What Is Time: Answers to Your Questions

[Andrew Mason]

...
Now I go up in a spaceship and orbit the Earth at a distance, say of 5000 miles. Now provided I can adjust my speed to the necessary I could position myself at precisely the point where the sun forever rises - early morning and stay in that orbit. Then my time frame is consistent with Earth clocks. And I'm traveling at a constant speed.

Now I decrease that speed and I'm now falling behind Earth's time frame. Now I increase my speed and I'm exceeding Earth's time frame. At each position I am traveling at a constant velocity.

No, you are not traveling at constant velocity. You are in orbit. In orbit, your velocity is constantly changing. You are not an inertial frame of reference. There is a fundamental difference between being on the Earth and in orbit around the earth.

AM

 

[cragar]

did time exist before the big bang?

 

[tiny-tim]

Here's my scale. I'm in a busy street. … Then I go to the top of a really tall building … my time frame is in fact also slower - marginally.

Now I go up in a spaceship and orbit the Earth at a distance, say of 5000 miles. Now provided I can adjust my speed to the necessary I could position myself at precisely the point where the sun forever rises - early morning and stay in that orbit. Then my time frame is consistent with Earth clocks.

ah … I'm not sure what you mean by "time frame" here …

you do know the Sun doesn't go round the Earth, don't you? …

if you're at constant sunrise, then your position relative to the Sun and Earth stays the same, so basically you're orbiting the Sun exactly once a year, just behind the Earth.

But even if you were in geostationary orbit, above the same point on the Earth all the time, so that you could "share" its time, you wouldn't be in an Earth "time frame", because your clock would be slower owing to time dilation.

Time dilation, relative to the Earth depends mostly on speed, and very very slightly on distance from the Earth (it actually speeds up a little as you go away, with a maximum factor of approximately U = 2gr/c², which of couse is extremely small ) … see the https://www.physicsforums.com/library.php?do=view_item&itemid=166" for details.

 

[Andrew Mason]

did time exist before the big bang?

If the big bang theory is substantially correct and all baryonic matter that makes up our present universe came into existence in the big bang, then possibly many of our laws of physics also came into existence at that time. But this does not mean that time or space would have had no meaning prior to the big bang. There could have been, and there could be, other universes that have spatial and temporal existence.

Time and space appear to be fundamental and there is no obvous reason why they would depend upon the existence of baryonic matter.

AM

 

[rosie]

Tiny tiim - I mean that it would take 24 hours plus/minus some fraction to complete an 'axial' orbit - with the Earth regardless of my distace from the Earth and provided I can get up speed. And I would prove it by showing that my clock ticked through 24 hours in synch with the Earth's clocks. But you're right. At certain distances and at certain points in this hypothetical picture - the sun and moon and sundry plants - would probably get in my way. The trouble with reality - solid fact - is that it gets in the way of hypothesis. But I still need to be convinced that velocity isn't a critical value to time.

Why would my clock be slower? It corresponds to Earth time. Its 24 hours is identical to Earth's 24 hours. That's what I mean when I say that we're in the same time frame. But if I speed up that orbit - or slow it down - only then are our times different - exponentially so the further out the orbit.

 

[Andrew Mason]

Tiny tiim - I mean that it would take 24 hours plus/minus some fraction to complete an 'axial' orbit - with the Earth regardless of my distace from the Earth and provided I can get up speed. And I would prove it by showing that my clock ticked through 24 hours in synch with the Earth's clocks. But you're right. At certain distances and at certain points in this hypothetical picture - the sun and moon and sundry plants - would probably get in my way. The trouble with reality - solid fact - is that it gets in the way of hypothesis. But I still need to be convinced that velocity isn't a critical value to time.

Why would my clock be slower? It corresponds to Earth time. Its 24 hours is identical to Earth's 24 hours. That's what I mean when I say that we're in the same time frame. But if I speed up that orbit - or slow it down - only then are our times different - exponentially so the further out the orbit.

But you are not in the same time frame. In orbit you are not in the same frame of reference as a person on the earth. You are falling in a gravitational field and the person on the Earth is not. There is a very slight difference between the orbiting clock and the identical clock on the earth. This has been proven with atomic clocks: See http://hyperphysics.phy-astr.gsu.edu/HBASE/Relativ/airtim.html"

AM

 

[seasnake]

time is temperature, any temperature however minute over Absolute Zero results in motion and change and time is the measurement span that such motion and changes take place against

 

[rosie]

" time is temperature, any temperature however minute over Absolute Zero results in motion and change and time is the measurement span that such motion and changes take place against"

I agree. it's the best definition I've ever heard.

 

[cragar]

so you are saying that time is the average translational kinetic energy.

does light have a temperature?

 

[seasnake]

so you are saying that time is the average translational kinetic energy.

exactly

 

[cragar]

does light have a temperature and does light expirence time?

 

[rosie]

I assume so. That's what seasnake recommended. I like it. Better than all other explanations.

 

[seasnake]

light is absorbed and it reflects when it hits mirrored surfaces, and different colored beams travel at slightly different constants (I've looked them up before), as such I prefer to think of light as having mass no matter how small it is, in any case light is simply the wave medium through which we are capable of seeing and to which our solar system seems to function (any experiments we conduct by ridding internal atmospheres are conducted with containment materials of speed C, which to me kind of invalidates the testing), ironically we can not see black mass, black matter, black holes, and we are missing a complete color in the color wheel, to me it seems logical that if speed were capable of traveling faster than lightspeed (the medium we can see) we wouldn't be able to see whatever was traveling at such a frequency speed (which can be entire systems if you view that our system travels at our light speed)

light does not in my opinion represent kinetic energy, as light initiates no motion of choice on its own, as such its potential energy, energy in motion that can be tapped but not motion of change (it is not observed to change direction by its own choice and it does not have any known half-life which indicates change... this is interesting on its own accord as all mass we know about has a half life, so if light does have mass it is mass in prime form that is mass that is no longer capable of further reduction, unless it does have a half-life)

 

[tiny-tim]

" time is temperature, any temperature however minute over Absolute Zero results in motion and change and time is the measurement span that such motion and changes take place against"

I agree. it's the best definition I've ever heard.

Sorry, but it's rubbish …

in what sense can it be a definition of time?

Why would my clock be slower? It corresponds to Earth time. Its 24 hours is identical to Earth's 24 hours. That's what I mean when I say that we're in the same time frame.

Its 24 hours is identical to Earth's 24 hours only because you've cheated by adjusting your clock!

If you hadn't cheated, your clock would be going slower!

You can make your clock go at any rate you like, just by turning that little knob at the back …

that isn't being in the same "time frame" …

that's just you!

 

[rosie]

If my velocity is adjusted to exactly match the axial spin of the Earth - then my time would surely be coincident with Earth's? I cannot see how it could be otherwise. No adjustment. Just my speed adjustment. And then I orbit at the same time - in fact I stay at the same point in relation to Earth's spin - always dawn. Why Tim should be clock be any different to Earth's time. I just can't get it. But I realize I'm probably wrong.

 

[seasnake]

Sorry, but it's rubbish …

in what sense can it be a definition of time?


Its 24 hours is identical to Earth's 24 hours only because you've cheated by adjusting your clock!

If you hadn't cheated, your clock would be going slower!

You can make your clock go at any rate you like, just by turning that little knob at the back …

that isn't being in the same "time frame" …

that's just you!

Time only exists when change exists, without change time stops/ceases to be, Absolute Zero is the temperature when all motion is said to stop. With temperature you have change, both kinetic energy and potential energy and all mass decays and has half lives, if mass has half-lives then it has an internal clock, gravity and speed seems to affect clock speed but no matter how slow time appears in relation to time in another area, time always moves forward, not backwards (relativity)

 

[tiny-tim]

… if mass has half-lives then it has an internal clock …

The "internal clock" of a lump of uranium does not depend on its temperature …

I'll admit you can't get the lump down to absolute zero, simply because it generates its own heat … but above absolute zero, temperature does not affect an internal clock.

If my velocity is adjusted to exactly match the axial spin of the Earth - then my time would surely be coincident with Earth's? I cannot see how it could be otherwise. …

No, adjusting your speed does automatically adjust your clock, but by a factor √ (1 - v²/c²) …

it has nothing to do with a comparison with the rotation of the Earth.

 

[seasnake]

ahhhh... I never claimed that temperature affects the rate of time, but merely creates the existence of time, time is temperature, without temperature you shall find you don't have time.. after that I'll go with crager when he wrote, "time is translational kinetic energy"... kinetic energy comes into play the moment you have temperature exceeding absolute zero

note: your question was, what is time, not how does time function, and I consider these to be two distinctly different questions, expecially when you toss in relativity

 

[Andrew Mason]

If my velocity is adjusted to exactly match the axial spin of the Earth - then my time would surely be coincident with Earth's? I cannot see how it could be otherwise. No adjustment. Just my speed adjustment. And then I orbit at the same time - in fact I stay at the same point in relation to Earth's spin - always dawn. Why Tim should be clock be any different to Earth's time. I just can't get it. But I realize I'm probably wrong.

You may stay in the same position relative to the person on the Earth but your perceptions of time will be slightly different. This is a consequence of relativity. You have to study relativity to begin to understand why this occurs. It has to do with the speed of the same light signal being the measured the same by all inertial observers - even by one who is moving at close to the speed of light relative to another.

AM

 

[epenguin]

Time is what clocks measure, nothing but.

So

did time exist before the big bang?

If nothing existed, or better, if nothing happened before the big bang then there was no time before the big bang. If you had been there you would not have got bored waiting for something to happen, because no nervous impulses would be arriving - those impulses are something happening that is telling you maybe that nothing much else is.

 

[seasnake]

Time is what clocks measure, nothing but.

so under your definition, time doesn't start until somebody first builds a clock

 

[epenguin]

so under your definition, time doesn't start until somebody first builds a clock

No - physical events constitute a clock. E.g. the rotation of the Earth is used as a clock. It was not constructed by humans if that is what you mean.

 

[cragar]

a clock is used to observe time . time is something that is there.

 

[Stratosphere]

Can time exist without matter and space? And can space exist without time?

 

[cragar]

space and time are one thing. the spacetime continium.
i would say that time could exist without matter.

 

[rosie]

Wasn't that Einstein's discovery - that time had to be factored into a description of matter? Without it - descriptions are incomplete? That's why I liked Seasnake's description. It relates to fundamental changes to matter.

"space and time are one thing. the spacetime continium.
i would say that time could exist without matter. - Cragar"

Then time would first need space and that's another question. Did the space for the universe exist before the big bang? Something out there for the universe to fit into?

As I'm a proponent of the Steady State theory - a ridiculous minority - I buy into the concept that time has always existed - since the beginning - whenever that was?

But it's just the measure of change from the most fundamental perspective. And that change is always associated with temperature.

 

[tiny-tim]

Einstein

Wasn't that Einstein's discovery - that time had to be factored into a description of matter? Without it - descriptions are incomplete? That's why I liked Seasnake's description. It relates to fundamental changes to matter.

No, Einstein said no such thing.

(That's why I don't like Seasnake's description.)

Einstein said that time and three-dimensional space are (to some extent) interchangeable …

that has nothing to do with matter!

(Einstein also said that matter and energy are interchangeable …

that has nothing to do with time!)​

 

[rosie]

Tiny-tim - yet again. I stand corrected. These concepts are way beyond me. I need an elementary guide for the particularly stupid. I can't event get past the clock difference if I orbited Earth in synch with the Earth's orbit - no matter the distance. Maybe you can recommend some reading. Meanwhile I'll try and find something on the net.

 

[Andrew Mason]

Tiny-tim - yet again. I stand corrected. These concepts are way beyond me. I need an elementary guide for the particularly stupid. I can't event get past the clock difference if I orbited Earth in synch with the Earth's orbit - no matter the distance. Maybe you can recommend some reading. Meanwhile I'll try and find something on the net.

Search for articles on Special Relativity.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relcon.html#relcon
http://en.wikipedia.org/wiki/Special_relativity


Also look at General Relativity:

http://en.wikipedia.org/wiki/General_relativity
http://www.spacetimetravel.org/


In orbit you would be able to observe the same events as a person on the surface of the earth. It is just that you would disagree slightly on the time between events. You would see the sun rise every day and count the same number of days. It is just that your atomic clocks would differ on how long that day was.

AM

 

[rosie]

Thanks Andrew. I'll go for it.