An idea.

If you look at this a bit deeper you see that light speed isn't a barrier. It's a boundry - the boundry in terms of spacetime as the break-point between space and time.
Click to expand...

I probably should expand on this idea for you.

When you're standing still (zero velocity with respect to the inertial observer) you experience all time and zero space. That is, you move forward in time but have no movement in space. Your situation is completely "timelike".

As you start accelerating you begin to move more slowly in time (with respect to the observer) and more quickly in space. Your movement in spacetime is becoming more "spacelike".

At the speed of light the observer sees your clock stop. At this point your movement is neither spacelike nor timelike - it is "lightlike" (you simultaneously occupy all of time and space in your universe - you're infinitely "smeared out" in spacetime.

If you could move even faster your movement switches from being timelike (sub-light velocities) to "spacelike". You move faster through space than a photon can move in space.

There is a problem. Your time signiture becomes negative. You move through negative time (backwards). But something else also ocurs that no one ever talks about. Your space signature also switches to negative. You begin to move through "negative space". And no one knows just what that means.

It is a truth of symmetry in the mathematics of special (and general) relativity but that's just the math. The math doesn't define what negative space is. It might be another universe, it might be some form of space that we have never encountered or it might be just a solution to the math that has no meaning in the "real" world. It could also mean that if the solution is "another universe " that the conditions of that universe are such that both time ans space have negative signitures with respect to our universe and you end up traveling forward in both space and time in a "normal" fashion that you experience in this universe, i.e. you are in a tachyon universe. But in that universe to slow down you have to add energy and to speed up you have to lose energy. At zero energy you accelerate to infinite velocity. At infinite energy you slow to light speed.

General relativity is so complex in its math that no one has been able to solve it during the past 90 years since Einstein first published it.
 
"General relativity is so complex in its math that no one has been able to solve it during the past 90 years since Einstein first published it. "

i find it all very interesting. i am starting to think that maybe more is known about it than i thought. but im not sure.

i have a question, may sound silly. why is light speed so hard to achieve?

i also wonder about other things, like how gravity bends light, etc. so if we caught light in a bottle, would it be considered time in a bottle?
 
i have a question, may sound silly. why is light speed so hard to achieve?
Click to expand...

It's not at all a silly question.

There are several ways to approach the answer but one approach that we're familiar with is helpful.

You remember E = mc^2 from Einstein's special relativity.

That manner of expressing the equation is for a mass at rest. When we accelerate the mass it takes an energy input. When velocities begin to approach half the speed of light the equation has to be expressed in its full relativity form...

E = mc^2/(1-v^2/c^2)^1/2

The divisor is the clue. At low velocities you are dividing by ~1. But as velocity (v) begins to approach the speed of light the divisor starts to approach zero. The value of the mass (m) in the equation starts to zoom toward infinity. Therefore the energy required (E) to accelerate the mass (m) also also begins to approach infinity.

Every time you input energy into the system to acelerate it the energy is tansformed into mass, which is exactly what E=mc^2 states. The next energy input has to not only attempt to acelerate the "original" mass but it also has to accelerate the additional mass. A property of mass is inertia - defined as the property of mass to resist acceleration.

It's a no win situation. You eventually get to the point where you have a near infinite mass which isn't quite traveling at the speed of light and which requires an additional near infinite input of energy to eck out an infinitesimally small increase in velocity. The inertia of the mass is almost infinite. To get it "over the top" so that you reach light speed requires an infinite amount of energy to be input, but that energy is resisted by infinite inertia. No amount of energy will be sufficient to overcome that last bit of inertia.
 
very interesting.

a few more questions if i may:

how is the speed of light measured?

and do you think there is maybe another way to reach the speed of light? like an avenue that physics hasnt explored, or some abstract idea?

for instance, look at the universe as if it were a CAD program, using the standard XY coordinate. could physics take advantage of that?
 
and do you think there is maybe another way to reach the speed of light?
Click to expand...

Perhaps there's a way to JUMP OVER the speed of light boundary. Relativity does not prohibit particles to travel faster than light. It only prohibits them to travel AT the speed of light (unless they are massless, like photons).

Of-course, you can't jump over the light boundary by simple acceleration. Darby already explained why this is impossible. It is, however, concievable that there are other ways to do so - ways which are unknown to current science.

By the way, travelling faster than light is not the same thing as travelling backwards in time. The two concepts are closely related, though. If you have access to faster-than-light technology, time travel becomes trivially easy.
 
its all very interesting. i have alot of ideas, none will probably work though.

is there by any chance a such thing as a light vaccum? just wondering, was something im thinking about.

i really need to go back to school, ive got tons to learn lol
 
i think i finally get it. just before light speed, the power to weight ratio is 0.1 so it has no more acceleration. is this correct darby?
 
i think i finally get it. just before light speed, the power to weight ratio is 0.1 so it has no more acceleration.
Click to expand...

I assume you meant 0, rather than 0.1?

Yes. You're correct. The faster you go, the heavier your ship gets, and the same amount of power gives you less acceleration.
 
"I assume you meant 0, rather than 0.1"

what i meant was right before light speed, the power to weight ratio is 0 to 1 meaning 0 power and 1 weight. in other words, no amount of known force can push it that hard.
 
So you meant 0 : 1. Now I understand.

Since 0 : 1 is the same thing as 0, my previous answer still holds.

To be precise, the ratio never reaches 0. At the speed of light it would be 0, but you can't reach the speed of light. You simply get less and less bang for your buck, getting closer and closer to the speed of light.

There is a way to see this very intuitively. It is called "rapidity".

Rapidity is a measure of how fast an object is moving, and can be calculated from its speed. The rapidity scale is designed so that the same amount of power always give rise to the same increase of rapidity. Rapidity goes from zero (for an object at rest) to infinity (at the speed of light). At everyday speeds, rapidity and speed are virtually identical. At 0.50c (50% the speed of light), the rapidity is 0.55c. At v=0.80c, the rapidity is 1.1c. At v=0.99c, the rapidity is 2.65c. And at v=c (the speed of light), the rapidity is infinite.

It is rapidity, rather than speed, that behaves intuitively at high speeds.

Here is a simple example:

In everyday mechanics, speed is comulative. If you're riding a car going at 80 mph, and you're throwing a ball forward at 60 mph (relative to the car), the ball will go at 80+60=140 mph relative to the ground. Combining speeds is a simple matter of adding the numbers up.

In relativity this is not the case. If you're in a ship going at 0.80c (80% the speed of light) and you fire a torpedo at 0.60c (relative to the ship), the torpedo isn't flying at 1.40c. You obviously can't just add the speeds here, because 1.40c is faster than the speed of light.

So what do you do? You add rapidities instead of speeds:

A speed of 0.80c corresponds to a rapidity of 1.10c
A speed of 0.60c corresponds to a rapidity of 0.69c

Add them up, and you get the rapidity of the torpedo: 1.10c+0.69c=1.79c

Which you can convert back to ordinary speed if you wish: 1.79c => 0.946c


By the way, did you know that the calculator of Microsoft Windows can easily convert speed to rapidity and vica versa?

To convert speed to rapidity, type in the speed, and then press I,H,T.
To convert rapidity to speed, type in the rapidity, and then press H,T.
 
Consider this one. Ok....light and sound must evidently be a part of each other since both are a part of frequencies. Frequencies can vary from fast and slow. Wouldn't it be interesting if our consciousness would allow us to see light and sound co-ordinate together a put on a show? Anyway....I feel the fast, higher frequencies go toward the future, and the slow, lower frequencies go toward the past. But......regardless of speed.......I feel the main thing is to allow our minds to accept the reality of traveling either to the past or to the future. I believe that the past, present, and future are all in the NOW. /ttiforum/images/graemlins/smile.gif <font color="blue"> [/COLOR]
 
Experiment,

Light and sound in one sense are fundamentally different. Sound, as we usually perceive it, is a change in air pressure that is sensed byt our ear drums. In another sense they are both part of the electromagnetic spectrum - nothing more than different frequencies in the totality of the spectrum of "light".

What do you mean by "fast" or "slow"?

Wave forms travel at the speed of light in a vacuum - or at the speed of light allowed in a specific medium, i.e. as allowed by the Index of Refraction in that medium.

EM waves forms propogate, in either case, toward the future. The only way for a wave form to propogate toward the past is for it to have a negative frequency (whatever that means). But in that case the wave form would be traveling in negative space (whatever that means).
 
Experiment,

I didn't mean to be obtuse when I refered to negative frequencies or negative space. But the problem involved there is one of balancing an equation. The sign, negative or positive, of an element of a mathematical equation...if the formula is actually an "equation", i.e. both sides of the equals sign really are equal...means that if you change the sign of one side you have to find a way to change the sign of the other side of the equation so that it balances... so that is is really "equal" on both sides.
 
Darby-
I have an observation on this comment-

&gt;I didn't mean to be obtuse when I refered to negative frequencies or negative space.&lt;

And this earlier comment-

&gt;When you're standing still (zero velocity with respect to the inertial observer) you experience all time and zero space.&lt;

It occured to me this morning that if you truly could stop/freeze time, you would quickly die. Why? Because if you truly stopped time, you stopped the movement of the universe... atoms would freeze and stop around you. You would find yourself surrounded by inert matter- the very air around you would be impossibly solid. You would push the air but (through the nature of 3D/insert physics formula here) you'd find the harder you tried to push the air around you, the harder it would push back. Why? Because time is standing still/movement itself is standing still.

You would inhale and inhale o2 molicules at absolute zero, which would quickly kill you. For all intents and purposes, there is no difference between floating in the vacuum of space and standing in non-time. Do you agree and what the hell am I referring to- someone had to already have pondered this notion.
 
"It occured to me this morning that if you truly could stop/freeze time, you would quickly die. Why? Because if you truly stopped time, you stopped the movement of the universe... atoms would freeze and stop around you. You would find yourself surrounded by inert matter- the very air around you would be impossibly solid. You would push the air but (through the nature of 3D/insert physics formula here) you'd find the harder you tried to push the air around you, the harder it would push back. Why? Because time is standing still/movement itself is standing still.

You would inhale and inhale o2 molicules at absolute zero, which would quickly kill you. For all intents and purposes, there is no difference between floating in the vacuum of space and standing in non-time. Do you agree and what the hell am I referring to- someone had to already have pondered this notion. "


ive thought something along the lines of that, but a little different. i thought it might be like when a computer program locks up, and you have to restart. or everything blows up.

gives a whole new meaning to "its a little too quiet." /ttiforum/images/graemlins/smile.gif
 
At the extremes like Absolute Zero (which is never reached) and at the other end where the mass becomes infinite along with the energy needed (again never reached) perhaps there is a Chronological Protection and Correction there. Thus one can never really stop the vibrations at the Absolute Zero end and one can not Correct or Change the Time Flavors at the Speed of Light end. So in the end, you can never absolutly know those inertial frames of reference because although you can get close, you are dealing with "zero" and "infinity".
 
maybe stopping time is what caused the big bang /ttiforum/images/graemlins/smile.gif

i have a question, how does physics handle lightspeed and weight? for instance, if you wanted to find the impact of an object that is going 1 tick before the speed of light and weighs 1 ton, and you slam it into a planet,would the math be accurate? and can physics comprehend ALL of the variables?
 
&gt;At the extremes like Absolute Zero (which is never reached) and at the other end where the mass becomes infinite along with the energy needed (again never reached) perhaps there is a Chronological Protection and Correction there.&lt;

Agreed.

&gt;Thus one can never really stop the vibrations at the Absolute Zero end and one can not Correct or Change the Time Flavors at the Speed of Light end.&lt;

I disagree- after all, this is what a time machine does: alter the logical progression of time... it "time travels". I think when we figure out what we're all swimming in, we'll figure some new tricks- foremost time travel.

Say you froze time and took someone who is sitting on the roof of a building and carried him down to street level then started time- would he instantly splat when time started again? Why or why not?
 
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