Probability / Probability density

  • Thread starter Jelfish
  • Start date
  • #1
Jelfish
144
5
Quick question:

I just started reading Feynman's Lectures and in one section (6-4) he says that for a system in which a particle (in 1 dimension) can move in either direction (with equal prob. of either direction). For each 'step' that the particle takes, the distance it moves can be any length such that the average length is, say, 1, then the probability of the particle being any specific distance away from its starting position is zero.

Is this because there are theoretically an infinite number of lengths that the particle can step, and thus the probability for any specific distance approaches 1/infinity?

(note - I haven't taken any quantum physics classes yet, which I imagine is where this stuff may be taught)
 

Answers and Replies

  • #2
mathman
Science Advisor
8,065
542
Your question is an elementary probability question (you don't need quantum physics). In the case described, the probability distribution is continuous, so that any specific value automatically has probability 0.
 
  • #3
Jelfish
144
5
I'm sure I don't know enough about probability as I should. I realize that this doesn't rely on any quantum physics. I was just mentioning that it seems like something that would show up more often there. Just wanted to make sure I understood it correctly. Thanks for your response.
 

Suggested for: Probability / Probability density

  • Last Post
Replies
4
Views
4K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
11
Views
833
Replies
1
Views
590
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
644
Replies
6
Views
939
  • Last Post
Replies
4
Views
680
Replies
12
Views
685
Top