Speed of light...instantatious Travel??

[Uncle Martin]

Hello all,

 

This is my first post in your forum. I had hoped to get into a discussion about light speed, but no matter the topic, it is always, eventually infected by the pandemic virus that calls itself "religion".The insidious diseasefinds a wayin no matter how small the opening. Where do they get the audacity? I wouldn't ever consider going to a creationist/religious forum with the intent of proving them wrong, and I certainly wouldn't change the topic of discussion from NDEs to light speed travel !!!

 

Maybe if we pray hard enough thegreat Invisible Pink Unicorn will grant us the wisdom to invent a vaccine to inocculate ourselves from this ubiquitous plague.

[Bo]

justwondering: What kind of lightspeed discusion where you hoping for?

 

And about religion well, the problem is you can't prove nor disprove it. Therefore it's not falcible (don't know if this is the correct english word ) and according to Popper can never contribute to a scientiffic discussion. However it can contribute to some moral/philosophical discussion. (and there area lot of philosophical considerations in modern physics).

 

i dont think anything could delight me more then a pink unicorn giving to theory of everything to mankind

 

Bo

[Freethinker]

Originally posted by: Bo

just wondering: What kind of lightspeed discusion where you hoping for?

 

And about religion well, the problem is you can't prove nor disprove it.

With concern about dragging this yet again into a discussion of religion....

 

While there is some truth to a statement that the existence of a god can not ulitmately be disproved, as the non-existence of ANYTHING can never be ultimately proved, the same can not be said for "religion". A religion will have a specific set of assertions behind it. Some religions are more specific than others. e.g. Christianity and Islam have a specific set of written tenets and beliefs. As such scientific methodology can be applied to see if those tenets and beliefs are credible or not. While Wicca does not have a specific mutually agreed published reference source and as such is not as completely open to review. But any specific claims made can be evaluated by logic and science.

 

Therefore it's not falcible (don't know if this is the correct english word )

 

The word you are looking for is "falsefyable". Yes part of the Scientific Method is falsefyabilitity. Any assertion needs to have a way to show it is FALSE as well as a way to show it is TRUE.

 

and according to Popper can never contribute to a scientiffic discussion. However it can contribute to some moral/philosophical discussion. (and there are a lot of philosophical considerations in modern physics).

This depends on the structure. e.g. Christian Creationism, the idea that things popped into existence by the finger snaps of some sky god. If the assertion is that this mythical entity caused everything to come into existence fully functional 6,000 years ago is not directly testable as it can not be check for what would make it false if the "support" is ultimately "god made it that way" when ever an obvious objection (disproof) is presented. Such as saying that the universe had to be around longer than 6,000 years or based on the speed of light, we would only see things in the universe that are closer than 6,000 light years. If the reply is that this entity made the universe fully functional, that objects further than 6,000 light years were created with their light already 1, 5, 12, ... billion lightyears away from the source. This stops any serious SCIENTIFIC discussion if the answer is always "god happens".

 

However when repackaged as "Intellegent Design", Creationism can then be tested. When the assertions become specific and packed into psuedo-scientific claims, those claims can then be individually tested and will allow for falsefyability.

 

i dont think anything could delight me more then a pink unicorn giving to theory of everything to mankind

 

That is the Great INVISIBLE Pink Unicorn!

[Uncle Martin]

First I must say that modern physics is a philosophy in and of itself, so there are certainly philisophical considerations. The dogma of most organized religions is the antithesis of philosophy, therefore is only of any value when considering religion. Offhand I can't think of any discipline that wouldn't benefit from the application of philisophical considerations.

 

As for light speed, I was referring to the topic title. But since you ask.... Perhaps a person more learned than I can tell me where my logic goes off track when it comes to Einstein's classic thought experiment on time dilation.

 

For the sake of simplyfying the math let us assume that our spacecraft is large enough to allow us to place two mirrors one light second apart. One on each side of the ship. Our ship can also travel at v =.99 c. While at rest in relation to an observer we start an improbable laser pulse bouncing between the two mirrors, this special pulse does not lose any energy to these mirrors and travels perfectly perpendicular to both mirrors ad infinitum.

 

We accelerate to v =.99c, now this is where I have problems. To an observer and the traveler the pulse travels in a straight line and misses the second mirror and is absorbed by the hull .99 light seconds toward the rear of the ship. End of our light clock. In order to get the results that are generally accepted we have to change the angle of the mirrors so that our laser pulse is traveling towards where the next mirror is going to be in 1 light second. For lack of a better term, we must lead the target. This is nothing less than recalibrating the clock and to me invalidates the whole experiment.

 

If we do recalibrate the light clock the laser pulse would appear to the traveler to move between the two mirrors at .01 c because99% of the light's velocity is in a forward direction. To an observer the pulse would be traveling inthe standard zig zag at 1c, but only if observing from above or below the ship. If the stationary observer is looking from the side of the ship they will see the laser pulse travelingsideways at.99 c since1% of the light's velocity is in a forward direction going away from the observer's point of view, the sideways direction of the traveler.

 

I'm not refuting SR, and I know that time dilation effects have been experimentally observed. Although I think not to the point of acceptable verification. In my mind, the jury is still out on time dilation. I'd be totally foolish to refute Einstein, so someone tell me where my logic fails in the thought experiment above.

[Freethinker]

Uncle Martin, thanks for the post. Interesting. I am far from an expert. (Even though I play one on this list! lol) I had considered waiting for someone that actually KNOWS to reply. But:

 

1) I thought I'd weigh in and see how well I do.

2) those that know me here know I can't resist posting SOMETHING anyway.

 

From my limited knowledge, you thought experiment has a flaw. You say:

 

"Our ship can also travel at v =.99 c... We accelerate to v =.99c"

 

You then describe the path of a photon moving perpendicular to the direction of the ship.

 

But from what I see, the photon would have the forward momentum already achieved by and imparted from the ship. Thus to the photon, it would not matter than the ship, phton source, mirrors are moving as they are all locked to the moment of the ship.

 

The only time the photon's path would deviate from the established path between the mirrors is during a change in inertia/ acceleration/ deceleration.

 

Thus your concept of the .99 lightsec target to the rear (front) of the ship would only take place during the acceleration (deceleration), not once a constant speed was reached.

 

A stationary observer from above/ below would still see a zig zag even though an observer located IN the ship, locked to it's momentum, would see a straight path back and froth between the mirrors.

 

Now let's hope that someone that actually knows will join in! lol!

[Bo]

well freethinker is quite right in his explaination i think. The only part where problems arise is whenn the ship is accelarating (at a constant velocity, the light will just get by bouncing from the mirrors the right momentum of the ship) and SR simply doesn't describe accelarating objects... (these are described by GR, but such thought experiments in GR are very hard) but the main point is i think: yes the light can bounce off the mirrors (if the accelartion is high enough) but this doesn't effect the thought experiment of Einstein, since the thought experiment assumes an infinitessimal slow accelartion, that doesn't disturb the experiment. the comparison is made between 2 cases where the accelaration is zero.

I dont really see why one of the observers outside the ship, perpendicular to the travel direction, wouldn't see the zig-zag. Sure one sees the light coming towards and away from him, but still this is a zig zag (you can see the effect of light travelling towards/away by measuring the doppler shift, just like with sound).

i hope this clarifies some things, Bo

[Uncle Martin]

Freethinker/ Bo,

 

Thanks for replying, yes, that does help to explain. Yes, the zig zag could be inferred and the angle determined by the measured velocity I suppose. I was not differentiating between an accelerating body and one at rest, (which I gather is equal to a body traveling at constant velocity). A terribly obvious flaw in my thinking, but alas, I'm not a trained physicist. This would also explain why the image we see of a distant gravitating/accelerating body is where it was when the photons were emitted, and not it's present location.

 

It is still difficult to wrap my brain around the concept, but I'm getting much closer. Thanks.

[GAHD]

"I dont really see why one of the observers outside the ship, perpendicular to the travel direction, wouldn't see the zig-zag" perhapse because the light involved in the experiment needs to diffuse for someone to see it? if the light is trapped by mirrors, in space, it could not interact with the observer; thus the observer could not "see" it.

[Uncle Martin]

Very good point Gahd, if the photons are not actually contacting the observers retinas, no observation!! This was more of a hypothetical thought experiment just meant to prove a point. Google "time dilation" for more info. It is a fascinating subject.

[WDevon]

Glad to see the subject was brought back to the subject. I'm still thinking about mass (you and I) moving at the speed of light. In effect, becoming mass-less. Inside a ship moving at the speed of light, we'd still have have our physical attributes, even though to someone not traveling at the speed of light, we'd be seen as a mass-less flash of energy. Correct?

[Uncle Martin]

WDevon,

 

According to current laws of physics, mass (you and I ), cannot travel at or in excess of v =1c. Theoretically mass can approach the speed of light but cannot ever achieve it. Some theories state that any matter that does actually achieve v=1c would convert to energy ie: Light/photons, so any physical attributes would surely be lost. I have to assume irretrievably so.

 

Light and Time, sometimes the simplest things are the most difficult to explain. I hope to someday truly understand.

[Bo]

well first of all, i think things like time aren't understood by anyone; but it's fun/extremely interesting to see where you can get.

Gahd said:

if the light is trapped by mirrors, in space, it could not interact with the observer; thus the observer could not "see" it.

Good point , but you should remember that this is a thought experiment in which we assume that at any time we can measure the speeds light and velocity, but in principle you are right; you can't see trapped light...

WDevon said:

(you and I) moving at the speed of light. In effect, becoming mass-less.

in principle true, the problem is: we don't move at the speed of light The point is: when a massive particle goes faster, it's mass increases. While the mass increases, it becomes more difficult -you need more energy- (by standard Newtonian mechanics) to get it to an even higher speed. Eventually when your speed approaches the speed of light, your mass will become infinite, and also the energy needed to get you really *at* the speed of light will become infinite; so that just can't happen (we don't have sources of infinite energy, unfortunatly). This is also the reason that a particle, actually travelling with the speed of light, should have exactly 0 mass, otherwise it would have infinite energy. -Bo

[Uncle Martin]

Bo,

Isn't it RELATIVE mass that increases with velocity, and not actual mass? Have you read any of Peter Lynds' work on time? He claims to have solved Zeno's paradox. It is interesting, even though I don't completely get what he's saying sometimes.

[Bo]

yes that is most certainly true, but that doesn't disprove my previous point. It's even in general true that no relativitistic effects are measured if you travel allong woth the particle you study, but then again, you move along with that particle, so you will never see it reach any speed. -Bo

[GAHD]

Originally posted by: Uncle Martin

Very good point Gahd, if the photons are not actually contacting the observers retinas, no observation!! This was more of a hypothetical thought experiment just meant to prove a point. Google "time dilation" for more info. It is a fascinating subject.

 

Time dialation is a facinating subject, But it's still a matchstick house based on our perfect math applied to an imperfect ever changing universe. Ex; by the universe increasing the speed of expansion/inflation "C" suddenly assumes a smaller value. As well the facts of time dialation have yet to be proven to any significant, irrifutable extent. Freethinker and I have had extensive discussions on this in this very thread and others. Time dialation is based on "faith" in someone else's experiments (such as the Hafele-Keating experiment ); which I refuse to have any faith in without the complete and raw, unaltered data. This data has prooven exceedingly hard to find in complete form.

 

 

Originally posted by: Uncle Martin

Isn't it RELATIVE mass that increases with velocity, and not actual mass? Have you read any of Peter Lynds' work on time? He claims to have solved Zeno's paradox. It is interesting, even though I don't completely get what he's saying sometimes.

Zeno's Paradox 1 2, two sites on that. The paradox are more like "jedi mind tricks".

 

We havn't actually pushed a camera of significant mass, with a specific amount of element 'x' which has a half-life, to relativistic speeds, slowed it back down, then dated it (based on half life) and played the tape to determine if it has infact moved through less time than us (the observers) thus viewing time dialation in progress, and the flattening of space predicted, irrefutably. IE your angle of view increases physically, but decreses in scope; everything is infront of you at 1c.

 

Again, a matchstick house I cannot disprove, but isn't sufficently stable for me to truly accept it; thus I will try my hand at doing so yet again in the interst of 'pushing the envelope' weather or not my views turn out to be true or simple mind exercises.

<u>here we go</u>

 

E=MC^2, mass and energy are inherently the same thing(this I have no problem with) so in theory(IE not yet prooven beyond doubt or statistical anomoly) kinetic energy = mass. We KNOW Speed+Mass=force transfered on impact, the rest is math derivitives which assume because a moving body has kenetic energy, it then suddenly aquires more mass. The line I don't like crossing is relating motion to a larger gravity well.

My view on this; mass has gravity, mass=energy, yes. A moving mass has it's kinetic energy used in movement; not into the rather solid "matter". Matter=gravity, not energy=gravity; otherwise Photons WOULD have a measureable mass. By the same token this allows gravity to interact with energy indirectly through the warping of space(a property of the structure of matter) and for electromagnetic forces to interact with matter(the polorisation of space and energy).

 

The actual concept of time is more the decay of matter, induced by the 'waves' moving through the universe(again, theory, but one that holds some tenure).

 

Deconstruction of the general theory; Apparently getting a massive dose of oncoming waves all at once isn't as destructive as taking reduced dose over a longer period(my main problem with it). This equates that matter seems to inherently make itself resillient to this decay based on the amount of energy it posses'.

 

This doesn't seem anywhere right t

[Bo]

The hafele keating experiment is indeed quite hard to analyze in this way, and i have no idea what to believe in this case... there are many examples of physicist drawing conclusions from experiments, because the theory predicts them so. (unfortunatly the pictures in you rlink didn't work on my computer...) However there are other, (better in my oppinion) proofs of time delation: one of them is the following: when in rest muons (some heay version of the electron)have a half life of about 2.10E-6 sec. We know that muons are created by cosmic rays in the upper atmosphere (say 10km high) and that they then have a speed of about 0.98c. if we measure the amount of muons created, and asume no time delation, we can predict how many muons we should see on earth. say 1% (don't know the numbers, you can probably find them on the web). Well now it's measured that we see e.g. 10%. How can this be? The answer is: since the muons are fast moving from our point of view (the 'earth'), thier clock is ticking slower, so from our point of view their half life will increase, which means that less have decay'd in their trip from 10km high to us. From the muon point of view, it's halflife will still be 2.10E-6sec. but for the muon the 10 km we measure from earth will be contracted, so from the muon point of view the distence travelled is less, so in that smaller distence less muons could decay.

If you do the calculations, the amount of muons that has decay'd is the same from both points of view (as it should be) and also in accordence to measurements done. (have no reference here, but i guess you can find it on the web. Also note that the experiment described above is constantly used (and since they measure something: verified!) in particle accelarator facilities like CERN.

(we KNOW Speed+Mass=force transfered on impact, the rest is math derivitives)

Well first of all: We KNOW nothing. we dont know what time is, we dont know what space is, we dont even now what truth or reality is. Physics is all about trying to find the best discription of nature. For this we use mathematics as language, and we dont even know if this is the right language... But apart from that: i guess you mean: accelaration*mass=force? The thing you wrote down is not something generaly accepted . So we only know that the formula a*m=F is a good discription (so no truth!) of nature as we can see it (and there is a lot we can't see!)

...we havn't actually pushed an object (camera, with a specific amount of element 'x' of which has a half-life, would be nice) of significant mass to relativistic speeds, slowed it back down, then carbon dated it and played the tape to determine if it has infact...

well as said above: this is done all the time at particle accelerators. The point you make about 'significant mass' is not in order here, since time delation is only dependend on relative velocity.

What you say after this i really don't understand. What waves are you talking about? i will be glad if you could give some better description of your ideas.

Bo

[GAHD]

whoopse, I did make a slip there...