Simon Singh is stumped...

[jhe1984]

At the end of his Big Bang lecture, Simon Singh gets a question from an audience member to which he didn't have the answer. He asked if anyone in the audience (other physicists) had the answer, but no one did.

Here's the question,

"When you go back in time, all matter comes close together, why wasn't it in or why wasn't there a black hole?"

Anyone care to help?

Here's the link, its the Big Bang talk --

http://streamer.perimeterinstitute.ca:81/mediasite/viewer/FrontEnd/Front.aspx?&shouldResize=False

[Chronos]

No surprise there. Physics, as we know it, comes to a screeching halt about 1E-43 seconds after the big bang.

[franznietzsche]

Hawking originally argued in favor of the idea of a Big Bang singularity, but later rejected it.

Inflation theory suggests something quite different altogether, a sort of high energy density vacuum that decays into a normal vacuum with matter, rapidly expanding.

[jhe1984]

From your answers I'm still not able to understand how the black hole question has been resolved?

[JesseM]

This section (http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/universe.html) of the physics FAQ on John Baez's site gives the answer according to general relativity: Why did the universe not collapse and form a black hole at the beginning?

Sometimes people find it hard to understand why the big bang is not a black hole. After all, the density of matter in the first fraction of a second was much higher than that found in any star, and dense matter is supposed to curve space-time strongly. At sufficient density there must be matter contained within a region smaller than the Schwarzschild radius for its mass. Nevertheless, the big bang manages to avoid being trapped inside a black hole of its own making and paradoxically the space near the singularity is actually flat rather than curving tightly. How can this be?

The short answer is that the big bang gets away with it because it is expanding rapidly near the beginning and the rate of expansion is slowing down. Space can be flat while space-time is not. The curvature can come from the temporal parts of the space-time metric which measures the deceleration of the expansion of the universe. So the total curvature of space-time is related to the density of matter but there is a contribution to curvature from the expansion as well as from any curvature of space. The Schwarzschild solution of the gravitational equations is static and demonstrates the limits placed on a static spherical body before it must collapse to a black hole. The Schwarzschild limit does not apply to rapidly expanding matter.

[Chaos' lil bro Order]

I would offer the idea that a Black hole is a singularity in space, whereas the Big bang 'singularity' created space and therefore was not embedded in it. In other words, since no space exisited before the big bang (10*-43s) it would be impossible to call the singularity a Black hole. Also, its widely believed that Gravity broke symetry with the Unified 4 fields at 10*-42s, so if there was no Gravity at the point of creation, the definition of a black hole which is intrinsically defined by Gravity's force, clearly could not exist.

Still you ask a very interesting question that cannot foreseeably be known, perhaps the best kind of question to ponder:smile: