A Question For All Science Geeks Out There Like Me.
Professor Albert Einstein asked a question: If you were to travel at the speed of light or faster and held a mirror in front of our face, would you be able to see yourself?
NOW....here is MY question: What are we compairing the speed to? The object we are moving away from or the object we are moving towards? If we are compairing the speed to the object we are moving away from (such as Earth) are we moving away from it and towards the other, or are we slowing down and the other object is coming towards with the starting point moving away?
Are WE moving away from the starting point and actually moving toward the other object? Or are the objects moving at all or are we?
Again we are complexed with the problem of what are we basing the speed on since there is no fixed or stationary central point?
So the original question comes back. If we travel faster than light and look in the mirror would we see ourselves in the past, but if we slowed to light speed would we see a still reflection? Would the mirror be black?
But here is the problem. What are we compaing the speed to? Now if you and the mirror are traveling at the same speed you are in a sense standing still in relation to one another. Since this being, you should be able to see what you look like in the mirror. Now, if we were to travel away from earth at 160,000 miles per second (light speed), the light could not bounce off our face and strike the mirror. At the same time we would be traveling toward some other object. We could be traveling towards this object at 186001 mps and the light COULD bounce off of our face and reflect in the mirror. But since we would be only (haha only) going light speed away from the earth, we did not cross the speed boundry. But we always run intot he same problem, what are we compairing the speed to? While we could be traveling at 186,000 miles per second away from one object, we could be traveling at 10 mps towards another. But what are we compairing THEIR speeds to?
You really cannot answer this question because there are too many "what ifs" involved. This was a question I had in my physics class, and we could not (even the professor) come up with one answer. Almost everyone in the room had their own opinion and the strange thing is that they all made perfect sense.
even if your traveling towards the mirror you are traveling faster than the light you are reflecting, it would however be possible to to travel past the speed of light up to the mirror and see a blank reflection, having your reflection form in the mirror before your eyes .....
If you held a mirror in front of you, you'd look exactly as you always have... one of the things about special relativity is that if you weren't looking at all of the scenery passing you, you couldn't tell that you are moving at all.
But what are we compaing the speed to? This seems to be the question that everyone avoids? While we are speeding away from one object we are approaching the other, so what is the correct speed? The object we are moving away from or the object we are moving towards? They cannot be the same speed because everything is moving. If the other object is coming towards us and we are going towards it, then we are not going faster (or faster than) light, if the object we are moving away from we are so doing it at the speed of light. Now lets throw a wrench into the machine... a third object that is moving away to your right at a slow speed (lets say 1 MPH), but is keeping a track with you. Are you simply moving away from this object at only 1 MPH, are you moving away from the starting point at 1 C, or are you moving towards object 2 at less than 1 C?
I don't understand why you've narrowed in on a comparitive speed, the speed of light is the speed of light and thats that .... can light be warped, yes, but thats not the basis of the statement, the basis of the statement is that you are moving faster than the speed of light .....
You have to narrow in on the speed. because you need to know what the speed is based on. The speed of light is compaired to what? Example: A person is standing still... and you walk away from them at 1 mph, but someone is approaching you at 2 mph. What speed are you going to use? Are you moving away from the start at 1 mph or are you approaching the other person at 3 mph. This was the other question that the professor threw in.
In the class people were avoiding the subject of what are we compairing the speed to? The starting point, the destination, or a third object? Since everything is moving, how fast are they moving, and what are we solidifing their speeds on? Another object, but what speed is that object based on? I am just asking in here to see people's different opinions. I find it interesting, just as in the class, and I am trying to put together some sort of theory.
Yes. So when you think about it that way, we could (in theory) travel faster than light away from one object, yet only be traveling at 100 MPH (for example) towards another object. Unless we engage the warp drive... lol
Light can be warped and bent so it is like every other object (Particle) in the universe but it has properties that are exhibited within a certain spectrum. You can't measure anything going faster than light since there is no way to record that with any quantifiable accuracy. What we really are talking about in terms of speed is distance. Speed has no meaning outside of distance. So you are correct in that you need a reference point in determining how fast an object is traveling. Also another factor is the mass of said object. Here is where it gets interesting, since the mass of an object can be altered momentarily by acceleration since it would be impossible to accelerate everything at the same time. (The back of a train cannot arrive at the same time as the front of a train if the train is in constant acceleration.) Two things to consider is that nothing is ever motionless (Within our current universe) second we are all accelerating so having a "fixed point" to determine speed is impossible.
So the mass of each object has an effect on its acceleration and thus its speed, each object (In theory) approaching zero mass as light speed is reached, therefore the reflection from the mirror will not occur since the light moving towards it will never reach it. (Speed really screws up equilibrium)
The larger question is whether or not everything can coalesce. Or, "Why the universe will never happen again."
Whow.... Tony... you got it. I like the flashlight idea. No matter your speed... be it 1 C, ot 100 C, if you have a flashlight you can shine it on your face, and TADA.. your reflection SHOULD appear. We think. I love Cosmology
Light on Earth and light in the vacuum of space don't travel at the same speed. Here you have to factor in the atmosphere, particles, the different gases, and gravity. In space there are different gases, different gravities as light approaches different objects (gravity of Jupiter will not be the same as an asteroid). The measurement of the speed of light is a theory, based upon other theories. Scientists are continuing to research and learn more about our universe, yet still have many questions and unknowns.
I wouldn't be concerned about the mirror or light, I'd be more concerned about the Romulans. (Yes, Star Trek is very cool.)
if one were traveling faster than the speed of light you wouldn't see anything because the light would be catching up to the mirror. if anything you might see streaks of color more than anything else. the mirror and yourself are moving at the same speed presumably, the light isn't fixed.
Then again, you have to have some sort of light source in your spacecraft. This would make it so you can see yourself, the controls of the spacecraft, and the mirror in your hand. How else would you be able to do things in the spaceship without a light source? The light outside of the spacecraft will not have any impact on the mirror.
I think the answer is fairly simple and was touched on above. Imagine yourself sitting in a car. While relative to things outside the car you are going 70 miles a hour inside the car you arent moving at all as far as your seat or other objects in the vehicle. So as long as you hold onto that mirror you should see your face just as you always would. But let go and it will disappear behind you...as a ball would tossing it out the car window.
If I'm standing in a boxcar on a train moving 100 mph, and I through a ball to my brother standing at the front end of the boxcar, the ball will not be any faster to him than if we were standing on the ball diamond back home where I toss it at 50 mph. However, if someone standing outside the train tracks were to measure the speed of the ball with a radar gun, as we passed by, the ball would be traveling 150 mph. When my brother throws the ball back to me from the front of the boxcar at the same speed (50 mph), the radar gun the man is holding will say 50 mph or (100 mph minus 50 mph = 50 mph).
Since in your hypothesis, the person is also presumably traveling at the speed of light, they would see no difference in the mirror than if they were at home in the bathroom. If however they were not traveling at the speed of light, their image would never appear in the mirror.
First , a perfect mirror is black as it has no color but reflects all colors as we think they look which sounds a contradiction so, if not black then a perfect white.
As regards would you see yourself in the past, you always see yourself in the past as it takes x units of time for light to travel from you to the mirror and back to your eye, so in the past. For some bizarre reason never properly explained to me, If 2 trains hit head on, each doing 100 miles per hour the impact is 200miles per hour, but when 2 light beams hit head on They do not hit at twice the seed of light as you would imagine but still only 186,000 miles per second, not twice that as would seem logical. So I think there is much wrong with the theory as time may tell in the future. I for one do not believe the relativity theory as science is supposed to be logical but this is not so probably wrong.
Warning... I am no expert and my physics was learned at The University of Armchair, Infrontofthefire Campus. However as I understand it it goes like this...
The short answer is that if you're travelling at lightspeed time stands still for you, therefore there is no 'room' time-wise for anything to happen, so no time to observe the mirror. Even - to somebody waiting for you - it has taken a thousand years to traverse from point A to point B - for you no time has passed at all. By the time you arrive he's 1000 years older and you're exactly the age you were when you started out and have apparently travelled zero miles to cover that 1,000 lightyears, space having compressed completely too. Going faster than light is still reckoned impossible (it would take an infinite amount of energy to get you to that speed) and the only loopholes (literally) would seem to be taking shortcuts through space in the form f well-discussed wormholes.
Why is the speed of light a limit? As I understand (and I don't understand too much) it's happens to be the speed at which the fabric of the universe expands. It's the cakemix and raisin theory of expansion whereby the fabric of space (the cakemix) expands and pulls the material universe (the raisins) with it as it goes.
Johnny Trippick's answer is a good one, in terms of physics.
It would also take infinite energy to accelerate that fast, so your fuel bill is going to be... beyond astronomical!
Because it is not a single thing, a wave front can move faster than the speed of light. Light from a star not directly above the center of the galaxy can arrive on one side of the galaxy right now, and on the far side of the galaxy one minute later. This simple thought experiment shows that the speed of a wave front can exceed the speed of light.
Because both space and time are "granular" due to quantum effects, not continuous, minute variations in location can cause extreme variations in position and location. For example, a quantum effect can precede the cause, implying time travel/tunneling, implying exceeding the speed of light. This is a simple expression of Planck's constant and Heisenburg's Uncertainty Principle.
The speed of light was measured using the earths distance from the sun as 93,000000mls. If that were wrong, then our current estimate of lights speed is also incorrect. See crystalcodex.com for the math, history and rationale. A very different picture emerges.
I still think that someone going the speed of light would see a normal passage of time with regard to obects following him on the journey at the same speed (, ie nothing will have changed). His voice won't sound like donald duck, and he won't find himself doing the break dance in slow motion. But, when he slows down he will discover everything outside his "bubble" has aged immensely in proportion to how long he traveled that fast.
If the speed is relative to the light source, you will see nothing. If you turn on a flashlight and shine it on your face while moving at or above the speed of light in the vacuum of space the light will act normal BUT what are you in fact moving relative towards or away from to give you that "speed?"
Here is what I mean. Say, at the beginning of the big bang, you are propelled to the very edge of the known universe as it continues to expand. The light at the edge of the universe is moving at the speed of light away from the center of the bang as are you in this hypothetical existence. Thus, while the center of the universe has existed for 16 billion years or so, you in fact have only existed for a small fraction of a nanosecond or truthfully, existence only at this instant. (Which, if we were allowed to talk religion here is why I believe God and science are not at odds but that is another discussion for a different place an time.)
Now, letís say you can suddenly reverse your direction of travel and you start moving inwards towards the bang-spot. Relative to the light moving outward at the edge of the universe YOU will be exceeding the speed of light regardless of your speed. If you turn on a flashlight, it will move inward at the speed of light relative to the bang-spot and you so your personal laws of physics will remain constant though you will not be able to see the light from the flashlight you left on your perch at the edge moving outward.
Close, JC. As you approach the speed of light, your local time slows down, in relationship to the rest of the universe. So if you are traveling AT the speed of light, time would be stopped, and from the traveler's point of view, he would arrive at his destination instantly, no matter how far away that might be. This is demonstrated in this not-quite-so extreme example here on earth, as cosmic rays collide with our upper atmosphere at very high speeds. Some of the The high speed particles created as by-products of those collisions have extremely short half-lives, and would normally not be seen at the surface of the earth, except for one thing. Those particles are traveling at near the speed of light, so this stretches out their delay time. So they DO reach the surface of the earth before they decay. Come on guys, this is elementary special relativity, taught in high school. Get with it!
Not quite right, Tony. Time and distance are both spatial dimensions. So time and distance are almost (or exactly?!) the same stuff. Time IS quantifiable, you just have to define "local" time from a given frame of reference..
Time is only spatial as it relates to distance. You can define "Local" (location) any way you want but you are still using only abstract units of measure not real substance. Time does not exist outside of human constructs. For example it is ludicrous to say how "Old" the universe is based on measurements of time. We don't know if it is a quantum singularity or a repeating decimal.
Time is fundamentally wound up with the spatial dimensions and they are all obviously required (in this universe anyway) for anything to happen. Where time differs from the spatial dimensions (how ever many there may be) is that movement through time is one-way: events only go past to future. No U turns... unless it were possible to go faster than light within your own frame of reference of course. What struck me as very interesting was the recent OPERA experiment that had seemed to show particles travelling faster than light: it wasn't so much that this would have torn the physics rulebook asunder - it was the comparative open-mindedness with which physicists were prepared to do this should the need arise. In short it displayed for all the world to see a fundamental fragility in scientists' faith in their product. Very reassuring I felt.
Physicists (I am led to believe) dislike arbitrary measurements, but acknowledge that things are indeed measurable by using ratios and contants. Time certailnly does exist. Anyway - it all goes a bit beyond me and I suspect this will go round in circles for all eternity until the FAA Large Discussion Collider implodes into a strangelet and destroys the Earth.
It is all "Timey Wimey Wobbly Stuff"....to borrow from the British TV show Dr. Who. If you really want a headache, watch some of last seasons episodes when the Doctor is jumping around in time in one episode (from the present to the past, to the future--which is the present).