# The Naked Scientists Forum

### Author Topic: What is Time Dilation?  (Read 3750 times)

• Jr. Member
• Posts: 18
##### What is Time Dilation?
« on: 19/01/2008 20:01:27 »
I've heard of this, but don't know what it is. Can anyone help me out?

#### lightarrow

• Neilep Level Member
• Posts: 4586
• Thanked: 7 times
##### What is Time Dilation?
« Reply #1 on: 20/01/2008 12:54:59 »
I've heard of this, but don't know what it is. Can anyone help me out?
You are stationary in an inertial ref frame (as first approximation you can take earth) and you analyze a very fast moving object which has a clock attached to it. You measure with your clock the time the object takes to go from point A to point B of your ref frame, call it Δt; you also take notice of the time interval measured from the clock on the object, call it Δt'. It results that Δt > Δt'.

#### kalayzor

• Jr. Member
• Posts: 24
##### What is Time Dilation?
« Reply #2 on: 20/01/2008 14:39:51 »
Essentially, a clock on a moving object goes slower than one available to an observer in an inertial (unaccelerated) reference frame.  It only really becomes noticeable above 0.9c, though.

From what I've read, it has to deal with going perpendicular to the fabric of space-time (sort of like black holes) and thus going "outside" of normal time.

• Jr. Member
• Posts: 18
##### What is Time Dilation?
« Reply #3 on: 20/01/2008 19:21:08 »
Cheers

#### lightarrow

• Neilep Level Member
• Posts: 4586
• Thanked: 7 times
##### What is Time Dilation?
« Reply #4 on: 21/01/2008 00:12:49 »
It only really becomes noticeable above 0.9c, though.

Not exactly:
http://en.wikipedia.org/wiki/Hafele-Keating_experiment

#### The Naked Scientists Forum

##### What is Time Dilation?
« Reply #4 on: 21/01/2008 00:12:49 »