Faster Than Light Travel

Roboramma said:
Woops, I misread the quote that I was responding to. Sorry about that. I think you're right. But I think it's interesting to take another look at why you're right.

I think a good way to think about this is to still look at it as though your ship is stationary. In this example, it is the mirrors that are moving past you at .51c. Let's say the mirrors are 1 light second (300,000km) apart.

Here's a diagram of what it looks like in the mirror's reference frame, if I were to use the example as you give it:
light:
.......^..........^
...../...\......../
..../.....\....../
.../.......\..../
............\../
..............v
You:
----------------->

My problem is that there are two dimensions of movement, and I can't easily figure out how to solve the problem that way. So, I think works out the same if we look at it with only one dimension, but where it happens like this:

(blue dashes are where the light travelled only once, red coloured dashes are places where the light has to cover that distance twice. Black dashes are just for formatting and should be ignored. Again this is from the mirrors' reference frame)
light:
----------\
----|----------\
---------|----------\
You:
--------------------->
The dashes are mirrors that are only very very slighlty tilted (so little that I don't have to take it into account), the straight lines are mirrors that direct the light perpendicular to your line of movement (from the mirror's reference frame of course). The light goes forward 300,000 km, then is reflected back 150,000km, where it hits a second mirror, turning it back for 300,000km again, etc. This will still double it's path, and thus allow you to outrun it.
But all of that is from the mirror's reference frame. What does it look like from yours?

Now, I think I've got this right, from your perspective what happens is that the path of the light beam is distorted. You are stationary, and a set-up of light emiter and mirrors is moving toward you at .51c. When the light emiter passes you, it emits a burst of light.
The light moves away from you at c.
After going something less than 300,000km, it hits a mirror which is moving toward it at .51c. The reason that it didn't have to travel 300,000km is that the mirror covered part of that distance in that time.

Now it moves back toward you at c. It travels back more than 150,000km where it hits another mirror. The reason that it travelled more than 150,000km is that the mirror moved away from it during that time.
Here's the important part - if you do the math, it will turn out that it traveled back more than the "something less than 300,000km" that it had already travelled. In fact, it will have passed by your ship.

Now it travels toward you again, at c. This time, before it reaches you, the next mirror which has been wizzing up toward it intersects it, again after it's gone something less than 300,000km. It starts traveling away from you again at c.

As you can see, even though in your reference frame, you aren't moving, the light will be continuing to get further and further away from you, even though it is aways travelling at c.

I think that with your original zig-zag set-up it works out the same because the angle that the light is reflected will be changed. But I'm not quite sure. Can anyone enlighten me about this?

Anyway, I mostly just did all that as a fun exercise, but I do think it helps a lot to ask yourself "what reference frame am I talking about?"
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I found some math that might apply to the FTL travel subject and wanted to know what you all think. It came from this link, but is common physics math.

I still have problems with the inverse square functions (they dont seem to account for actions at a distance properly). common fractions come into play and we know little about the slow forrier transformas that reach near 0 (long period) that we negate.

this link:http://mb-soft.com/public/gravitat.html

and specifically this equation attached as jpeg might be getting closer to a concept of FTL travel: This equation as it applies to perterbations in gravational field ressonance.

Brief Mathematical Discussion
A more technical presentation of this is that in standard engineering, the equation of motion of a forced vibration can be represented by a differential equation (in this example, a weight suspended by a spring in a gravitational field):

Where W represents the weight or inertia of the object, g is the acceleration due to gravity, the x terms represent the first and second derivatives of position (essentially velocity and acceleration), P represents the amplitude of the harmonic disturbing force, t is time and omega is the frequency of the disturbing force, the other items being constants.

In any system, this initially results in a vibration made up of two parts, a free damped vibration at the natural frequency (omegan) of the object (due to the interplay of the inertia of the object's mass and the restoring force of the spring), which virtually always soon gets damped out in engineering applications, and a forced vibration which will continue as long as the disturbing harmonic force is applied.

For that relatively simple case, as the free vibration is quickly damped out, the vibration is then just the forced vibration component. The expression for this is:

Where X (amplitude) and phi (phase) are given by:

Zeta is the 'damping factor' that acts to dissipate the vibration, and the omegas are again the 'forced' frequency and the 'natural' frequency.

In the case of gravitational applications, P would represent the distance-variable gravitational attractive force of the perturbing body (nearly sinusoidal), omega would be the synodic frequency, omegan would be the orbital frequency of the object being perturbed, and the left side terms in the equation of motion would represent the original unperturbed orbit characteristics. There are some aspects of gravitational systems that are sufficiently different from standard engineering forced vibration, as to require modifying these factors and equations. Specifically, the force of gravitation is an inverse-square dependence rather than the simple linear dependence of a spring. For co-planar orbits, the vector distance between the two objects varies during the synodic period as the square root of (R12 + R22 - 2 * R1 * R2 * cos(theta)), where theta is the instantaneous primary (solar) angle between the two orbiting objects. The cumulative effect of the perturbative effect would involve the Integral of the inverse square of this quantity. The point here is primarily to present the basic concept.

It is easy to see from the resultant amplitude equation above, if the forced frequency is exactly the same as the natural frequency, the denominator of the X term drops to its lowest value, which causes X, the amplitude, to reach its greatest value, the so-called 'magnification factor'. The limit on the magnification factor is therefore based on the amount of damping present. It would seem that in gravitational problems little damping would be present, and the amplitude of the perturbation could become extreme. In the case of an orbit, such a very large perturbation amplitude could cause the existing orbit to rapidly become unstable, shifting the orbital elements to a different orbit that was stable or at least meta-stable.

any comments would be appreciated!

lh
 

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ponderingturtle said:
The particles to wave issue is irrelvent, what is relevent is its mass, if it has no mass it travels at the speed of light if it has mass it can not.
Click to expand...

PT,

I must say I agree that is what we have been taught. Waves on wednesday and particles on friday... But the gravity equations still seem to defy logic. Ressonance theory is a very funny bunny. (schrodinger and experience tells us that these ressonance constructions in both math and physics can perform amazing feats in physical reality, both create and destroy) So I would wonder/ponder (as we all do) if the answers are in these wave (ressonance) perterbations of (fast/slow forrier transforms) frequency domain...e.g. Light, RF spectra etc.. and time domain, actualized Matter (from waves) or photonics? I some how feel the large (cosmos) and the small (photonics emissions) tachy particles (strong forces of the atoms) are inseperabally linked via a wave or ressonance holy grail of equastion(S) or a new model so to speak? I think many of us here are touching on it conceptually. maybe a new model can be made from these vector(s) and complex variables being added or modeled conceptually and then mathematically described. I am quite poor at math most times but good at conceptualizing. So I constantly draw on those with math calc strength to form better descriptions in math. o maybe a 3D+ Model in autocad or wolfram research / mathcad or similar might help us with these concepts and models? somehow the large (matter/ressonance waves) and small (waves/ressonance) are linked. This I think is the key to mathematically descibe in detail this link.?

lh
 
luvhumility said:
I
Where W represents the weight or inertia of the object,
Click to expand...

Why would you care about the weight of an object, it is the mass that matters as that is related to innertia, any type of advanced physics that mentions weight generaly means that the person doesn't know what they are saying.
 
luvhumility said:
PT,

I must say I agree that is what we have been taught. Waves on wednesday and particles on friday... But the gravity equations still seem to defy logic. Ressonance theory is a very funny bunny. (schrodinger and experience tells us that these ressonance constructions in both math and physics can perform amazing feats in physical reality, both create and destroy) So I would wonder/ponder (as we all do) if the answers are in these wave (ressonance) perterbations of (fast/slow forrier transforms) frequency domain...e.g. Light, RF spectra etc.. and time domain, actualized Matter (from waves) or photonics? I some how feel the large (cosmos) and the small (photonics emissions) tachy particles (strong forces of the atoms) are inseperabally linked via a wave or ressonance holy grail of equastion(S) or a new model so to speak? I think many of us here are touching on it conceptually. maybe a new model can be made from these vector(s) and complex variables being added or modeled conceptually and then mathematically described. I am quite poor at math most times but good at conceptualizing. So I constantly draw on those with math calc strength to form better descriptions in math. o maybe a 3D+ Model in autocad or wolfram research / mathcad or similar might help us with these concepts and models? somehow the large (matter/ressonance waves) and small (waves/ressonance) are linked. This I think is the key to mathematically descibe in detail this link.?

lh
Click to expand...

Well for one thing I already pointed out how the speed of light can be concidered to be the speed at which everything travels through space time. This is because if you factor an objects speed through time into its speed through space you will always get c.
 
Dave1001 said:
What's your day job, luvhumility? I'm guessing mathematician or physicist?
Click to expand...

Dave,

Thanks for the complement! but no, I am a simple self taught Electromechanical designer. Mostly electronics. (high voltage, lasers, IC wafer fabrications technology etc) I have worked with math and physics people but aspire to know more of both. I have been interested I these areas since I was a wee child. (mostly magnetics and gravity) THe math though, seems to constantly kill me. I can recite from memory many electroncis formulas but the trig and calc can send me for a loop...So I really DO LOVE and RESPECT math heads!!!

lh
p.s. time for me to go back to school? maybe so!
 
ponderingturtle said:
Well for one thing I already pointed out how the speed of light can be concidered to be the speed at which everything travels through space time. This is because if you factor an objects speed through time into its speed through space you will always get c.
Click to expand...

So If I understand correctly mass can "bend" light (change velocity) but not change "C" or speed thereof??

lh
 
ponderingturtle said:
Why would you care about the weight of an object, it is the mass that matters as that is related to innertia, any type of advanced physics that mentions weight generaly means that the person doesn't know what they are saying.
Click to expand...

PT,

I am not sure, but I think It can become a significant variable when looking at complex dynamic mass/weight systems from a relativistic frame set. yes Mass is considered a constant (for the ease of calculations) but weight is not.
But the fact that "weight" is not a "constant" does not negate it importance... I dont know maybe I digress here?

I think its true that both you and I weigh slightly less (very slightly) at High altitudes than we do at sea level...(but our mass is the same at both alt's) so maybe it is important for these calculations at long distances? Maybe someone else knows more on this subject? This reminds me of the clock tower experements or the precision clocks experments (cesium clocks I think) (one being stationary (so to speak on earth) and another in an aircraft flying around... and the one in the aircraft displayed time slightly slower time then the earthbound clock...can't quite remeber exactly. BUt I think thats correct.

the clues may lie herein??

lh
 
So If I understand correctly mass can "bend" light (change velocity) but not change "C" or speed thereof??

I think I confuse the definition of speed and velocity?...
 
luvhumility said:
So If I understand correctly mass can "bend" light (change velocity) but not change "C" or speed thereof??

lh
Click to expand...

Well an important thing to remember is that c is the speed of light in a vacume, and yes gravity does bend light, but no matter who measures it and what has happened the speed of light is always c in a vacume.

Everyone will always measure c to be the same always.
 
luvhumility said:
PT,

I am not sure, but I think It can become a significant variable when looking at complex dynamic mass/weight systems from a relativistic frame set. yes Mass is considered a constant (for the ease of calculations) but weight is not.
But the fact that "weight" is not a "constant" does not negate it importance... I dont know maybe I digress here?

I think its true that both you and I weigh slightly less (very slightly) at High altitudes than we do at sea level...(but our mass is the same at both alt's) so maybe it is important for these calculations at long distances? Maybe someone else knows more on this subject? This reminds me of the clock tower experements or the precision clocks experments (cesium clocks I think) (one being stationary (so to speak on earth) and another in an aircraft flying around... and the one in the aircraft displayed time slightly slower time then the earthbound clock...can't quite remeber exactly. BUt I think thats correct.

the clues may lie herein??

lh
Click to expand...


weight, here is the math!!! hehe

lh

Message:

Hi Bill,

Before we attack your question per se, let's define weight. Weight is really the force of gravitational attraction between two objects and is given by Mr. Newton's formula for Gravitation: F=GmM/r2 (I guess if you really feel like torturing yourself, you could try deriving the appropriate formula in Einstein's theory of general relativity :). Anyway, the radius of separation here would be the distance from the center of the Earth to whereever you are. So let's try this first for Cincinnati and then for Puebla.

Some Preliminary Data:
r is the radius of the Earth: 6378137 m
G is the gravitational constant: 6.672 59 × 10-11 m^3 kg^-1 s^-2
M is the mass of the Earth: 5.9736x10^24 kg
m is your mass (let's assume 50kg)

Cincinnati: 870' above sea level (approx. 265.176 meters). Therefore, for Cincinatti, r is (radius of Earth + 265m = 6378402) which gives a gravitational force of approximately:

F = GmM/r2 = 489.87N = 110.22lbs

Puebla: 7,500' above sea level (approx. 2286.00 meters). Hence, for Puebla, r is (radius of Earth + 2286m = 6380423) and the gravitational force would be approximately:

F = GmM/r2 = 489.56N = 110.15lbs

This is a percent decrease of (110.22 - 110.15)/110.22 * 100 = .06%. That's quite a small change in weight but if you were keeping careful track, or weighed quite a bit, then I guess it would be noticeable. There's a way to make this formula a little more tractable. You might have noticed that the GmM doesn't change in this formula (in fact, the g in W=mg is just GM/r2); so you could take that out as a constant and just compute the % change in 1/r2 and that would also give the percent change in weight. Let's test this out:

For r1=(r + 265m) and r2=(r + 2286m), r12=40684012073604.00 and r22=40709797658929.00; therefore, (1/r12 - 1/r22))/(1/r12) * 100 = (2.457968005197809e-14 - 2.45641112829424e-14)/2.457968005197809e-14 * 100 = 0.0633399987419193 which is approximately .06%, as predicted.

So, putting all this together, if you need a formula to see how much your weight changes when you go from one locale to another, all you need to do is:

1. Get your current altitude, add that to the radius of the Earth, and call it r1
2. Get your new altitude, add that to the radius of the Earth, and call it r2
3. Finally, plug your values into the following formula: [(1/r12 - 1/r22)/(1/r12)] * 100
 
luvhumility said:
PT,

I am not sure, but I think It can become a significant variable when looking at complex dynamic mass/weight systems from a relativistic frame set. yes Mass is considered a constant (for the ease of calculations) but weight is not.
But the fact that "weight" is not a "constant" does not negate it importance... I dont know maybe I digress here?
Click to expand...

Of course weight is not a constant, as it is solely dependant on the normal force and such. That is why it is a poor concept. Weight is a form of force, and anyone who treats it as being like mass is doing it wrong. On the whole it felt to be more like something written by a crank than by someone who knew what they are talking about.
I think its true that both you and I weigh slightly less (very slightly) at High altitudes than we do at sea level...(but our mass is the same at both alt's) so maybe it is important for these calculations at long distances? Maybe someone else knows more on this subject? This reminds me of the clock tower experements or the precision clocks experments (cesium clocks I think) (one being stationary (so to speak on earth) and another in an aircraft flying around... and the one in the aircraft displayed time slightly slower time then the earthbound clock...can't quite remeber exactly. BUt I think thats correct.

the clues may lie herein??

lh
Click to expand...

But those all have nothing to do with reletivistic velocities, if you are moving at 200,000,000 m/s 9.8 m/s^2 is nothing you will really notice. And trying to put weight into it instead of force is just wrong.

Yes weight does vary on location and not just altitude, but so what that is just a varying of force to do irregularities in the density of the planet.
 
ponderingturtle said:
Well an important thing to remember is that c is the speed of light in a vacume, and yes gravity does bend light, but no matter who measures it and what has happened the speed of light is always c in a vacume.

Everyone will always measure c to be the same always.
Click to expand...

Could one say mass "attracts" light? in some sort of way?...If bending is consider attraction then the masses "strong" force (the maxwell number) is certainly a force to affect light. (at a distance) BUt exactly how I guess is my question?

I get lost here because the inverse proportion squre e.g. magnetic flux density is inversely proportional to the square of the distance) rule (that applies to magnetic fields) seems to break down here... I do not know why...? maybe I digress again?>?

lh

brb need to cook breakfast!!!
 
maybe small parts of the mass (e.g. electrons that have little or no mass) at the outer radius of the mass object "slingshot" the light as it approaches and slow it as it leaves the center of the solar vector of the mass???

lh
 
Dave1001 said:
What's your day job, luvhumility? I'm guessing mathematician or physicist?
Click to expand...

No, Google-junkie.

I suspect his/her understanding of what he/she posted is on par with my understanding of ancient greek nose hair. The vast majority of the post earlier (with the math and such) was lifted whole from another site (she posted the link, but did not make this clear). Only the first two and last paragraphs are his/hers.

The posting of equations for weight underline this viewpoint, as the dependent nature of weight is specifically why it's a bad choice for these types of equations, something that should have been taught in high-school level physics. It's only used int he paper he/she linked because they are specifically discussing a weight on a spring.

Not to mention that the paper she linked to has about as much to do with FTL travel as I have to do with running the U.N. What luvhumility is doing here is throwing up a lot of scientific-sounding things he/she doesn't understand in a desperate attempt to give his/her speculations a semblence of support. Much as one might claim their psychic powers are "like, quantum, man".
 
ponderingturtle said:
Of course weight is not a constant, as it is solely dependant on the normal force and such. That is why it is a poor concept. Weight is a form of force, and anyone who treats it as being like mass is doing it wrong. On the whole it felt to be more like something written by a crank than by someone who knew what they are talking about.


But those all have nothing to do with reletivistic velocities, if you are moving at 200,000,000 m/s 9.8 m/s^2 is nothing you will really notice. And trying to put weight into it instead of force is just wrong.

Yes weight does vary on location and not just altitude, but so what that is just a varying of force to do irregularities in the density of the planet.
Click to expand...

So we come full circle to the Harvard clock tower experement and Gravitational red shift. Does the blue shift balance this out through conservation of energy concept?

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/gratim.html>

Gravitational Red Shift

According to the principle of equivalence from general relativity, any frequency shift which can be shown to arise from acceleration of a radiating source could also be produced by the appropriate gravitational field. Thus the expected shift in radiation frequency in a gravitational field can be related to the relativistic doppler shift experienced from an accelerating light source.

I get a little lost here: PonderingTurtle can you expound for me?

lh
 

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