diamonds

[steveb]

do diamonds degrade over time if left for long enough? does everything degrade if left for long enough? cheers, could help me settle a bet.

[brachiopod]

In theory, diamond should 'degrade' to graphite at surface temperatures and pressures, as the latter form is the lower energy state of pure carbon, and matter tends to revert to its lowest energy state.

However, to re-arrange the carbon atoms in the lattice structure requires an initial boost of energy, known as the 'activation energy'. This is very high for diamond, and thus, the energy required to get the process going is never attained at (Earth's) surface temperatures.

For this reason, diamond (being the high temperature / high pressure allotrope of carbon, since it is formed at great depths within the Earth) is referred to as being meta-stable - meaning it should become graphite, but doesn't !!

So that means;
"A diamond is a girl's meta-stable best friend"

[Hippy]

The interesting theory of entropy states that everything will degrade and return to chaos from which it was formed originally. There are some premises for the theory that are fare from established, and there is no evidence that if it applies to on order of matter that it will apply to another.

In Thermodynamics, entropy is the degree of disorder in a system, measured in terms of the natural logarithm of the probability of occurrence of its particular arrangement of particles. Highly ordered stuff is highly improbable; chaotic stuff is much more probable.

It is true that all the works of mankind are finite and therefore futile, so why the heck shouldn't everything else follow this same flow. Supreme arrogance or solid theory? You decide.

[MargeB]

How  come I'm a human sitting at a computer if everything tends to entropy? Never did work that out.

[Hippy]

Vastly more chaotic than that cosmic dust (hahaha).

No, seriously, I think the idea is that there are stronger forces at times to cause groupings of atoms and molecules, but in the long run chaos is supposed to win out. The chaotic dust floats randomly. particles bang into each other and some stick. eventually larger clumps form that hoover up more random matter. The critical size is reached and then another one comes along and bangs into the first and, wollop! an explosion takes place causing heat and light. Over many more of these events stars, planets and all the rest gradually gather themselves into an organised system.

Alternatively, in a collosal cosmic elastic twang, all the matter is formed, having been sucked from a different state/dimension, and the acretion and organisation is given a kick start by this "Big Bang". In either case, as the universe cools, slows and generally gets further away its birth, organising energy is reduced and it decays into random particles. (Well sort of something along those lines. The Stephen Hawkings types have a lot more to say on the subject.)