26th February 2005 - 06:29 AM
This might be a stupid question for I am just a mere high school student. But I have somehow gotten the idea in my head that time is considered to be a dimension. Or at least it is described as such. However my question is this...
Time can be slowed down by moving at a speed close to the speed of light, in any direction, x, y, or z. However my basic physics states that movement in a dimensionis independant from movement in another dimension. So how can x, y, and z have an effect on time if time is a demension just like them?
My conclusion would be that time is not a dimension.
26th February 2005 - 10:37 AM
Hang on to that thought its highly likely to be correct
26th February 2005 - 12:41 PM
I think the reason we call time a dimension is so that we can define the same location (x,y,z all the same), in a different time frame, thus creating two separate incidences.
The notion of space-time as a dimension is one that you will encounter as your physics progresses and various contributors will probably add a few more.
Good luck with it.
26th February 2005 - 02:08 PM
Yo, think of it like geometry, time is in a certain direction perpendicular to your "space"
now, if your spacetime is your local frame of refference time never speeds up for you localy, your clock always moves the same ( the one you are holding in your reference frame ). Another object appears to have time moving more slowly but this is because its time axis is in a different direction than yours. because of the discrepancy in direction, his time axis does not line up with yours and points for you into space time at some angle to the time axis, hence his tick marks projexted onto your time axis look differenly spaced. Geometric reasoning would tell you that this would speed up apparent time for the object, but the geometry between space and time is metrically hyperbolic so the tick marks are farther appart.
The reson time is a dimension makes sense is because velocity can be thought of as a hyperbolic angle , since dx/dt = v is a slope on a graph of distance and time, it can also be interpreted as an angle, and this velocity angle (a hypebolic angle) means that for the moving object, his time axis and x,y,z axis are pointing different directions than yours as the observer. The angular difference IS the velocity. Draw some pictures of this and it will make a lot of sense, with in mind that the results will be a little backwards because the geometry is metrically hyperbolic rather than spherical.
26th February 2005 - 02:18 PM
Relativity is explained shadily in books and especially highschool, to them its a bunch of disconnected effects and meaningless equations. Check out Gravitation by Misner, even though that book is a general relativity graduate book, if you can find it at a library or something the begining reviews some concepts from SR in the most cogent manner I have ever seen.
I also have many thoughts on it:
go look at a picture hanging on the wall, head on, now look at it from an angle, your horizontal axis will measure the painting as "contracted" because you are viewing it at an angle. Now imagine that that angle is not between the plane of your periphery and depth and rather space and time.
26th February 2005 - 06:46 PM
Here's another way of looking at it. I'd 'discovered' this idea while reading The Elegant Universe and wondered how I'd missed before.
Think of Time and Space as 2 different dimensions you can 'move' in. If you are standing still and not moving in Space at all, you are traveling through Time at the speed of light. Now, start moving in space. You are no longer moving through Time at the speed of light but at the speed of light minus the speed you are now moving through space. As you increase the speed through space, your speed through time slows, which is why, to an outside observer, those that are moving close to the speed of light are moving slow through time (using the 'twins' example that is usually used in relativity: one twin takes off in spaceship moving close to speed of light, returns years later but hasn't aged).
18th January 2012 - 08:11 AM