Expansion of the universe and Einstein

I don't understand what the confusion is about.
The rate of expansion is the only thing that is ftl. Do not confuse this with something having speed or going anywhere.
Better name would be expansion of empty space. Think of it in terms of walking on the escalator in the wrong direction, those steps comming out of the ground is space expanding

a reply to: Jubei42

The space it is expanding into is empty, yes (for as far we know atm)..the emptiness isnt expanding in any way
But the universe is the one moving into it at ftl, thats what is confusing.

originally posted by: andy06shake
a reply to: Devino
It's a mistake to think of the expansion as being in 3 dimensions as that would certainly be inconsistent with the 4 dimensional world suggested by relativity.

Relativity and the expansion of the universe are perfectly compatible.

Four dimensions being 3 dimensional space plus time, yes?

Relativity and expansion are compatible until we violate relativity by claiming expansion is faster than 'C', is this not correct? In my opinion there is a problem with either 'C', speed of light, or 'H', the Hubble redshift, as being a constant. Albert Einstein was confident that the speed of light was a constant yet Edwin Hubble was not convinced that the redshift of light was. Is it not likely that there is a property for intrinsic redshift?

originally posted by: HellaKitty

originally posted by: Devino

originally posted by: andy06shake
a reply to: HellaKitty

Possibly overlooked the existence of dark matter/energy, which comprises the other 95% of the universe. That explains the expansion to a fashion.

If dark energy is a force that accelerates mass faster than 'C' then how does this not violate relativity?

This was exactly my point when I mentioned "The universe is/contains mass, so how come the equation does not count in the case of the expansion of the universe? " in the original post


I have seen some reactions saying everything moves away, this is not true.
Andromeda is moving towards the Milky way which indicates there's holes in the theory (yes, I know gravitational forces play a part in this)

There are other galaxies in our local cluster that are moving towards us and one, Sagittarius, that is sort of connected. these are the rare blue shift galaxies. Other galaxy clusters behave the same way, smaller galaxies moving towards the parent galaxy. I may be wrong but I don't think objects moving towards us violates the expansion theory though as the theory seems pliable enough to account for this.

originally posted by: Jubei42
I don't understand what the confusion is about.
The rate of expansion is the only thing that is ftl. Do not confuse this with something having speed or going anywhere.
Better name would be expansion of empty space.

So empty space can expand or contract all it wants but that is not what we are observing. We are observing large redshifts that seem to indicate objects, QSOs and galaxies made of mass, accelerating at faster than light speeds.

Science has made great leaps but I suspect we will one day see a resurgence of string theory after we realize that our universe was not created by a singularity but from an ongoing collision of two branes which created a hole in which new spacetime enters our material universe. Giving the illussion that spacetime is expanding faster than speed of light.

a reply to: Devino

I don't claim to have any understanding or knowledge but I have a feeling that the relative movement between us and that distant galaxy is meaningless or at the least misleading

originally posted by: badw0lf

originally posted by: wildespace
It's the space itself that expands. There's no rules against that. The best example to illustrate that is a rising piece of dough with raisins in it. The raisins don't actually move through the dough, but the expanding dough makes the raisins move away from each other.

Expanding dough with raisins in it, doesn't explain initial expansion. Where nothing existed. It does explain, or at least give argument to, the expanding universe.

"Nothing" can never truly exist. There is always something. Given enough time, this "something" can give rise to life.

a reply to: HellaKitty

The general explanation is that space itself is expanding between objects and that the objects themselves are not actually moving. Of course Space-time is strongly defined within Einsteinian relativity and so this is a nonsense.

I have a theory that the boundary conditions (the very outer edges) of the proto-universe, had no room for the Higgs mechanism to establish. Therefore at this boundary, there was no speed limitation because mass itself was meaningless. As soon as there was sufficient 'space' for the Higgs mechanism to work, mass was established and therefore movement of mass was limited by C.

You could imagine the universe growing faster than C at its outer edges only and mass being 'frozen' in place just behind this 'leading edge'.

originally posted by: chr0naut
a reply to: HellaKitty

The general explanation is that space itself is expanding between objects and that the objects themselves are not actually moving. Of course Space-time is strongly defined within Einsteinian relativity and so this is a nonsense.

How is it a nonsense?

To get some perspective on the matter, here's how I understand space expansion works:

Vacuum always has some energy, due to the Uncertainty Principle creating quantum fluctuations. This energy (called vacuum energy or zero-point energy) is what drives the expansion. This energy manifests itself in virtual particles that pop in and out of existence almost instantaneously. The actual mechanical effect of this energy has been observed in lab experiments (the Casimir effect).

This "something out of nothing" phenomenon provides a great explanation for how our universe came into existence. Basically, space is endless and eternal; space and time did not just pop into existence willy-nilly in the Big Bang. Rather, some areas of space (which has always existed) can be at a slightly higher energy level than it usually is, and undergo spontaneous decay to a lower energy state, creating an expanding "bubble" of space seeded with matter and energy. The term for this is Chaotic Inflation. This model is in some trouble after the latest measurements from Planck satellite, but it makes perfect sense to me, so I'm holding on to it.

This should help -

a reply to: Devino

I'm just attempting to explain it to you the way i understand the process as apparently the velocity of light C in a vacuum is constant.

However, in a medium the light is absorbed and re-emitted as it passes through the medium, which slows it's average speed.

Between absorption events it travels at C but it's overall speed through the medium is slowed.

The universe is not empty nor is it a complete vacuum possibly this could account for the apparent discrepancies?

Maybe the dark energy/matter that comprises the rest of our known universe somehow accelerates or appears to accelerate light past C?

Keep in mind science is simply our best guess based on the information we have available at the time, and our theories and results change as we come into possession of more accurate measurements and data.

A few hundred years ago a significant percentage of the people of the world thought it was flat so who knows what we will learn regarding our universe in the next few decades?

Chances are it will turn out to be holographic by nature, and that will be very interesting if proven to be the case.

The universe only expands at the rate matter is moving into empty space. a reply to: HellaKitty

a reply to: andy06shake
It's been a few years since I have discussed this subject so I appreciate the comments and this thread. lately my interests have been American history, whatever keeps my brain occupied I guess.

The problem I faced back then was a feeling of hitting a dead end. It appeared to me that main stream science was refusing to accept a far simpler explanation to the observations that seem to contradict current theory. In the end this threatened the big bang theory which apparently is a big no-no. To put it simply I think 'H', or the Hubble constant, is not a constant.

I think that many of these high redshift objects like; Quasars, Seyfert Galaxies and BL LACs could possibly have an intrinsic redshift property to them. This would mean that they are not as far, and therefore not as impossibly bright and large, as their redshifts might imply, assuming 'H' is constant. Halton Arp has an overwhelming amount of observational evidence that supports this contention.

Arp theories that Quasars are proto-galaxies and their high redshifts reduce over time as they mature, gaining stellar mass, becoming Seyferts and BL LACs and finally companion galaxies. This theory is considered a "crackpot idea" and no funding is spent attempting to disprove his theory. Instead we have these ad hoc theories about dark matter, dark energy, expanding space that is faster than light, a 13 BY old Universe and of course, the underlining theory, the big bang.

How could I ever argue against these brilliant minds? The Universe is expanding faster than the speed of light, so they say. Sure, why not.

Also bear in mind that it was the Catholic church that proposed the flat Earth and the geocentric Universe theory. Many scholars of the time knew the Earth was a sphere and that we orbited the Sun. Evidence of this can be found in Mayan and Egyptian architecture dating back many thousands of years. It seems fitting that the big bang theory came about from a Catholic priest.

originally posted by: wildespace

originally posted by: chr0naut
a reply to: HellaKitty

The general explanation is that space itself is expanding between objects and that the objects themselves are not actually moving. Of course Space-time is strongly defined within Einsteinian relativity and so this is a nonsense.

How is it a nonsense?

Try coming up with any math to explain how expanding space between objects does not equate to a velocity of increasing distance between the objects?

How about instead of claiming Nonsense, you could tack on an addition to special relativity to account for different aspects, as it is open to additions and not a closed off final conclusion.

a reply to: chr0naut

You could imagine the universe growing faster than C at its outer edges only and mass being 'frozen' in place just behind this 'leading edge'.

You could imagine that, but the problem is that your imagination doesn't fit the observed data.

The Universe is expanding everywhere at the same time, not just at the edges.

originally posted by: rnaa
a reply to: chr0naut

You could imagine the universe growing faster than C at its outer edges only and mass being 'frozen' in place just behind this 'leading edge'.

You could imagine that, but the problem is that your imagination doesn't fit the observed data.

The Universe is expanding everywhere at the same time, not just at the edges.

I was not denying that the expansion of the universe was happening.

I was just suggesting that the idea, that space itself expanded between objects without creating a relative velocity between the objects, is not valid.

There is nothing to say where and how this 'extra space' came from, and which we know has a vacuum energy of about 10^-9 ergs/m^3, and all descriptions that expand space between objects, have those objects moving apart at relative velocity from each other. And this is all supposed to have happened after the Big Bang.

It isn't science until there is testable theory about it, it is myth.

a reply to: chr0naut
Relative velocity (and the resulting redshift, as well as time dilation) is there. I don't know why you assume that's not part of the mainstream model.

Relative velocity still doesn't mean the objects are accelerated through space like a rocket accelerates.

The red# increase with distance is a direct observation. The "tired light" model was disproved a long time ago. That leaves the actual expansion of space. Plenty of strong observational evidence has been found to support it: en.wikipedia.org...

The redshift is found in all galaxies outside our Local Group, not just quasars.

Just because you don't understand it, doesn't mean it's a myth.