- •Vibrations and waves
- •Very far? The gravitational force pulls you back down again very quickly. You could jump much higher on
- •1. A white dwarf supported by the fermionic repulsion pressure of the electrons in the heavy atoms in the
- •2. A neutron star supported by the fermionic repulsion pressure of the neutrons in the nuclei of the heavy
- •If the mass of the collapsing star is too large, bigger than twice the mass of our Sun, the fermionic
- •In the center of every galaxy, including our galaxy, the Milky Way. The black hole shown above sits in the
- •2. If you go twice as far away, the force will only be one fourth as strong.
- •If three space dimensions is consistent with current gravitational physics and interior decorating, then why
- •In spacetime. So that's what is meant by saying that our spacetime has four dimensions. Usually we label
In spacetime. So that's what is meant by saying that our spacetime has four dimensions. Usually we label
them (t,x,y,z).
Special relativity is an approximate theory that is a good approximation when we can neglect the force of
gravity and the acceleration of observers in the system. Einstein's full theory of spacetime, called general
relativity, takes the concept of a four dimensional spacetime and extends it to a curved spacetime, where
time and space make one united fabric that is curved and stretched and twisted by the distribution of
matter and energy in the fabric.
From a mathematical point of view, both special and general relativity can be extended easily to higher
space dimensions. If we have D dimensions of space and one time, then we say there are d = D + 1
dimensions of spacetime. The equations of motion can be solved and classified in d dimensions just like in
four spacetime dimensions.