Higgs Field, Big Bang, and Spacetime

[coktail]

This is several questions crammed together because they overlap in my mind. Thanks!

Is the Higgs Field something that occupies the complete void of space, or is it thought to be a property of space itself?

Was the Higgs Field caught up in the mass of the pre-big bang singularity, or would it have been all around it? Is it subject to gravity?

Was spacetime caught up in the singularity big bang? If so, was there just pure void "outside" of the singularity?

If the Higgs Field gives objects mass, what gives the Higgs Field mass?

 

[Mark M]

Remember two things. Firstly, the universe has no boundary. When we say that the universe is expanding, we mean that the distance between everything is increasing, and space is expanding. NOT that the universe is expanding into some 'void'. So, it is similar to the surface of the Earth - you can travel in any of its two dimensions (generalize it to three for the universe), but you will never find a boundary, you will only return to your original position. So, the big bang happened everywhere at once, and the universe expands form every point. It is homogeneous and isotropic, so any galaxy appears to be at the center, seeing every other galaxy recede.

Secondly, the singularity just refers to a breakdown of classical general relativity at the high energies of the very early universe. It simply means that we don't have a classical idea of what went on, but the fields of quantum gravity and quantum cosmology have made some progress towards proposals regarding the early universe, none of which involve a singularity.

So, to now answer your questions:

The Higgs Field is a scalar field, meaning it takes a value at every point in space. But, it is not space itself, just a field that permeates it.

The other questions regarding singularities should have been answered above.

The Higgs gives mass to itself. Like all particles, it interacts with itself via 'loops' in a Feynman diagram.

 

[coktail]

Thanks, Mark M.

I don't fully understand what you mean when you say that "space is expanding." How can space itself expand? I understand that the distance between everything can can expand, but if space is the absence of all things, how can space itself expand?

Secondly, you mentioned that the universe has no boundaries. I understand that it may be infinite, and infinity has no boundaries, but that doesn't seem to be what you're saying. You're saying, if I'm interpreting you correctly, that if you got the the edge of the known universe, that you'd somehow be redirected and back to someplace you'd already been. This just doesn't make sense to me.

Lastly, is the current thinking that the universe itself was part of the big bang, or just all the known energy and matter in the universe.

Thanks again, and I'm not intending to be contrary. I'm just trying to wrap my head around all of this.

 

[Mark M]

Remember that general relativity allows space to be dynamic. Just as space can take on curvature, it can expand. The expansion of space is required by GR for a universe filled with energy. The balloon analogy does a good job of showing how the universe expands even though it dopes not have boundaries. See this page.

Yes, it would be like an old arcade game, where moving in one direction just gets you back to the other side, though there are 'sides'. Again to use a two dimensional analogy, it is like two dimensional circles that live on the surface of a sphere. It is important to remember that we're only speaking of the surface. This is difficult to imagine in three dimensions, since we are adjusted to having a third dimensions. Just keep in mind that just as our three dimensional universe is all there is (by 'universe' I mean the totality of spacetime, I am in no way speaking about a multiverse. Also, when I say our three dimensions are all there is, I should say 'extended' dimensions, as there may be extra microscopic dimensions. But that is besides the point). Since the global geometry of their world is curved, continuing to move in one direction will wrap them back to the other. This is what our universe is like if it is finite.

Now, since we can imagine four dimensional spaces, we cannot get an objective view on this. Also, note that even though the sphere is embedded in 3D space, the universe does NOT need to be embedded in 4D space. That is a limit of the analogy.

As I mentioned in the previous post, the big bang is a moment in time, not a point in space. It occurred everywhere in our spacetime. In terms of your question, different people may give different answers. The general understanding was that the big bang was the first moment, and that space and time themselves began there. But this seems less and less likely, with the dawn of quantum cosmologies and cosmologies based off of string theory and LQG. Either way, it occurred everywhere throughout the universe. Whether or not it represents a beginning to spacetime or not, is still an open question.

 

[coktail]

Does this wrap-around effect apply to seeing the "edge" of the universe as well? For example, if we had a powerful enough telescope and could somehow see past the event horizon to the edge of the known universe, would we end up viewing the other side of the universe past it?
That's just crazy.

How do we know this? I thought my mind was done being blown by the universe once I learned about time dilation and other such phenomena, but now it's getting blow all over again!

 

[Mark M]

Our observable universe is limited by what is called a particle horizon. Since light has a finite speed, the father away you look, the older the light you see. So, viewing a galaxy 1 billion light years away allows you to view it as it looked 1 billion years ago. Looking at the sun let's you see what it looked like 8 minutes ago (light takes roughly eight minutes to traverse one astronomical unit.). So, since the universe has a finite age, there is a limit to how far we can see. It is a common misconception to say that this is 13.7 billion light years, as you would think (the universe is 13.7 billion years old). Instead, we must also account for the expansion of the universe over time, so that we can see 46.5 billion light years away. Now, as we look further, we see the universe as it looked closer and closer to the big bang. Eventually, 380,000 years after the big bang, you would hit a limit. Why? Because the universe was so incredibly hot, atoms could not yet exist, only atomic nuclei. So, all photons were immediately scattered by electrons in the this quark-gluon plasma. Eventually, 380,000 years after the big bang, the recombination occurred. The universe cooled to a sufficient temperature that the first light escaped the plasma, creating what is called the cosmic microwave background, or CMB. The CMB is like the baby photo of the universe, and provides the most direct evidence for the big bang. It is extremely redshifted, and fills up all of space at a measly temperature of 2.7 degrees Kelvin.

For more on the CMB, see here, and here.

So, there is a limit to how far we can see. Also, WMAP's estimates of curvature have hinted that the universe is much, much, larger than just the observable universe, so any hope of seeing a repeated galaxy is for the most part, non-existent.

Here are a few links for information about cosmology that should answer many of your questions (Make sure to read the first!):

http://www.astro.ucla.edu/~wright/cosmoall.htm
http://www.astro.ucla.edu/~wright/cosmology_faq.html
http://casswww.ucsd.edu/archive/public/tutorial/Cosmology.html

Wait until you learn about quantum mechanics.

 

[coktail]

Thanks for all of your help! I'll check out the links you've provided. I appreciate you taking the time.

 

[diogenesNY]

Perhaps I might also contribute the following link:

http://www.mso.anu.edu.au/~charley/papers/LineweaverDavisSciAm.pdf

An article by Charles Lineweaver and Tamara Davis (published in Scientific American) that gives a very accessible but fact laden run down on 'The Big Bang' and corrects many popular misconceptions. It directly addresses several of the points raised above.

diogenesNY