Measuring Time

[mrbc19]

I am not very knowledgable on this subject, but from what I understand, a clock in motion at a certain velocity compared to a synchronized clock on the ground that is not in motion will "slow down" and be out of sync with the clock on the ground after the motion, and this was something predicted by special relativity.

 

Now my question is regarding how time is actually measured, and I guess relates to the nature of time itself. Now a clock itself does not measure time by somehow tapping into whatever we call "time," it is just an arbitrary measure of intervals, using a quartz crystal, or an atom or whatever other measure you want to use. If you were to measure the velocity of a stream of water, you can literally put something into the stream, or "tap" into it to find out its velocity. Clocks do not tap into the "stream" of time do they? They are controlled and run by energy, or a battery that powers the clock. If the battery weakens, the clock may slow down or stop all together, but this does not mean that time is slowing down or stopping. So how exactly does the slowing of a clock in the above situation show that time itself is changing or slowing down. Is it not just a slowing of the physical mechanisms operating the clock? The quartz crystal is vibrating or ticking more slowly, or the atom (I dont know how atomic clocks work) is just "ticking" more slowly. If an object is travelling at a certain velocity, and then slows to a lesser velocity, that does not mean that time has slowed down. I just can't seem to grasp how a slowed clock can provide evidence for slowed time. I'm not trying to come up with a new theory about time or trying to disprove relativity at all, I am just confused on this particular issue, and any help is welcome.

[5614]

electronic clocks go at a fixed speed, they will not change even if it were travelling at varying speeds along the time dimension.

[TrueHeart]

Every aspect of time is slowed, but ONLY in relation to the clock standard of the presumed still observer. The effect is NOT an absolute unequivocal one! ..as various differently moving observatories will reckon various different time distortions for the same observed entity. (Get it?) But the distortion applies equally to ALL time flow mechanisms: the rate at which atoms vibrate, the rate at which humans age, the rate at which batteries drain, etcetera etcetera.

[Ophiolite]

Could you try that again, in English.

 

Edit: that was for 5614

[xom]

I thought I understood this not so sure now. Do you mean this, motion has the effect of distorting time. The distortion varies and is not exact This can only be detected by the still observer because the nature of time is relative. therefore its not just the clock which slows down but everything.

Have I just made myself look foolish

[mrbc19]

How do we know that everything slows down? Wouldn't this slowing down be measured by a clock? Additionally, the "rate" at which humans age can be varied by other mechanisms outside of time, for example through drugs or genetic alteration, and the rate of battery drainage can also be attributed to slower moving parts, or more efficient energy use, and this does provide evidence that time is slowing down, at least in my mind. Maybe I am just confused about what time relativity really is?

[swansont]

The slowdown seen by the observer is independent of the type of clock used.

[swansont]

electronic clocks go at a fixed speed, they will not change even if it were travelling at varying speeds along the time dimension.

 

There are many types of electronic clocks, and they all obey relativity.

[xom]

Its the non moving observer who does the measuring.

[TrueHeart]

Have I just made myself look foolish

No, you haven't made yourself look foolish! the land is chock full of secondary school science teachers who are just as confused about relativity, I opine.

I thought I understood this not so sure now. Do you mean this, motion has the effect of distorting time? ..

The problem of your confusion begins and ends with your (apparent) belief that there is such a thing as a body's unequivocal motion "through space". But there is no such reality, because the common human conception, "space", is flawed. Space is the absence of ANYthing, and does not constitute a framework, a grid, a backdrop. All motion is relative, so you must put every assertion about "motion" into perspective by identifying what real object that motion is relative to. No distortions can be ascribed to an object just because it is "moving", as that unqualified phrasing makes it seem that an object has velocity with regard to "space" itself. An object has velocity only with respect to another real object. Either object can (in turn) serve in the capacity as the "presumed still observatory", with respect to which the other entity is then in motion.

[Jacques]

Space is the absence of ANYthing, and does not[/u'] constitute a framework, a grid, a backdrop.

Then what is the space curvature used to explain gravity?

[PersonCube]

I have always thought of time to be a creation by man. I know that all things age and all things constantly move through time, but is that not a different time? We, as humans, take time to be "meet me here at 4:00 o'clock sharp." Where as time is actually "particle A moves to location A at a rate of 200,000,000mph." So then, time is actually a measurement of speed? A speed of aging, where as time is aging, for as we age we measure it in time.... wait... Okay, regroup.

 

Time is the flow in which matter moves, scatters, forms together, and forms apart. All matter flows on the river of time, but time is similar to matter in that it cannot be destroyed or created. For once 5 minutes have passed they have passed forever. That is time, the time we have is irrelevant; it is just a measurement. Such as 16 ounces are in every pound, 60 minutes are in every hour.

 

On the subject of a clock slowing down: When a clock slows down, it is only the clock... Think of when you throw a ball, the ball does not go on forever, it slows and falls due to gravity. As does an electric clock, if a clock's battery runs out, then the clock slows down and "falls." Thus, it is not time that slows, but the clock, meaning that the observer (you) is misjuding time but the actual time in which humans judge using the Sun and Earth's relationship to each other is still the exact same as it were 30 billion years ago

 

I hope I did not just make an idiot of myself,

Stephen Wooten II

AKA Cubes

~Evolution is real and so is God

[TrueHeart]

Then what is the space curvature used to explain gravity?

It's a way of talking, a phrasing? it's a gravitational field superimposed upon the empty space? Yes, I sort of knew that this exact objection would arise, and I admit I don't have the perfectly glib answer.

 

But still, those so-called space curvatures don't change the basic fact that motion "through space" is a non sequitur. Gravitational fields, or "curved space" as some would say, are associated with real celestial objects, and so motion through them is still a way of reaffirming that motion is relative (to such bodies), and not absolute. Saying that one is travelling through a space that is curved is just another way of saying that one is moving with respect to another real object. Space is mostly flat anyway, it has been found.

 

Sure, there is that balk, but to truly understand special relativity, one must first entirely extinguish the notion of unambiguous motion "through space". A craft isn't just plain "moving at 60,000 kilometers per hour", because that phrasing is unqualified and it IS truly meaningless.

[MadScientist]

electronic clocks go at a fixed speed, they will not change even if it were travelling at varying speeds along the time dimension.

 

The clocks on satellites have to compensate for time dilation.

 

This might help mrbc19

http://www.scienceforums.net/forums/showpost.php?p=121168&postcount=21

[Cadmus]

Space is the absence[/i'] of ANYthing,

 

If I understand your correctly, then I disagree. Space is the presence of something.

[mmalluck]

It has been theorized that even empty space contains something, mainly virtual particle pairs. From this stems black hole evaporation, zero-point energy, and a host of other theorized events.

 

Time dilation and relativity stem from the paradox the speed of light is both a maximum and fixed constant, independent of your frame of reference.

 

This paradox can be illustrated with a simple clock.

 

Let’s say we have a clock consisting of 3 pieces, two perfect mirrors and a beam of light. It's set up so that the beam of light bounces back and forth between the two mirrors. Thru the wonders of ascii art, the setup would look something like this:

 

---Mirror---

 

^

|

|

 

---Mirror---

 

Now your job is to measure how fast the light is traveling between the two mirrors and the amount of time it takes the light beam to bounce between the two mirrors.

 

Case 1: The apparatus is sitting at rest in front of you.

 

You measure the distance between the two mirrors and the amount of time it takes the beam of light to bounce from one to the next. You come up with the figure of 2.998 *10^8 meters a second, just as you expected.

 

Case 2: The apparatus whooshes by you.

 

To you, the observer, the beam of light no long takes a straight path from one mirror to the next, instead it travels at an diagonal as it bounces between the mirrors like so:

 

---Mirror---

^

/

/

 

---Mirror---

 

You recalculate the distance between the mirrors accounting for the new path the light is traveling and recalculate the speed. To your surprise, light is still traveling a 2.998*10^8 meters a second, but the kicker here is that the amount of time it takes for the beam of light to travel between the two mirrors is longer than in the first case. This is due to this longer path.

 

The observer just experienced time dilation! To him, the time required for the beam of light to bounce lengthened even though we did nothing more than change his reference point.

[mmalluck]

my ascii art was a little killed, but I think you get the idea.