Fusion vs. Antimatter vs. Gravity

[xilman]

Originally Posted by mfgoode

Please check it on the web if you like, go to
http://www.creationofuniverse.com/ht...librium02.html

For an alternative explanation of the cosmic coincidences described at that site, consider the anthropic principle. This states that the reason why the universe is the way we observe it is that if it the laws of physics did not allow for observers, there would be no-one around to observe it.

A natural hypothesis is that there may be (or have been and will be) many (possibly an infinite number) of universes but only those for which the local laws of physics allow for the evolution of observers will be directly observable. This leaves open the possibility that an otherwise inobservable universe (because no observers within it can exist) may be indirectly observable through the effects it has on an observable universe.

Some deep metaphysics there, and any further development of these ideas should be in a separate thread,


Paul

[cheesehead]

{enter off-topic mode}

Originally Posted by mfgoode

"Although most physicists accept the idea that the gravity field is really quantized, it is unlikely that the graviton - the quantum of gravity- will ever be detected -------
Gravitons interaction are simply too weak ever to be seen.
Strictly speaking,if a graviton should hit a proton the proton would recoil. But this recoil is so tiny, we can never detect it.
Gravity is the weakling of the quantum particle interactions"
Source: 'The Cosmic code' by Heinz R. Pagels

Actually, the magnitude of the quantum of gravity has been measured. A couple(?) of years ago, Scientific American had an article.

Someone set up a device in which cold (i.e., slow-moving) neutrons, travelling horizontally, entered a chamber, bounced off the floor of the chamber under the influence of gravity, then exited through a movable slot on the other end of the chamber. The position of the slot allowed only neutrons at a certain height to exit the chamber into a detector.

Neutrons were observed to exit only at certain discrete heights, not at heights in between those. The spacing between the discrete heights corresponded to the quantum of gravity, enabling calculation of its magnitude.

{exit off-topic mode}

[cheesehead]

Hey, waitaminute! This is the separated "Fusion vs. Antimatter vs. Gravity" thread, not the "How did you get your forum name?" thread.

I wasted a perfectly good off-topic mode entry/exit pair.

[BluePhoenix]

I object that my post was not moved to this forum! It had info...! Kinda.... *sigh*

[garo]

Unfortunately, BluePhoenix, it also had some on topic content so moving it to this thread would not have been satisfactory either. Too bad phpBB does not give one the option of copying posts. Here is the relevant content:

And I believe antimatter exists naturally linked to normal matter to make up sub atomic particles and dont ask me why they dont destroy each other. It has also been suggested that matter/antimatter pairs are created constantly in empty space and promptly destroy each other.

And finally there is currently an argument over where to build the first prototype fusion plant - either in France or Japan. Japan has the support of US and South Korea while France has the support of (I think) China and EU. So they are close to making fusion worthwhile.

[Fusion_power]

Xilman,

You are correct, I butchered that rather badly. See if I do better with this.

The basic energy release mechanism in the sun is the carbon catalyzed sequence of C12 -> 13 -> 14 -> 15 absorbing a proton at each step and finishing by throwing off an He nucleus with 2 protons and 2 neutrons and releasing a C12 which starts the sequence again. Each step results in release of substantial amounts of energy. There are 3 other significant fusion sequences involving a hydrogen nucleus, deuteron, etc.

The energy released decreases dramatically as the size of the nucleus being fused increases with Fe56 being pretty much the end of the line with any further fusion action absorbing energy instead of releasing it.

The collapse of a star to form a neutron star fuses almost all the matter in the star into neutrons. This requires a net energy input since the star could not reach this stage without having first converted most of its hydrogen into larger molecules. That energy muct come from gravitational heating. The core of such a star (pre-collapse) would by necessity be composed mostly of Fe. The star could be considered to have layers similar to an onion with an Fe core and progressively smaller nuclei at the surface. When the core collapses, the outer layers of the star may still retain significant amounts of hydrogen and Helium which under the impetus of the gravitational collapse undergoes a runaway fusion reaction that then blasts the external layers of the star into space. This is the cause of the nebula around such stars as the Crab.

From a strict viewpoint, none of the 3 forces releases energy, but they can be considered to affect certain reactions. By that, I am trying to say that the strong nuclear does impact the fusion reaction, the electro-weak "may" impact the matter/antimatter (an electron is attracted to a positron, I won't touch the graviton/gravitino since they are still theoretical) and gravity can impact all since all matter is subject to gravity.

The energy released by gravity is frictional energy. The only parallel I can think of is an ice skater who is spinning in a circle with arms extended. When the arms are drawn in toward the body, the spin increases. (its a lousy parallel) Similarly, when gravity forces degenerate matter to push closer together, the only way it can maintain its stability is by interacting with other nuclei at dramatically increased rates. The net effect is that particles overcome their restraints and transform into neutrons. The actual conversion to a neutron is enabled by the dramatic increase in energy caused by the gravitational collapse.

Here is a question I am really curious about. What happens when a truly huge star (like the pistol star - or the other recently detected one - with from 120 to 150 times the mass of the sun) fuses a large Fe core and then collapses. By its nature, it must have lots of hydrogen still in its outer shells. Would such a reaction produce something like the mysterious Hard Gamma bursts that are occaisionally detected?

mfgoode - I think your website is a bit out of date. The Electrical and the Weak Nuclear were integrated a few years ago as a result of high energy particle interactions. In effect, they are manifestations of the same force, the Electro-Weak.

Fusion - who is not a physicist but in extremely curious about stars.

[mfgoode]

mfgoode - I think your website is a bit out of date. The Electrical and the Weak Nuclear were integrated a few years ago as a result of high energy particle interactions. In effect, they are manifestations of the same force, the Electro-Weak.

Fusion - who is not a physicist but in extremely curious about stars.

I’m afraid I don’t agree with you fully and your explanation is only partly correct.
Also I have grave doubts that the neutron experiment you mention will have successful results due to the peculiar properties of the graviton.
I do concede, however, that only above the critical temp 3*10^15 K (S. Weinberg) the weak force and the electromagnetic force are combined into the electra weak force when they become indistinguishable and follow the the same inverse square law and are about the same strength, possibly in the core of stars.
In an article as recent as dec.2001 the science correspondent of the NYT service George Johnson has this to say
Quote/ In the beginning was a single force----- Then along came the big bang to ruin it all.
The universe cooled and expanded, the single force splintering into the four VERY DIFFERENT forces observed TODAY (capitals mine) Electro-magnetism and strong and weak nuclear forces which workinside atoms are described by Quantum mechanics and special Relativity.The fourth force gravity is described by an entirely different theory, General Relativity./ Unquote.

Xilman: The anthropic principle has fallen out of favour today by physicists afaik.
A hostile view was given by Heinz Pagels in his book ‘Perfect Symmetry’ as way back as 1985 and also by Eugene Wigner.
In favor are John Barrow and Frank Tipler in their book ‘The Anthropic cosmological Prtinciple’. Well its good that you mentioned it as an alternative viewpoint.
At most this issue is highly debateable. I refrain fom commenting any further.

Mally.