Astronomers See Evidence of Something Unexpected in the Universe

All inertial reference frames, actually.

Yes, I agree with that.Thus it could be that local clocks and rulers show that the cosmos appears to be expanding locally, yet there is no meaning of "expanding" that applies to the cosmos as a whole.To be clear: I'm suggesting everywhere in the cosmos, local observers might see the local appearance of expanding. And yet that does not make "expanding" a meaningful term to apply to the cosmos as a whole.

All of creation's conclusions were based on time not behaving the same as it does here. For example, he said that we could not know how far light traveled because we did not know the rate of time passage in those distant places. He may well have believed more than that, but at this point, you appear to be putting ideas into the rather small place that was creation's thinking on this topic.Despite the differences, I would respond to both nwr and creation in pretty much the same way Taq has already answered. We have at least some evidence for the position that our formulation of physics is applicable in distant space, while the opposing position is just denial and supposition.

Hi NoNukes, Just one of my foolish thoughts but I thought it was a given that time in space does not behave the same as it does on earth.In one of the twin's taking a journey into space and returning that twin is supposed to have aged a lot less than the twin on earth.So wouldn't that mean that the speed something traveled in space would change time compared to here on earth.Just asking.God Bless,

You are confused and if you are looking for my help, you can stay confused. I am not going to discuss special relativity with you again. You are the one adult on earth with whom I refuse to have a dialog about physics.Edited by NoNukes, : No reason given.Edited by NoNukes, : No reason given.

Special Relativity posits that all inertial observers agree on the speed of light.General Relativity, lacking global inertial observers (i.e in general there are no inertial frames) doesn't even posit that. The speed of light will be observer dependent.

If the expansion was local then all galaxies outside of the local area would be redshifted by the same amount, but they aren't. More distant galaxies are redshifted more strongly than nearby galaxies, and there isn't a point in the cosmos where redshift caps out. The only explanation that makes sense is that the entire length of space between us and all galaxies is expanding at the same rate per unit of length.

Could you describe a situation where the speed of light is observer dependent within GR?

Clocks do tick at different rates with respect to gravity and relative velocity. The famous Hafele-Keating experiment used atomic clocks on jetliners to determine that clocks tick faster further away from the Earth's center of gravity. In modern times we observe that the clocks on GPS satellites tick at a higher rate than those same clocks on the surface of the Earth. However, the differences are in the nanosecond range, so not that significant.Cosmologically, you don't see significant time dilation until you get to the highest redshifted galaxies. In these cases, scientists have seen time dilation in the form of type Ia supernovae taking longer to brighten and dim compared to the same supernovae in nearer and less redshifted galaxies. Within our own galaxy, movements are dominated by gravity so any redshift we see is due to movement through space instead of expansion of space itself.

I don't know how much detail you want (actual calculations?), but if you shine light on a mirror above the event horizon of a black hole and time the return of the beam and the distance, you won't get the usual speed of light.

Sigh!This is still a complete misunderstanding of what I have been saying.

You can hardly blame us if you then refuse to clear up any misunderstandings.

I would assume that this would also be true for a laser beam shot from space and bouncing off of a mirror 500 miles below on the face of the Earth (but obviously with less of a difference than with a black hole)?

Yes indeed, the black hole is a dramatic exaggeration where it would be obvious to a human, but it'd be true above the Earth.For spherical gravitational fields the speed would be: where c is the usual speed with no gravity around and the speed in the presence of gravity. M the Mass of the body, G is Newton's Constant and r is the radius of the observer.For the case you mentioned that results in light being less than a m/s slower.Edited by Son Goku, : No reason given.

The map of distance to red-shift is empirically derived and is checked against phenomena that do not require measuring the travel of light. In addition, in those few situations where we can use the speed of light to make a measurement, such as SN 1987a, we have confirmation using an additional method.Against all that we have your proposal of a completely different universe for which we have no confirming science whatsoever. Why do you believe in your model over those of others?