Shouldn't we know where the Big Bang occurred?

[Analog]

When something explodes, we can ascertain where it began by tracing the outgoing matter back to an origin. Shouldn't the universe have a void area where everything exploded out of?

 

[Biftheunderstudy]

Short answer, no.
The Big Bang was an explosion of space not an explosion into space. A good analogy is to think of a balloon. On the balloon are bunch of dots, now when the balloon is inflated the dots will move apart from each other. Your question is like asking where on the surface of the balloon did all the dots come from? Remember you have to restrict yourself to the surface of the balloon since the inside of the balloon or the space outside the balloon doesn't exist.

Now in the real world you have to think of the 3 dimensional universe as the surface of the balloon and thus it is not a perfect analogy.

 

[KIAman]

Slight derail but interesting.

Looking out into space at all the stuff out there... they are no longer there at this moment int time.

A galaxy that is a million light years away might as well be 2 million light years away by the time we finally observe its light.

Even the sun. The moment it sets in reality is far below the horizon as it takes 8 minutes for the light to get to us.

Just mindboggling.

 

[CTho9305]

Even the sun. The moment it sets in reality is far below the horizon as it takes 8 minutes for the light to get to us.

If you were somehow watching the clock ticking in your CPU, by the time you saw a given clock cycle happen, then CPU would already be a few cycles past it.

 

[Soccerman06]

Now Im not sure on the exact comparison I saw about why we currently can't find the center of the Universe, but it goes like this: take a rubber band and make a naught at random points in it. Then put any naught in the middle and stretch the rubberband, all points move away from each other. Now pick another point and stretch from there, everything moves away from each other. What its like is that everyone looks like they are at the center of the universe, even though they aren't.

 

[TuxDave]

Originally posted by: CTho9305

Even the sun. The moment it sets in reality is far below the horizon as it takes 8 minutes for the light to get to us.

If you were somehow watching the clock ticking in your CPU, by the time you saw a given clock cycle happen, then CPU would already be a few cycles past it.

Heh... nice analogy, never heard that one before.

 

[wanderer27]

Sheesh, I was pretty much thinking about this exact thing when I went to bed last night.

I'd like to add my observations to this (and probably muddy the water even more).

First, yes, I understand that from any one Galaxy (used as a reference) that all the others would be moving away from each other - use either the Balloon or the Rubber band with knots, and this effectively demonstrates this. Actually the Balloon thing concerns me somewhat, but I won't address that at this time.

So as the OP has asked, why can't a "center" be determined? Yes, everything is moving away from each other, but how about the Red shift?

Won't Galaxies that are pretty much moving in the same direction have a lower Red shift, and those moving at a more angular direction (to ours) have a greater Red shift? It seems by taking these values into account Vectors could be derived that would produce a "center", even if nothing is there (as I would expect).

To my knowledge a Blue shift Galaxy hasn't been observed. Logically, I wouldn't expect one, though I'm no expert on this.

My personal thoughts are that we haven't yet detected a Galaxy that is 100% directly moving away from us (or nearly 100%) - that is to say, on the exact opposite side of the Balloon. I think the Universe is actually bigger than anyone thinks . . . .

 

[KIAman]

^ The problem with that thought is that galaxies and other objects are moving with their own velocity other than the expanding universe.

I might be wrong but at this moment, we can't distinguish a movement from stretching of space/time from movement of a body. We don't have an absolute point of reference.

 

[Biftheunderstudy]

The redshift of galaxies is due to something called the cosmological redshift. This arises because as the universe expands, the light in the intervening spaces is being stretched along with it.

Now, the space between galaxies is expanding but you have to remember that galaxies also have their own motions due to gravity interactions. There are actually quite a few galaxies which are blue shifted, most notably the andromeda galaxy which is actually on a collision course with our own. The problem is that the further you get away from your point of view, the faster the recessional velocity is.

So the reason you can't have a center is that if you start running back the clock, the universe keeps getting smaller and smaller. Its not that all the stuff is getting closer together inside of a 'container', its that the 'container' itself is getting smaller.

So neglecting their own motions due to gravity and things, they are in fact all "moving" directly away from us. But keep in mind this isn't motion in the normal sense, since its the space between getting bigger.

 

[gururu2]

Originally posted by: Biftheunderstudy
Short answer, no.
The Big Bang was an explosion of space not an explosion into space. A good analogy is to think of a balloon. On the balloon are bunch of dots, now when the balloon is inflated the dots will move apart from each other. Your question is like asking where on the surface of the balloon did all the dots come from? Remember you have to restrict yourself to the surface of the balloon since the inside of the balloon or the space outside the balloon doesn't exist.

Now in the real world you have to think of the 3 dimensional universe as the surface of the balloon and thus it is not a perfect analogy.

good analogy, very difficult to understand though. required some research on my part to realize exactly how to conceptualize it.

edit:

 

[Biftheunderstudy]

I've actually done a complete balloon analogy mock up. All you do is inflate a balloon half full, then put some dots on it. Measure the distance between the dots. Next inflate the balloon and measure the distance between the dots again. Choosing 2 or 3 reference points will get you good results. Now you can calculate a sort of velocity using an arbitrary time for the inflation time (in reality we're doing this backwards, we have the distance and velocity and deducing the time). When you choose a reference dot (represents Earth) and measure the velocities of all the other dots versus their distance from the reference dot you will find that you get a straight line. Do this for a couple of reference dots and you'll see that the line is roughly the same slope. This is basically hubble's law, the further you look, the faster things are moving away. Keep in mind if you actually do this simple experiment that your line will probably not be straight since your balloon is not a perfect sphere. Also keep in mind that there are some more things happening in the universe such as accelerated expansion and inflation to sort of mess up the line a bit in real life.

The real problem with this analogy is trying to extrapolate when all of the dots were at the same place, effectively running the clock back or seeing where the vectors meet. At this point since the balloon can only get so small the analogy stops. The real universe would have kept going until a singularity (theorized anyway). The other major problem is that its a 2D example. Real space is naturally 3D, a somewhat better example is using raisins in bread dough as it rises.

 

[heyheybooboo]

WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP)

The WMAP mission reveals conditions as they existed in the early universe by measuring the properties of the cosmic microwave background radiation over the full sky.

This microwave radiation was released approximately 380,000 years after the birth of the universe. WMAP creates a picture of the microwave radiation using temperature difference measured from opposite directions (anisotropy).

The content of this image tells us much about the fundamental structure of the universe.

And a possible different opinion . . .

He does not dispute that the majority of the radiation comes from the early universe, but says small amounts of additional radiation from sources in our own galaxy are causing many if not all of the apparent variations from uniformity.

He suspects the bright patches seen by WMAP are spots of plasma ? a soup of charged particles made by electrons being torn from hydrogen atoms ? where knots or filaments of hydrogen in our galaxy have collided.

From: Big-bang satellite data 'not flawed'