461–470 of 547 posts
Articles like these make me want to stop doing everything and isolate in the basement for several months to study physics. Then I realize I have a family to feed and elderly parents to take care for. Sigh, so many beautiful mysteries in the world, and only one life. edit: A friend told me germans have the word "Sehnsucht" to describe such a feeling. So I guess it might be somewhat universal.
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I guess it's reasonable to assume that there are parts of the universe that are far older and much further away (ie, their light hasn't reached us yet). Which would mean we can never really guess the age of the universe. We can only guess the age of our local area? Which kind of sounds a bit like the whole "everything revoles around earth" transitioning to "everything revolves around the sun". The universe is what li…
> I guess it's reasonable to assume that there are parts of the universe that are far older and much further away (ie, their light hasn't reached us yet). Which would mean we can never really guess the age of the universe. We can only guess the age of our local area? But older parts of the universe would emit light that would have more time to travel. So unless space is not continuous, we can confidently say that no…
How can we confidently assume this isn't the case?
Articles like these make me want to stop doing everything and isolate in the basement for several months to study physics. Then I realize I have a family to feed and elderly parents to take care for. Sigh, so many beautiful mysteries in the world, and only one life. edit: A friend told me germans have the word "Sehnsucht" to describe such a feeling. So I guess it might be somewhat universal.
I don't know if it's any consolation, but a few months are not nearly enough to understand this on a meaningful level. I spent almost a decade studying physics, still feel like I don't really understand it and could barely wait to get out at the end.
This is the part that’s actually consoling.
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> the uniform ultimate backdrop we have when looking in any direction Is the CMB exactly uniform in every direction? Or is this early light slightly more redshifted when we look up versus when we look down or left or right? Does the oldest light we see in any given direction vary slightly in color? I'm imagining the universe expanding as a sphere from a central point, but we're located off-center. Wouldn't the early…
The CMB is famously not exactly uniform https://www.esa.int/ESA_Multimedia/Images/2013/03/Planck_CMB I have not read that any particular directions are evident in the sense you suggest though.
This page has three pictures: https://wmap.gsfc.nasa.gov/universe/bb_cosmo_fluct.html
The first is the actual observation. It's boring and looks completely homogeneous.
So you subtract the average value, which brings you to the second picture. Its temperature is 0 on average, but shows the obvious dipole.
When you remove the dipole, you get the last picture, which show only the physical temperature fluctuations.
I don't know if this instance qualifies as one, but I think its fair to say that cosmology is the one domain of "fundamental" physics where "discrepancies" or question marks keep piling up and not really resolving. It the pattern of previous science revolutions repeats, there could come a point where reinterpreting the large existing body of knowledge using a different paradigm would explain an number of "oddities" i…
There is the esoteric "Cosmological Natural Selection" theory that predicts the discrepancies. This guy at https://theeggandtherock.substack.com/archive explains his version of this theory (albeit in an emotional way) that I find a pleasant read.
F R A C T A L H A T C H E R Y
Articles like these make me want to stop doing everything and isolate in the basement for several months to study physics. Then I realize I have a family to feed and elderly parents to take care for. Sigh, so many beautiful mysteries in the world, and only one life. edit: A friend told me germans have the word "Sehnsucht" to describe such a feeling. So I guess it might be somewhat universal.
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> Rather it's that the rate of expansion of the universe is accelerating, so that we're moving away from parts of it faster than its light can cover the distance to us. It will never reach us. It's actually even worse than that. Because of the accelerating expansion of the universe, over time the part of the universe that we can observe will get smaller, allowing us to see less and less of it. Eventually, all that we…
So galaxies are falling off the edge of the universe never to be seen again?
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The CMB is famously not exactly uniform https://www.esa.int/ESA_Multimedia/Images/2013/03/Planck_CMB I have not read that any particular directions are evident in the sense you suggest though.
There is a very obvious dipole in the CMB due to our peculiar velocity. This has been removed in almost all images you saw because it's just an artifact of our particular movement and not physical. It's just the Doppler effect. This page has three pictures: https://wmap.gsfc.nasa.gov/universe/bb_cosmo_fluct.html The first is the actual observation. It's boring and looks completely homogeneous. So you subtract the ave…
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>Certainly there are many unexplained effects in solid state physics Wait for it… Why ice is slippery? Usual explanation is completely incorrect. Actual semi-conclusive research just recently happened.
I had to look that up. Here's research[1][2] from 2019 about "why ice is so slippery", including some of the apparent surprises. I dunno. I'm not a physicist so some of the surprises seem like very minor things to me. Spoiler: According to this research, ice is slippery because of a thin layer of water. (As we expected, no?) But the water layer is 1) thinner than expected, 2) more viscous than expected, and 3) contai…