Understanding time measurement

[LKD]

Forgive me if I am simplifying things.

We measure time as the processing of a reaction. Whether an atomic vibration or the process of electricity through a circuit or the distance that light travels through space. And because of gravity, and whatever reactions are associated with that well, our means of measurement is flawed.

Is this accurate?

Is it because gravity distorts space, making it so that the path or process is altered and stretched, that any meaningful clock of any accuracy is impossible?

 

[Kessy]

Well, sort of. Gravity does distort time as well as space, but it does so in a predictable way. So you can (at least in principle) make an arbitrarily accurate clock in a particular frame of reference. (Well, maybe down to the Planck time? I think time is quantized.) But you'd need to use relativity to figure out how to convert that clock's measurements to what would be observed in another frame of reference.

 

[LKD]

Forgive me, but I fail to follow that terribly well. How does time not progress consistantly?

 

[Jerromy]

Time does progress consistantly in a given environment. Here on the surface of Earth whether at sea level or on the highest mountain peak, time is almost perfectly consistent. It is only under very different circumstances that time varies by a percievable amount... such as at very high velocity ("relativistic" speeds meaning close to the speed of light), under high gravitational potential or under heavy acceleration. Seeing as these conditions are very rarely observed directly by human beings it goes without saying that time stands still for no man.

 

[origin]

Forgive me if I am simplifying things.

We measure time as the processing of a reaction. Whether an atomic vibration or the process of electricity through a circuit or the distance that light travels through space. And because of gravity, and whatever reactions are associated with that well, our means of measurement is flawed.

Is this accurate?

Is it because gravity distorts space, making it so that the path or process is altered and stretched, that any meaningful clock of any accuracy is impossible?

Our means of meausring time is not flawed - it is just that time is not absolute. The same can be said about space, if you are traveling in a space ship at a high rate of speed, close to c, your ruler on board might say your ship on was 1000 meters long. But someone outside of the ship that was stationary (relative to the ship) would may measure your ship as only 500 meters due to length contraction. Who is right? Both measurements are right for your intertial frame.

The point is we tend to think of time as an absolute. So when we measure time and find that it measures differently depending on who the observer is and what thier inertial frame is, we might say, "gee our measurement is flawed", when in reality it is our belief that time is absolute that is flawed.

 

[Saiph]

The measurement of the passage of time is only flawed if you fail to consider the forces that can change it.

We can easily set a standard of measurement by finding a very regular, controlled process to measure, and by controlling the factors that may change it (temperature, gravity, motion, etc). As long as it's all accounted for, and held constant, it is not an issue.

We have the same consideration with any standard of measurement. Take a 'meter'. Is the material durable? does it bend? Does it expand with heating? If so...you must support it, control (and specify) the temperature, and such, otherwise your standard will change over time.

 

[MeteorWayne]

"Unit of length Meter: The meter is the length of the path travelled by light in vacuum during a time interval of
1/299 792 458 of a second.

 

[Vax]

In that vacuum gravity would not affect the curvature of space and therefore the light would travel in a straight line. As for a way to measure time, you could measure the speed that galaxies move apart from each other to determine how old the galaxies move, but I think this was recalculated when they determined that the universe could not be 2 billion years old (younger than the earth itself which I think is 4.52). From this they determined the expansion of the universe was increased over time. How they figured it out beyond that is beyond me (actually if someone could explain that it would be awesome).

 

[LKD]

If you have the time, this link from FlatEarth explains how they determined age.
viewtopic.php?f=10&t=21229&start=0#p405078

Sadly he breezed over time and I couldn't grasp that topic. But hoped others could fill me in. As they have above. And thank you of course.