# Unaswerable Question!!!!!

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I read in a book once, einstein when he was youNg had a question,''IF WE HAD A SMALL MIRROR IN OUR HAND AND WERE TRAVELLING AT THE SPEED OF LIGHT, WE LOOKED AT THE MIRROR HOPING FOR A REFLECTION, WHAT WOULD WE SEE?''

As reflection itself is light travelling at 3,00,000 kms/sec, is it possible for a reflection.

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I'll take a shot at this, having been reading Brian Green's "The Elegent Universe" this week. Someone please correct me if I'm wrong.

First of all, the answer has no solution because you can't travel at the speed of light. Hypotheticals have no frame of reference. However, we can try to envision what might happen if a photon were to, say, split into two photons, and one of them bounces off a mirror and returns to the starting point, where the first photon is waiting and observing. (Two photons walk into a bar. One of them looks into the mirror and says to his mate, "Hey, where'd you get that shiner!") (drum riff please)

I'll answer "Yes". And when the light bounces off something and returns, it will appear to be travelling at the speed of light.

The problem is actually an illusion rather than a paradox, and it's caused by a failure on the part of humans to visually comprehend the true (i.e. four-dimensional) nature of space. If you realize, as Einstein himself pointed out, that we're all travelling at the speed of light, expending most of our momentum along the "T" axis, and that photons expend none of their momentum along the T axis (i.e. they're "frozen" in time, expending all of their momentum along X/Y/Z), it makes a lot more sense.

Put another way, we know that the shortest distance between two points is a straight line. So if you visualize every object in the universe moving at the speed of light along the T axis, then in a sense these paradoxes are just due to the subtractive rather than the additive nature of relative observations of time.

In other words, it SEEMS like when one object passes another that there's a relative difference in time measurement. But in fact one of them is actually "falling back" a little along the T axis in order to translate some of its momentum along the X, Y, and/or Z axis.

In the case of our two photonic buddies, this is irrelevent, since they have no T axis of travel. From their perspective, photons fly about them at the same speed, time never changes, and nothing else (aside from other photons) appears to be moving at all (along X/Y/Z).

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the mirror, and your self. but my answers more of a joke

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WHAT WOULD WE SEE?''

You would see yourself, sitting in one sweet spaceship/Winnebago, that you hope wasn't built by Ford, because if it was, then you know you're going to get stuck far far away from home.

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not a science whizz by any stretch of the imagination, but using just logic.... well my logic! lol as I see it the answer would be yes you can see yourself in the mirror, as you are stravelling at the speed of light, meaning the light and you are side by side, I would have thought that you would have to be travelling faster than the speed of light for the mirror and all your surroundings to be pitch black. I dont know hehehe just a thought

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Firstly, at that speed you should have your eyes on the road not in the mirror.

Secondly, this is like that train travelling at 100mph, man throws ball from back of train to front, how fast is the ball going…

It’s relative to your POV

In you lightship.

The light generated by your cockpit lighting system hits your face is reflected by the mirror into your eyes.

So the photons are travelling at their normal speed.

The containment device you invent to enable your life processes to work at that speed must also create an environment to allow light to work normally.

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not a science whizz by any stretch of the imagination, but using just logic....

Logic? This is relativity. Relativity has left the platform while logic is still stuck at the security checkpoint.

The thread should have stopped when Pangloss wrote the answer has no solution because you can't travel at the speed of light.

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I should have mentioned this in my first post, but another thing to keep in mind would be that whether you're moving at 1mph, 1000mph, or the speed of light, if you turn on a light bulb then the assumption under Newtonian physics is that it would automatically exceed the normal speed of light on at least one vector (your forward vector). The fact that it does not do so tells us exactly the same thing in all three cases.

So the part of the question in Post #1 that states "and we're travelling at the speed of light" is really not relevent at all. Total red herring.

(Nothin' wrong with asking, though. Only one person in the entire history of the human race ever figured out for himself why this happens, so unless you're smarter than he was, you might as well ask.)

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Ok,

Say we don’t take this literally

and look to the core question.

What happens to mass as it tends towards the speed of light.

Anyone? anyone?

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I clearly offended swansont by using logic, but at least my mind was open to the possiblity. So what if logic left me at the check point at least I was willing to explore in the first place as opposed to self ritchious indignation leaving me stuck firmly at home. Although your comment does leave me with a question: If logic is relativity and that is in the left platform then how can it be at the checkpoint too? Isnt that like being in two places at the same time?

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I clearly offended swansont by using logic, but at least my mind was open to the possiblity. So what if logic left me at the check point at least I was willing to explore in the first place as opposed to self ritchious indignation leaving me stuck firmly at home. Although your comment does leave me with a question: If logic is relativity and that is in the left platform then how can it be at the checkpoint too? Isnt that like being in two places at the same time?

why are we talking about trains.

I like trains as much as the next guy,

but whats that got to do with the question?

stay on track please.

now you got me doing it.

my question,

is the light source behind you, in front of you or travelling with you?

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I clearly offended swansont by using logic, but at least my mind was open to the possiblity. So what if logic left me at the check point at least I was willing to explore in the first place as opposed to self ritchious indignation leaving me stuck firmly at home. Although your comment does leave me with a question: If logic is relativity and that is in the left platform then how can it be at the checkpoint too? Isnt that like being in two places at the same time?

You didn't offend me, but I also think you didn't understand my statement.

You cannot simply extrapolate your observations of common everyday experiences (i.e. use logic) and hope that they apply under extreme conditions described by relativity and quantum mechanics, since it has already been observed that the universe behaves very differently under conditions of small size and large speeds. Relativity and QM are often counterintuitive.

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I clearly offended swansont by using logic

He doesn't seem to be offended at all. He seems to be saying that logic is not sufficient for answering the question (which happens to be true).

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Thank you for clarifying that swansont, as I had already stated I know nothing of science, so I thank you for explaining to me why my theory doesnt apply. I was just so shocked by your reply initially as you totally shot me down and I just didnt understand why.

Thanks Sayonara, swansont covered it so all is well.

Reverse? I wasnt talking about trains I used the same terminology as was applied to me, but I can see how you made that assumption.

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Heres my attempt. Within the spaceship light will travel at a constant It will hit the mirror and bouce back and you will see your reflection as usual. This is because light will travel at a constant speed reletive to its frame of reference. Just like in the train example...A light is place in the centre of a train carrige at either end are light activated doors the train is traveling half the speed of light. An observer on the train will see the doors open simultaneously while an external observer will see them open at different times. This is why someone on the spaceship will see the reflection appear as usual but someone outside the spaceship will not see the reflection appear.Thats just my 2c hope that helps.

~Scott

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Thank you for clarifying that swansont' date=' as I had already stated I know nothing of science, so I thank you for explaining to me why my theory doesnt apply. I was just so shocked by your reply initially as you totally shot me down and I just didnt understand why.

Thanks Sayonara, swansont covered it so all is well.

Reverse? I wasn’t talking about trains I used the same terminology as was applied to me, but I can see how you made that assumption.[/quote']

naww, i knew what you meant, just entertaining myself.

they are right you know...i mean about the counterintuitive nature of reality beyond certain thresholds...i even think ice behaves strangely is far as contraction is concerned...and things like bumblebees can fly despite the rules aerodynamics.

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naww' date=' i knew what you meant, just entertaining myself.

they are right you know...i mean about the counterintuitive nature of reality beyond certain thresholds...i even think ice behaves strangely is far as contraction is concerned...and things like bumblebees can fly despite the rules aerodynamics.[/quote']

Coprolites. Bumblebee flight does not defy the rules of aerodynamics. That's an urban myth.

They only defy the rules if you assume rigid, smooth wings, Under those conditions it can't generate enough lift or glide. The conclusion is not that the laws of aerodynamics are wrong, it is that the assumptions are.

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why are we talking about bees now?

The sinusoidal path of the wing is not the thing .

it's how Air at the scale of an airplane behaves as we expect , but when you get a small thing like a bee , the air seems to act counter intuitively.

because at that threshold the air starts to look like soup.

the size of the air molecules relative to the bee is now a factor.

Albert was getting at a certain point.

anyone know what point he was alluding to.

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You would see yourself.

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I thought light always traveled at light speed no matter what :s

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I thought light always traveled at light speed no matter what :s

light speed does not equal c. C is the speed of light in a vaccum, the speed of light changes depending upon the medium it's traveling in... although light traveling through air is almost c.

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Photons always travel at c no matter where they are.

In air the photons are continually being absorbed/remitted from atoms in the air, this takes time and so the overall effect is that light seems to have slowed down (relative to in a vacum) however the reality is that the photons are always travelling at c between atoms, it is just the absorption/emission process which slows them down.

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