## Tuesday, 27 November 2012

### The Fourth Dimension

We live in a world of three dimensions.We can take the simplest of examples of driving in our car: We go forward. That's one direction. We turn left or right, that's a second. Our journey up a mountain road, that's a third. The fourth dimension is time. Well, we only perceive three dimensions. We can hypothesize many more dimensions. But, they are difficult to imagine.

Because of Einstein, we often call time the fourth dimension. Special relativity shows that time behaves surprisingly like the three spatial dimensions.The Lorenz equations show this.Coordinate transformations between inertial reference frames are given by the Lorentz transformation tensor  Length contracts as speed increases. Time expands as speed increases.
Isn't that fascinating for you if you are a physics maniac and a bit surprising perhaps if your relation with physics isn't so good?
Well that must be the case...I am a physics maniac and this thing fascinates me..day in and day out.

Mathematically, and in accordance with relativity, time and space are,in some sense interchangeable, but we do know that they form co-equal parts of a larger 'thing' called space-time, and it is only within space-time that the most complete understanding of the motion and properties of natural objects and phenomena can be rigorously understood by physicists. Space and time are to space-time what arms and legs are to humans. Although,in some sense they are interchangeable.
By combining space and time into a single manifold, physicists have significantly simplified a large number of physical theories, as well as described in a more uniform way the workings of the universe at both the supergalactic and subatomic levels.
Scientists have been graphing time, as if it were a length, for hundreds of years. Time never behaves exactly like a spatial dimension. You cannot go backward in time. And you normally cannot go forward at different rates. But, there are surprising parallels. For some purposes, it is handy to call time a fourth dimension. For other purposes, it is not.
The fourth dimension is also used in Cartesian geometry and orthogonality. Euclidean geometry is what provides many different shapes to exist in dimensions well beyond just three. Learning how the fourth dimension works also helps reinforce your knowledge of the other three dimensions, and spatial patterns using dimensions.
I will get back next time with some interesting facts of TIME TRAVEL!