Ping
Interesting ...
I've always questioned this. I once read that light will also have a red shift as it passes through intergalactic dust and gas. So all galaxies will show a red shift, and the farther away they are, the more dust and gas the light will pass through. Hence a larger red shift.
But I don't have anything like a degree in science. I'm just a dumb lawyer, so I wouldn't bet the farm on my "theory."
Thanks for posting
- Niels Bohr
This statement is objectively false. There is no requirement that objects in relative motion must be moving slower than the speed of light.
Then there is the cosmological red-shift itself, which is another mystery. Physicists often talk about the red-shift as a kind of Doppler effect, like the change in frequency of a police siren as it passes by.
It's not a "kind" of Doppler effect. It is the Doppler effect.
But the cosmological red-shift is different because galaxies are stationary in space. Instead, it is space itself that cosmologists think is expanding.
The galaxies are not stationary in space. Both the galaxies and space are moving relative to other objects at other parts of space, and a Doppler shift is predicted in either (and both) cases.
The mathematics that describes these effects is correspondingly different as well,
Nope. Not true.
not least because any relative velocity must always be less than the speed of light in conventional physics.
Nope. Not true.
And yet the velocity of expanding space can take any value.
This is true. It can. Doesn't contradict any known physics. Doesn't require any new mathematics to describe.
One interesting idea is that the red-shifts of distant objects must increase as they get further away.
Already known. Already measured. That's what the Hubble Constant is.
But the evidence is paradoxical. Astrophysicists have measured the linear nature of the Hubble law at distances of a few hundred megaparsecs. And yet the clusters visible on those scales indicate the universe is not homogeneous on the scales.
Nope. No paradox. The large scale clusters are the result of quantum fluctuations that existed in the universe in the time before the first nanosecond. They are the result of Quantum Mechanics, which is more fundamental than General Relativity, and certainly much more fundamental than the "Hubble Law" which depends on assumptions which are not Quantum Mechanical in nature.
And so the argument that the Hubble law’s linearity is a result of the homogeneity of the universe (or vice versa) does not stand up to scrutiny. Once again this is an embarrassing failure for modern cosmology.
Nope. It's not. It's a result of the fact that we don't have a Quantum Mechanical version of General Relativity. In terms of general, rough morphology, it's perfectly adequate, and not contradicted by any information we have.
Does this mean they’re going to retire “string theory”?
This makes me suspect the whole article. Space may indeed be expanding, but it is a well known fact that the Andromeda galaxy is currently crashing into our Milky Way galaxy. This is true of other galaxies throughout the universe - you see them tearing into each other as the collision slowly happens.
Here's an example:
I just want to state, for the record, that it is NOT my fault.
It’s inconceivable that the universe has been in existence forever, and will go on and on forever - on the other hand it’s inconceivable that the universe suddenly came into existence from nowhere, and will one day just suddenly cese to exist...so......
ping
Feynman talks about not understanding these paradoxes from about 23 minutes on:
https://www.youtube.com/watch?v=EyssfKRsgMU
It starts with this pair of ducks ...
Love, Tim Allen
And yet there are millions upon millions of people who just want to eat.
we know gravity bends light and can in fact trap light (black hole) so wouldn't a redshift be expected from the effect of gravity itself on light as it moves further and further away from the gravity source...
as a Galaxy's gravity's weaken as light move farther away from the gravity source.. the wavelength on the light should stretch out... the further the light is away from the source and its gravity the greater the shift in the light wavelength giving the effect that the further away galaxies are moving out faster than closer in galaxies
Another possibility is we are inside the event horizon of a Black Hole. Galaxies closer to the singularity are redshifted travelling faster than us toward it, those farther behind are redshifted because we are travelling faster than they.
And since we calculate distance based solely on red shift for objects beyond a limited window where we can measure angles from our own orbit around the sun, we really don’t know much of anything.
For the last six years it’s seemed to me that events are being steered by a Black Hole I didn’t vote for. I may be even more right than I suspected!
bfl
The Doppler effect arises from the relative movement of different objects. But the cosmological red-shift is different because galaxies are stationary in space. Instead, it is space itself that cosmologists think is expanding.
The mathematics that describes these effects is correspondingly different as well, not least because any relative velocity must always be less than the speed of light in conventional physics. And yet the velocity of expanding space can take any value.
Interestingly, the nature of the cosmological red-shift leads to the possibility of observational tests in the next few years. One interesting idea is that the red-shifts of distant objects must increase as they get further away. For a distant quasar, this change may be as much as one centimetre per second per year, something that may be observable with the next generation of extremely large telescopes.
It is early. I have just started drinking my coffee.
But I don't see the paradox here.
I don't even see where the author is saying there is a paradox here.