final paragraph are entirely correct. (Though the terms "blue shifting" and "red shifting" are used for all forms of electromagnetic radiation as well as for visible light.)
Nov
11
comment How does the second law of thermodynamics forbid the possibility of perpetual machine of the second kind?
Ok, so suppose your machine takes heat from the reservoir in the manner you suggest, by being colder than it, let's say 290K. This heat transfer will produce entropy as you say. But now you still have to convert this 290K heat into work somehow. This will decrease entropy for the reason I explained. in fact it will decrease entropy slightly more, because you're dividing by a smaller entropy, and the total entropy decrease will be exactly what I calculated above.
Nov
10
answered How does the second law of thermodynamics forbid the possibility of perpetual machine of the second kind?
Nov
4
comment How does rogue planet PSO J318.5-22 stay 800ºC?
@ziggurism yes, I'm sure that's correct. Observing a cool object that size away from any star would be very difficult, but this one's glowing in the infra-red and visible spectrum so it's much easier. Hence I think we're far more likely to observe young objects like this one, even though they must be pretty rare compared to much older ones that have cooled down to low temperatures.