# Space-time Concept by Einstein

1. Oct 11, 2012

### F1225

Good day!
I am quite blur with the Space-time concept proposed by Einstein.
Can anyone explain briefly on what he meant by that term(Space-time)?
3-D space+1-D time???

2. Oct 11, 2012

### HallsofIvy

Staff Emeritus
Yes, "A four dimensional space time continuum" means three dimensions of space and one time dimension.
It simply means that physics deals with "events"- something that happens at a specific point, at a specific time. In any coordinate system, it will four numbers to specify an "event".

3. Oct 11, 2012

### Staff: Mentor

To bounce off what Ivy said, imagine you want to describe where something is. To do so we need to have 3 numbers for space, one number for each dimension (or axis on a graph). Their meeting point is where that object is located at. But, it turns out that we also have to have another number to describe where something is at in time. So 4 numbers equals 4 dimensions, 3 of space and 1 of time.

4. Oct 11, 2012

### robphy

Actually it was Minkowski (one of Einstein's mathematics professors) who formulated the idea of space-time.... and used it to explain Einstein's relativity to others.

5. Oct 11, 2012

### F1225

Thanks... As i knew physicist likes to tabulate results and put them as a graph right? Erm...let's say i wanna put the Space-time on a Cartesian plane, is that possible? Or are there any other more advance graphing methods for a 4-Dimension graph?

6. Oct 11, 2012

### Staff: Mentor

I think so. A simple example of a particle traveling one direction through space can easily be shown on a normal graph. You only need one axis for space and one for time.

7. Oct 12, 2012

### F1225

Oic..Which means that we won't be able to draw a 4D graph on a 2D cartesian plane?
Other than cartesian plane are there any other graphing methods?
:what:

8. Oct 12, 2012

### Staff: Mentor

Not sure. I'm would bet there are plenty of different methods, but I really don't know. Try searching around a bit.

9. Oct 12, 2012

### harrylin

See: http://www.bartleby.com/173/17.html

10. Oct 14, 2012

### Naty1

11. Oct 14, 2012

### Naty1

The 'space time concept' alludes to that fact that when you want to meet someone, for example, you have to specify a PLACE and a TIME...one without the other won't do. In addition, it turns out that at very high speeds, time and space transform into one another...
they are not entirely independent entities as they appear to be in our everyday world.

You may also want to study Minkowski space. Nice diagram and explanation here:

http://en.wikipedia.org/wiki/Minkowski_space

note that the horizontal 'hypersurface of the present' is merely and x and y space,
while the passage of time is plotted vertically....up for the future, down for the past.....

Einstein concluded the spacetime interval is fixed for all observers, and you can't go as fast as 'c' if you have mass....so we are stuck within the plotted 'lightcones'.