Expansion and acceleration of the Universe

In summary, the conversation discusses the observation that galaxies and stars are expanding away from our own galaxy due to dark energy. The possibility of time slowing down is also brought up, but without a clear definition of time, it is difficult to discuss. It is recommended to read up on the basics of cosmology before further exploring this idea.
  • #1
nicholasmath
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I know that it is observed that galaxies and stars thousands and millions of light years away are expanding away from our own galaxy and that it's observed that not only are they moving away from us but they're accelerating away from us. This is thought to be the anti gravitational field of dark energy.

But I was wondering if perhaps time for us is slowing down? Hence it only appears like everything is accelerating in the universal expansion when perhaps everything may be moving at a constant speed but degrading time. since s=d/t. If time slows down speed would increase. Anyway its just a thought and I'd like to know if anyone else thinks that it may be plausible
 
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  • #2
nicholasmath said:
I know that it is observed that galaxies and stars thousands and millions of light years away are expanding away from our own galaxy and that it's observed that not only are they moving away from us but they're accelerating away from us. This is thought to be the anti gravitational field of dark matter.

Actually it's dark energy that causes this, not dark matter.

nicholasmath said:
Hence it only appears like everything is accelerating in the universal expansion when perhaps everything may be moving at a constant speed but degrading time. since s=d/t.

I'm not sure this is coherent, but rather than try to disentangle it, I recommend that you read Ned Wright's Cosmology FAQ on this question:

http://www.astro.ucla.edu/~wright/cosmology_faq.html#CC

Read his answer, and then follow the links he gives to more detailed explanations of the concepts he's using. That may help you to formulate your question better.
 
  • #3
I'm just asking if its possible that time itself is slowing down. maybe not universally but at least for our galaxy. I mean if we are accelerating then for the speed of light to remain constant our time must decrease and hence everything outside the galaxy may in fact look like its moving faster than it actually is. But if time is slowing down for some unknown reason there may not even be any dark energy and galaxies may not be accelerating away because its covering greater distances in the same amount of time, but it may in fact be covering the same distance in the same amount of time, but because our time is slowing ( just a theory) it would appear as though the galaxies are moving away at a faster rate. It would just appear as though its speed increases as time goes on I hope. I'll look through the link above in more detail I know there are a lot of things I still need to read up on but as a novice I think it allows me to think about these things without any predefined boundaries of thought.
 
  • #4
It's hardly possible to discuss whether "time itself is slowing down" as long as we do not specify the definition of time:
- coordinate time
- proper time
- time of macroscopic or thermodynamic physical processes
 
  • #5
nicholasmath, your follow-up post didn't really help to clear things up to the point where I can usefully comment. Thinking about things on your own "without any predefined boundaries of thought" is a good thing, but in order to communicate your thoughts to others it really helps if you at least know the basics of the standard vocabulary for talking about the subject. The link I gave you, and the other links that appear there, may help with that.
 

1. What is the expansion and acceleration of the Universe?

The expansion and acceleration of the Universe refers to the ongoing process in which the distance between galaxies, clusters of galaxies, and other cosmic structures is increasing. This phenomenon was first discovered by Edwin Hubble in the 1920s and has been confirmed by multiple observations since then. In addition to the expansion, scientists have also observed that the expansion of the Universe is accelerating, meaning that the rate of expansion is increasing over time.

2. What is causing the expansion and acceleration of the Universe?

The exact cause of the expansion and acceleration of the Universe is still unknown and is currently an active area of research in astrophysics. One theory is that there is a mysterious force called dark energy that is driving the acceleration. Another theory is that our current understanding of gravity is incomplete and a new theory is needed to fully explain the expansion and acceleration.

3. How do scientists measure the expansion and acceleration of the Universe?

Scientists use a variety of methods to measure the expansion and acceleration of the Universe. One commonly used method is to study the light from distant galaxies and look for the tell-tale shift in the light's wavelength, known as redshift. This redshift is caused by the expansion of the Universe and allows scientists to determine the rate of expansion. Other methods include studying the cosmic microwave background radiation and using supernovae as standard candles.

4. How does the expansion and acceleration of the Universe impact our understanding of the cosmos?

The expansion and acceleration of the Universe has significant implications for our understanding of the cosmos. It suggests that the Universe is not static, but rather constantly changing and evolving. It also raises questions about the ultimate fate of the Universe and the possibility of other universes beyond our own. The ongoing research into the expansion and acceleration of the Universe is crucial for expanding our understanding of the cosmos.

5. Can the expansion and acceleration of the Universe be stopped or reversed?

At this time, there is no known way to stop or reverse the expansion and acceleration of the Universe. However, some theories suggest that in the far future, the expansion may slow down or even stop. This would require a significant change in the fundamental properties of the Universe, such as the amount of dark energy present. Further research and observations will be needed to better understand the potential fate of the Universe.

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