Matter destroyed?

[blike]

One of the first things we learn in science is that matter can neither be created nor destroyed. But what about when matter and antimatter collide? I've been reading "The Elegant Universe"; and it talks about matter and antimatter colliding and destroying each other. So how does this all fit together? Has that law since been changed?

[fafalone]

That law only applies to normal reactions... it's more of a practical law than an absolute law.

[Sayonara]

I was under the impression it was energy, not matter.

[fafalone]

Energy had to be created some time.

[Sayonara]

So did matter.

[fafalone]

Matter is a form of energy.

[Sayonara]

So I understand.

 

So..... "yes" then?

 

[fafalone]

There's a conservation law for both matter and energy.

[blike]

ok, be right back while i go laugh at myself.

 

You're correct, it is energy.

 

But seeing as how matter = energy, then is it valid to say matter can neither be created nor destroyed? I guess its preserved since it shifts states.

[aman]

My wife is matter. I shop when I am hungry and bring home all sorts of extra crap. Now I'm anti-matter. When I get home there is a big release of energy. One of the interesting things about nature is there are so many analogies in our existance. It's like we get clues as to how the complicated stuff works.

The structure of the universe has written a book on its structure for dummies. That's how we climb each step.

Strike to stones and get a spark. Compress the mass of plutonium and get an explosion.

Our existance seems to have been written down in simple things as clues the entirety.

Makes it all a piece of cake.:slaphead:

Just aman

[Radical Edward]

Conservation of energy is a result of symmetry in time, when you work it out through Quantum Mechanics. If there is no time, there is no need for energy conservation, as at the point of the big bang. That's my intuitive view on it anyway, though granted I haven't managed to unify QM and GR yet, so I can't tell you if I'm right or not.

[Michael77]

I have a much simplier resopnce than that last one....there's too many question marks to even discuss it.......you can have a discussion on one or two questions.....but this....its not a plausable discussion......its like asking where the universe came from....there is too uch we don't know......its incomprihencable at this time......

 

forgive me.....I've been drinking.....

[blike]

though granted I haven't managed to unify QM and GR yet

 

Superstring theory for you.

[Radical Edward]

Originally posted by blike

 

Superstring theory for you.

 

still working on it. heh.

[aman]

I like superstring theory cus it tastes like chicken. It has problems that get more difficult the deeper we probe into the microcosom. It asks us to accept quite of a lot of unprovovable and unverifiable presumptions only on the basis they make the whole idea work.

It is good to explore with our imagination but I think in the end it will prove to be a wild goose chase, and if you cook a goose wrong, it tastes like chicken.

Just aman

[fafalone]

But what is time?

 

The standard quantum mechnical definition of time is the direction in which entropy increases; but since it has been shown the law of entropy can be broken on small scales, this calls into question time. And of course there's the entire time dilation issue.

[aman]

That's too good of a question and I sat here till my head smoked. I liked your examples but I believe there is some better answer. Just can't think of it at the moment.

Just aman

[slickinfinit]

I dont have a phd but if we use the big bang theory does that mean we started out with the same amount of energy that we still have now ? If u are saying u cant destroy or create energy ?

[Damion]

But what is time?

 

The standard quantum mechnical definition of time is the direction in which entropy increases; but since it has been shown the law of entropy can be broken on small scales' date=' this calls into question time. And of course there's the entire time dilation issue.[/quote']

 

I thought time was a relative, man-made concept.

[123rock]

I thought time was a relative, man-made concept.

 

It's relative, but I don't think it's man-made.

[swansont]

I dont have a phd but if we use the big bang theory does that mean we started out with the same amount of energy that we still have now ? If u are saying u cant destroy or create energy ?

 

Conservation of energy is a consequence of the laws of physics not changing over time, and vice-versa. Can't have one without the other. So if energy nonconservation has happened, then the laws of physics changed.

[CPL.Luke]

I have said it before and i'll say it again if you can't define a dimension it doesn't exist

 

how can you define a point or an object in more than 4 dimensions Ill start believeing it

 

I do know the whole idea of strings wrapping around dimensions and keeping them small but, why bother talking about them if their that small. It would seem that you could say that there are millions of dimensions that are just really small and strings wrap around them and keep them small.

 

I do like the idea of strings themselves just not all of the hoopla that comes with them

[slickinfinit]

Conservation of energy is a consequence of the laws of physics not changing over time, and vice-versa. Can't have one without the other. So if energy nonconservation has happened, then the laws of physics changed.

that realy confused me lol but i ma learning

[alt_f13]

But what is time?

 

The standard quantum mechnical definition of time is the direction in which entropy increases; but since it has been shown the law of entropy can be broken on small scales' date=' this calls into question time. And of course there's the entire time dilation issue.[/quote']

 

Could you explain how the law of entropy being broken on small scales calls time into question? Could time not just become distorted with the disruption of entropy?

 

These two concepts still sound like mutually exclusive properties of matter to me however, and one should be able to exist without the other in different situations. That is of course, unless somone decided "time" as a definition is the result of entropy, in which case time would not be called into question with the disruption of entropy, but changed with respect to the change in the entropy of the small system.

 

Stop me if I sound like a blathering moron, I isn't the mots best in the phuziks.

[thoreau21]

In chemistry, there are two laws: the Conservation of Matter, and the Conservation of Energy. They each state that matter/energy can be neither created nor destroyed *by normal chemical means*.

 

However, each can be destroyed, in a sense, in physics.

 

An example is the atom bomb. By nuclear fission, the nucleus of an isotope of the element uranium, uranium 235, is blown apart. In this process, uranium 235 loses matter, but this lost, or "destroyed", matter is converted into an equivalent amount of energy, thus creating the highly destructive mushroom cloud of radioactive energy.

 

Einstein recognized that the laws of Conservation of Matter and Energy apply to chemistry and other sciences, but during his work with nuclear physics, he modified the law to one almost everyone is familiar with: E = mc^2.

 

Where E = energy, m = matter, and c = the speed of light, Einstein's equation states that where matter is lost or destroyed, an equivalent amount of energy is created, and vice versa. Where energy appears to be lost, an equal amount of matter is created.

 

Thus the laws of Conservation of Matter and Energy are applicable, unless dealing with the highly theoretical science of nuclear physics.