New answers tagged cosmology
4
The misconception here is that with enough stars the gravitational pull would form an event horizon that would stopping light from escaping it. If the light emitted by a star could leave it's surface heading out of the centre of mass, then it isn't an event horizon. If light can't escape, then the star is going to be ripped apart by the enormous ...
2
It is going to be hard to make thousands or millions of stars to orbit the central star, since largest stars are just hundreds of solar masses. Ie barycenter of this system would be outside its center, and the "central" star would rather orbit the system itself.
Also stable orbits do not exist inside event horizons, so such system is not physically ...
9
Einstein's opinions were not static, and he lived at a time when there were several competing theories and not much observational evidence.
Einstein introduced a cosmological constant $\Lambda$ into his equations, the purpose of which was to allow for a steady cosmos with no expansion or contraction. He is said to have later regretted this addition. He was ...
6
The statement "They're only emitting infrared light" is wrong, or at least poorly phrased.
The Ly$\alpha$ forest
The Ly$\alpha$ forest (LAF) is caused by the spectrum of the quasar being redshifted along its way; wherever a cloud of neutral hydrogen is located, the part of the spectrum that at that at that position has been redshifted to $\lambda_0 = 1216\,...
0
Far away quasars emit light at many frequencies. However, we can only see them in the infrared. This is because all of the light emitted with a shorter wavelength gets absorbed.
See this illustration
The light from distance quasars is redshifted on its way towards us and absorbed by the intergalactic medium. Because of this, the "bluer" light emitted by ...
0
They would only be visible in IR if they emitted IR They would only be visible in IR if they emitted IR, Right? Even if that's not true, I'm pretty sure he was talking about the fact that those very old quasars are only visible in IR (I say this because quasars definitely emit more than just IR). Quasars emit energies of millions, billions, or even trillions ...
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