Define time

[entwined]

How do we know that time exists?

As far as I know, it has no physical properties, no weight, no width, length or depth, yet we seem to think we can measure it and some even think we can alter it, so how would you define time?

[ecoli]

time is a deminsion of the universe, inseparable with space.

[the tree]

Ditto. It's just another dimension.

[entwined]

Then it should be quite easy to define.

So..........


Exactly what is time?:-)

[ecoli]

Then it should be quite easy to define.

What makes you think that? Time is a property of the universe just like 3 demensional space. But is the word "space" any easier to define? What about other demensions like "hypercubes'...that's just as hard to define.

[ffsjoe]

There have been numerous threads on this subject. Ill let you in on a secrect, there is a tool, its known as the search function you should take it for a whirl sometime.

Here is a couple you can take a gander at.

http://www.scienceforums.net/forums/showthread.php?t=12783&highlight=time

http://www.scienceforums.net/forums/showthread.php?t=14589&highlight=time

[entwined]

There have been numerous threads on this subject. Ill let you in on a secrect, there is a tool, its known as the search function you should take it for a whirl sometime.


I am sincerely sorry if I caused you any inconvenience.......:rolleyes:

[Shadowness]

hehe^^

[GORDON HERMA]

get 2 clocks one the size of a thumbtack and another the size of a planet both ticking at the same speed in relation to themselves. One on a spaceship moveing close to the speed of light and one on a skateboard...easiest way i can see it..hope it helps

[patcalhoun]

How do we know that time exists?

The same way we know width, length and depth exist.

[Dr. Zimski]

How do we know that time exists?

As far as I know, it has no physical properties, no weight, no width, length or depth, yet we seem to think we can measure it and some even think we can alter it, so how would you define time?
Count from 1 to 5. Congatulations! You just measured time! But the answer isn't that simple.

Time, like speed, mass, location, and distance, is relative. I'm afraid I can't explain further though, sorry.

[entwined]

So far I have not seen anything in the way of a definition, only evidence that we perceive it to exist.

[gcol]

So far I have not seen anything in the way of a definition, only evidence that we perceive it to exist.

You have called their bluff. I dont think a generally accepted one exists, But here's one that suits me:

Time is an artificial mathematical construct that is convenient to measure the passage of events.

Any dissenters? More suggestions?

Many bedrock modern theories make assumptions as to the basic nature of time...... er, did I just suggest some bedrock theories are founded based on the quicksand of unfounded assumption? Oh well, have fun and shoot me down in flames.

[GORDON HERMA]

So far I have not seen anything in the way of a definition, only evidence that we perceive it to exist.


In my last post i posted get 2 clocks one the size of a thumbtack and another the size of a planet both ticking at the same speed in relation to themselves. One on a spaceship moveing close to the speed of light and one on a skateboard...easiest way i can see it..hope it helps
I didnt do a very good explanation of why so ill give it a shot.

First both clocks are not conscious, they dont perceive anything, nor does an atom,thunderstorm,popcicle,ect. If you want to put your mind around time imagine you are standing next to a clock the size of a planet. With every tick you hear a thunderous boom. Each tick takes like 5 mins because of its "SIZE IN SPACE". Between ticks you look down at your feet and there is a clock ticking 60 times per minute that has the "SIZE IN SPACE" of the tip of you thumb. Now both these clocks are identical and equal in every way except the fact that they are different sizes.
If we put the thumbtack clock into a spaceship and get it moveing faster and faster towards the speed of light then the ticks of that clock become larger with each increase of speed. Eventuall, if you have A fast enough "MOTION IN SPACE" the ticks will match that of the planet size clock, ticking every 5 minutes with a thuderous boom.
These 2 properties are the relationship between TIME and SPACE. They are unseperable. The more space(SIZE) that is used in a clock the slower the relative ticks become. The faster the "MOTION" of a clock in space, the slower the relative ticks become. This has nothing to do with precpetion because if you could set up the experiment and walk away it would still happen.
However in our perception, we do portion these properties into scales so that we can reference "WHERE" and "HOW BIG" all our differnt clocks were previously, are currently, and where they are going in "SPACE/TIME".
In conclusion, both clocks being equal with size not withstanding, the only 2 varients are "SIZE AND MOTION". These are properties of "SPACE" and "TIME" and can only exist together as one.

Hope this helps some...
Gordon Herman....:cool:

[entwined]

In my last post i posted
I didnt do a very good explanation of why so ill give it a shot.

First both clocks are not conscious, they dont perceive anything, nor does an atom,thunderstorm,popcicle,ect. If you want to put your mind around time imagine you are standing next to a clock the size of a planet. With every tick you hear a thunderous boom. Each tick takes like 5 mins because of its "SIZE IN SPACE". Between ticks you look down at your feet and there is a clock ticking 60 times per minute that has the "SIZE IN SPACE" of the tip of you thumb. Now both these clocks are identical and equal in every way except the fact that they are different sizes.
If we put the thumbtack clock into a spaceship and get it moveing faster and faster towards the speed of light then the ticks of that clock become larger with each increase of speed. Eventuall, if you have A fast enough "MOTION IN SPACE" the ticks will match that of the planet size clock, ticking every 5 minutes with a thuderous boom.
These 2 properties are the relationship between TIME and SPACE. They are unseperable. The more space(SIZE) that is used in a clock the slower the relative ticks become. The faster the "MOTION" of a clock in space, the slower the relative ticks become. This has nothing to do with precpetion because if you could set up the experiment and walk away it would still happen.
However in our perception, we do portion these properties into scales so that we can reference "WHERE" and "HOW BIG" all our differnt clocks were previously, are currently, and where they are going in "SPACE/TIME".
In conclusion, both clocks being equal with size not withstanding, the only 2 varients are "SIZE AND MOTION". These are properties of "SPACE" and "TIME" and can only exist together as one.

Hope this helps some...
Gordon Herman....:cool:

Well it doesn't.

what you have discribed are two devices designed to measure time and the relative difference in their "tick rates" when one is moving faster than the other.

What I am looking for is a definition of time.

Does it exist everywhere? Did it always exist? Are there any other physical laws that affect it? is it detectable from afar? Is it like space, whereas, I am told, if no matter exists to be separated by space, then no space exists?

Just a definition, that's all,

[gcol]

Entwined: "What I am looking for is a definition of time........Just a definition, that's all".

A heartfelt plea. After much Googling and dictionary searching, I have found only one that seems to have a specific scientific meaning (as apart from, for example, a legal meaning).
It is this:

"The scientific definition of time is that period occupied by a body in passing from one given point in space to another, and therefore, according to this definition, when there is no space, there can be no time....

Judge Thomas Troward, Edinburgh Lectures, 1909.

Or perhaps in street cred argot: "ain't no happening, ain't no time, tha'sall".

It will do for me until something better comes along, and I think it may be proveable. If anyone finds a time-based theory that uses something different, try questioning it using that definition and have fun.

[GORDON HERMA]

a body in passing from one given point in space to another, and therefore, according to this definition, when there is no space, there can be no time.... thats what i was trying to say In conclusion, both clocks being equal with size not withstanding, the only 2 varients are "SIZE AND MOTION". These are properties of "SPACE" and "TIME" and can only exist together as one.


Some people mistake time as a progression that we make up to portion it for our understanding. Time itself is dependent upon space and motion, we make it linear and non linear, we decide what a second is by creating progression, but we can not create the properties of physics associated with motion through space.
Gordon...

[patcalhoun]

So far I have not seen anything in the way of a definition, only evidence that we perceive it to exist.

You've seen plenty of definition. Time is a dimension, one parameter among many used to specify locations of events in some sort of spacetime. If you need a deeper explanation, then you've stepped into the domain of philosophy and definitely out of the realm of physics