|
| If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|||||||
| Register | FAQ | Members List | Calendar | Mark Forums Read |
![]() |
|
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
|
||||
|
Quote:
Last edited by jlhredshift; 14-December-2006 at 07:14 PM.. Reason: bust chops |
|
||||
|
I couldn't find on a quicksearch what the clock differences were at 600mph. and with the invention of the winblows OS, i can't multitask-peddle wares and to BAUT (v.): To spend time posting inane questions on a scientific web forum. Generally applies to posts by Fazor
__________________
I'm like one of those idiot savants...well, except for the savant part. "In order to increase awareness of the homeless, security have been given binoculars." |
|
||||
|
There are also gravity effects, but to get the general ballpark, we can just say that the Moon ages at a rate that differs from the Earth by about (v/c)^2, which is about 1 part in 100 billion. So even after 4.5 billion years, the Moon (neglecting the fact that it used to be closer and faster) would only be a couple weeks younger than the Earth. It might actually be a couple months if you do it right, but still, that's not much for a planet.
|
|
||||
|
no but i just thought it's kinda cool to think of it that way. *shrugs*
__________________
I'm like one of those idiot savants...well, except for the savant part. "In order to increase awareness of the homeless, security have been given binoculars." |
|
||||
|
If you all want to do some ballparking. In GR's weak field, low velocity limit, we can write this for clock rates:
dT/dt = sqrt(1 + 2(phi)/c^2) * sqrt[1 - (v/c)^2 ] The first factor is the gravitational effect, and the second is the SR gamma effect. 'Phi' is the Newtonian gravitational potential (which will be negative, don't forget that, and its important that Phi be normalized to a reference of 0 at infinity for that to work). That gives the clock rate relative to a fixed clock at infinity (where the potential is 0 ). I stress the above is accurate only in the weak field and low velocity limit. The SR gamma factor in strong fields would become something that was actually the "local gamma", depending on the metric, and the g_00 term would be different that just the sum of the the inverse square potentials (that's the non-linear aspects of the field equations, there -- in the weak field limit, it becomes linear). So if you want to compare clock rates, say for clocks on the surface of Venus vs the earth or moon, add up all the Newtonian potential terms, that of the sun, and the body you're on (you can ignore other far way bodies, as they will be very small indeed. For the earth-moon system, use both if you like). Then calculate the first factor above. Then get the orbital speed and calculate gamma. -Richard |
![]() |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Does travel through a "wormhole" violate causality | Kemal | Astronomy | 49 | 25-February-2008 08:53 PM |
| GR and the Universe | RussT | Against the Mainstream | 32 | 05-November-2006 11:58 AM |
| Problems with General Relativity | snowflakeuniverse | Against the Mainstream | 79 | 10-January-2005 05:05 AM |
| timeless universe | kusumamrit | Life in Space | 0 | 06-October-2003 08:24 PM |
| time dialation question | Kebsis | Astronomy | 10 | 21-July-2003 06:37 AM |