Thinking? Sometimes I do.
The velocity of light is a constant, but time is not. Time is affected by gravity and velocity, but no matter how time is affected, the velocity of light will measure the same in what ever medium it is measured.
As the Pioneer leaves the gravitational influence of the sun, the time factor changes, but the velocity remains the same. However there would appear to be a change here on earth.
All motion is time dependent. Without time there can be no motion.

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Thinking? Sometimes I do.
The velocity of light is a constant, but time is not. Time is affected by gravity and velocity, but no matter how time is affected, the velocity of light will measure the same in what ever medium it is measured.
As the Pioneer leaves the gravitational influence of the sun, the time factor changes, but the velocity remains the same. However there would appear to be a change here on earth.
All motion is time dependent. Without time there can be no motion.

Interesting musings. I wonder if there would be time without motion in the Universe.

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Certainly, time exists without motion, but describe a motion without a time factor.

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Hi there Stephen Macy,

I was thinking myself too (outbreak?), and I wanted to expose my point of view regarding motion and time.

Time exists based on motion, how can you know how much time has elapsed? You use a clock, which based on 'something' moving can give you a measure of time. That 'something' can be a pendulum, the 'oscillation' on Cesium-133 atoms. I don't have a Ph.D. on atomic clocks, so I consulted this "childish-but-still-cool" website:

How Atomic Clocks work

On page 3 of the article, you can find this:

"To create a clock, cesium is first heated so that atoms boil off and pass down a tube maintained at a high vacuum. First they pass through a magnetic field that selects atoms of the right energy state; then they pass through an intense microwave field. The frequency of the microwave energy sweeps backward and forward within a narrow range of frequencies, so that at some point in each cycle it crosses the frequency of exactly 9,192,631,770 Hertz (Hz, or cycles per second)."

If I understand it correctly, Celsium-133 is energized, then its electrons are expelled from their orbits, and then only those within a particular energy level are used as a clocking source at 9,192,631,770 Hz. These electrons are moving!

Even if you decide to measure time using sunrise, sunset, the moon, the universe, motion is involved.


Well, those are my thoughts, they don't have to be 100% right =p

Happy crunchin'

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Hi,

reading and re-reading this thread for a while now and thinking about that 'time'-problem:

Time can't be measured directly, because time is an abstract (theoretical) instrument in physics. It is the number of a repeating outcome of an expected (predicted) helper-experiment (e.g. Cesium-133), which is then called time. Therefore time is and has a mathematical structure.

''Physics has to solve the problem to connect a mathematical structure with reality. In fulfilling this task physics makes statements about reality.'' (H. Reichenbach)


I hope i'm not to far off here, i'm not a physicist nor a mathematician.


Urs

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U r s

Certainly, time exists without motion, but describe a motion without a time factor.

From the perspective of the object in motion, or an observer?

At absolute zero an object has no motion, and is effectively in suspended animation so does not experience time. While an observer looking at that object (say at room temp) does experience time.

An object traveling at light speed also wouldn't experience time, but the observer looking at that object would.

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me@rescam.org

At absolute zero an object has no motion, and is effectively in suspended animation so does not experience time. While an observer looking at that object (say at room temp) does experience time.

Interesting thoughts, really. This could imply that Relativity must not only link time with space and speed, but also temperature? Cool...

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From the perspective of the object in motion, or an observer?

At absolute zero an object has no motion, and is effectively in suspended animation so does not experience time. While an observer looking at that object (say at room temp) does experience time.

Time can't be measured directly, because time is an abstract (theoretical) instrument in physics.

Was pretty much thinking along the same lines. Time (in the abstract) was initiated when space began to move (via the BB--based on CMB results). Granted it doesn't take into account other theories that propose this universe could have evolved from a previous crunch, coexists with parallel universes or is embedded in higher dimensional framework that has, as of yet, been undetected.

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Interesting thoughts, really. This could imply that Relativity must not only link time with space and speed, but also temperature? Cool...

Yeah, good point--entropy. Gravity is the real kicker, though, isn't it? Knowing what it does and what it actually is--well, just exciting to think about.

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At absolute zero molecular motion ceases, but atomic motion continues.

Gravity slows time. Is there a point that extreme gravity can stop time? A black hole's gravity is such that light can not excape. We measure earth's gravity as acceleration, 32ft sec/sec. Is a balck hole's gravity equal to the velocity of light, i.e. 386,000 miles sec/sec? Would that stop time? Will that stop atomic motion? If so, what happen to atoms? Do they break down to quarks or something else?

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At absolute zero molecular motion ceases, but atomic motion continues.

Gravity slows time. Is there a point that extreme gravity can stop time? A black hole's gravity is such that light can not excape. We measure earth's gravity as acceleration, 32ft sec/sec. Is a balck hole's gravity equal to the velocity of light, i.e. 386,000 miles sec/sec? Would that stop time? Will that stop atomic motion? If so, what happen to atoms? Do they break down to quarks or something else?

A Black hole's escape velocity is that of light, or greater. As mass gets sucked in, the gravitational pull gets stronger, increasing the black hole's escape velocity.

(Introduction to black holes)
http://www.damtp.cam.ac.uk/user/gr/public/bh_home.html

(Anatomy of a Black hole)
http://archive.ncsa.uiuc.edu/Cyberia/NumRel/BlackHoleAnat.html

I've once read that if you could live through the process of entering a black hole, and leaving the black hole, eternity would have passed for every one outside of the black hole.
I'm not sure about this of course, but I'll look it up and bring you what I find.

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