Big Bang 4of4: From the Big Bang to the Earth & Poetry

Lecture by Professor Richard Muller of the University California, Berkeley. Taken from Lecture 26 of the spring 2006 webcasts of Physics For Future Presidents. Also known as Descriptive Introduction to Physics. Empahsis is on conceptual understanding, rather than mathematics.

All Lectures:
http://www.youtube.com/view_play_list?p=095393D5B42B2266

Category:

Education

Tags:

• big
• bang
• expanding
• universe
• creation
• physics
• science
• infinity
• relativity

[RichardRoy2]

@theinquisitor Thank you for your response. There is still so much I have yet to wrap my head around, such as time space curvature, no pun intended, but I make myself chuckle nevertheless. I suspect someone has yet to present that concept in a manner that I can connect to conceptually. Once in a while I come upon gems I may find connection to in the future. Your reference to deformations in the fabric are fascinating. Thanks.

[theinquisitor]

@RichardRoy2, indeed, what science has shown us more than anything is the vastness of our ignorance, how much there is still to learn.

Regarding the vacuum, as I understand it, it does have structure and properties. Such as the curvature of the space-time, and the energy of the vacuum created in particle pair-production and annihilation. On the quantum scale, the vacuum is full of activity. Matter and energy themselves may be deformations in the fabric of space-time, twists in the vacuum.

[RichardRoy2]

2a. @theinquisitor: ...not aware of. I think there's still much to discover resting outside our perceptual range.

[RichardRoy2]

1a. @theinquisitor Here, try this on for size; space is a medium through which we can witness the impact of energy. In other words, space is not nothing; it's a medium we have yet to identify the full nature of. As with anything else, I expect we'll discover it has limits, such as compressibility. We call it a vacuum only because it is so, relative to what we're used to dealing with. If we rid space of everything we're aware of, what remains is what we're...

[gregg4]

@theinquisitor

It was Fred Hoyle who coined the term in a somewhat sarcastic/mocking way.

He believed in the steady state model.

[theinquisitor]

The idea is that matter is waves in the fabric of spacetime, so matter can no more leave the "edge" of spacetime than the waving part of the rope can leave the rope, or a water wave can leave water.

Ultimately mathematics is the only way we can really get a handle on things so far beyond our intuition. The analogies are drawn from the equations and are necessarily limited.

Either the universe is finite, or goes on forever, and neither alternative is comprehensible to our intuitions.

[theinquisitor]

Yeah it's a limited analogy. The problem is that our brains evolved to handle things on a certain scale, and so the curvature of spacetime is just beyond our intuitive grasp. So there's really no way to get a gut level understanding of the geometry of curved space.

But perhaps another analogy that might help is if you imagine a rope that's been shaken so that a wave moves along it. The wave can't move outside the rope, and so it is with matter in space.

[91BROWNIE91]

you have a point. But with your analogy of the surface of a sphere, if it is like a sphere, that implies that there is something or "nothing" beyonce the sphere. The sphere has to be somewhere, it can't just be there all by itself can it? Does that make sense

[theinquisitor]

Well space isn't nothingness, it's space. Empty space itself is something that has properties.

Also, there wasn't anything around the "point" of the big bang. It's probably not accurate to call it a point either. If the universe is infinite, then it was just infinite space at infinite density, and if it's finite, then it's space was curved so it wrapped around itself with no boundary, like the surface of a sphere.

Asking what's outside space is like asking what's north of the north pole.

[91BROWNIE91]

if the vacuum of space is the space of nothinigness between to objects, what do you call the nothingness that was outside and around the "point" of the big bang before it happend? Is there a vaccum outside of our universe?