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-   -   OT: System Clock Loses Hour (http://forum.shrapnelgames.com/showthread.php?t=34104)

douglas April 18th, 2007 09:35 AM

Re: OT: System Clock Loses Hour
 
Quote:

se5a said:what narf is saying, is if you use said torch, and mesure the amount of time it takes for light to get from the torch to an known distance, you should be able to work out how fast, and in what direction the torch is moving, and therefore be able to say what "still" is.

What I'm saying is that this exercise will just tell you that whatever you had already decided was "still" for purposes of calculation was, in fact, correct. Simply stating that something is moving at speed X inherently requires a definition of what is at rest. The point of relativity is that this definition can be absolutely anything and the speed of light will be the same regardless.

For example:
Suppose you are on Earth trying to carry out that torch experiment. You carefully measure the distance between the torch and a mirror, you light the torch, and you time how long it takes for the reflected light to get back to you. You will calculate from this data that you (actually your measuring device) are at rest.

Next, you move to Mars and repeat the whole experiment. You will again calculate that your measuring device is at rest even though it is clearly moving at a different velocity than it was on Earth. Consideration of this simple fact is how the entirety of the Theory of Relativity was derived.

se5a April 18th, 2007 04:59 PM

Re: OT: System Clock Loses Hour
 
that contradicts what fyron said.
I think...

narf poit chez BOOM April 18th, 2007 11:10 PM

Re: OT: System Clock Loses Hour
 
I think it may have something to do with the time slowdown.

AngleWyrm April 19th, 2007 12:39 AM

Re: OT: System Clock Loses Hour
 
Quote:

douglas said:
For example:
Suppose you are on Earth trying to carry out that torch experiment. You carefully measure the distance between the torch and a mirror, you light the torch, and you time how long it takes for the reflected light to get back to you. You will calculate from this data that you (actually your measuring device) are at rest.


There was no mirror in the original torch example. Whether or not it has travelled the same distance/taken the same time in both directions is what is at question.

In this illustration, a red bulb sends a signal to a red mirror. Time goes by, and the bulb/mirror experiment moves to position green. The pulse strikes the green mirror and heads back. More time goes by, and the bulb & mirror move to position blue. The light pulse returns to the bulb at position blue.
http://home.comcast.net/~anglewyrm/roundtrip.jpg
If it takes a different amount of time on each leg, then we can say that the experiment moved (as illustrated), and the speed of light was the same throughout. And as Narf said, it implies that the speed of light is relative to something other than the bulb&mirror. If it comes back in the same amount of time that it took to go out, then something is amiss.

Shouldn't the stars change color sleightly as the earth approaches them, and then as the earth pulls away? If earth's motion about the sun is about 29km/sec, or roughly [edit]0.001%[/edit] speed of light, then there should be a +/-1% red/blue shift in colorbands throughout the year.

douglas April 19th, 2007 03:56 AM

Re: OT: System Clock Loses Hour
 
Quote:

AngleWyrm said:If it comes back in the same amount of time that it took to go out, then something is amiss.

According to any device that is moving at the same velocity as the experiment, that is exactly what would happen. Scientists tried to do something like that to determine the speed of the Earth as long ago as 1881 with the most famous "failed" experiment ever. No matter what speed you are moving at, your perceptions of time and distance will conspire to give the same result.

Quote:

AngleWyrm said:Shouldn't the stars change color sleightly as the earth approaches them, and then as the earth pulls away? If earth's motion about the sun is about 29km/sec, or roughly 1% speed of light, then there should be a +/-1% red/blue shift in colorbands throughout the year.

Yes. The speed of the light involved remains the same, however, no matter how much the light wave's frequency may change.

AngleWyrm April 19th, 2007 05:38 AM

Re: OT: System Clock Loses Hour
 
The Michelson-Morley experiment was trying to detect wind from the earth passing through aether--the fluid that conducts light waves. It failed to notice any, and is considered proof that there is no aether.

your perceptions of time and distance will conspire to give the same result.
I recently read a philosopher's quote, that I'll paraphrase: A theory which claims to be unmeasurable is probably best left unspoken as well.

Walter Ritz proposed Emitter Theory that suggested light speed was added to local motion, but that was not observed in binary stars as they orbited each other. The example given is that light from the approaching orbit would appear to be C+orbital speed, and therefore the light would overtake previous light, and our observation would be...strange. (maybe reversed)

douglas April 19th, 2007 12:29 PM

Re: OT: System Clock Loses Hour
 
Quote:

AngleWyrm said:
your perceptions of time and distance will conspire to give the same result.
I recently read a philosopher's quote, that I'll paraphrase: A theory which claims to be unmeasurable is probably best left unspoken as well.

Except it's not unmeasurable. There are all sorts of experimentally measurable implications of the constancy of the speed of light independent of reference frame, and many of them have been tested and found to be correct. For example, take two atomic clocks and synchronize them. Then put one of them on a supersonic jet, have it fly around at high speed for a while, and put them back next to each other. One of the implications of the speed of light being constant regardless of reference frame is that the two clocks will now be out of sync - they will disagree about how much time has passed since they were synchronized. The exact amount of the difference can be calculated using equations derived strictly from conceptual analysis of what would have to be true for the observed fact about the speed of light to be true. This experiment has actually been conducted, and the result was well within experimental error of the calculated value.

AngleWyrm April 21st, 2007 08:25 PM

Re: OT: System Clock Loses Hour
 
http://home.comcast.net/~anglewyrm/workthatpremise.jpg
(Tricia Helfer, Battlestar Galactica)

capnq April 25th, 2007 12:18 AM

Re: OT: System Clock Loses Hour
 
Quote:

narf poit chez BOOM said:
Why not just measure the speed of the earth relative to the speed of light?

Because that results in the inconveniently small number (0.001% of c) that AngleWyrm mentioned further upthread.

narf poit chez BOOM April 25th, 2007 06:28 AM

Re: OT: System Clock Loses Hour
 
...I'm totally lost. Too many explanations.

Atrocities May 1st, 2007 09:19 PM

Re: OT: System Clock Loses Hour
 
Ok so I got sick and tired of manually adjusting the clock every few days so I sent in a customer / tech request to Microsoft asking for help.'

Quote:

Even after I applied the DST update to my computer it keeps resetting the system clock back an hour every few days. What the hell is the problem? I have to manually reset the time on my pc every few days even after applying the most recent update from the DST web site. I have tried to reinstal the patch again and it won't install because it is ALREADY installed. Please fix this bug, as there are many others experiencing the same issues. Thanks


This is the response I got.

Quote:

Thank you for contacting Microsoft Online Customer Service.

I understand that your computer shows the time an hour behind even after installing DST Update.

For assistance with your issue, I would like you to know that if you are experiencing issues with Daylight Savings Time (DST), please use the automatic patches provided by the DST Help Center through the following link:
http://support.microsoft.com/gp/cp_dst

However, if you have additional questions or issues with the updates, please contact our Support Professional at 1-800-MICROSOFT.

Ray, I hope the above information is helpful and I appreciate your patience in this regard.

Thank you for using Microsoft Products and Services.

Basavaraju
Microsoft Online Customer Representative


*Sigh*

Quote:

Um, Basavaraju, or whoever reads this, your response to my concern is, as usual, of absolutely no help to me. Did I or didn't I state in my message that I had already been to the DST web site and tried all the "fixes?" I have to be honest, I am not at all impressed with your cookie cutter response. I find it proof positive that Microsoft is exactly what people think it is, the home for low brow software programmers who couldn't get a job at a real software development company. I mean, had you taken the time to actually read my concern you would have known that I did go to the DST web site BEFORE I contacted Microsoft with this problem? I sincerely hope that at some point in time you die a horrible painful slow death. And thank you for your assistance.

What can I say, I am utterly disgusted. [img]/threads/images/Graemlins/Envy.gif[/img]

Suicide Junkie May 1st, 2007 09:40 PM

Re: OT: System Clock Loses Hour
 
Quote:

capnq said:
Quote:

narf poit chez BOOM said:
Why not just measure the speed of the earth relative to the speed of light?

Because that results in the inconveniently small number (0.001% of c) that AngleWyrm mentioned further upthread.

Actually, it results in a relative speed of 1.0 c (relative to light)

You could measure your speed relative to the earth, or relative to the sun, or relative to the calculated center of the galaxy, or relative to the middle of the local cluster.

But light itself always travels a 1.0c relative to the observer.

narf poit chez BOOM May 1st, 2007 10:18 PM

Re: OT: System Clock Loses Hour
 
Gotta be the time dilation.


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