PDA

View Full Version : Time! Time! Time!



ashleyisabadnerd
2008-Apr-07, 12:03 PM
what is time? how does it slow down as you reach the speed of light? does it even exist? HELP!

Kaptain K
2008-Apr-07, 12:55 PM
what is time?
Good question!
1) Time is one of the four coordinates of space time.
2) Time is the perception of duration!
3) Time is natures way of keeping everything from happening at once. :whistle:



how does it slow down as you reach the speed of light?
It's a consequence of the constancy of the speed of light.


does it even exist? HELP!

I hope so!

alainprice
2008-Apr-07, 09:24 PM
One way to think of it is:
If you are sitting still, time is moving at the speed of light.
If you are moving at the speed of light, time is sitting still.

The two are connected and inseparable.

Neverfly
2008-Apr-08, 05:12 AM
does it even exist?
I hope so!

I dunno... Your beard was getting rather shaggy last I saw...:think:

Kaptain K
2008-Apr-08, 05:54 AM
I dunno... Your beard was getting rather shaggy last I saw...:think:

You should see it now! :lol: Actually, I plan to trim it some time in the next two weeks. :)

parallaxicality
2008-Apr-08, 08:06 AM
"Everyone knows what time is, but no one can explain what time is."

Some random scientist

Mike Holland
2008-Apr-08, 11:21 AM
Time passes at a fixed rate for all observers - one second per second.

Mike

m1omg
2008-Apr-08, 01:05 PM
Not if relativity is correct.

Kaptain K
2008-Apr-08, 03:37 PM
Time! Time! Time!
...See! What's! Become! of! Me!

P. Simon

speedfreek
2008-Apr-08, 10:00 PM
Whoever the observer is, their seconds always pass at one second per second. If they look at someone else, they might see the other persons seconds running faster or slower than their own, but an observers seconds always pass at the same rate, whatever they are doing. You won't notice a difference in the way your watch ticks, if you go from a standing start all the way to 99.999...% of c. Your seconds simply become less synchronised with everyone else's seconds, and it all depends on what everyone is doing in space!

Occams Ghost
2008-Apr-20, 06:27 PM
From relativity we learn many secrets, including the 'Twin Paradox.' In this theory, a twin that travels away from earth a fraction shy of ''c'' (lightspeed), time becomes highly stretched. Let's say he travels a distance of 1,500 lightyears at a speed of 185,888 mps, and when he finally returns, he will find his twin brother on earth has aged remarkably... in fact, his twin brother will probably be six foot under, while he himself might have only aged a couple of years!

This is the paradox of space and time when you move through it at a very fast speed. The twin who traveled the 1,500 lightyears moved so fast that his time slowed down. Let us look at some particles here, to describe some velocities, and how the speed of something marks a territory between real time (imaginary space), zero-time and real space (imaginary time).

A Bradyon, also known as a tardyon, (v<c) moves always with a velocity under ''c''. The speed of light, it turns out, is a kind of border - this barrier is able to limit all Bradyons with a speed always under 186,000 miles per second. For a mass to exceed the velocity of ''c'', means that it needs to increase in mass (we are Bradyons, thus we cannot travel faster-than-light). Thus if a particle exceeded the speed of light, it would need to double in mass - it would also require an infinite amount of energy! This is what relativity explains.

A particle that moves like a Bradyon moves in 'real time' - which is the same as 'imaginary space.' We move so fast through time, and we hardly ever move through space. Time moves through us at the speed of light. We move through time at 186,000 miles per second - this means you are 186,000 miles away from where you where just sitting or standing in each passing second. The root word Brady literally means 'slow' - hence the fictional family, 'the [Brady] bunch', hinting at a family with slow-working intelligence.

A particle with a velocity equaling ''c'' is a bit of a surprise. This particle is ageless. This is, what is called a zero-time particle. A zero-time particle also means zero-space, as it neither moves in 'real space' (which is imaginary time) or 'real time' (which is imaginary space). A photon is a zero-time particle, and ever since it left its source, it existed as if no time was ever spent. In this sense, a photon is never really born, and never really dies!

There is a hypothetical substance called, ''tachyonic matter.'' This matter travels in imaginary time. It spends no time in real time, as it will oscillate back and forth throughout the time dimension. This tachyonic matter moves faster than the speed of light. Such a substance is permitted by relativity because it started with a velocity over ''c''. It is also made of a strange substance called 'imaginary matter'. The word 'tachy' comes from 'tachycardia,' which is fast heart rate.

To make your way through all these imaginary concepts, just remember this following rule; A Bradyon, like most matter in the universe moves below the speed of light, which means it will travel in real time, which is the same as imaginary space. A particle that moves at the speed of light means it experiences no time at all, nor any space. And a particle that moves with a velocity over the speed of light moves in real space, which is in relativity, imaginary time.

The scientific explanation of time is treating it as a vector of spacetime. The following equations are called ‘’Cartesian’’ coordinated systems, and they describe the distance between two points:

s^2 = (∆x)^2 + (∆y)^2

In a rotated system, we twist coordinates around in space, and we find them as a geometry of distance. The new coordinates are given as:

s^2 = (∆x′)^2 + (∆y′)^2

Being almost identical math, they are easy to remember. In this case, we say that distance is an invariant of these equations. More interesting is that we learn that time is also an invariant of space.

Because of this, we can therefore find the following equation describing a spacetime interval:

s^2 = −(c∆t)^2 + (∆x)^2 + (∆y)^2 + (∆z)^2

Where (t, x, y and z) are the coordinates of spacetime, because we can rotate space, and find a corresponding value with time, and this is why we say that space and time are one thing.

We also have a formula that described the changing of time as it is dilated against a body reaching ''c''...

t′ = t cosh φ − x sinh φ
x′ = −t sinh φ + x cosh φ .

Here we have a set of Boosts, where the transformed coordinated are t' and x', and this transformation has a moving value of x'. And therego, we say such a Boost has a velocity of

v = x/t= sinh /cosh  = tanh

To cut them down we can replace φ = tanh−1 v to obtain,

t′ = (t − vx)
x′ = (x − vt)

Where 1/√1 − v2. This satisfies the expressions for Lorentz transformations. Applying these formulae leads to time dilation, length contraction, ect. In Lorentzian spacetime, their components are unbalanced.

ωμ = (−ω_0,ω_1,ω_2,ω_3)

But, even in a more complicated form, a curved spacetime, seems to solve the problems. If an object is accelerating through spacetime, it will experience a time warp. This is also been known to be called time dilation. If we experience time warps, then according to relativity this must also mean space warps.

We don’t experience space warps so much because we move so fast through time. In fact, we spend more time in the time dimension than we do in space. The time dilation formula is given as:

∆t=∆t_0/(1-v^2/c^2) 1/2

So in short notation, we say that space contracts and time dilates by a factor of:

√(1-v2/c2)