# Creation of matter

1. May 5, 2005

### lwymarie

just a simple question: do u think matter can be created? nowadays some scientists do believe that

and what's your reason?

2. May 5, 2005

### quasar987

At the light the the many experiments that confirm this, it is difficult to doubt it anymore.

When a particle and its anti-particle colide, they anihilate each other and "transform" into a photon (light). Photons have no mass, so one could say that mass "disapeared".

The opposite process also happens. Sometimes, a photon splits into a particle and its anti-particle. In this case, mass seems to be "created".

In these two classes of interaction, mass is not conserved. But something is: energy. And since $$E = mc^2$$, this is not really surprising.

3. May 5, 2005

### Andrew Mason

It is not a question of what one thinks. Energy is used to create matter. It is routinely done in large particle accelerators.

AM

4. May 6, 2005

### lwymarie

since mass is not conserved, why is energy conserved?

5. May 6, 2005

### ZapperZ

Staff Emeritus
Energy by itself isn't conserved. Mass by itself isn't conserved. The more GENERAL form of the conservation law is the conservation of mass+energy. So when there is an interaction where mass and energy coverts from one to the other, only the conservation of mass+energy is the relevant conservation law to consider.

Only when they don't convert into each other are the conservation of energy and conservation of mass valid separately.

Zz.

6. May 6, 2005

### LURCH

I think it depends on how loosely we define "created". If you mean created ex nihilo ("out of nothing") than the answer would be "no". Mass can be converted from energy to matter and matter to energy, but there is no method either known or theorized (AFAIK) that could create or destroy mass.

Last edited: May 7, 2005
7. May 6, 2005

### lwymarie

but recently some scientists believe that matter can be created out of nothing.

8. May 6, 2005

### ZapperZ

Staff Emeritus
Then you need to give the exact citation on where you "heard" this. I can tell you that in many cases, there's often a signficant difference between what the physics is, what is being reported, and what is being understood by the reader. It is difficult, almost impossible, for any of us to explain what you heard what "scientists believe" if all we have to go by is just what you have said.

The ONLY possible source of such a thing would be the creation of virtual particles. If this is what could have been refered to, then this is not any real creation because the matter doesn't live long enough for the rest of the world to detect it. It still doesn't violate the conservation of mass+energy.

Zz.

9. May 6, 2005

### Andrew Mason

The answer to this question is the holy grail of physics: how did the universe begin? Why is there not nothing?

Under our laws of physics, it is not possible to create matter or energy out of nothing. But that just means that under the laws of physics that exist in our universe, matter as it exists in our universe and energy as it exists in our universe cannot be created or destroyed in our universe.

Do other universes exist where matter can be created and destroyed? under different laws of physics, perhaps? While science does not provide an answer, science does not exclude it as a possibility. Is it a reasonable possibility? Many think it is. But that is as far as science can take us at this point. Beyond that it is a matter of speculation and faith.

AM

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