# Time concept.

1. Feb 12, 2009

### Erasmus

I'm only 16 but am attending college and I want to be a great physicist one day. I would like to learn as much as possible through this forum and throw some ideas out there and see whether they're stupid or not. Ok, here it goes:

Since time can be measured in milliseconds, microseconds, nanoseconds, picoseconds, femtoseconds, attoseconds, zeptoseconds, yoctoseconds, etc., it is assumed that we can reach an infinite number of smaller units for time. Infinitessimal amounts of time, even. My idea is that no two things can happen at the exact same time. The chances of it happening are 1/$$\infty$$. In Calculus 1/$$\infty$$ is equivalent to zero. So, essentially, there is zero chance of two things happening at the exact same time.

Again, I know it's a little far-fetched. But aren't most theories?

Also, I'm trying to put 1 over infinity in my previous statements but I haven't quite figured out these codes yet.

2. Feb 12, 2009

### Staff: Mentor

To do the inverse of infinity in Latex, use this:

$$\frac{1}{\infty}$$

Latex is also availble under the $$\sum$$ symbol above the Advanced Reply Dialog box or in the Post New Topic window that you were in. There is a Latex tutorial thread in the Tutorials forum, I believe, that should help.

Welcome to the PF. I do need to caution you about posting with the words "new theory" or "my theory". We take science very seriously here on the PF, and you are not allowed to propose new theories without a lot of real science behind it, including references to supporting papers in reputable, refereed journals.

You can, however, phrase posts as straightforward questions. Like in your post above, you could say, "I'm confused how any two things can happen simultaneously, given the apparent infinite nature of smaller and smaller time slices..."

I'm also not sure that the S&GR forum is the right place for this thread. I'll ask the other Mentors if it should be moved.

I have an idea for the answer to your question, but I'm going to let the physicists give you a better answer.

Welcome again, the PF is a great place. Be sure to re-read the Rules link at the top of the page, if you haven't already.

3. Feb 12, 2009

### Mentz114

Welcome.

If time is infinitely divisible, then the probabilty of anything happening in any 'infinitesmal' period is zero, by your argument.

You are right in thinking that any segment of the real line is zero compared with the whole, but these are mathematical thoughts.

Physics is really about things, so I'd suggest you study electricity and magnetism, or dynamics to start with.

4. Feb 12, 2009

### Fredrik

Staff Emeritus
This is true in the mathematical models of space and time that are used by the established theories, but we know that none of those theories can be an exact description of space and time in the real world. The best theories are valid for a very large range of experiments, but they have to break down at some point. A simple order-of-magnitude estimate (similar to guessing that the volume of a sphere is the radius to the third power because the correct formula has to include some length to the third power) tells us that the breakdown should occur at the Planck scale. So it doesn't make much sense to talk about times shorter than the Planck length, since we don't have a theory that's expected to be valid at that scale.

But then if you put two objects on your kitchen table, they are both tracing out a path (called a "world line") through spacetime, and this path is continuous (in the current theories), so whatever point you pick on the world line of the first object, there's a point on the world line of the other object that's simultaneous with it.

What Berkeman said, but if you only need a symbol or two, it might be easier to just copy and paste symbols from https://www.physicsforums.com/blog.php?b=347 [Broken]. Also, use itex tags instead of tex tags if you use math in the middle of a sentence instead of on a separate line.

Last edited by a moderator: May 4, 2017
5. Feb 12, 2009

### atyy

What is "one" thing (versus "two" things) which "happens"?

Last edited: Feb 12, 2009
6. Feb 12, 2009

### Erasmus

Thank you all for your responses. I will definitely keep in mind to phrase these as questions. I really did expect my idea to be shot down seeing as I have little experience physics but I wanted to know why it was wrong.