That "#:~:text=" highlighter is so annoying it has made me switch from Google Chrome to Firefox.
That reminded me to look for extensions that automatically move mobile wikipedia links to desktop ones; thankfully there's one for both Chrome and FF.
Olbers' Paradox
31–40 of 86 posts
Re: Olbers' Paradox
#32What's the main piece of evidence against the hypothesis of "something" (a force, dark matter, dark energy, some exotic effect) dimming/slowing/distorting the light over very high distances?
Re: Olbers' Paradox
#33This doesn't make sense to me. They're assuming that brightness is a continuous function that you can keep dividing in half over and over and result in a real number, but brightness is not continuous, at a certain point you only have one photon left. It stops being a question of how many photons per second and becomes a question of how many seconds between a photon.
Re: Olbers' Paradox
#34Earlier quoted context omitted.
> even with a powerful telescope stars don't fill up your entire field of view. Suppose the experiment is repeated on a black pixel from the Deep Field image, and another swell of stars are observed, hinting at a kind of fractal distribution. Were the universe eternal and static, why could this pattern not repeat indefinitely in infinite time, space and matter? The paradox seems to assume a kind of infinite level of…
No, the paradox as described in the Wikipedia article doesn't assume the infinite level of sensitivity. The figure explains it visually - the further away you go from the observer, the more stars you capture in your camera's field of view and the apparent brightness stays the same. The 1/r^2 term for light intensity is cancelled by the r^2 for the number of stars. It's interesting think what an experimental result yo…
Thanks for spelling it out. Makes more sense now.
Re: Olbers' Paradox
#35This doesn't make sense to me. They're assuming that brightness is a continuous function that you can keep dividing in half over and over and result in a real number, but brightness is not continuous, at a certain point you only have one photon left. It stops being a question of how many photons per second and becomes a question of how many seconds between a photon.
The point is that any decrease is offset by the increase in the number of stars. Also your distinction between >1 photon per second and <1 photon per second is meaningless.
Re: Olbers' Paradox
#36This doesn't make sense to me. They're assuming that brightness is a continuous function that you can keep dividing in half over and over and result in a real number, but brightness is not continuous, at a certain point you only have one photon left. It stops being a question of how many photons per second and becomes a question of how many seconds between a photon.
The point is that any decrease is offset by the increase in the number of stars. Also your distinction between >1 photon per second and <1 photon per second is meaningless.
Can you elaborate a bit more? I don't understand how this responds to the commenter's critique. Under the hypothesis, almost all stars in the universe would be so far from Earth that we would see at most one photon from their light by the time it reached us, for whatever the applicable time interval is. Would that single photon be sufficient to register the star's existence?
I'm not a physicist so presumably I'm wrong. But why is this wrong? As far as I understand it, this paradox is the reason we have the theory that space is expanding at a rate which makes objects in effect move away from each other faster than the light they emit.
Re: Olbers' Paradox
#37Earlier quoted context omitted.
The point is that any decrease is offset by the increase in the number of stars. Also your distinction between >1 photon per second and <1 photon per second is meaningless.
Can you elaborate a bit more? I don't understand how this responds to the commenter's critique. Under the hypothesis, almost all stars in the universe would be so far from Earth that we would see at most one photon from their light by the time it reached us, for whatever the applicable time interval is. Would that single photon be sufficient to register the star's existence? I'm not a physicist so presumably I'm wron…
the point is 1 photon from a star seems like nothing, but 1 photon multiplied by infinite stars is infinite photons blinding us
Re: Olbers' Paradox
#38Isn't this just an issue of comparing a countable and uncountable infinity? The number of points on the unit sphere is uncountable, but the number of stars is countable. As such there are in some sense more points on the sphere than there are stars, even though there are an infinite number of each. Take this together with the fact that intensity falls off as the square of the distance and it seems like the sky should…
No, the rational numbers are dense.
Re: Olbers' Paradox
#39Earlier quoted context omitted.
That reminded me to look for extensions that automatically move mobile wikipedia links to desktop ones; thankfully there's one for both Chrome and FF.
yes: https://github.com/spixy/NoMoreMobile
Would love to see that rendered superfluous https://meta.wikimedia.org/wiki/Community_Wishlist_Survey_20...
Re: Olbers' Paradox
#40Earlier quoted context omitted.
Can you elaborate a bit more? I don't understand how this responds to the commenter's critique. Under the hypothesis, almost all stars in the universe would be so far from Earth that we would see at most one photon from their light by the time it reached us, for whatever the applicable time interval is. Would that single photon be sufficient to register the star's existence? I'm not a physicist so presumably I'm wron…
the point is 1 photon from a star seems like nothing, but 1 photon multiplied by infinite stars is infinite photons blinding us
"at most one". As you get further away zero protons are reaching you on most cases, and zero photons times infinite stars is zero, which would appear to be darkness