# The Naked Scientists Forum

### Author Topic: The shortest path between 2 points in time and space it is a curve  (Read 1011 times)

#### DanielIon

• First timers
• Posts: 1
##### The shortest path between 2 points in time and space it is a curve
« on: 17/06/2014 12:47:02 »
Explanation:
Assumptions : one can travel travel back in time, and then in one the direction of choice.

two points, A and B, distance between them 5 m, as time is both a constant and relative, as you move from point A towards point B and you travel in a straight line in real time you will reach B + 5 seconds at 1 m/s (correct?) however if you travel back in time to B-5, following the real time analogy, you travel at 1 m/s, when you travel 1 m of the distance, your coordinates changes and you now travel to b-4, then to b-3, and so on, for you at the end of the journey it will be 5 s, but for everyone else you will disappear from point A and reappear at point B in the same time.

If you put this on paper you will see that your path is a curve.

#### PmbPhy

• Neilep Level Member
• Posts: 2773
• Thanked: 38 times
##### Re: The shortest path between 2 points in time and space it is a curve
« Reply #1 on: 20/06/2014 01:09:40 »
Quote from: DanielIon
Explanation:
Assumptions : one can travel travel back in time, and then in one the direction of choice.
This post makes no sense. You made a blanket assumption that the shortest path between two points in spacetime is a curve whereas its really a straight line. It makes no difference what your assumptions are. No matter whether you use the Euclidean metric or the Minkwski metric the curve of shortest length (which is a geodesic) is a straight line.

Quote from: DanielIon
two points, A and B, distance between them 5 m, as time is both a constant and relative, as you move from point A towards point B and you travel in a straight line in real time you will reach B + 5 seconds ..
That makes no sense. B is a point. It's not a number. If you move between A and B in constasznt time then you don't do so "in real time" since its not done "in time" but done instantaneously.

Quote from: DanielIon
at 1 m/s (correct?)
No. You're not making sense. Where did this notion of moving come in? Where is the speed in the calculation. You never mentioned a speed or the physical interpretation.

Quote from: DanielIon
however if you travel back in time to B-5, following the real time analogy, you travel at 1 m/s, when you travel 1 m of the distance, your coordinates changes and you now travel to b-4, then to b-3, and so on, for you at the end of the journey it will be 5 s, but for everyone else you will disappear from point A and reappear at point B in the same time.

If you put this on paper you will see that your path is a curve.
That doesn't mean that it's the distance along that curve is the shortest distance between the two points

#### The Naked Scientists Forum

##### Re: The shortest path between 2 points in time and space it is a curve
« Reply #1 on: 20/06/2014 01:09:40 »