What is Time

[Robotoer]

What is time? Some scientists say time is the 4th dimension.

If so... do we live in a 4 dimensional world? Time in this world is infinate. Objects do not last only for a period of time then disapear once their 4th dimension(time) has run out. Because of this, would we qualify as not being 4 dimensional beings?

In 2 dimensions, the 3rd dimension, depth does not exist. It could be either infinate or null. so following that logic, wouldn't that match our situation. The only problem i run into is that we can measure time. But still... Time doesn't seem to be related to matter very much

 

[Woodchuck2000]

Wrong question. Try asking "What is Spacetime."

We probably do qualify as four-dimensional beings if you frame the question like that, yes.

Also, why would someone's time run out anyway?

We can't actually measure time. We can't even prove its existence as any measurement is entirely subjective. It's just a convient way to perceive things without our little hard-wired biological brains dying horribly.

 

[Markbnj]

Unless you're a physicist time is just memory and the perception of change...

maybe .

 

[DrPizza]

Here's a wonderful related question: is time continuous? Or does time move forward in discrete (albeit very small) steps.


edit: note - I'm not even sure if there's an answer for this... I remember the question being postulated before, and a discussion of Planck time, etc. What I'm trying to remember is if
a) there is an answer for this or
b) if it is even possible to know if there is an answer to this

 

[alienal99]

go for woodchucks last answer....time is not an actual "thing"....look at it as a way comparing the same thing at different points, similar to a graph of movement on an a coordinate plane....we are simply the earth @ 2005


yes, there are more complicated analyses than this one, but when it comes down to it, time is simply relative to the situation that is being analyzed....there is no ultimate time, time has no beginning and hopefully no end....

alex

 

[Soccerman06]

Time is notset at a certain speed, it can go faster or slower depending on your position comparing gravity and speed. I dont know the physics involved, but an experiment was done where 2 atomic clocks were placed at 2 seperate points on earth. One at the Northern most point of Earth and the other near the equator. It just so happened that after a period of time, the atomic clock at the north pole was actually a few seconds behind the clock at the equator.

Physicists have also proven mathmatically, that if you were to send someone somewhere at a very high velocity (1/2 c for example) that the person would age differently than another person here. Heres an example: There are 2 men, identical twins, one is sent off in a spaceship, with an atomic clock, at half the speed of light and the other stays on Earth. The twin inspace is taking a 12 year round trip somewhere. When the twin arrives back on earth, scientists discover that the atomic clock only showed a time lapse of 6 years round trip, and to prove there was no glitch in the clock, the twin appeared 6 years younger than the twin on Earth.

The times arent exact with that example but we cant really tell how much difference there is in "time" when conserning speed and gravity until we test the limits.

The universe will eventually lose all energy and settle down. All the stars will use up all their energy, things are cooling down, our solar system (well the sun) has gone from a giant red star to a yellow star, losing mass to the planets. Eventually all the energy will completely stop and the universe will be dead. This is also considering black holes dont eat up everything or the opposite of the Big Bang happens, the universe collapses on itself.

 

[alienal99]

note on soccermom's post: my alarm clock seems to always be on the wrong time, yet this does not affect actual time.....same thing with the atomic clocks....just because one is wrong does not mean that "time" has changed, it just means that polarity (or some other factor) has something to do with messing up atomic clocks.

 

[Torched]

Time can only be said as a tool to measure existence. Therefore the only thing that understands time to the fullest would be something that is omnipresent. Time is different at all times in all places. And to therefore experience time would be to be present for everything that has ever happened be it on the otherside of the world or the otherside of the universe in the beginning and the end. It could be said that the only thing that has experienced time is time itself. However the ponderance of such issues means the lack of experience of the time that surrounds you at the moment. This therefore means that you are not experiencing you own time to its fullest. BTW my time with this post is done.

 

[Soccerman06]

Originally posted by: alienal99
note on soccermom's post: my alarm clock seems to always be on the wrong time, yet this does not affect actual time.....same thing with the atomic clocks....just because one is wrong does not mean that "time" has changed, it just means that polarity (or some other factor) has something to do with messing up atomic clocks.

dude, atomic clocks are much different than your alarm clock. Atomic clocks use a radioatctive isotope to count its time. Since the isotope releases the exact same (or so) amount of radiation every second, it is always accurate, it can never fault until either the sensor stops working (there are a few) or the isotope basically evaporates. There is no ifs ands or buts about that.

If the clocks are set at the exact same time and are at the same point in space they will have the same time, and apparently the speed of an object has an effect on time.

Einstein also came up with the theory that time is not absolute. The idea is that the passage of time is dependent on the frame of reference. This concept is demonstrated by the famous "twin paradox." This thought experiment involves two twins, one who stays on earth and one who embarks on a high speed journey into space. The theory is that the traveling twin will come back to earth to be younger than his twin. If, for example, one twin travels through space at three fifths light speed for eight years from his point of view, ten years would have actually passed for the twin on earth, making him two years older than his traveling twin. This effect becomes even greater as speeds are increased. In other words, the faster one travels, the slower time passes until the speed of light is reached at which point time theoretically stops all together.

This theory does have experimental support. An experiment was done in which two synchronized atomic clocks were used. One was placed at a location near the equator, and the other was placed at the north pole. It turned out that the atomic clock at the equator after a period of time was noticed to be running slightly slower than its counterpart at the north pole. According to relativity, this result is due to the rotation of the earth being faster at the equator than at the north pole. This slowing of time due to increased speed becomes a problem in space travel because, even if we found a way to explore space at speeds near light and minimize travel time, the passengers would return to a futuristic world and still have the problem of lost time. So what can be done to get around these problems?

link

 

[RemyCanad]

To fully understand the experiement you should probably read up on Special Relativity. Then if you are still wanting more (such as how this applies to accelerating objects) read up on General Relativity. If you are in school (and not a physics major) I recommend taking a Modern Physics class.

Also the uncertainty principle used in quantum mechanics is based on time.

 

[patentman]

As I work a fuill day and go to school at night, time is just what I must endure before sweet death puts me out of my misery.

 

[Xyo II]

Originally posted by: RemyCanad
To fully understand the experiement you should probably read up on Special Relativity. Then if you are still wanting more (such as how this applies to accelerating objects) read up on General Relativity. If you are in school (and not a physics major) I recommend taking a Modern Physics class.

Also the uncertainty principle used in quantum mechanics is based on time.

if you want to learn more, just pick up:
God's equation: einstein, relativity, and the expanding universe
or:
The Universe in a Nutshell

both are great books, and do use layman's terms, i understood it when i was 12-13, you can understand it, and the first will give you a very nice overview of Einstein's life, better than the one in On the Shoulders of Giants- and discusses plenty on the theoretical astrophysics side and the theoretical quantum physics side.

or...............you could just google it.

 

[YoshiSato]

Originally posted by: Robotoer
What is time? Some scientists say time is the 4th dimension.

If so... do we live in a 4 dimensional world? Time in this world is infinate. Objects do not last only for a period of time then disapear once their 4th dimension(time) has run out. Because of this, would we qualify as not being 4 dimensional beings?

In 2 dimensions, the 3rd dimension, depth does not exist. It could be either infinate or null. so following that logic, wouldn't that match our situation. The only problem i run into is that we can measure time. But still... Time doesn't seem to be related to matter very much

Here is a question. While it would not be possible for a 3 dimensional being to exist in 2 dimensional space is the reverse true or can 2 dimensional beings exist in 3 dimensional space?


If the latter is true then yes space is 4 dimensions, we can only preceive 3 of them.

 

[jersiq]

The only problem i run into is that we can measure time. But still... Time doesn't seem to be related to matter very much

When presented with these quandries, just beg off the question completely using Godels Second Theorem of Incompleteness in a more logical than mathematical fashion (to the naysayers, I know this is an unintended consequence of the Second Theorem):
A closed set cannot have ALL the axiomatic truths about the set determined without existing outside the set. Because the set with which you are working in will produce contradictions.
Assumption: Time is the fourth dimension
Truth: we exist in three dimensions (last time I checked)
Problem: We cannot relate the truths of our third dimension to the fourth dimension (time)
Reason: Per Godel, the only way to relate all the axiomatic truths is to exist outside the third dimension. Of course, there are some truths we can uncover, however we do not get to pick and choose which truths they are.

My first post here (H.T.), so I look forward to all the bright people ripping this apart, which undoubtedly will happen.

 

[Woodchuck2000]

Originally posted by: YoshiSato

Originally posted by: Robotoer
What is time? Some scientists say time is the 4th dimension.

If so... do we live in a 4 dimensional world? Time in this world is infinate. Objects do not last only for a period of time then disapear once their 4th dimension(time) has run out. Because of this, would we qualify as not being 4 dimensional beings?

In 2 dimensions, the 3rd dimension, depth does not exist. It could be either infinate or null. so following that logic, wouldn't that match our situation. The only problem i run into is that we can measure time. But still... Time doesn't seem to be related to matter very much

Here is a question. While it would not be possible for a 3 dimensional being to exist in 2 dimensional space is the reverse true or can 2 dimensional beings exist in 3 dimensional space?


If the latter is true then yes space is 4 dimensions, we can only preceive 3 of them.

That's not strictly true. A three-dimensional construct can intersect two-dimensional space, even though it cannot strictly exist there. Two-dimensional people would see a sphere moving through that plane as a series of circles.

Similarly, it's entirely possible that we are four dimensional beings and we are only seeing a three-dimensional representation, most probably with respect to time. In the same way a sphere moving on a z-axis will appear as a series of circles to people constrained to a x-y axis, it's entirely possible that things moving along the time axis will appear as a series of x-y-z projections to us.

I'm fairly certain that it is impossible for a 2-d construct to exist in a higher-dimensional space as it would be possible to define it properly.

 

[Kyanzes]

Time is what you see in the lower right corner of the screen.

 

[Xyo II]

Originally posted by: jersiq

The only problem i run into is that we can measure time. But still... Time doesn't seem to be related to matter very much

When presented with these quandries, just beg off the question completely using Godels Second Theorem of Incompleteness in a more logical than mathematical fashion (to the naysayers, I know this is an unintended consequence of the Second Theorem):
A closed set cannot have ALL the axiomatic truths about the set determined without existing outside the set. Because the set with which you are working in will produce contradictions.
Assumption: Time is the fourth dimension
Truth: we exist in three dimensions (last time I checked)
Problem: We cannot relate the truths of our third dimension to the fourth dimension (time)
Reason: Per Godel, the only way to relate all the axiomatic truths is to exist outside the third dimension. Of course, there are some truths we can uncover, however we do not get to pick and choose which truths they are.

My first post here (H.T.), so I look forward to all the bright people ripping this apart, which undoubtedly will happen.

we live in 4 dimensions, not three. ill relate the 4th dimension in respect to everyday life;

you are traveling in a car, with your 3-dimensional buddies. there is a fine 3-dimensional lady walking by on the sidewalk. since you are traveling at 30 mph, and she is walking at 2 mph, your time frame (the space inside the vehicle) is going slower than hers is. while it is absolutely miniscule at these speeds, it does have an effect. if you spent your entire life on a jet plane, people on the surface of the earth would age faster than you would. to you, in what time 8000 seconds pass by before you land back on the earth (timed with an atomic clock), a clock on the earth will read that 8024 seconds have passed by. for more on relative time frames, pick up: God's Equation: Einstein, Relativity, and The Expanding Universe.

 

[mjia]

No one really nows how many dimensions exist. String theory proposes 11 dimensions, but can't be proven.

You can't classify 'things' as having different dimensions. If you accept theories like general relativity or string theory, then it mean that all matter at the subatomic level, exist in multiple dimensions.

 

[Zerohm]

Originally posted by: Robotoer
What is time? Some scientists say time is the 4th dimension.

If so... do we live in a 4 dimensional world? Time in this world is infinate. Objects do not last only for a period of time then disapear once their 4th dimension(time) has run out. Because of this, would we qualify as not being 4 dimensional beings?

In 2 dimensions, the 3rd dimension, depth does not exist. It could be either infinate or null. so following that logic, wouldn't that match our situation. The only problem i run into is that we can measure time. But still... Time doesn't seem to be related to matter very much

Just think of each dimension as an axis. In a two dimensional world everything can be described using (x,y) coordinates. In a three dimensional world, things need the addition z axis (x,y,z). Well, you can describe things even more accurately with another axis, t or (x,y,z,t). It's hard to visualize the 4th dimension, because istead of an object, it's an object over time, but time as the fourth dimension is just another describer for where something is in the universe.

"Objects do not last only for a period of time then disapear once their 4th dimension(time) has run out" I'm not sure what you mean by this, but I don't think something can exist in a world of greater dimensions. i.e. a 2 dimensional object can't exist in a 3 dimensional world etc.

 

[Monkey muppet]

Time is mans only feeble attempt to grasp on to, trying to, understand the complexities of the universe

 

[Tom]

time is the difference between when something is here and there.

 

[the splat in the hat]

hahahahaha
time is a measurement.
we made it.
we can change time effectively but not on a spacetime scale, only by the way we measure it.
time .
Was it around before the big bang?
What level of time/math accuracy do we need to achieve to crack quantum physics laws ?
If we dont understand time and its math properties at or near light speeds how can we predict with any accuracy?
Questions questions questions, time and light and the big bang maynot be mortally linked, will be interesting to discover the truth.

 

[DrPizza]

Wooohooo! I logged on and my computer just traveled 1 hour into the past!
Ohhh, that doesn't count as time travel? It ought to

 

[villageidiot111]

There was some cosmonaut who was in space for a long time (I think it was a year) and that made him age about 2 seconds less than people on earth. So, it's like he traveled two seconds into the future!

 

[Particle]

Spacetme seems to be more object state, like a perspective, then object rate which is time or velocity
Still to me, time is a velocity of a paticuler object while velocity would seem to me just speed alone.
Smack me if I'm off.
I always thought time was a measurement of an objects velocity. Like how fast is the earth (for example) rotating. Well it is going at 24 hours per day. So we relate ourselves to that or whatever object we choose. But I am still confused as to how distance can change a persons aging rate. If the person left the planet and then came back wouldn't he regain earths timetable. I never grasped that.