# Thoughts about the Universe

1. Jun 26, 2010

### ckaiser

Hello

I've been doing alot of thinking about blackholes, dark matter and all this great stuff. I consider myself more of an idea man since I'm better at understanding concepts rather than being able to do the math that allows the concepts to exsist. Not that I don't think I could I just dont have the time and money to go to school at the moment.

To start I'm curious what would be the extent on the reach of blackholes on their ability to affect both Time and Matter around them?

I've heard that blackholes are capable of affecting not only matter but time itself. From what I've seen the closer to a black hole an object gets the slower the object appears to move and when looking away from the blackhole objects that are distant appear to move at an accelerated rate. Is this correct?

Also I've heard that the universe is expanding at an ever increasing rate instead of slowing down due to gravity like some think it should and that it shows no indications of slowing down due to a force known as dark energy. Another thing i've heard is that inorder for galaxies to exsist the way they do there is something called dark matter that accounts for the majority of the mass in a galaxy.

Another thing that i've read and seen on videos is that as an object enters a blackholes event horizen it is represented on both 2 dimentions and 3. That as you view an object falling into a blackhole that it would appear to slow down and eventually appear to stop even though the object itself has already fallen into the hole. Another thing I've heard that in reality everything we experience is both represented in 3d space which we can see and are experiencing now as well as exsisting somewhere "out there" on a 2d surface.

Now if we are all in the pull of this supermassive blackhole and we are looking out at distant objects in the universe wouldn't it make sense that objects moving away from us at a great distance would appear to be moving away at a very accelarated rate due to the super massive blackhole's affect on time.

Also if we are both represented in 2d and 3d space couldn't it be possible that we are already well within the range of the event horizen and that its affect is well beyond just the surface of the blackhole? If the gravity of a blackhole goes well beyond what we can see of our galaxy and we are infact within the event horizen then couldn't its distortion of Time and space account for the extra mass or dark matter in the galaxy. Also i've heard that dark energy is what seems to be driving the universe apart even going against the force of gravity. If the above is true then couldn't the distortion of time also be responsible for the illusion that everything is moving at an accelarted rate and not slowing down? If this is so and we are within the event horizen of a black hole then wouldn't we occupy a much smaller space than we think and that when the wmap was taken it in may have maped the heat within this horizen which would should appear the same throughout due to the fact that we are caught in this small space of time caused by the event horizen.

Either way I think that the problem with the model of the creation of the Universe is that the affects of gravity on Time and its distortion of it is not being taken into account. If this is true then would'nt the model for the universe be wrong and everything is not as it previously appeared to be?

2. Jun 28, 2010

### ckaiser

Hello I'd like to have some thoughts on what I've posted if possible and what would be wrong with them if possible so that I can refine the idea or at least get my brain to stop thinking about it

3. Jun 28, 2010

### Max™

Why would you want your brain to stop pondering the universe?

Look for more stuff by NDT:

Neil deGrasse Tyson, he's great at this.

42 minutes in he goes over this a bit more, fun video though.

Last edited by a moderator: Sep 25, 2014
4. Jun 28, 2010

### ckaiser

well i guess the basis of my question is are the people who are developing this model of the big bang theory / darkmatter / darkenergy / etc taking into account the affects of strong gravity created by super massive black holes on our perception of what surrounds us. My biggest problem with the big bang is when i'm told that in the earliest moments gravity lost its hold on things and allowed the universe to inflate extremely fast and that is why the wmap shows the universe as having a uniform temp throughout and does so without explaining how gravity was disabled in the first place.

The only thing that i'm constantly not hearing people talk about when debating this stuff is how time is affecting our perception. Obviously it takes thousands/million/billion/trillions of light years for some of the light from distant objects to reach us BUT there is no mention of how the black holes at the centers of these galaxies including our own could be affecting the way this light is reaching us due to the effects of that a super massive object can have on time itself.

5. Jun 28, 2010

### bapowell

It isn't that gravity 'lost its hold on things' during inflation, but rather that the universe was filled with a unique form of energy that was gravitationally repulsive. This repulsion drove the accelerated expansion. The field that drives inflation is central to the inflationary mechanism and its observational investigations, and has not been ignored by cosmologists.

On large scales, the universe is well approximated as a homogeneous and isotropic spacetime. While extraordinarily massive wrt to typical astrophysical objects, black holes at the centers of galaxies still only exhibit local gravitational effects. That is not to say that the CMB photons don't interact with large-scale structures -- they certainly do, although the structures most relevant are galaxy clusters. These effects are very well understood and taken into account when analyzing the CMB.

6. Jun 28, 2010

### ckaiser

I'm not familiar with short hand when it comes to these things so what would wrt, CMB be and is there a list of short hand terms for this kinda stuff located anywhere lol.

7. Jun 28, 2010

### bapowell

Apologies. CMB = Cosmic Microwave Background.
wrt = with respect to

I mention the CMB because this is the most distant light that we measure here on earth.

8. Jun 28, 2010

### ckaiser

So what is the red shift that I've heard of and to what objects does it apply. I've heard it called the Doppler effect and described as when an object is moving away from you it appears slightly red and when its moving closer to you appears slightly blue. The question would be does the red shift apply to everything outside of our galaxy or does it only apply to objects beyond a specific distance beyond our galaxy?

Also I'd like to learn more about these things in general (physics, Astronomy, Cosmology, etc.) but I don't have the cash to go to school at the moment. Is there any where in the internet where i could get reliable information where I could teach myself the things i would need to know in order to contribute in some real way? I've looked around a bit but haven't found anything that really lays out the theories and stuff I'd like to know.

Last edited: Jun 28, 2010
9. Jun 28, 2010

### apeiron

If we were halfway down a blackhole, then there would be a visible asymmetry in what we see looking outwards. So that could be ruled out.

However, some do believe that dark energy might be just an observational artifact of looking through cosmic gravity fields. We could be sitting in an underdense region of the universe and so it appears that there is a more general acceleration going on.

http://www2.phys.canterbury.ac.nz/~dlw24/

10. Jun 28, 2010

### bapowell

When we model the universe as a smooth, expanding spacetime, the redshift that we observe is indeed a result of distant galaxies moving away from us. The wavelength of the light that these galaxies emit gets stretched by the expansion of the universe while en route to earth. As a result, more distant objects appear redder than those closer (the farther the light travels, the more it gets stretched). Since more distant galaxies are also receding at greater velocities than those closer, this redshift is also seen to be a result of the Doppler effect. Since stars within our galaxy are gravitationally bound, they don't feel the expansion of the universe and therefore we don't see them receding from us. Of course, locally we might see some stars moving towards earth (and thus blueshifted) and others moving away (and thus redshifted), however these motions are a result of the gravitational dynamics within the galaxy, not a result of the expansion of the universe.

You can always hang out here on the forums, but I understand your desire to get a more comprehensive understanding of the concepts. The internet is a vast resource (see, for example, Ned Wrights Cosmology Tutorial), and there's always the local library. I'm not sure what your level is or what specifically you are interested in learning more about, but I can certainly recommend some good books if you let me know. You might want to start a new thread soliciting this kind of information, since there are lots of knowledgeable people here who can tell you their favorite books and such.

11. Jun 28, 2010

### Max™

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/index.html

Einstein for Everyone, I was trying to remember the exact thing that popped up when I saw your questions, had it in my favorites it turns out!

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/black_holes/index.html

12. Jun 29, 2010

### ckaiser

Thanks I'm gunna do some reading and lurk on the forums a bit and see what there is to learn take care