Relativity and expansion question

Can it be said with confidence that the inverse of universal expansion is also true?

Are all particles and waves shrinking, relative to the space that is expanding?

If we know this is, or is not the case, how do we know that?

Can this even be measured?

a reply to: Archivalist

It seems common theme that for every action there's an equal and opposite reaction, so it wouldn't surprise me that there would be an unknown force that is contracting equal and opposite to any perceived expansion.

I am curious though, and if anyone can point me in the right direction I'd be thrilled, what is the actual empirical observable evidence that the universe is expanding?

a reply to: cooperton

what is the actual empirical observable evidence that the universe is expanding?

Doppler effect/redshift may be one way we observe the expansion?

Article from 2012 suggests that "each year there are more reasons that point to the theory that our universe is expanding" link

We know this because of the redshift of distant galaxies. The "dark energy" that is expanding space is happening between galaxies and galaxy clusters. Which tells us that dark energy is not as strong as gravity because it has not been observed to expand the space between stars in a galaxy or between galaxies in their local groups.


References:

What is Redshift-Wiki

What is Dark Energy-NASA

a reply to: Archivalist

Particles and matter do not shrink as the universe expands, this expansion is more like if you draw a lot of circles on a balloon and inflate it. The circles get bigger but their sizes are always a relative to the geometry which is being "inflated".

a reply to: odzeandennz

The balloon analogy is best suited for illustrating the expansion of space and the growing distance between the dots, not the relative sizes.

The galaxies aren't getting bigger because space is expanding. The space in galaxies and local group clusters is not expanding. Within these structures, gravity wins. In the vast regions of intergalactic space, dark energy wins.

a reply to: projectvxn

Unless Edwin Hubble's constant is wrong, which is possible, but improbable. An interesting (to me) facet of Hubble's work indicates that nearby galaxies are moving away from ours at a slower rate than those much further away. That might tend a person toward an Earth-centric view, however it is likely that nearby galaxies everywhere are moving apart at a slower rate than those further away.

That suggests to me that the constant c, might be variable. Of course, that's absurd that the speed of light is gradually increasing and has been since the formation of time itself. It's crazy, and yet I can't help pondering it. For that to be true, the Hubble Constant MUST be incorrect. I am not that arrogant.

Still, on sleepy Sundays, a person might ponder the ramifications of a slowly increasing speed of electromagnetism and all its associated particles. It changes everything, if true.

a reply to: argentus

Theoretical physics 202 with a critically logical perspective.

Why in the world don't you have more threads like this?!

Well either we accept that all particles and waves are shrinking, relative to the expanding space, or you have to acquiesce that the phrase "space is expanding" is an incomplete statement.

Space is expanding at a rate faster than the light traveling within it.

Is perception the limiting factor here?

If all space is equally expanding, equally, wouldn't it be an unobservable change? As the devices of observation/perception would have to be expanding at that same rate, it wouldn't indicate a difference.

What is our reference point, for stating that the expansion is occurring?

a reply to: Archivalist

It feels like we're having our cake and eating it too, claiming that this is observable because of red shift.

While at the same time, believing that conservation is functioning at 100% efficiency.

Is our model such that this red shifting light, isn't losing energy? Odd. I suppose if you argue it is physically taking up a larger surface area in space, to keep it's energy the same, even though it is red shifting... That would make it "correct" ?

You see, I was under the impression that for light to red shift, it must have an energy deficit.

a reply to: Archivalist

Space is not equally expanding everywhere.

As I said and referenced, dark energy, which is what is causing the expansion and acceleration of that expansion, is overcome by local group clusters and has no effect within galaxies at all. The galaxy has been around since the beginning and it is still a cohesive structure.

Look up IC 1101. It is the most massive galaxy ever discovered. 1 million ly across, with over a trillion stars worth of mass. It is among the most ancient objects in the known universe. If it were going to fly apart due to the accelerating expansion of space, it would not be visible to us at all now because the structure would have fallen apart.]

a reply to: argentus

The universe has no absolute center (to read Preferred Observer). But we are the center of the observable universe. All of our observations are Earth-centric. They can't be anything else.

originally posted by: projectvxn
a reply to: Archivalist

Space is not equally expanding everywhere.

As I said and referenced, dark energy, which is what is causing the expansion and acceleration of that expansion, is overcome by local group clusters and has no effect within galacies at all. The galaxy has been around since the beginning and it is still a cohesive structure.

Look up IC 1101. It is the most massive galaxy ever discovered. 1 million ly across, with over a trillion stars worth of mass. It is among the most ancient objects in the known universe. If it were going to fly apart due to the accelerating expansion of space, it would not be visible to us at all now because the structure would have fallen apart.

So, dark energy...

Dark energy is the coefficient we add in to our formulas, as a way to explain the fact that our expansion model doesn't seem to work the same, when looking at clusters of matter?

So... Why do we assume dark energy is a thing, and that our model of expansion is correct?
Rather than assuming our expansion model is incorrect?

a reply to: Archivalist

So... Why do we assume dark energy is a thing, and that our model of expansion is correct?

We infer that dark energy is energy. We just don't know how it is produced or where it is coming from. The Universe isn't just expanding, it is accelerating in its expansion. We know this because of consistent observations have shown us that distant galaxies are accelerating away from us at an exponential rate.

Speed of Universe's Expansion Measured Better Than Ever

The most precise measurement ever made of the speed of the universe's expansion is in, thanks to NASA's Spitzer Space Telescope, and it's a doozy. Space itself is pulling apart at the seams, expanding at a rate of 74.3 plus or minus 2.1 kilometers (46.2 plus or minus 1.3 miles) per second per megaparsec (a megaparsec is roughly 3 million light-years).

If those numbers are a little too much to contemplate, rest assured that's really, really fast. And it's getting faster all the time.

a reply to: Archivalist

Dark energy is the coefficient we add in to our formulas, as a way to explain the fact that our expansion model doesn't seem to work the same, when looking at clusters of matter?

No. There are 4 fundamental forces in the universe. The strong interaction (Strong Nuclear Force), the weak interaction (Weak Nuclear Force), the electromagnetic force, and gravity. Gravity, in localized regions, is much stronger than all the forces combined. Black holes come to mind. However, spread across the universe, gravity seems to weaken significantly. In less extreme localization, like galaxies and local group galaxy clusters, the effects of gravity are significantly more powerful, still, than the effects of dark energy on the local space they inhabit at any given moment. But at grander scales, dark energy is expanding the space between the distant galaxies and galaxy clusters. The further away those galaxies are from us, the faster they expand.

originally posted by: Archivalist
So... Why do we assume dark energy is a thing, and that our model of expansion is correct?
Rather than assuming our expansion model is incorrect?

If you want to try to educate yourself, here is a good article for you to read. You are lacking much education in this topic so this is a good place to start.

What Astronomers Wish Everyone Knew About Dark Matter And Dark Energy

Among the general public, people compare it to the aether, phlogiston, or epicycles. Yet almost all astronomers are certain: dark matter and dark energy exist. Here’s why.

Whether the expansion model is correct or not is a valid question and I don't think we can say with certainty the current Lambda-CDM model is correct. It may end up being revised in some way or we may end up with a different model as we collect more data. This field is fairly young considering dark energy was discovered only about 20 years ago.

The details about what mathematical model best describe it is not quite the same as whether the expansion is really happening or not. I think most scientists would tell you we are fairly sure the expansion is happening, and it's very likely accelerating, but since we are still collecting more accurate data the exact details are not certain and as always our models will be adjusted to be consistent with any new and more accurate observations.

They are finding that Hubble's constant equation isn't so constant. Didn't Hubble himself doubt the universe is expanding and the big bang didn't actually happen? When Hubble's assistant tried to carry on his work and discovered that red shift wasn't the galaxy expanding, but the age of said formation. Once the assistant tried to bring that data public, all of his scope time was denied and he was pretty much exiled for going against mainstream.

Hubble Eventually Did Not Believe in Big Bang: Associated Press

``Astronomer Edwin P. Hubble says that after a six-year study, evidence does not support what we now call the Big Bang theory, according to the Associated Press. “The universe probably is not exploding but is a quiet, peaceful place and possibly just about infinite in size.''''

I firmly believe that this information will be fundamental within 20 years and mainstream will act like they never though the universe was expanding to begin with. Like always.

Here is a good video from Hubble's assistant, Halton Arp:




Another article:

Redshifts and Microwaves

“No one has found a quasar with such a high redshift, with a redshift of 2.11, so close to the center of an active galaxy,” said the late astronomer Geoffrey Burbidge at the time. The discovery team included his spouse, E. Margaret Burbidge, another noted astronomer. The find was significant because it is the most extreme example of a quasar in front of a galaxy with a lower redshift.

Conventional cosmology relies on an electrically neutral Universe ruled by gravity. Without this dogmatic consensus, the Big Bang would never have become so predominant. Scientists, needing to renew their grants every year, “confirm” the theory when, according to reports, it has been discredited. Magazine publishers desire to maintain good relationships with established institutions, so they accept the latest news releases with little background investigation or critical analysis.

Once we get ride of our outdated theories that gravity is the greatest force in the universe, dark matter and dark energy will no longer be needed to plug the gravity theories that are slowly being torn apart. It is an electrical universe baby.

a reply to: projectvxn

Yes the dots don't scale relative to the balloon' size. But the distance increases because the size and volume and surface area increase. But the scale of the dots relative to each other remain the same.

The inflation model is under a lot of scrutiny as its not necessary to explain the big bang. The cosmological constant isn't so constant.

I for one am a big proponent of the cyclic universe model by Dr Roger Penrose.

a reply to: ClovenSky
Hubble contributed a great deal to astronomy and cosmology, and we recognize his accomplishments by naming things after him like the Hubble Space Telescope for example.

But we now know based on better observations that he was wrong about a number of things, like the distances to other galaxies. Using Hubble's estimates, the big bang idea would have made the universe only 2 billion years old and even in his day we already knew that the Earth was over 3 billion years old:

EDWIN HUBBLE 1889-1953 By Allan Sandage

There was, of course, the embarrassment that the inverse of the Hubble expansion rate (i.e. the Hubble time) was only two billion years on Hubble's 1930 to 1953 distance scale whereas the Earth was believed to be a bit older than three billion years even in 1936.

Therefore I don't think it's helpful to propose the idea that we should take everything written by Hubble at face value. I don't think the fact he was wrong about so much detracts from his contributions, he still gathered much useful data even if some methods to interpret that data more accurately weren't even available when he was alive; some methods were only developed after his death.