# Question on Quantum Leaps

1. Sep 19, 2005

### shep_pb4y

My high school physics teacher touched breifly on quantum physics, but most of what I know I've learned myself. But there's one thing I haven't been able to get a good answer to. My teacher told us that when matter goes through a quantum leap (while moving through space-time), sometimes a particle may "go into" a quantum leap, but fails to reapear. Is this accurate?

2. Sep 20, 2005

### James R

That doesn't sound quite right. A basic principle of physics says you can't create or destroy energy, and if a particle carrying energy just disappeared this principle would be violated.

A quantum leap is really just a change in the energy of an object (like a particle) by a specific amount. For example, an electron in an atom can make a leap from one "orbit" to another. The energy change required to do that is always the same. The quantum part comes from the fact that the electron is not "allowed" to have just any energy. It can only have certain particular values of energy. If it wants to change from one allowed value to another, it has to lose or gain just the right amount (or "quantum") of energy to take it to one of the other allowed energy values. Moreover, it does that in one single "leap", so that it is never found to have an energy which is half way between the two "allowed" energies, for example.

Strangely, for an electron, that means that there are certain orbits around atoms at which an electron can NEVER be found, even when it is moving from a lower orbit to a higher one. So, it somehow gets from the low orbit to the high orbit without ever passing through the intermediate orbital distance. That's another reason for talking about "leaps" or "jumps".

The quantum world is quite strange in many ways, but quantum theory provides our best picture of things like atoms.

3. Sep 20, 2005

### ahrkron

Staff Emeritus
The way this is phrased gives the impression that quantum-leaps are places that you can go visit. It is not like that. "Quantum leap" is the name we have for a particular behavior of particles; one that all particles undergo when under the proper conditions.

4. Sep 20, 2005

### shep_pb4y

I think what my teacher was refering to is most closely related to the that bit about electrons. He indicated that something like that would seem to cease to exist while moving from orbit to orbit, since it cannot pass through the intermediate space in an analog style. As for the violation of the conservation of matter and energy, I have a personal (albeit VERY far-fetched) theory to compensate for that. What if a particle like that actually passes through alternate realities (i.e. many worlds interpretation) while moving from orbit to orbit? Therefore it never truly ceases to exist, thus maintaining conservation of matter and energy.

5. Sep 20, 2005

### tdunc

Are you sure you want to say it like this? Preceded by...

"The energy change required to do that is always the same"

Wikipedia states
"a quantum leap is the smallest possible change, as when one's bank account balance goes from $500.00 (five hundred dollars) to$500.01 (five hundred dollars and one cent). There are no possible amounts intermediate between those."

If we can define say 3 general orbital points, high, mid and low keeping in mind that an electron has numerous available resounances withing those general catagories we defined. Think of a ruler. So using the statement from "low orbit" to "high orbit" is like saying a leap is possible from 5 to 20; Is that correct if "The energy change required to do that (make a leap) is always the same"?

According to that statement follows that an electron should always go from one number to the next number ie. from 5 to 6 from 6 to 5 because the same amount of energy is in or out. So you need to clarify whether you consider that incremental change "from low orbit to high orbit". Because if not, the only alternative is to say that an electron can skip numbers, which necessitates different energy in or out, does it not?

Last edited: Sep 20, 2005
6. Sep 20, 2005

### ZapperZ

Staff Emeritus
Oh no, you don't!

You have misrepresented many-worlds theory. It has nothing to do with an electron sneaking into another world and then reappearing back in the same world. Do not misuse such a thing without understanding what it is in the first place.

Zz.