Thursday, October 16, 2008

Return of gravity

Sweetly Single asked me more questions about yesterday's post. Today I answer.

What about Hawkings' discovery in 1974 (called Hawking Radiation)? If the negative gravitational forces causes no radiation (light) to get through... then how could Hawkings be right?
There is some radiation emitted by matter passing through the event horizon. The event horizon being the point where light can't escape. But I don't think that's what Hawking was talking about.

You know the equation E=MC2. Energy (E) equals (=) mass (M) times the speed of light (in a vacuum) (C) squared (2). This means that mass can be converted to extremely large amounts of energy.

A black hole that is pulling in no matter still puts off thermal radiation, which for today's arguments we're gonna call heat. Heat isn't influenced by gravity... as far as I know. So what you're getting is matter inside the black hole breaking down into heat and the heat radiating away. The smaller the black hole the greater the effect. Given enough time the black hole would evaporate.

The Large Hadron Collider cannot produce black holes but it might, mind you I said "might", be able to slap two particles together with the density of a black hole. Being so small it would immediately dissipate into Hawking radiation.

How does the magnetic field of the moon and the opposite magnetic field of the earth effect the moon's orbit? Wouldn't it have the same effect as two magnets that are opposite of each other?
The moon has no magnetic field.

Permit me to digress. I'm going to give a lot of background that will help with this but help even more with a later question.

Stars form from hydrogen clouds. When there's enough for the gravitational pull to cause the hydrogen molecules to fuse (smoosh together) into helium it releases energy and the star starts to burn. It fuses the hydrogen into helium and sometimes splits helium into hydrogen. When the bulk of the hydrogen is used up the star turns red and begins to expand as the helium is fused into heavier elements (lithium, berillium, boron, carbon, nitrogen, oxygen, fluorine, and that's as far as I can remember). This is how pretty much everything that isn't hydrogen is formed. When that star explodes it releases the matter that becomes planets later.

So in a swirling cloud of dead star gunk a lump forms and starts drawing in more gunk. The gunk smacking together produces heat so the lump is molten. That and much of the gunk is radioactive. Particularly the uranium and whatnot. The heavy stuff settles to the center of the molten mass which is quickly becoming something you could call a planet. By heavy I mean larger atoms that are at the bottom of the periodic table and radioactive. One day something large hits the mass that eventually became Earth. The something that hit Earth is thought to be roughly Mars sized but is probably not Mars. It knocks loose a big chunk of Earth's surface. That chunk becomes the moon.

So, what you have to make up the moon is a small (large for a moon but small relative to Earth) lump of material absent most of the good radioactive stuff which, as I said, was safely down in the middle of the big molten glob. As the two bodies cool (sorry, no idea what happened to the thing that hit us) one just kinda becomes a rock while the other maintains a spinning molten core that gives it a magnetic field. Part of why it maintains the molten core is because it's bigger and cools slower. Part of it is because it's packed with radioactive material. And part of it is because there's this big rock spinning around it causing it to shift and flex.

So that is why the moon has no magnetic field.

How does the gravitational pull of the moon effect the stability of the polar ice caps?
Good question. I can make some guesses but I don't recall reading anything about it. This answer may sound a bit different than some others because I'm trying to think it out instead of just explaining.

The moon orbits on a plane at a roughly 5° angle to the plane on which we orbit the sun. I may need to draw that. In short, the reason there's not an eclipse every month is because the moon doesn't orbit on the same plane as we orbit the sun.

So, if the Earth rotates at a 23° angle relative to our orbital plane then the furthest north or south that the moon could pass over the Earth would be 28° and change. So the moon will never pass over the poles. The greatest tidal effects overall would be along the equator but there would be greater and lesser effects over the mid-latitude. There would be some manner of tides at the poles but not like elsewhere. I would imagine that there might be more icebergs calving (dropping off the glacier into the ocean) on the side of the pole facing the moon than the side not. Never seen any stats on that but I'd like to.

That's what I've got. If anyone has better answers I'd love to hear them.

Was the black hole caused by an implosion or explosion of the surface of the star that caused it?
Ok, lets go back to the star I was talking about earlier.

Hydrogen is running low. The star continues to draw it's fuel from fusing helium into heavier elements. Much of the heavier stuff falls in toward the core of the star. The fuel runs out and the surface starts to fall in toward the denser middle. The surface contracts, getting denser, gathering up gases between the surface and the core. It falls and falls until it hits the dense core. The unstoppable force meets the immovable object. It explodes. Lots of surface matter (at this point that's defined as a mix of the old surface and what it slammed into) gets blasted off into space to form new stars and planets later.

What remains depends largely on how big the original star was. Our sun will most likely become a brown dwarf star. Small, dark, and cold as far as stars go. Not anything you'd want your planet orbiting. Which is fine since Earth got roasted when the sun expanded.

A larger star will have enough mass left over after the surface gets blown off that it will just keep collapsing and keep collapsing and keep collapsing. The very atoms will start to press in on each other and a Black Hole will form.

At that point, where the atoms start to intrude on each other, we lose any idea of what's happening. Our theories of the universe come into conflict. Einstein, Hawking, and others keep trying to come up with the Unified Field Theory to reconcile the two. Some thinks String Theory will cover that for us.

So, to answer this last question: Neither.
The explosion is not particularly relevant to the formation of the black hole. It's just what happens as the star dies.


JTankers said...

Micro black holes do not evaporate according to several recent studies challenging Hawking Radiation[4] as fundamentally flawed conjecture that does not exist[1][2][3].

Dr. Hawking's 1975 paper speculated that only the anti-matter half of a virtual particle pair might enter a black hole and anti-matter would have "negative energy" (that is incorrect, anti-matter is positive energy) or that time reversal or faster than light tunneling (Dr. Hawking's conjectures that refute Dr. Einstein's theories) could cause the radiation effect.[4] Unfortunately Dr. Hawking's logic process is flawed as even Dr. Higgs points out[5], Dr. Hawking's conjecture violates known laws of physics, no part of the electromagnetic spectrum escapes a black hole's event horizon, not light, not magnetism, nothing. Micro black holes should not be expected to evaporate[1][2][3].

[1] Do black holes radiate? Do black holes radiate? - Prof. Dr. Adam D. Helfer Paper. (2003)
[2] On the existence of black hole evaporation yet again On the existence of black hole evaporation yet again - Prof. VA Belinski Paper. (2006)
[3] Abraham-Solution to Schwarzschild Metric Implies That CERN Miniblack Holes Pose a Planetary Risk, Prof. Dr. Otto Rossler (2008)
[4], Particle Creation by Black Holes, S. W. Hawking (12 Apr 1975)
[5] Peter Higgs launches attack against Nobel rival Stephen Hawking, TimesOnLine (Sep 11, 2008)

Ibid said...

We do have laboratory models of Hawking Radiation, but it's been difficult to detect in the real world. The slight radiation would barely be noticable over the general background radiation of the universe.

If course, in 2004 Hawking settled up on a bet he made in 1975. He said that information would be randomized and lost when if tell into a black hole. He now says that he was wrong and that the energy emitted could tell you about what went in. He hasn't completely sold everyone.

I can't speak about the other physicists but I take what Higgs says with a grain of salt due to the ongoing feud between he and Hawking. Hawking claims that the Higgs-Boson doesn't exist while Higgs claims that black holes don't emit anything.
At this point they seem to disagree on everything just out of general principle.