# How does time "slow down" when you reach c?

## Recommended Posts

I was tought that time stops when you reach the speed of light. How so? what I mean is what is time? isn't time just a measurement/schedule. For example, I am waking up at 6am tommorow, that just counts specific measurements on a mechanical clock for a specific amount then it rings. It is a schedule sort of. So how can one say that time stops?

If you carried a clock on a space ship traveling at the speed of light, would it keep ticking like it always does? I mean for time to stop, the clock has to stop right? Please clear this up for me, because it all makes no sense. I just believe we are always in the present.

##### Share on other sites

The clock would keep ticking as it always does, because time is relative. To you, time would appear to be going the same, as it always does. But to an outside observer, time would change for you.

##### Share on other sites

In short -

Light always moves at the same speed, relative to everything.

If you shine a beam of light onto a train moving away from you, the light HAS to hit the train at the speed C, whether the train is stationary, or moving away very fast.

This is not what happens, of course, with a ball, or anything other than light. If you throw a ball at a person running toward you, it will hit them with a velocity that is equal to that of the velocity of the ball after you throw it plus the velocity of the person running toward you.

One way to think of how light works is to think that for light to hit at a constant velocity, time must move at different rates. For instance, if light is hitting you at, say, five photons per second, and you start to run away from the source of light, you would think that you would be hit by only 3 or so photons a second, but you are still hit by 5 - yet the same number of photons are being emitted (5 per second). So time has to slow down for you, for light to catch up.

I hope that helps a little!

##### Share on other sites

My theory (which is here in the relativity section) explains your question perfectly. aswell as pulsars, black holes, light speed, mass increase, speed limit, explanation of electromagnetic radiation, time, space, why light seems to have mass but doesnt, and many other things. it is einstiens theory (or whoevers theory, slightly reversed. and works with the equations!!!

I will post the theory paper soon. so it can get critqued by smarter scientists.

##### Share on other sites

You never see your own clock slow down, observers in other reference frames see it slow down.

There are a number of threads already in existence on this topic. There is a search function you might consider using.

##### Share on other sites

In short -

Light always moves at the same speed' date=' relative to everything.

If you shine a beam of light onto a train moving away from you, the light HAS to hit the train at the speed C, whether the train is stationary, or moving away very fast.

This is not what happens, of course, with a ball, or anything other than light. If you throw a ball at a person running toward you, it will hit them with a velocity that is equal to that of the velocity of the ball after you throw it plus the velocity of the person running toward you.

One way to think of how light works is to think that for light to hit at a constant velocity, time must move at different rates. For instance, if light is hitting you at, say, five photons per second, and you start to run away from the source of light, you would think that you would be hit by only 3 or so photons a second, but you are still hit by 5 - yet the same number of photons are being emitted (5 per second). So time has to slow down for you, for light to catch up.

I hope that helps a little![/quote']

I understand what you are saying. But, what is time?

##### Share on other sites

The frequency of the universe interpretted as how you choose to combine the frequencies to call it one unit.

##### Share on other sites

time is another dimension in which we are travelling, though a very different one. we travel up, down, side to side in the three dimensions that we can see. we travel [forward] through time. it is theorized (though with no physical evidence) that all particles have an opposite particle which moves backwards in time relative to the other which moves forwards. this would be the dark energy to the normal energy. i think that is why, in our present state as carbon-based organisms, it would be impossible or extremely improbable that we could ever travel through time (other than the normal relativity-type time travel).

##### Share on other sites

The frequency of the universe interpretted as how you choose to combine the frequencies to call it one unit.

I read this over and over and over agin, but I still can't figure it out.

I take it the second part: "interpretted as how you choose to combine the frequencies to call it one unit."

means: "however you feel like interpreting that and whatever you like to call it"

But the first part: "the frequency of the universe"

When I read frequency I automaticly think of vibration.

Are you trying to say time is defind by the frequency of the vibration through it's dimention? And if you are saying that, the vibration of what?

A particle? The entire universe?

##### Share on other sites

So if time is a 4th dimension, meaning moving forwards and backwards, if you traveled at the speed of light you would actually stop? since time is physical movement? Please clear this up, making progress here

##### Share on other sites

I read this over and over and over agin' date=' but I still can't figure it out.

I take it the second part: [i']"interpretted as how you choose to combine the frequencies to call it one unit."[/i]

means: "however you feel like interpreting that and whatever you like to call it"

But the first part: "the frequency of the universe"

When I read frequency I automaticly think of vibration.

Are you trying to say time is defind by the frequency of the vibration through it's dimention? And if you are saying that, the vibration of what?

A particle? The entire universe?

It does not refer to one single object...

The earth revolves around the sun at a "frequency" close to 365 spins to make a orbit around the sun. This freqency can be turned into smaller units, to make time, and seconds, or if you wanted to call 60 seconds 30 geegles or somthing like that.

The sun, from point of creation, will over go a chemical/nuclear reaction, the frequeny/rate in which it functions determines its "Time" as a sun as a life.

All around the universe you can apply the "frequency of actions" to determine a time. lights red shift frequency change can be calculated into the "time" it has been in action.

##### Share on other sites

I think that is a lousy defenition of time when talking about relativity if that was what you meant then.

If All matter would come to a stop, would time stop to? Would the fabric of time, the dimention suddenly sease to exist?

##### Share on other sites

So if time is a 4th dimension, meaning moving forwards and backwards, if you traveled at the speed of light you would actually stop? since time is physical movement? Please clear this up, making progress here

You are saying: "if I break the laws of physics what will happen according to the other laws?" because you are saying what happens if you travel at c (c = speed of light), which you cannot do.

You cannot violate a law in physics (that you can't travel at c) and then ask what the other laws (about time dilation etc.) say will happen because all laws are reliant on each other. When one law in physics fails, others will fail too.

##### Share on other sites

If All matter would come to a stop, would time stop to? Would the fabric of time, the dimention suddenly sease to exist?

Matter isnt a planet.. matter is a identical source of one thing organized in different facions to emmit different characteristics. I was refering to human time determined from the earths spins, and revolutions around the sun originating from which makes those things exist, the combination of "attoms" making the system operate, it all comes from 1 source u see. Every action comes from 1 thing, combined and organized in a cirtain way that then determines what happens from the relation ship between this interacting identicals.

If all matter, stopped, meaning all the atoms in the universe suddenly stopped functioning in any possible way imaginable. yes time would stop in the sense of a human watching time pass by. Because nothing would happen, without active atoms, no reactions occur (and i am not refering to absolute zero degrees tempeture) I mean putting a stop to everysingle atom. This would cause all light energy to cease to be in production, gravity would then cease to exist for it has to orginate from something that exists. So theoretically, sure if you paused atoms in time, atoms would pause time. Everything as you know today would quit interacting and darkness would be all.

##### Share on other sites

You cannot violate a law in physics (that you can't travel at c) and then ask what the other laws (about time dilation etc.) say will happen because all laws are reliant on each other. When one law in physics fails, others will fail too.

Explain why a particle traveling in an accelerater at .99c has no significant mass increase or stronger requirement to accelerate it.

If an atom was on the screatching edge of Infinate mass then you would think at this point that atom should contain the mass pretty close to the universe.

##### Share on other sites

time is another dimension in which we are travelling, though a very different one. we travel up, down, side to side in the three dimensions that we can see. we travel [forward'] through time. it is theorized (though with no physical evidence) that all particles have an opposite particle which moves backwards in time relative to the other which moves forwards. this would be the dark energy to the normal energy. i think that is why, in our present state as carbon-based organisms, it would be impossible or extremely improbable that we could ever travel through time (other than the normal relativity-type time travel).

I like that idea, makes dark energy / matter more probably, seemed like a gimmick to make everything work to me.

And if we travel forward in time, could we just travel forward quicker? lol

Also time dialation would seem like a form of time travel to the person traveling, though its not.

##### Share on other sites

Explain why a particle traveling in an accelerater at .99c has no significant mass increase or stronger requirement to accelerate it.

If an atom was on the screatching edge of Infinate mass then you would think at this point that atom should contain the mass pretty close to the universe.

Energy = Matter so when they accelerate the particles to .999c or w/e' date=' their masses dont actually increase its the energy. Their [i']relativistic[/i] mass that increases to infinity.

(If I said anything incorrect somebody correct me, lol)

##### Share on other sites

is no different than a group of particles(a ship) powered by a machine(engine) traveling at .9999c

##### Share on other sites

it isn't if your sitting on earth watching the ship fly past you at .9999c, it is different if your on the ship.

##### Share on other sites

So if time is a 4th dimension, meaning moving forwards and backwards, if you traveled at the speed of light you would actually stop? since time is physical movement? Please clear this up, making progress here

time is not a physical movement (or at least all evidence points to it not being physical in the sense that we know). the first three dimensions are physical, the 4th, time, we obviously dont have a sense that deals with it and so we cannot see if we are going 'forwards'. the physical world relates to what we can view with our 5 senses. since we cannot view time with any of our 5 senses, it is not physical. but it is still a dimension through which we, and all things, move.

##### Share on other sites

Matter isnt a planet.. matter is a identical source of one thing organized in different facions to emmit different characteristics. I was refering to human time determined from the earths spins, and revolutions around the sun originating from which makes those things exist, the combination of "attoms" making the system operate, it all comes from 1 source u see. Every action comes from 1 thing, combined and organized in a cirtain way that then determines what happens from the relation ship between this interacting identicals.

If all matter, stopped, meaning all the atoms in the universe suddenly stopped functioning in any possible way imaginable. yes time would stop in the sense of a human watching time pass by. Because nothing would happen, without active atoms, no reactions occur (and i am not refering to absolute zero degrees tempeture) I mean putting a stop to everysingle atom. This would cause all light energy to cease to be in production, gravity would then cease to exist for it has to orginate from something that exists. So theoretically, sure if you paused atoms in time, atoms would pause time. Everything as you know today would quit interacting and darkness would be all.

So you'r saying time is fictive term, a word we came up with to define the activity of events rather then time as a construct; the construct of space-time; a 4dimensional universe; an existing degree of freedom in wich energy moves?

##### Share on other sites

If you shine a beam of light onto a train moving away from you' date=' the light HAS to hit the train at the speed C, whether the train is stationary, or moving away very fast.

[/quote']

The properties of light seems even much more bizare to me than time dilation. It seems impossible for something to behave that way.

##### Share on other sites

In short -

Light always moves at the same speed' date=' relative to everything.

If you shine a beam of light onto a train moving away from you, the light HAS to hit the train at the speed C, whether the train is stationary, or moving away very fast.

![/quote']

Matt,

It occurs to me there is a problem with this statement. Becaue I am pretty sure I saw a NOVA program that said stars going away from us are "red shifted". They would not be red shifted or blue shifted if light was always constant to the observer.

Can you or anyone else explain this?

##### Share on other sites

Matt' date='

It occurs to me there is a problem with this statement. Becaue I am pretty sure I saw a NOVA program that said stars going away from us are "red shifted". They would not be red shifted or blue shifted if light was always constant to the observer.

Can you or anyone else explain this?[/quote']

they are redshifted because the universe is expanding faster than the speed of light. or, if not faster, then space and time are being warped such that it seems that it is expanding faster than the speed of light. the distance between all objects in the universe is increasing incrimentally and proportionately to how the 'edges' of the universe are expanding.

redshifting occurs due to the doppler effect or because the space between waves in a lightwave is expanding and causing that wavelength to lengthen, which makes the light more red. with the doppler effect, if the object is moving away from us at high velocity, it is redshifted; if it moving towards us at high velocity it is blueshifted. in a redshift the wavelengths are lengthened, in a blue shift they are shortened. large gravitational feilds can shift the spectrum of light too. but the light is always moving at a constant speed, no matter what its wavelength is.

##### Share on other sites

Matt' date='

It occurs to me there is a problem with this statement. Becaue I am pretty sure I saw a NOVA program that said stars going away from us are "red shifted". They would not be red shifted or blue shifted if light was always constant to the observer.

Can you or anyone else explain this?[/quote']

I don't know where people get this idea that the Invariance of the Speed of Light prevents a Doppler effect.

Anyway, here:

http://www.scienceforums.net/forums/showpost.php?p=196819&postcount=25

## Create an account

Register a new account