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Posted March 01, 2009 5:01 PM

Welcome to the March edition of Monthly Challenge Question from Specs & Techs by GlobalSpec:

You are traveling at half the speed of light and turn on the headlights of your vehicle. If you increase your speed to the speed of light, will you be able to catch up to the light from the headlights?

The answer is no. There is no way to catch the light since according to Einstein's Theory of Relativity nothing travels faster than light. However due to the refractive material in the head lamp the light could be slowed or bent but never caught. There are many that say it can be done, but yet no proof that actually supports their thoughts.

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Guru

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#1

03/01/2009 9:17 PM

No, you will not catch up because the light you are emitting, at the speed of light, will be traveling faster then the speed of light.

I know this from experience.

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#13

03/03/2009 12:48 AM

not so smart

So that was you then! Well, I was going at the same speed and I never even saw you. I was coming the other way, remember?

The only thing traveling faster than light is the distance we covered while approaching each other. When you put on your lights and I put on mine they will meet at half way. The combined distance of that, could not be covered if it was only one light source, trying to cover that same distance.

I wonder what sb will come up with!

I'm out of here, for now, Ky.

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#53

03/04/2009 8:06 AM

Two light beams crossing each other will not see each other well to see anything you need light and since you are light and you don't exist (since mass can not be speeded upto light speed else E will turn in his grave and I assume you did have mass at least in some part of past before you were lit up- you is plural ) hence you didn't exist as a mass hence you can not exist as light and something not existing can not see

QED

BTW do you travel to go from one place to other ? such a primitive way for aliens.

I just dematerialise and rematerialise. No question of converting mass to energy energy to mass simple dispppear and reappear. Just a bit complex for the materialistic or Energitic creatures.

Let me try to explain- what is light ? No EM Wave ? now waves can not propogate without media. Photons ? as per you a particle can not have zero mass. So it is more complex. Assume a particle with zero mass blinking and reappearing but that is almost like your priimitive science - we have got to the route root of it and we can route any thing to blink from one galaxy to other where-ever some complicated and accurate experiment is to be done by, well who else ? .

There is a call, see you in a blink.

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#48

03/03/2009 10:21 PM

Yes, You will. Considered the speed of light is also the maximum speed of light, and you generate and maintain the photon beam yourself while moving, you will catch up with the light when your speed is the same. At that point no light of the beam you emit will be seen by yourself while moving in the same direction at the speed of light.

I should not advise to try to attain the speed of light, but a simple test kan be made: Run forward peeing, at a certain speed you will completely run into the wet.

The speed of light is roughly MACH1000 the previous poster must be a "black hole"?

Anonymous Poster
#57

03/04/2009 9:09 AM

Unfortunately i tried this and found at about mach 2 the pee just turned to steam due to air friction, any help of trying to catch the wet!!!

Anonymous Poster
#117

03/17/2009 2:58 PM

It's not "vini", it's "veni" from the Latin infinitive "venire". But you do know more about light & its speed than I do!

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#152

03/26/2009 11:15 AM

There's no ENCE like XpiRiENCE

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#181

03/31/2009 2:30 PM

Witty, I like witty!

Cheers,

Bloefeld

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#190

03/31/2009 8:59 PM

It is very interesting, reading all printed idea of magnificent brains gathered here, wonderful!! But guys, is there nothing you can do other than trying to catch up the light? what happened if you can catch it up? that's the real question.

4
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#2

03/02/2009 1:33 AM

The fundamental postulate of relativity is that the speed of light is the same for all observers regardless of their relative velocities. This means that from the frame of reference of the car travelling at half the speed of light (relative presumably to another non accelerated frame of reference) the light is still travelling away from it at the speed of light. Regardless to what speed the car is accelerated to (as long as it is below the speed of light) the light will always apear to travel away from it at the speed of light. Now while it is theoretically possible to accelerate closer to the speed of light, I don't believe that it is possible for anything with non-zero rest mass, to travel at the speed of light so the car would continue accelerating forever never quite getting to the speed of light and would always see the light travelling away from it at the speed of light so would never catch up to its headlights. If the car had zero rest mass it would always travel at the speed of light as it would be made out of photons (I am not aware of any other particle with zero rest mass).

Anonymous Poster
#41

03/03/2009 1:47 PM

BobD has the physics right, although the relativistic equations diverge at the speed of light so maybe there is no determinate answer at that speed. From the point of view of an outside observer looking at this oncoming "car", the headlight would be blue shifted (Doppler effect) to an infinitesimally short wavelength. I don't think that would be good, either... Anyway, the vehicle is toast as soon as a relativistic bug hits the windscreen.

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#81

03/05/2009 2:45 AM

".....(I am not aware of any other particle with zero rest mass)."

Gravitons are supposed to have zero rest mass too.

(Graviton is a hypothetical massless particle which is the carrier of the gravity... as the Quantum Gravity theory claims...)

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#84

03/05/2009 9:49 AM

If my memory is correct and there's always a question about that, neutrinos can be also considered to have zero rest mass since they can never rest.

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#85

03/05/2009 10:40 AM

No, Redfred. Neutrinos have a tiny (negligible) rest mass but, definitely, non zero.

That's why they move at speed close to c, but not exactly c. (If they had zero mass they should move at speed exactly c.)

The neutrinos interact with the matter only via weak nouclear forces. That's why it is so difficult to be detected (they rarely interact with the matter).

I suppose that the only reason that "they can never rest" is, also, because of this. During their production (via nuclear reactions) they get huge velocities (due to their tiny rest mass) and they cannot be trapped by any way (e.g. inside electric or magnetic fields, due to their lack of charge). So, they cannot slow down or even rest.

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#86

03/05/2009 2:10 PM

True, neutrinos do have mass. My deliberate phrasing of my comment set a trap for me to make another point about this whole thread. I thank you for walking into this, please bear with me in my convoluted explanation.

Physicists apparently capriciously redefine common terms (rest mass) to fit rarely observed phenomena (neutrino kinematics) to preserve abstract concepts. Physics clearly confuses many people. A confused person will often find a similar parallel to relate with what they do not understand. When a person changes a rule or definition in the middle of a game, that person gets labeled a cheater. Cheaters frequently lie to preserve their opinion. To change a definition of a used term, implies cheating.

Let me now point out several important caveats before I generate a new deluge of postings. I fully understand that no sub-atomic particle ever fully comes to a complete rest. Brownian motion from thermal energy, plus the confusing quantum uncertainties of position and velocity, not to mention the need for a perfect balance of a myriad of forces makes "rest" only a theoretical concept at the microscopic scale. When Physicists use tangible understood macroscopic Newtonian concepts like "rest mass" in microscopic or relativistic conditions, misinterpretations will surely occur.

One need not look any further than the OP of a car traveling at the speed of light, let alone the following responses to see my point.

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#88

03/06/2009 5:43 AM

Good points. I'm not sure how scientists can indentify the rest mass of a particle.

Of course there is the well known equation m = m0 / √ (1-v2/c2) , where you can calculate the "m0" if the velocity (v) and the relative mass (m) are known. This is true for an ideal (isolated and undisturbed) system though, where you may know the "v" and you can measure the "m" (e.g. via the impact on a target). But in a real system, where a combination of many impoderables are taking place, I don't know how you can be sure about the exact value of "v". (There is, also, the quantum uncertainty: at the moment of the (e.g.) impact on the target the position of the particle is very specific, so you can't be sure about its velocity.)

This is a big issue. I suggest you to open a new discussion concerning this whole "rest mass" concept.

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#112

03/17/2009 11:14 AM

This "rest mass" thing got me thinking. Are we calling sitting still on the surface of the earth "at rest". The Earth is hurtling around the sun at somewhere in the region of 60,000 miles per hour, and the solar system is hurtling through the universe at who knows what speed, so anything in our frame of reference is only at relative rest. One of the fundamentals of relativity says that as velocity increases, mass increases, until at the speed of light mass is infinite, but if we go the other way and slow an object down, as it approaches zero velocity, does the mass of the object approach zero. Would all objects have zero mass if only we could keep them still. I'm not sure what happens to time if we become truly stationary, as velocity increases time slows, if we were able to be truly stationary, would all time be instantaneous, we would be outside of the time domain, and we would not care about catching light emitted from headlights.

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#142

03/24/2009 1:45 PM

You've never met my brother. He's always there, at rest... and makes no impact to the world around him.

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#174

03/31/2009 12:40 PM

Let's be practical boys...... If your car was accelerated to the speed of light, it would immediately incinerate as the space shuttle would without heat tiles when entering the atmosphere. Even if we do not compute the heat generated by a mass of plastic and steel at the speed of light in the atmosphere and the vehicle survives, we would always see the light at any speed no matter where your are viewing it.

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#176

03/31/2009 1:05 PM

Welcome to the insanity.

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#194

04/01/2009 5:16 AM

This answer to me sounds correct. I would also point out the cars mass would be increasing as more power is being applied to the wheels, thus satisfying the law of the conservation of energy.

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#3

03/02/2009 7:16 AM

No.

Particularly not if you have a Lucas electronics system in your car.

Anonymous Poster
#29

03/03/2009 10:15 AM

Hooray for the prince of darkness!

mgbdriver

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#30

03/03/2009 10:25 AM

No. Particularly not if you have a Lucas electronics system in your car. Lucas + electronics = oxymoron

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#31

03/03/2009 10:54 AM

If you have Lucas electronics in your car then you would catch the light, since the Lucas car would not emit light. On the back of my old TR-3 i had a bumper sticker made that said "Joseph Lucas invented darkness". plus this is the only time i owned SI tools.

I vowed to never let Lucas in my life again, and I converted the Triumph to a negative ground car.

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#96

03/10/2009 10:49 AM

Lucas and Bosch- the Princes of Darkness!

Anonymous Poster
#97

03/10/2009 1:45 PM

Why do the English drink warm beer? Because they have Lucas refridgerators

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#183

03/31/2009 2:33 PM

Mine Said "Joseph Lucas, Prince of Darkness"

Cheers,

Bloefeld

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#110

03/17/2009 10:47 AM

Since I own a 1979 MGB LE I totally agree that there is nothing but darkness - there is no light being emitted at any speed therefore the question is moot.

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#4

03/02/2009 1:19 PM

You were caught up to the light the tail end of it. The head lights being the source. So I say yes.

If you are talking about the leading front edge of the beam. No, once the vehicle obtains the speed of light the distance from the leading edge of the beam and vehicle would remain constant.

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#124

03/18/2009 6:13 AM

Assuming that your vehicle would be able to maintain the true speed of light, you would catch it. The photons in the beam of light would interact with microscopic particles causing friction and marginally slowing it.

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#5

03/02/2009 3:28 PM

Okay, first of all if you are travelling at half the speed of light you should already have your headlights turned on. It's just too dangerous not to. That's why most interstellar class ships these days come equipped with 'warp speed running headlights'.

Secondly, you need to distinguish between the light emitted by your vehicle in this universe, or the light emitted by your vehicle in a parallel universe. Obviously you can't catch the light you emit in this universe (you'd have to exceed 'C'), but it is possible to catch the light the 'parallel you' emits in a parallel universe (using a space-warp drive). The other option would be to try to warp back into the same universe, but you'd need to remove the 'Pauli Exclusion Principle converter' from the warp drive, which is against the law, and then risk running into yourself. Pretty dangerous.

Thirdly, there is the problem of energy consumption in trying to go the speed of light. Most vehicles average about 20 parsecs per gallon. Even running at 1 parsec per 20 gallons you'd still not quite reach the speed of light, and at the cost of gas these days it would be an awfully expensive experiment.

So, in general, I'd say the answer is 'no'.

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#130

03/19/2009 12:31 PM

In this papallel universe isn't the maximum speed the speed of light too?

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#131

03/19/2009 12:44 PM

But what if it is not Parallel but perpendicular? Which leg would be faster top or bottom? Or are they equal speed, just that one is ahead of the other.

Think teleporter, faster than light yes, in the possible distance traveled.

Hum.................

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#6

03/02/2009 10:50 PM

Mu!

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#7

03/02/2009 10:52 PM

Lets word this another way.

your traveling at 50km/h, Del the Cat is on fire and traveling like a cut cat at 100km/h

you accel to 100km/h Del is so far in front that you'll not catch him as your traveling at the same speed.

If you accel to faster than Del, an angry cat is not something you'd want to catch.

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#8

03/02/2009 10:54 PM

possibly one of the most inane questions.

nobody is getting in a "vehicle" and doing such a thing.

what the heck would you need headlights for anyway?

a node of light will travel alone, not with a heaping clump of matter.

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#32

03/03/2009 11:01 AM

Wow no sense of imagination or intuitious drive.

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#36

03/03/2009 11:44 AM

how does imagination figure in?

This is an engineering question

..oh.. and you don't know me.

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#38

03/03/2009 12:03 PM

Imaginer - Disney, Creating a practical solution from your imagination and then developing an engineered solution to creation of the imagined product.

Imagination is always a part of engineering. If not how do we develop such beautiful buildings if we do not "see it" first in our imagination and then create a practical solution for creation.

Have you ever drawn with cad? Have you imagined a product solution to a practical application?

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#71

03/04/2009 6:43 PM

I'm with you Sted,

And since you brought up imagination, thought is the only thing that travels FTL. Light emmited from your headlights, or your tail lights, no matter how fast you are traveling, is a (this) universal constant. If the emmiter was traveling at or above the speed of light, no light would be observable from your headlights, but your tail lights wouldn't need a red lens due to Doppler shift. Actually that's not right either. Whatever came from the tail lights would approach a flat line (radio waves?) if you were tied to the trunk (whee!) looking backwards. Someone following at your speed would see the light as normal, as would your local planetary watch group.

I'm wearing Kevlar/Nomex shorts for this. Go ahead, make my day.

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#72

03/04/2009 7:40 PM

Well thank you.

Though truly, I think the Kevlar and Nomex is not necessary unless you like the fell of it.

I think it may be a bit itchy.

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#83

03/05/2009 9:15 AM

yes. I have

..Imaginer .. Disney.. whoa

leave armatures out of this.

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#9

03/02/2009 11:27 PM

Light would travel at the same speed regardless of the speed of the vehicle emitting it. As is the case with sound. A supersonic jet will be well past a point before the sound emitted by reaches that same point.

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#93

03/09/2009 9:34 PM

But sound within the cabin still travels from point A-point be with reference of the observer within that cabin, say from the instrument panel to the pilot, or from the pilots mouth to the microphone?

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#10

03/02/2009 11:48 PM

Hey, I'm only a Newtonian kind-o-guy, so that's about as far as my brain can manage ...

BUT, if C is a constant, then it is leaving your headlights at that speed no matter how fast the emitter is traveling. Relative to your vehicle's C/2 speed, the light is traveling away from you at C/2. Now, bump up the speed to C, and you'll keep up with the traveling beam ... in other words, the light that is trying to leave your headlights can't, but the beam already emitted continues to travel in front of you at the same speed as you. It's not a matter of 'catching up', just that the beam of light in front of you won't continue to extend away from you, but remain the same.

(then the apple fell on my head, Steve Jobs smiled, I discovered both gravity AND applesauce ... then I woke up)

Kind regards ...

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#11

03/03/2009 12:41 AM

No, you can never catch up with the light unless you travel faster than the speed of light. . . . . . . only then you can

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#132

03/19/2009 12:44 PM

My Car is a very short one - shorter than a wavelength and my headligths just to the left and rigth!

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#12

03/03/2009 12:42 AM

Short answer : Nope, you will NOT catch up!

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#14

03/03/2009 2:06 AM

G'day,

From my recollection of "Relativity", a "car" could never attain the speed of light because at the speed of light the cars mass would be infinite. The car would need an infinite force to accelerate to light speed. (f=ma).

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#94

03/09/2009 9:37 PM

not quite right, you would need more than infinite force to obtain that speed.

If your looking at jet thrust, to obtain Mach speeds, the thrust from the rear of the aircraft would be travelling at a greater speed than the speed of the craft in the opposite direction.

If you have a look at jet thrust flame, the little triangles you see in the flame are the speed of sound pulses, if you count the diamonds, you get the approx speed of the engine thrust (could be wrong, but thats how I understood it)

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#133

03/19/2009 12:50 PM

these little triangles in the jet-thrust are shockwaves - but not one for every machnumber

the number of triangels differs from the machnumber and depends from the environment - its just to pass the environmental

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#15

03/03/2009 2:19 AM

The person in the car will notice nothing as he is increasing speed if the light is not reflected back at him. The only way for him to see any light is if it is reflected back towards him. Then as he is increasing his speed the frequency of the reflected light will change and become more blue and eventually dissapear into the ultra violet spectrum. As for running into his own light, this will not happen. In his frame of existence the light will always leave his headlamps at lightspeed. The light that has left his vechile will also move away at light speed if he could detect it, but will shift in frequency towards the blue spectrum.

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#16

03/03/2009 3:00 AM

In the galaxy there are lot of bodies travelling at near the speed of light. But will still get light from them. Likewise even if the car attains the speed of light, the light emitted from its body will always be ahead.

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#17

03/03/2009 3:05 AM

Definitely not!

A lot of reasons have been written before, but my two cents: Even it was possible for car to reach light speed, you driver must be at the same speed (unless jump out by a window) I don't believe a crushed mass of matter which some time before was flesh, bones, eyes, etc is able to catch anything.

Kind regards.

P.S: Were have all the good challenges gone?

Gone with the flowers everyone?

Oh! When will they ever learn!

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#18

03/03/2009 3:58 AM

1. I don't know
2. Maybe

New questions spawned by this seminal question:

1. If the speed of light is 299,792,458 meters per second (exact) (≈ 186,282.397 miles per second for us Americans) then how fast is Dark?
2. If I make a box out of mirrors (good ones – not those cheap, Wal-Mart kind), throw in some photons, and close the box really fast, will it stay light inside the box?
3. If I am driving a car at the speed of light and hit the accelerator and go faster than the speed of light, will my light be behind me, and will the guy in the back seat then look like me? Will the photons in front of the car get squished on the windshield like June bugs?

News Flash !!

Some stuff can travel faster than the speed of light:

1. http://en.wikipedia.org/wiki/Speed_of_light
2. If Wikipedia says so, it must be true

I apologize for the flippant and juvenile answers above. Being flip and juvenile is my way of compensating for personal inadequacies.

Sorry. So very, very sorry.

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#89

03/08/2009 4:55 PM

I have seem, so many crazy answers to this Question. WAKE UP!!!

Nothing is relalistic about this Question. If you could get a car to go the speed of light, where in the world would you find a hiway to run it on?

Anyway if the car was going at the speed of light, the light form the head light would be traveling at twice the speed of light. Rember the HEAD lights are in the front of the car, so if the car would be going twice the speed of light, the light would be going three time the speed of light. You have to take in account the speed of the CAR. The car is pushing the head light and the light is moving of the speed of light, so no matter how fast the car goes it will NEVER catch up with light. It does not take a ROCKET SCIENTISTS to figure this out.

THIS IS LIKE: There a ship anchored in the harbor and there is a 20 foot ladder hanging on the side, the distance between the rungs are 8 inches apart. The bottom rung of the latter is 3 ft and 4 inches above the water, the tide is coming in at a 6 inches per hour. It's 4:15 AM and high tide will be occur at 8:26 AM. At what TIME, will the water touch the bottom rung of this ladder ????????

I would suprise, if 90 percent of you GENIUSES could not figure this one out either.

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#90

03/09/2009 1:23 AM

Hi Bud,

Unfortunately, you can't view issues of such a speed (light) the same way you view 'slower' things. The rules of Newtonian Physics or Classical Mechanics just don't apply.

And, FYI, I've never been considered by anyone to be a 'genius' ... heck, they won't even consider me for MENSA .

Kind regards ...

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#19

03/03/2009 4:39 AM

Oh dear.....I wonder if this vehicle is a train ? It sounds awful familiar (hint - that's a fun prog btw)

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#20

03/03/2009 5:31 AM

mc^2=(Pi*D^2)/4=>Do (i++); Print"Blip Blip"; End; Stop; Process Terminated; Ctrl-C; 00010011011001000011...

Overflow

This relativity trivia is getting trivial.

4
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#21

03/03/2009 6:01 AM

Concerning an observer standing outside the vehicle:

At first he observes that: the speed of the vehicle is c/2, the speed of light coming out of the vehicle is c, the velocity of light relative to the vehicle is c/2. As the vehicle approaches the speed of light then he observes that: the speed of the vehicle tends to c, the speed of light coming out of the vehicle is c, the velocity of light relative to the vehicle tends to 0.

Concerning an observer standing inside the vehicle:

At first he observes that: the speed of light coming out of the vehicle is c. As the vehicle approaches the speed of light then he observes that: the speed of light coming out of the vehicle remains c.

As a conclusion, when the speed of the vehicle is c (if such a thing could be possible... which is not... better to say that the speed of vehicle tends to c...i.e. it can be as close to c as we like but not exactly c... anyway...): For an outside observer: the vehicle can't reach the light which was emitted before (the light will be always in front of it) but, the "new" light will never leave the headlights of the vehicle. For an inside observer: the vehicle can never reach the light because the light is always emitted at speed c (relative to him) no matter how close to c is the speed of his vehicle.

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#37

03/03/2009 12:00 PM

GK,

You've given here the best answer so far. Particularly with one critical subtle inclusion, "the vehicle approaches the speed of light..." The vehicle never achieves the speed of light. To achieve the speed of light requires breaking the known laws of the universe. If it actually is possible to achieve this velocity, surely we don't know what will happen when it does. We have some good guesses, but that's all that they are guesses. Until experimentation or observation identifies this condition happening, anything could happen. Even my other fictitious post on this topic.

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#134

03/19/2009 12:57 PM

and some of these 10-typepeople are from every type

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#59

03/04/2009 10:12 AM

"But, the 'new' light will never leave the headlights of the vehicle."

If that happens, how long before the headlights are full of light? If that happens, will the headlights overflow? If the headlights explode from that, will the headlight light up the broken pieces as they fly away?

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#92

03/09/2009 11:02 AM

I said: "For an outside observer: ..... the "new" light will never leave the headlights of the vehicle....." Of course, this should be true if the vehicle could reach exactly the speed c. But it cannot. In fact, as the speed of the vehicle tends to c, the light still (barely) leaves the headlights (because the speed of the vehicle is always something less than c).

(This is, also, a kind of answer for BobC on his post #59.)

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#22

03/03/2009 7:39 AM

I don't know a thing about traveling at the speed of light,

I did put instant coffee in the microwave once and went back in time. Wow what a rush.

Every now and then I look out the window up at the sky and smile for a satellite picture.

I put tape on the mirrors in my house so I don't accidentally walk through into
another dimension.

Sorry, my mind was wandering. One time my mind went all the way to Venus on
mail order and I couldn't pay for it.

A friend of mine once sent me a post card with a picture of the entire planet
Earth taken from space. On the back it said, "Wish you were here."

Is Steven Wright asking the challenge questions now?

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#33

03/03/2009 11:08 AM

You missed your calling, you should be writing for the Tonight Show.

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#44

03/03/2009 2:56 PM

Unfortunately its not my stuff, Those are the ravings of Steve Wright. He delivers all those lines straight faced and dead pan. Funny as heck to watch him do it though.

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#56

03/04/2009 8:39 AM

but you are already in the car, switch on the head-light and try.

never bother about cops, they can not match that speed (at leas now) and even if they do, to catch you they have to be faster than light and that will take them to their their nappies and nannies.

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#105

03/11/2009 9:48 AM

give the hardest job to the laziest person , and they will find the easiest way to do it

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#23

03/03/2009 8:07 AM

According to relativity: the mass changes as the speed varies. A body with a mass that would travel at the speed of the light, would have an infinite mass.

An infinite mass is a senseless statement. Therefore the question makes no sense, it is actually impossible to travel at that speed.

Now, if one rejects the relativity postulate by saying that the speed of the lights emitted from a body in motion varies with the speed of that body then the answer to this question would be different because the speed of the light would then not be a constant anymore.

Note that black holes have an enormous mass that allows them to literally swallow the light, that is actually the reason why they are black. Other objects such as stars curve the light. So it is likely that a body traveling at a speed close to the speed of light would because of its enormous mass also curve and maybe "swallow" the light. In brief at that speed we would be traveling in the dark.

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#35

03/03/2009 11:39 AM

"it is actually impossible to travel at that speed."

Nothing is impossible, we have cell phones today, we fly in and out of space, if it was not for the engineers that that believed that nothing was impossible we would not have this world of possibilities we work with each and every day.

Limited thinking only keeps us here!

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#46

03/03/2009 6:07 PM

If photons have zero rest mass why do they care what the mass of a black hole is?

I can probably believe that quantum gravity differs from Newtonian but the acceleration between two (or more) particles is relative to their mass?

Perhaps all black holes are wormholes to a space beyond the big bang event horizon?

With that premise; from the outside, the universe must look like a star expanding at the speed of light with mass prominences popping out everywhere that tracks back to a 'black hole'.

Enough rambling, we'll need to go outside to prove this.

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#50

03/04/2009 5:14 AM

Black holes don't actually swallow light. It's just that the escape velocity of the black hole exceeds the speed of light therefor light cannot escape.

Harrumph

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#51

03/04/2009 5:19 AM

Maybe the black hole is too massive for the itty-bitty light to push it away.

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#24

03/03/2009 9:18 AM

I know that if i could travel with a speed of light i won't be travelling with half of it from the very begining. So next question?

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#25

03/03/2009 9:23 AM

No and yes. Assume that you are traveling at C/2 at which point you emit a light beam. Then accelerate to C. Can you catch the previously emitted beam traveling at the same speed? NO. HOWEVER because once C is obtained, no further energy is needed. Just use your little thrusters to turn around backward and turn on the light. then slow down and wait for the light to catch up. This makes just as much sense as any when talking about relativity.

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#26

03/03/2009 10:04 AM

Assumptions:

1) Light ALWAYS travels at the speed of light (c)

2) Cars can also travel at c

The light emitted while traveling below the speed of light out paces your car by c/2 while you are traveling at c/2. When the car is accelerated to c, the light is still traveling at c (assuming light is impervious to friction). Therefore, at best, you will remain even with all previously emitted light. Whether your headlights are now, effectively, putting out light at 2c is another discussion.

At the dawn of the fighter jet age, and possibly some late WWII prop planes, running into their fired rounds was a major consideration. This question involves light which does not suffer the same effects as a bullet in flight (i.e. drag).

But the big question is: "Is your car now able to out-run police radar?"

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#58

03/04/2009 9:18 AM

arh but one may run into their own little laser gun fire now ... mmmm gotcha

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#135

03/19/2009 1:06 PM

Oh - they've tried sometimes. But I've been always corect!

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#27

03/03/2009 10:04 AM

No. Einstein's theory of relativity states that the speed of light will always appear to the observer to be 186,000 miles per second.

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#136

03/19/2009 1:08 PM

Hey I'm a ligth-wave-surfer

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#28

03/03/2009 10:05 AM

Another silly question that ignores fundamental trans-dimensional kinematics. (May I have my shovel and hip waders please, thank you. ) Traveling at half light speed is close to the limits of today's impulse drive technology. (Weapons systems being the exception, but nobody is supposed to survive these machines.) The high drag created by inter-spatial debris, both macroscopic and microscopic, seriously questions the structural integrity of any craft. This "living on the edge" challenge does bring both intrigue and suspense to the myriad of sub-light racing forums found in our civilization. But as others here have pointed out, traveling at this hazardous speed obligates the driver to turn their headlights on to permit evasive action to be attempted. (Wish you luck. )

But as anyone who has properly studied trans-dimensional kinematics knows, switching to superluminal velocities must be done at no greater than c/4 to create a successful transition to folded dimension space. Once a craft transitions into second, third, or other space, light from one realm does not interact with other realms. Fortunately mass one tenth the mass of the traveling craft does naturally produce trans-dimensional markers between adjacent realms or transitions would become prohibitively hazardous. This leads me to the discussion about scout ship requirements but that's way off topic here.

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#54

03/04/2009 8:15 AM

I don't know have you never been in a dark room, and created a spark with a flintstone and walked over to the mirror and seen your face in the light of spark.

I tried and could reach the mirror before the light from spark did.

So I say Yes You can catch up and not only that overtake the light.

Only problem is, as you speed up to speed of light you will move back in time, so within a few seconds your car will become iron ore and you will be embryonic of what ever you are.

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#34

03/03/2009 11:29 AM

Ah! but....

As post #23 points out, accelerating to the speed of light would bring the vehicle to infinite mass. Infinite mass would have infinite gravity. I could go through another few steps. But suffice it to say, "Yes, the vehicle accelerated to the speed of light would catch up to the light previously emitted by the headlights."

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#39

03/03/2009 12:42 PM

Since everything in the universe is moving in one direction or another, it would be impossible to create a coordinate system in space that is based off of any fixed points. Since there are no fixed points, the only way to know that you are moving at all is if you are going towards or away from something. But you still would not know if you are moving or if that object is moving towards or away from you. So we could be moving at the speed of light right now along with all of the other stuff around us ( I think that we probably are). If that is the case and we are moving at the speed of light then i have never seen anyone catch up with their headlights so, light must move at the speed of light away from it's source, regardless of the motion of its source. I suppose if you were not moving and turned on your lights, and then accelerated to just faster than the speed of light, you could catch up with the photons that left before you started moving.

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#40

03/03/2009 1:37 PM

With such unknowns as dark matter and dark energy and coupled photons, we really have to admit that we don't know if anything we think we know is known. So there is no answer today. Maybe sometime in the future.

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#43

03/03/2009 2:49 PM

There might be some dark matter here, or possibly here. Adding all those colours makes it a bit hard to tell.

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#42

03/03/2009 2:43 PM

I would like to see a car of this generation obtain the speed of light if not, at least half the speed of light without falling apart.

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#45

03/03/2009 4:24 PM

The situation in the question can never happen - traveling at the speed of light, only light can do that. therefor it is not possible to give a correct A. to this Q.

This is like asking: if 2+2 = 7 then how many minutes are in on hour.

It is simply not possible to find correct answer to uncorrect questions!

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#49

03/04/2009 2:08 AM

One hour is approximately 4.3 + 4.3

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#47

03/03/2009 6:53 PM

YES!! You will catch up to the light from the headlights. The analogy would be with respect to the speed of sound. The sonic boom is created soon after the aircraft speed exceeds the speed of sound ie a little more than 1000 kmph. After that the sound TRAILS the aircraft. Similarly, hypothetically speaking, if the vehicle's speed exceeds the speed of light, no light is emanated.

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#52

03/04/2009 5:43 AM

Oh brother. ;)

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#55

03/04/2009 8:33 AM

Let us assume the car is emitting light (from its head lamp) as pulses.

say t=0 , car is stationery, the pules moves at velocity C

Now at time say t=10 , car is c/2 and again emits a light The gap between the two beams now will not be 10sec (it will be less) but the second beam will not overtake first beam say the gap is 7 sec between the two square pulses.

at t=20 say car is at 3/4C - this beam now again will have a gap say 3 sec from second pulse (after leaving the car it is in free space and hence it is independent of source) the time gap changes are what we call the red-shift.

at t=30 say now the car is at C.

this beam will be at a gap of 1 sec from 3rd pulse hence 11 sec from first pulse but this is the gap that will be maintained.

Then onwards the lights will be as continuous beams (unbroken) but still they will move forward at a speed C away from the car and the car will never be able to catch-up with them (just like the 3rd beam is from a car that is already at 3/4 speed of light but is not going to overtake the first beam, only effect is in the wavelength/frequency of the beam.

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#60

03/04/2009 10:15 AM

No, at best you would be just behind the headlight beam.

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#61

03/04/2009 10:40 AM

At first we may be right that velocity is always relative to a reference point.
In that case the observer is inside the vehicle but the reference point to define his velocity as C/2 must have to be defined his velocity and position too. This can create a great field of discussion.
Abstracting from all variables and taking reference only about the sistem composed by the vehicle and the light from the headlight we can say that the velocity from the light will have the same value over the reference point he is measured, C.
The observer inside the vehicle will never reach the light.

But observers outside the vehicle... this is another history!

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#62

03/04/2009 12:15 PM

Welcome to the House Conference.

In fact there is quite a bit of mathematics in this subject,as I briefly remember having read in theory of relativity about when observer (or his reverence frame) is at speeds equal to C with respect to the source, and the equations show the spedd fo light is still c with ref to him or

c+c=c and c-c=c

But I have to read that back and then quote the equation. This aspect has already come up recently in another thread, if I am not wrong in Electromagnetism.

Too lazy to again trace the book, and read it back.

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#63

03/04/2009 12:28 PM

ic, so 2c=c and 0=c...........2c=0 uc2 ?

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#64

03/04/2009 12:47 PM

That's only true if your doing the Wah-2c, c?

2c or not 2c, THAT is the question !!! For if 1 is by land and 2 is by c, then 2c is 2 believe.

i believe.

I'm going or a light lunch ... c you later.

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#65

03/04/2009 1:04 PM

# YYURYYUBICURYY4ME

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