# Wondering what is time?

1. Jul 23, 2009

### bondinthesand

I don't know if this is in the right forum but i was wondering what is time? Does it have any relativity to the things happening in the universe and if not then what the point of it?(other then to get to the doctors on time)

2. Jul 24, 2009

### pavi_elex

Re: Time?

Time is completely relative. it is different for different thing according to one's frame of reference and frame of reference depends on velocity of object. object with larger velocity has slower time than smaller velocity object. We divide the time according to our solar system, what time earth takes to complete the one round of sun. and what times it takes to complete one round on its own axis, different planet takes different time according to their size and distance. so they have different values.
On larger scale These values can be totally different, another prediction of general relativity is that time should appear to slower near a massive body like the earth.This is because there is a relation between the energy of light and its frequency (that is, the number of waves of light per second): the greater the energy, the higher frequency.As light travels upward in the earth’s gravitational field, it loses energy, and so its frequency goes down. (This means that the length of time between one wave crest and the next goes up.) To someone high up, it would appear that everything down below was making longer to happen.it means time will always be slower near sun than earth and slower near Arcturus (large star) and slowest near an Antares(largest star). it means massive galaxies have slower time than lighter one and by Hubble's law, galaxy the farther, it has more velocity if it's velocity is near velocity of light, there will be time difference because of special theory of relativity
(time dilation).

3. Jul 24, 2009

### anonymoussome

Re: Time?

There is no particular definition of time....

For the time being : time is a 4th dimension in space.

4. Jul 24, 2009

### monty37

Re: Time?

time is a dimension and a fundamental quantity used as a reference.