If universe expansion is accelerating, have we witnessed things go "off the radar"?

Question

First, this community rocks. I only wish I could carry a conversation with some of the answerers, however this format is limited by (bad) design.

K, my question :

As I understand it. The universe is expanding. The further out we look, the faster the galaxies seem to be receding from us. There is a simple ratio involved : further out = faster speed of recession.There is also distance beyond which we can not see. My questions involves this distance.

Have any objects been seen, and can not be seen any more, because they are now beyond this distance?

Wouldnt objects beyond this distance be going (relative to us) faster than C?

If above is yes (seems likely to me) then an interesting side effect would be that we are able to get information about something going faster than light away from us. (gravitational pull of a galaxy near the edge, which could tell us how massive a nearby galaxy past the edge is)

Edit to the 2nd paragraph : We cant see beyond this distance due to the objects beyond it are going away from us at at least the speed of light, not because of telescope limitations.

Answer 1

Yes, space is expanding -- and pass the "edge" of the observable universe, it's expanding faster than light. So _in principal_ at time T1, we could see an object (quasar?) just at the edge, and at some later time T2 the space between it and us would be expanding faster than light, so that the light from the object will never reach us.

But ... any object at the edge will be *very*very* faint, because the space between it and us is expanding at *almost* light-speed. So what we would actually see would be extreme red-shift of a light source that is many times weaker than the cosmic background radiation. When it's about 10,000 times weaker than the background, it is invisible for all practical purposes.

But as far as I know, the brightness of quasars has not changed much since we started observing them. They are only (!) 13 billion light-years away, and the space from us to them is expanding at quite a bit less than the speed of light.

Answer 2

The Universe can be likened to the Black hole idea. There is no light escaping the Horizon of the Universe.
All Galactic motion and orbits take place within the limits of the Horizon.The reason is that the Universe is very massive.
Gravity has the tendency to push Galaxies together ;However what is pushing them apart must be the increasing temperature of the Universe.
The velocity of moving mass structure inside the containment of the Universe follows this equation;
V^2 = Pr / Dm
V^2 is the velocity squared of the Receding mass structure.
Pr is the pressure of dark matter surounding the Mass structure at that particular distance in space and time level.
Dm is the density of the mass strucure.

The actual diameter of the Universe is much larger than was estimated. Hence at the HOrizon of the Universe there has been no galaxy mapped out. It would just means that at least beyound two third of the Universe diameter no galaxies are contained.

Answer 3

Even though these objects cannot travel at or faster than the speed of light, because the space between them and us is expanding so fast, they are in effect receding from us at faster than the speed of light and therefore they will be lost to us visibly. This also how there can be objects measured by radiotelescope that appear 40 billion light years away when the universe is only 13-14 billion years old.

To my knowledge this hasn't happened yet, but our technology is young and there hasn't been sufficient time for us to observe this phenomenon. At least 50% of the universe isn't visible to us. And because of the rate of expansion, this can only increase.

If you think about it, even if you are traveling at 0.5 c, a light beam will still seem to pass you at light speed. There will be no perceptible slowing of light because of your relative speed. Similarly, as an object recedes from you at the speed of light, any light emitted from that object will be frequenct shifted, but the photons are still traveling at the speed of light with respect to you.

Answer 4

The objects in the solar system are about all one can 'see' with radar. Stars will not reflect radar. Even if they did they are so far away that the sender will not be around to receive it.

There is an effect called the 'Red Shift', which refers to the reduction in frequency of light from an object moving away from the observer. Based on the observed red shift, the currently estimated fastest going galaxy is about half the speed of light.

What we see now is light that left that source eons back. Unfortunately, simultaneity is meaningless in this context.

Answer 5

this is an extremely cool question and it particularly makes you think of. I accept as true with you in that there are some "holes" in the concept. Scientists could no longer clarify why they got here upon that the universe is increasing at an increasing value, so they developed a clean term suggested as darkish capability. we've not got any concept what this is, or the place this is coming from, yet it is the reason that our universe is increasing. i'm somebody that believes that our universe's enlargement IS accelerating (this grow to be the main precise length taken, and until somebody can disprove it, it particularly is the best that we've). in actuality, is that we don't comprehend what darkish capability is, and we are able to in all probability in no way comprehend (in our lifetime this is). Who is familiar with...possibly there are countless multiverses outdoors of our universe whose gravity is particularly pulling aside our universe. It particular may well be thrilling to be alive while they the two disprove or show of darkish count's existence!

Answer 6

i dont think we have witnessed anything go off radar for 2 reasons (we might have in a few cases, but probably not alot)

for 1 the galaxies are very far away, so even though they are moving very fast and covering a vast distance it doesnt seem that far to us here on earth.

secondly, our technology only continues to get better. so if a galaxy was on the verge of being out of the visible universe surly a better telescope or something would come along.

Answer 7

The answer to your question is no.

Although we can actually visualize objects moving away from us at relativistic velocities by the redshift of their electromegnetic radiation, it must be understood that such phenomena only exist on the outer limits of our observable universe meaning that those cosmological objects observed by us here on earth that are understood to be moving away from us, are many light years away implying that the light emanating from them has a considerable distance to travel before reaching us so we can evaluate their redshift. furthermore, such objects move relative to us while maintaining the same line of sight such that their electromagnetic radiation will always reach us, although it will take longer to do so as the source moves away.

To address your second question

Relativistically speaking, such objects in spacetime will not move faster than c, nothing material in nature can move at the same speed or faster than light as according to the equation E = mc^2 an object travelling at such a velocity will require infinite energy to maintain it as the body increases in mass relativistically. Such speed can only be achieved by things that have no intristic mass, like electromagnetic radiation