Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Origin of Matter
Name: Wilmer Bruce W.
Status: other
Age: old
Location: N/A
Country: N/A
Date: 2001-2002


Question:
In the matter of converting energy into matter, so far as I've been able to find out, or rather to not find out, no experiment exists in which energy is converted into matter with out the intermediary of matter, e.g., fast moving particles. That is, the energy in question is usually (always?) the kinetic energy of particles. The claim is that in the early moments of the big bang matter hadn't yet formed. So when it was finally formed, what was it formed out of? Presumably matter was formed out of energy of which there was a super abundance. So how did this happen? I'd like to know of an experiment in which the m*c*c's after the event is accounted for by just the total E before the event. I can see that once just even a smidgen of matter is somehow created, it can be used to create more matter through collisions and fusions, etc. What I want to know is how to get the whole thing started, i.e. how to get the first instance of matter. Somewhere in all of this ramble is my question. It's been decades since I studied physics, and even longer since my father in law (Joseph Walters C.), who instigated this query, did. So humor us a bit. What are we over looking?


Replies:
Wilmer,

Energy forming into matter usually happens on a very small scale. One example is a beam of high energy photons of light passing through a magnetic field. A photon of high enough energy can change into an electron and an anti-electron (called a positron). In most cases, the electron and positron rejoin into a photon again. In the large magnetic field, the two particles are pulled apart. This prevents them from rejoining.

To get more matter to form requires a much greater amount of energy, all in the same place. When the energy is in the form of fast-moving particles (kinetic energy and mass energy), it is very easy to contain. Two colliding particles is a great deal of energy at the collision site. Other forms of energy (e.g. radiation, heat, potential energy) are either very small or hard to contain.

You might then wonder how all the universe energy got into one location to begin with. One theory states that the universe expands and collapses repeatedly. When collapsing, all the matter gets so compact that it changes into heat, like a super-giant star collapsing. It then explodes, changing into matter when there is enough room to do so. The matter, with a great deal of kinetic energy, expands. As it does this, small pieces of matter join into larger pieces, eventually becoming stars. After expanding for perhaps trillions of years, the matter starts pulling back together. The whole process repeats forever. The universe had no actual beginning and will not really ever end.

If there is only one explosion, then we cannot scientifically talk about what was before the explosion. Before the universe began to exist, before the explosion, time as we know it hadn't actually started. We cannot even truly state what the universe was before the explosion. We know it was energy, but we do not know the kind of energy.

Dr. Ken Mellendorf
Physics Instructor
Illinois Central College



Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory