The discussion revolves around the existence time of an electron-positron pair in a vacuum, referencing energy requirements for their creation and the implications of quantum mechanics on their stability.
There are varying calculations presented by participants, with some questioning the assumptions made in the original problem statement. Guidance is offered regarding the use of significant figures in calculations, and there is a mention of a potential missing factor in the lecturer's formula.
Participants note the absence of specific details in the problem, such as the size of the space or the kinetic energy of the particles, which may affect the interpretation of the question.
Spinnor said:How big is the box you put them in? The more room the particles have to roam the smaller the chance they will "meet".
frogjg2003 said:I'm getting 3.22 instead of 3.28. If you're posting because your answer is wrong, that might be why. Try using more digits in your calculations.
I'm also guessing that you aren't supposed to consider that the electron and positron have kinetic energy as well as mass energy, otherwise you would have to take that into account, but no information has been given to you.
ZedCar said:...
The reason I ask is because the lecturer provided on the board the following solution:
Electron pair requires at least 2mc^2=1.02MeV of energy
Δt ~ (h-bar)/ΔE
...
Spinnor said:Is there a factor of 2 missing above? Δt ~ (h-bar)/ΔE