Do you think there is more to the universe than we can observe?

[Deleted]

What evidence support the universe is still expanding? I wonder if we're actually in the big crunch phase already. Suppose we are B In galaxies A, B, and C.

Time 1: A B C
Time 2: A B C
Time 3: A B C
---------------->>>>>

From B's perspective, everything accelerates away from us in every direction. In actuality, things could be moving in one direction. Things accelerate as they approach black holes. Is there a black hole large enough to attract every galaxy yet remains undetected? Unlikely. I think the attracting force is the big crunch and the universe's existence is fleeting.

What evidence do you have to disprove the expansion of the universe? This is a science thread, disprove the expansion of universe.

[Frogguh]

The great thing about science is that it's true regardless of whether or not you like it or believe in it.

Science has been wrong countless times. It is reality that is true regardless of opinion or belief. Science is a man-made methodology of studying nature, which means it can be, and has been, wrong.

[dextersmith]

What evidence do you have to disprove the expansion of the universe? This is a science thread, disprove the expansion of universe.

I said it's a possible theory. I redrew the diagram to fix the display.

[Deleted]

Science has been wrong countless times. It is reality that is true regardless of opinion or belief. Science is a man-made methodology of studying nature, which means it can be, and has been, wrong.

But what is it that corrects it?

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I said it's a possible theory.

We talking scientific theory here? If your using a theory how I think your using theory it ain't a real theory.

[Frogguh]

It doesn't matter if science is generally self-correcting. The statement "science is always true" is a false statement.

[Ghul]

we cant see infrared for starters :P

[Deleted]

It doesn't matter if science is generally self-correcting. The statement "science is always true" is a false statement.

But if science corrects science does that not make science always true?

"science is always true" is a statement made with the context of with what we can observe with current equipment.

[Adam Jensen]

we cant see infrared for starters :P

We can through instruments that convert it to visible light.

[Ghul]

It doesn't matter if science is generally self-correcting. The statement "science is always true" is a false statement.

yeah science is about making up assumptions and working out theories through testing and observing. its very obvious that science is not always true :>
it happens all the time, that old "laws" are getting revisited and rewritten, based on new observations and conclusions.

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We can through instruments that convert it to visible light.

yep, but there may be spectrums that cant even be made visible with our current tech. it's a direction.

[Orlong]

Astronomers freely acknowledge that we cannot see past a certain point because the light from that part of the universe hasn't reached us yet.

I'm not sure what you're asking.

What is outside the expansion of the universe would be my guess. There cant be a brick wall or something at the edge. There has to already be something there even if empty space

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Id just like to know how we can still receive pictures and data from Voyager 1 which has already passed Uranus, but yet still cant get a good cell phone signal throughout the whole country

[Forgettable]

the great thing about science is that it's true regardless of whether or not you like it or believe in it.

It's this very attitude that will ensure we never, ever understand the universe.

Ever.

This man is wise.

[Ghostpanther]

I said it's a possible theory. I redrew the diagram to fix the display.

But it is a theory based on some pretty strong evidence. Einstein had a theory the Universe was a constant state of existence. The evidence so far discounts that theory and strongly suggests a expanding universe.

[Adam Jensen]

What is outside the expansion of the universe would be my guess. There cant be a brick wall or something at the edge. There has to already be something there even if empty space

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Id just like to know how we can still receive pictures and data from Voyager 1 which has already passed Uranus, but yet still cant get a good cell phone signal throughout the whole country

There's a lot of physical interference between cellphone towers and your phone. Trees, mountains, buildings, etc.

There's very little between Earth and Voyager to block the signal.

[Dhrizzle]

Because we observe that the space tends to be relatively homogeneous when you look at large enough scales, and there's really no reason why it should suddenly stop being homogeneous as you go to even larger scales. There is absolutely nothing that suggests this might be the case.

Yes, and the question is whether the observable universe is a large enough sample to represent the universe as a whole. It's pretty much guaranteed that the volume of space around us won't have the exact average density of the universe as a whole but it's unknown how it differs or whether it is by a physical amount.

You mentioned crazy arrangements yourself:

So I did.

To answer the bolded part: Physical laws determine the distribution of matter, hence you would need different laws for the matter to be distributed in some different way. That is unless you're proposing that there are structures in the universe larger than our whole observable universe, which we have no reason to assume.

I'm sure the physical laws allow for more permutations of matter than the ones we observe. Look at our galaxy for example, the centre has a much higher density than the outer edges but the different parts are still governed by the same physical laws. If the "observable" volume only covered a small amount of the galaxy it is likely you would take measurements that do not accurately represent the whole.

I don't see the necessity for a single structure the size of the observable universe (although given we keep finding larger and larger structures I wouldn't be surprised if they did exist). Looking at space around us we see structures such as clusters and super clusters. We have no way of knowing how the concentration of these in the volume of space surrounding Earth compares to the rest of the universe. You're right that we have no reason to assume that the rest of the universe is different, but then again we have no reason to assume it is all the same. Going back to Earth as an example, if you could only observe a small portion of Africa you would only see jungle, but that doesn't mean you would be right to assume that the entire planet is a jungle.

"Theory" is not "guesswork."

A scientific theory is a highly supported explanation of natural phenomena based on observed evidence. A theory has been tested, refined, tested again, and refined again. They NEVER become laws.

Our strongest theories are highly unlikely to change at the core, even if some of the minor details change.

From the context I'm guessing they were using the general definition of "theory", meaning a thoughtful and rational explanation (as opposed to "practical", which would be the physical experimentation). A scientific theory does have the qualities you describe, but not all theories in science are scientific theories.

Often scientific theories may be based on theoretical results because the actual experimentation is impractical or impossible at that time. Cosmology often relies on these theoretical results due to the difficulties involved in repeating experiments involving billions of tonnes of matter and millions of years.

[Forgettable]

"Theory" is not "guesswork."

A scientific theory is a highly supported explanation of natural phenomena based on observed evidence. A theory has been tested, refined, tested again, and refined again. They NEVER become laws.

Our strongest theories are highly unlikely to change at the core, even if some of the minor details change.

Unless the definition of a scientific theory is different than that of any other theory, then yes, a theory is just "guesswork." Perhaps well thought out and with facts to back it up, but still not entirely provable or reproducible.

From the context I'm guessing they were using the general definition of "theory", meaning a thoughtful and rational explanation (as opposed to "practical", which would be the physical experimentation). A scientific theory does have the qualities you describe, but not all theories in science are scientific theories.

Often scientific theories may be based on theoretical results because the actual experimentation is impractical or impossible at that time. Cosmology often relies on these theoretical results due to the difficulties involved in repeating experiments involving billions of tonnes of matter and millions of years.

Maybe this is the differentiation I was looking for.

[dextersmith]

We talking scientific theory here? If your using a theory how I think your using theory it ain't a real theory.

I don't understand what you're saying.

[grimsanta]

Things you should do some reading on (and as a result, you'll find the answers). It's too much to really sum up in a thread post.

1. Redshifting.
2. Cosmological constant (and why it was proved wrong).
3. The untestable nature of things like string theory and its subsets.
4. Cosmic Background Radiation (this one is important).

There's a lot more. If you want a good introduction to this type of thing, go to astronomycast.com and listen to their podcasts. One of the best on the internet, if not the best. Star Talk Radio is ok, but Tyson has a tendency to get really excited about multiverse theory, which while interesting, has no evidence what-so-ever. Not saying it's wrong, it works mathematically, but a lot of things do that don't exist.