If I was on a space ship traveling at the speed of light (The natural speed limit proposed by Einstein) and I fired a gun would the bullet remain in the gun?
My belief is no it would not. I believe the bullet would leave the gun at the same increased velocity that it would achieve if I had fired the gun from a body at rest. This thought leads me to believe Einstein was mistaken.
I have heard about the new scientific discoveries of particles traveling faster than light. I'm just expressing another possible way we might discover the truth about light speed.
Funny. Very funny. No - I mean - hilarious.
Perhaps you could add a few links to these particles that travel faster than light?
Figured that is what you might be talking about.
http://www.forbes.com/sites/timworstall … t-so-fast/
An avergae bullet travels about 2,000 feet per second. Light travels 186,282 miles per second so Einstein was not mistaken.
On what are you basing that belief? All evidence to date shows that the bullet cannot travel faster than C; it will stay in the gun. Even photons "fired" from a speeding star do not exceed C, which is why we see a shift in the frequency of that light
If the bullet is to reach the speed of light it will result in it having an infinite mass; more than the rest of the universe combined. There is not enough energy in the gun to accelerate an infinite mass. This is also why your spaceship cannot actually reach the speed of light, just very close to it.
Ok, based on what you're saying (assuming what you're saying is true)
Then it follows that movement of any kind within the ship would be impossible as well...no?
since no movement(change) of any kind could take place, aging might arrest, which may be where Einsteins belief in relativity came from(started)...
Again, as you cannot actually reach C, movement will only occur at a very slow rate (to an outside observer). To you, traveling at near C, time dilation will result in your apparent movement (to you) to be at a normal rate.
Point of view is important; all is relative. It's why it's called relativity.
If I am on a craft already doing the speed limit (what you're calling C) and I move my hand forward, my hand "actually" would be moving faster than the craft and therefore faster than the speed limit.
Relativity to an outside observer to my mind is inconsequential. Either your hand moves forward or it doesn't.
***Time Dilation is a contradiction in terms, time is a measurement. Saying an inch would become three inches long doesn't change the inch, it changes the measurement.
If your body was subjected to the effects of the speed, then YOU wouldn't be able to move. The above shows the flaw in your line of thinking.
As the craft cannot reach C (already pointed out) your hand can still move forward. There will always be "room" between what the craft is traveling at and C and thus your hand can still move forward. The craft may be travelling at .9999C, which means your hand could travel at .99995C for example.
Relativity is not inconsequential. To an outside observer it might take 10,000 years for your hand to go from your belt to fully outstretched while to you it will take less than a second. The outside observer will not be able, in their lifetime, to see any movement; to you it will be normal.
Then the craft isn't traveling at the speed limit, I am saying it is traveling at the maximum achievable speed, the speed limit.
The maximum achievable speed for a particle with a rest mass greater than zero is less than C. Any number less than C. .99999999999999999C maybe. Or 50,000 9's.
If the ship is actually traveling at C then the mass of that ship is infinite and the entire universe will immediately collapse into it at a velocity of C; you won't move your hand with a star occupying your belly button. It addition the rate of time passage in the ship is 0; nothing can move anyway.
Ok, I may not be smart enough to understand the mass properties your talking about, that seem to somehow prove your point.
Can you dumb it down any?
Why does mass have to go away? If we simply increase thrust (no matter what mass we are attempting to move) 'the mass' will move in proportion to the thrust (more thrust=move movement)
In my example we have infinite thrust, meaning we do not lack the ability to move the ship at unlimited speeds, the only thing that slows our craft is the 'Einstein Speed Limit'. Once we are at (not close to but at) that speed limit, why wouldn't additional thrust cause faster/more movement?
***If your answer is the math proves it, then explain Zeno's Paradox.
The mass of an object in motion is found by the equation:
M(motion) = M(rest)/(sqr rt[1-v^2/c^2]).
As v (velocity) approaches C the mass approaches infinity. As the mass approaches infinite, it requires more and more energy to accelerate it. At some point there isn't enough energy in the entire universe to accelerate it any further, but it still hasn't reached C.
That's why, from a practical standpoint, you can't even get a BB to actually reach C; there isn't enough energy in the entire universe to accelerate it to that speed as it's mass would be infinite at C. Only "particles" of 0 mass can travel at that speed; while moving a photon is a wave form, not matter, and has 0 mass and thus can travel at the speed of light.
ok that is clear, but as always I have more questions.
Since "light speed" is the speed limit (C) doesn't that mean each particle that makes up light would be using all the resources in existence every time they traveled at that speed, which is always, and seems to be a paradox...
(the whole mass changing thing doesn't make any sense to me) an object is what it is, mass would remain constant. Requiring more thrust to achieve a greater velocity I can agree with.
My thoughts run more along these lines:
When driving very fast in a car the telephone poles appear to become a solid wall because you get to each one quicker based on your speed. The particles that make up(constitute) space (if space isn't actually 'nothing') would at higher speeds be like the telephone poles in that our craft would come into contact with them more and more quickly, in effect making them(making space) take on the properties of a net. (think of space as having similar properties as water)
Perhaps the amount of resistence they supply would be greater than the amount of thrust we can draw from all of existence, hence the 'speed limit'.
the smaller the mass of the object, the less resistence the 'net' would supply, therefore smaller particles can travel faster....
You are making assumptions that are not true. Light is either a particle or a wave, depending on circumstances. When at rest (bouncing off a wall perhaps) it is a particle - when moving it is a wave. It is not normally in the particle state, and can thus move at the speed of light. Quantum mechanics complicates the matter further in that a light wave can act as a particle while being a wave, but we won't go into that.
Space is actually "nothing". It is not made up of particles of any type. In addition, were space itself to provide resistance to, say, light the light wouldn't get very far. There is no propulsion system in a photo or light wave - any resistance at all would quickly slow it down to a stop.
Relativity and, to an even greater extent, quantum mechanics is not an easy field to understand because it is so alien to our normal everyday life. It is not intuitive at all and the rules are not ones we commonly use in everyday life. Nevertheless the rules laid out by Einstein have been shown to be true; may of our everyday gadgets (such as GPS) rely on those rules. They work.
ok... I'm not making assumptions, I'm asking questions and thinking out loud... so to speak (since I'm actually typing).
Light particles have mass.
Do light waves have mass?
No, and therein lies some of the "weirdness"for those of use that don't deal in this kind of thing all day long. It's hard to get a gut feeling for this stuff because it just match anything we deal with.
Ok... so light particles which have mass transform into light waves which do not and then they transform back into light particles which once again have mass... correct?
something transforms into nothing and nothing transforms back into something...correct?
come on, now. Energy is not nothing. If it were you wouldn't feel the sun on your skin and it could not not heat food in a microwave.
Energy IS matter, just in a different form. Remember E=MC^2? They are simply different manifestations of the same thing.
Then they do retain mass?
Light waves do have mass?
according to wiki:
Matter is a general term for the substance of which all physical objects consist. Typically, matter includes atoms and other particles which have mass. A common way of defining matter is as anything that has mass and occupies volume
So to my mind we either have something to nothing and back again or relativity is shot down. (because if any type of matter is traveling at close to c it would require an almost infinte amount of the limited energy in existence... right?)
Does a corpse retain life? It is the same mass, still there. No, as I've said, light in the wave form has no mass - if it did it couldn't travel at C.
I believe energy is made up of particles, particles that have mass, what you feel in the sunlight is the friction of those particles rubbing on your skin when contact is made. Sunburn to me is a friction burn.
Which means a form of matter can travel at near c without consuming almost all the energy resources in existence(because literally billions and billions of them are doing just that all the time) and therefore the proof that all energy resources would be depleted if a form of matter reached c seems improbable.
or we are witnessing something transforming into nothing and the creation of something from nothing all the time.
What am I missing?
...light, actually photons act as both a particle and a wave...
particles have mass, waves don't (according to wilderness and about.com)
"Photons act as both a wave and a particle all the time.(is that truly possible, for an object(photons) to both have mass and not have mass at the same time? Which is what is stated in the definitions... ) One of the effects of this wave-particle duality (or particle-wave duality) is that photons, though treated as particles, can be calculated to have frequency, wavelength, amplitude, and other properties inherent in wave mechanics..."
Your "beliefs" about the properties of light have no correlation to reality. It comes down to do you want to make up your own beliefs about light or do you want to learn? You certainly didn't get those ideas from any physics textbook.
I have done all I can to teach you a little about light and relativity, while you refuse to accept and cling to your own made up ideas. I'm sorry, I can do no more.
You are correct, we won't find these results in a physics text book.
What happens when the 'books' aren't correct? What happens if the 'books' we believe are absolute and unfallable, aren't? Do we lose our ability to think? In my experience, truth makes sense. Things just seem to add up or to fall into place. When things don't add up or don't fall into place it is because something isn't right, something isn't correct.
Obviously something doesn't add up here, I'm not saying I know what it is, but it can't be both ways. Can it?
I'm sorry I've worn out your patience, but simply saying that isn't what the book teaches doesn't answer it for me.
You could always take your hypothesis and attempt to form your own theory. First read about the light wave particle duality.
The one I posted on the previous page of this thread?
this one>>>>> "Photons act as both a wave and a particle all the time.(is that truly possible, for an object(photons) to both have mass and not have mass at the same time? Which is what is stated in the definitions... ) One of the effects of this wave-particle duality (or particle-wave duality) is that photons, though treated as particles, can be calculated to have frequency, wavelength, amplitude, and other properties inherent in wave mechanics..."
It's funny how a simple guy, like Mikel Roberts, has the ability to use his brain for critical thinking,....while others who are decorated with Ph.D's and Nobels can only use their brain to parrot what they memorized by rote in their Bibles of Relativity.
Mikel has single-handedly destroyed the Religion of Relativity with these simple statements. Now everybody else is chasing their tails to shoot down his statements with their own contradictions.
This discussion is epic. Keep up the good work Mikel.
And oh,...if you want to get more laughs from these Relativity Bible-Thumpers....ask them to explain exactly WHY 'c' has a limit. What is the mechanism which keeps light at 'c' and not at 'c+n' or 'c-n'? Who is in charge of enforcing this limit in the highways of the universe....the spirit of Einstein perhaps? Is Einstein now a Heavenly Traffic Cop? Does he use a radar gun to do it? You will fall off your chair by the contradictory responses you get from Relativists who attempt to defend their Religion.
If you are on a craft going 99.9999% the speed of light, and you turn on a flashlight, the light will travel away from you at the speed of light. Somebody standing outside the craft holding still would see it going the speed of light as well...
Relativity is really weird.
Ya that's right. The power of the C can be easily understood in terms of time even the time which slows down in the fast moving spaceships to ensure that threshold of speed is not crossed.
F..K I had a whole lot of thoughts on this subject... but they have completely passed me by faster than yesterday's sunlight!
The spaceship is traveling at the speed of light with you in it. The acceleration due to a gravity would be negligible , so the bullet Would fire out of the gun normally ( except with a little more bang because of the lack of oxygen) and travel for ever until acted upon by another force. You in turn would be thrusted the opposite direction. You could solve for the relative velocity using relativity and find that the bullet will travel a little bit less than c.
Without pretending to know more the Albert E. I'll have to agree with your guess.
"The person in the spaceship only needs to travel near to the speed of light. The faster they travel, the slower their time will pass relative to someone planted firmly on the Earth. If they were able to travel at the speed of light, their time would cease completely and they would only exist trapped in timelessness"
Your quote and link actually are the opposite of what my guess is.
Timelessness denotes an existence without change. Everything just is means it eternally remains the same.
Evolution, change, motion and time are all aspects of a reality that starts, has a now and ends/changes.
Personally I don't believe faster than light travel is impossible. I don't believe existence just always was. I don't believe time dilates or mutates.
We have no proof that the Milky way Galaxy isn't already traveling faster than light, all our motion may be faster than light motion. Light in our reality may be accelerated light speed much like the bullet fired from the gun in this thread.
The only thing I know for sure is, even Einstein isn't/wasn't sure the math added up.
You will get only nonsense as answer to this question.
By the way I think that is a correct question and your own answer is correct, that is, the bullet will travel at the speed of the bullet plus the speed of the space ship(If it is "c", then "c").
Einstein also said that particles with mass cannot travel at the speed of light. Your premise is false from the get go.
Must you always require hand holding at such elementary levels? Your premise is false in that a ship can travel the speed of light. Do you understand now?
You know Mikel, Einstein will personally come and shoot anything that try to attain the speed of light, so nothing can ever attain the speed of light, so your premise is false.
Einstein is scripture. So it shall be written; so it shall be done.
Thanks to Einstein, we have amazing things like synchronized clocks and GPS. Nobody ever said his theories won't be overturned some day, but they explain things the best anyone has been able to, and they make things possible that wouldn't be possible without them, so we go with it.
According to my understanding of einsteins Special theory of relativity, as you approach the speed of light time dialtes (slows down), so tha faster you go the slower the clock moves. To the outside observer the bullet would be stationary, even if it was in midair, when the spaceship whizzed by, as the time inside the ship would be slowed but the time outside would be normal.
To the guy inside the ship the gun would seem to behave normally, but in relation to the rest of the universe the bullet may take years to leave the barrel if the gun.
But as stated elsewhere here matter can't be accelerated to the speed of light (according to einsteins special theory of relativity), but if matter could travel at the speed of light time would stop, so the bullet would stay where it was until the ship slowed to below light speed and the clock started again.
I would also like to remind everyone that the speed of light is a theory, and even though it may seem to be true there is still room for doubt.
...and the moment you hit the speed of light you travel around every nook and cranny of the universe in an instant because time outside your ship passes at an infinite rate. So you would effectively find yourself alone and without a universe to look at because it would have died and gone.
Actually, the clock on the ship ticks perfectly normally for those aboard the ship. It is the clocks that are at rest relative to the ship that are ticking slower.
Actually, it is a precisely measured fact.
Of course the gun would fire at the same rate it usually does. The gun, the person firing the gun and the environment in which it is being fired at isn't subjected to actually traveling the speed of light.
The passengers of the ship and it's contents are not going to be subjected to any affects or effects that which the outside part of the ship is. So, technically, anything inside the ship would work normal.
This does nothing to change Einstein's work or knowledge about the Speed of Light.
Do realize and I only use this as an example? In Star Trek, whenever have you ever seen them fire any weapon while in Warp? It's never happened, because they had to drop out of Warp before firing.
So the bullet if fired would stop (or would slow to the speed of the ship) once it reached the outside part of the ship?
You're joking right? The bullet would never reach the outside part of the ship, because you would never be unable to fire so that it could go outside the ship. The material the ship would be made out of, the bullet wouldn't go through.
Bullets can penetrate metal hulls, they do so all the time. In fact they have named the bullets designed to do so "armour piercing rounds" perhaps you have heard of them.
Regardless of the abilities of the bullet, let's say the designers of the space ship capable of traveling at the speed limit proposed by Einstein, had installed a gun on the front of the craft and fired it, would the bullet leave the gun?
I think that the bullet will leave the gun since when it was fired it was travelling at the same speed and the firing a bullet will add more force to the bullet. As soon as it leave the gun it will rapidly decrease speed and would be back on the barrel.
No Mathematical equation sorry
It doesn't matter how fast the craft moves. The person, the gun the bullet and the air around the gun are not moving in relation to each other. So they are 'not moving' for purposed of bullet trajectory.
Yes this concept wants more research on this topic actually the face is that the science will never achieve its best.
What was unclear. If you stand on a bullet train and drop a rock, it goes straight down, right? I can talk about light speed or near light speed, but for any lesser speed where conventional macro-physics applies, what I said holds.
Yes, but if the bullet train is moving at the fastest possible speed in existence and you attempt to throw the rock in the direction the train is moving, isn't quite the same thing is it? Since the thread isn't about traveling at "lesser" speeds your ability to "talk all day" about them doesn't really apply then, but thanks.
Given that we don't know if we can move at light speed at all, we don't know if standard macro-physics could apply. And I'll post a suggestion on forum whenever I fee like it, thanks all the same (an activity you have "done all day" even more than me BTW).
No it does not go straight down. It travels in a parabola, having an initial velocity in the direction the train is going and undergoing an acceleration force from earths gravity.
If you are traveling at that same initial velocity (in the train) it will appear to fall straight down but it is a false appearance. If you want to get very technical you will have to add in earths (curved) path around the sun, the suns (curved) path around the galaxy and galactic motion as well.
Mike, the bullet will leave the gun but it will be moving very slow from the observer's perspective on the ship since it cannot exceed the speed of light because time slows down as a moving object approach the speed of light. The closer it is to the speed of light the slower it will move. The bullet will move slower since it is moving faster than everything on the spaceship.
This is the same approach particle scientists used at the particle accelerator in Switzerland to study the behavior of sub-atomic particles after a collision experiment. All the observed events of the particle progresses at a slower rate due to the speed of the particles which are traveling around the tube near the speed of light. Time slows down to prevent anything from traveling faster than the speed of light. To an observer standing outside of the spaceship he will not see the bullet leave the gun but it will appear to go backward if he was able to see it.
One little mistake - the observer on the ship has had time slowed for him, too - the bullet will move quickly in his perspective.
It is the outside observer that will see it taking a year to reach the end of the barrel.
You are right Wilderness, the bullet is moving faster than the observer traveling near the speed of light so time will move even slower for the bullet to keep it from exceeding the speed of light. The speed of the bullet is closer to the speed of light than the observer that is why it will move slower than the observer.
I kinda wish I could believe like you guys do. But the fact remains that I don't.
I believe sometime in the future people will be whisking around at 10X the speed of light. Time will remain constant to both them and the millions of outside observers. I believe there will be people sitting around in chat rooms discussing the mathematically sound principle of Relativity that is proven to be yet another paradox of reality by the faster than light trips to work they take everyday. Just like the conversations that we of today have about Zeno's Paradox, the mathematically sound principle that touch is impossible.
Do you suppose the Zeno's Paradox and this Relativity Paradox might be the same thing? Some kind of mathematical anomoly?
Congrags for thinking!
All knows not the answer! Your view and Einstein's view are NOT mutually exclusive! Both can be correct! The postulate states:
The speed of light is the same for all OBSERVERS!
It is this redundant beast called 'observer' which brings all confusion! It means;
The speed of light is APPARENTLY constant. It is this way, a car moving with the same velocity as you is APPARENTLY stationary. It is not REALY stationary.
Whether or not it is physically imposible to move at c is absolutely irrelevant to your question because yours is an hypothetical assumption that you are already moving at c initialy.
According to SR, you are still in an inertial frame of riference irrespective of your velocity. So you firing the gun, the bullet will certainly receed from you with normal velocity as per the postulate;
The laws of physics APPEARS the same in all inertial frames of riferences.
Someone capable of thinking like you immediately see that the bullet REALY moves faster than light. That is 100% correct!! The confusion? Einstein is talking of the APPARENT velocity of the bullet. Just as seen by the ground OBSERVER. For reasons unexplained in SR, the ground observer will a slowmotion movie of reality. In the case of you moving at c, the 'broadcasters of reality' will have slowed for you the 'movie' to an halt. You will only stare to one instance and won't see the bullet moving. This is called 'time stopping on you' in their idiotic language.
The Einstein's barrier is sanely stated this way;
APPARENTLY, nothing can move faster than light.
That is to say we can't measure and find a velocity faster than light. It is a theory not of reality but of measurements! But to measure and find apparent velocities isn't extraordinary. The fact that should ring in the mind of fools is that measurements does NOT necessarily reflect reality. Nature can perform very simple tricks on us! 'Time dillation' can even be experienced by a boy counting drum beats from a vehicle receeding away from him. Infact, two similarly beaten drums will be heard each beating slowlier than each other in two cars receeding away from each other. Yes, if you judged only using ears, infact you won't hear anything receeding away from you faster than sound no matter how fast the thing is ACTUALLY moving!!
You are mistaken. Consider the following scenarios:
An observer, a drum player and a plane with a pilot. Let the drummer produce a beat every 2 seconds and the driver move towards him at twice the speed of sound. The observer and drummer will hear a beat every two seconds, the pilot will hear a beat perhaps every 1 second as each beat has less distance to travel. As the pilot passes the drummer he will no longer hear any beats as the sound cannot catch him. Upon the end of the test pilot and observer compare their watches, each says the same time.
Now consider a pulsar, pulsing once each hour, an observer and a spaceship pilot. Set the pilot moving at very near C towards the pulsar. Each pulse has less distance to cover and you would expect the time between pulses to decrease. In practice, this is a function of V (speed), but the time dilation experienced by the pilot is a function of V squared; the pilot will experience pulses at perhaps once every 10 hours instead of the expected 30 minutes. When the text is over, compare watches of the pilot and observer; the pilots clock will say it is much earlier than the observers, again from the effects of time dilation. As the pilot passes the pulsar he will still see the pulses as he is travelling less than the speed of light and it will catch him. The time between pulses will remain very nearly the same, but the frequency of light reaching him will decrease enormously as he is now moving away from the pulsar.
Actual speed in the plane (relative to the drum) could be calculated from the time between beats, while the spaceship can use only the doppler effect to calculate speed; his notion of passing time is skewed from that of the observer and the pulsar.
Your example of using sound to observe time dilation is flawed. It can produce a simulation of time dilation, but the watches will remain the same; it is not actual time dilation.
and again, I agree the math says and proves it is so. But the Math also Proves that touch is impossible and yet... it isn't.
Unfortunately for that argument experience in the one case demonstrates that the math is right and works - in the other case experience proves the opposite.
Math may "prove" you can't touch a table with your finger but... what if you apply the exact same math concept to the back of your finger instead of the front. Eventually the front will touch the table. The back won't; it is stopped by the flesh and bone of the finger, but the math still works to the point that the front touches.
If you try to apply that to the speed of light - you run into a problem in that the entire ship is traveling at the same speed. It isn't like your finger where measuring distance from one part results in a different result than measuring from a different part.
Twisting the concept so it seems there isn't an anomoly in the absoluteness of mathematics doesn't accomplish anything. It is simply a form of denial.
The mathematics that "prove"you can't touch a table carries a basic flaw in that the "proof" assumes a constantly varying acceleration away from the table. That doesn't happen in real life. If the physical conditions in that proof were to actually take place it would then be correct.
There is no anomaly.
Ok what part of this is wrong?
Zeno's Paradox(Math) states touch (arriving at a destination) is impossible.
Touch proves Zeno's Paradox(Math) is incorrect.
Math is an absolute science. (1+1 always equals 2 etc.)
That is an anomoly.
The maths is correct. The problem lies in the application of it.
In Zeno's paradox the fact that the motion of the objects remains constant whilst the maths is dividing the distance between the two exponentially is not taken into account. For Zeno's paradox to have any validity, the velocity of the objects would need to slow down exponentially along with the maths.
The paradox (when applied) actually shows that the velocity of the objects coming together increase in relative velocity until they reach an infinite speed. The problem is that the maths changes the rules every 50% of the way.
I would have said that the velocity decreased to 0, not infinite.
Other than that, this explains the paradox well. A negative acceleration must be applied, resulting in a constantly decreasing velocity, which is exactly the objects cannot come together in less than infinite time. A paradox which is easily found and explained.
Identical to the math involved in 'Relativity'. Which is why I believe we will be able to go faster than light speed and time will remain constant for all of existence.
This mathematical anomoly is something profound.
Zenos paradox is not only not identical to the math involved in relativity, it is nothing at all like it. The paradox basically says that (1/2)^n is always positive, while relativity says that mass and time dilation become 1/0 at the speed of light. One is certainly true (the paradox) but has little to do with physics unless the limit as n approaches infinity is used instead of 1 divided by 2 to the nth power. The other is a meaningless figure - while the numeral can be written, the number it supposedly represents does not exist. We laymen may interpret it as infinity, but it is not - it does not exist at all and has no meaning in mathematics.
I don't understand this. How do you interpret it as infinity, when the Lim n==> inf 1/2^n = 0 ?
We will never be able to travel faster than light because it would take infinite energy to do so.
The best way to understand this is to think of a car hitting a brick wall. At 5MPH the wall will probably stop the car, but at 50MPH the car will smash through it. It's the same car with the same mass at a stand still, but at velocity its mass increases. This is how energy converts to mass, and we can calculate how much energy would be required to propel the car at certain speeds. You don't need to be a scientist to understand this even if you don't understand the maths.
Sure, just like we will never be able to arrive at a destination and touch, because the math proves that is impossible too.
Apart from the fact you are simply not listening to what is being said to you, things never touch each other anyway. So your argument is flawed.
Momentum only comes into play once the object has been released from the source of energy used to accelerate it to speed. Even so, the energy used to cause movement in an object increases the objects mass, if we are to agree that energy and mass are the same thing. Maybe I'm wrong...
This does not always apply, especially in the case of light, where the momentum would be in magnitude to the amount of energy the light possessed, and vector in the direction of motion excluding mass. mv does not apply.
What you call energy is the motion that is transferred to the car, so what increased is the momentum. Whether you are taking a static car or moving car, everything is same except that one is in motion and other not. The more the thrust you give the car, the more its velocity increases and nothing else changes.
So if we take 2 vehicles with equal mass that are travelling at the same velocity except that one vehicle is free-wheeling to the wall and one is being powered to the wall, both vehicles will have the same effect on the wall as they hit it?
If both are hitting the wall at the same velocity, yes they have the same effect(assuming the engine stopped just at the collision. If the engine is still kicking, the effect is more, as for the former one, there is no additional thrust).
In real life if both are starting at the same speed, the speed of free wheeler decreases owing to friction.
But if the free-wheeler is deccelerating naturally and the powered vehicle is accelerating, and we get them to hit the wall at the same time with the same velocity and mass, then what would the effect be?
Are the drivers of either vehicle using a cell phone?
Even if it was accelerating, the moment you take your foot out of the pedal, its stop accelerating. An accelerating car gives only gives more impact because the thrust from the engine continues even after the collision. The reason we always calculate using velocity, as acceleration is change in velocity. The impact depends only on the velocity at the time of collision, provided no further thrust is given.
That's my point. You need to cut the thrust at the moment of impact in order for the momentum to equal that of the free-wheeling vehicle.
In the equation P = mv the thrust of the vehicle is irrelevant and does not take into account the mass of the energy converted into forward motion during acceleration to its current velocity. Therefore an object does indeed gain mass when moving.
Now, that's the way I remember it from my physics lessons when I was a teenager. But I always remember being told moving objects gain mass.
You're only taking into account part of what happens in the collision. It's inelastic, where Fd = - 1/2mv^2 average force required to stop the car. There is no change in rest mass. Aditionally, I think you're confusing rest mass and relativistic mass.
Velocity is constant speed, while acceleration is increase in velocity. So during positive acceleration the momentum increases due to increase in velocity not mass. The mass remains the same.
I understand that. As ediggity says, I'm talking about relative mass, so there's the problem. But I need to look deeper because something doesn't seem right here.
What they say as relative mass is the force that is needed to stop the car. For a free wheeler its equal to the momentum, while the latter one, it is the momentum+the force to stop the engine, so actually nothing to do with the mass of the car.
Yes, I understand that, but what about the conservation of energy?
What happens to the mass of the fuel spent to achieve velocity? It can't just disappear. Doesn't fossil fuel lose some of its mass as it is burned?
It is an inelastic collision, only momentum is conserved, and energy is lost (technically transferred).
In this case the loss of fuel is negligible, however; you have also changed the dynamic of the initial question because you originally stated the only difference between the two cars was one powered to Velocity.
The only way fuel can lose mass is if it is a nuclear reaction. Burning chemical fuels such as gasoline do not lose mass - it only breaks or creates chemical bonds and creates new chemicals while retaining the actual elements that were always there.
Nuclear fuel, on the other hand, creates new elements and some of the mass does change to energy - it's what makes an atomic bomb so powerful. Some of the energy may appear as light, some as increased momentum to surrounding materials and some goes into increasing the momentum (potential energy) of the vehicle. When that vehicle stops, that extra energy imparted to it typically comes out in the form of heat and some change in momentum (to the brick wall here, if it comes apart and pieces fly away).
When fuel is burned, it just change form. Say the simplest fuel methane when burned becomes water and carbon dioxide(CH4 + 2O2 => CO2 + 2H2O) The total number of atoms and there mass remains the same. What happens is that new molecules have a greater velocity than the previous ones which is imparted to the piston of engine then to the wheels. Only a change in and transference of velocity, no mass, no energy.
I said IF and only if you have a drum beat as the only clock, you will certainly be fooled by dopple effect into thinking that you are experiencing 'time dillation' of course another clock will not be as 'foolish' as 'sonic relativists' just as we would if we discoverd a signal moving faster than light!
Understood. My point is that the "time dilation" from sonic observations is not the time dilation referred to by special relativity. One is a simulation of the actual effect while the other actually happens.
The pilot/driver, etc. actually experiencing the dilation cannot detect it; it is only found by comparing with an outside observer. Remember, it is not the actual movement of the car that produces dilation; it is the relative motion of the drum to the car that produces the relative dilation effect. Otherwise we would have to include the motion of the earths rotation, the earth around the sun, the sun around the galaxy and the galaxy through space.
Of course mine was just an analogy. My point is that nature can easily fool us.
There is something I don't get you about 'actuality' what is the definition of 'actuality' in relativity? So what do you mean by
"the time dillation of SR ACTUALLY happens"
I mean each of the two clocks are observed to each tick slowlier than the other. So which clock is ACTUALLY dilating? As far as I know, NON! It is just the same as my drums! What you don't seem to realise is that SR does not say that both observers will at the end compare their clocks and find that they ticked differentially. VERY WRONG!! the differential ticking is only observed while the frames are in relative motion. The halting and comparing clocks moves the problem to GR!!
When you send up one of two identical clocks, showing the same time and date, with an astronaut and it shows a different time when it lands (it has "ticked" slower) than the one left on ground it is due to time dilation.
It is very confusing because while the universe doesn't differentiate between two items moving relative to each other, WE do. One of the two is designated as the reference - the best we can do is to claim that the one that has experienced acceleration is the moving one, but even that doesn't always follow. After all, the earth is constantly being accelerated in a circular path around the sun.
It would be impossible to travel at the speed of light, but if you DID travel at the speed of light you would freeze in time and pass through every corner of the universe until it (and you) ceased to exist.
But essentially, if you fired the gun at the speed of light, no one outside your spacecraft watching you fly by would see anything happening because you would be frozen. The bullet would never emerge from the gun.
What part of math absolutely proves it is impossible to touch, don't you guys understand?
If you are referring to Zeno's Paradox, none of it. I understand it quite well. I'll even write you a hub on it tomorrow.
I found it. I'll still write it - I have an entirely different take on the matter. I'll even link to you as a different viewpoint and explanation. Should be interesting.
Nice Hub. I still disagree, but nicely done.
*** The part I have trouble agreeing with is the part where you state the ball (that IS moving at a constant velocity) slows down as it gets closer to the light beam. That continual reduction in velocity being why it can't ever get to the light beam.
Then in the next paragraph you restate that ball is in constant motion at a set velocity.
Again, all seem to know not the flaw in zeno's paradox. First, it is a purely logical question. Einsteins barrier is a statement about nature that need observation to debunk.
The flaw in Zeno's paradox is the inherent but hidden assumtion that motion proceeds in jerky manner. This flaw is done in caculus but there is no problem since calculus is just a tool.
Zeno goes ahead and becomes only interested with the moment when the cheeter has arrived at where the tortoise was. Notice that by so doing, he renders the velocity of cheeter undefined!! The cheeter could have gone at varying velocities BUT STILL ARIVE THERE AT THAT TIME. the only thing required is the 'average velocity' consider the classic combination of velocities which zeno won't differentiat in his disection. zero and infinite. Instead of cheeter moving from point p with constant velocity arriving at q, where the tortoise was, at time t, cheetah could have simply tarried at point p until time t and then jerk with 'infinite velocity' to point q. The point is that zeno can't state that this is not what is infact happening! Yet if indead cheetar was jerking in such a manner, he won't catch the tortoise.
In the end, zeno proofs in a looong not that motion is imposible but that it is imposible to shoot at infinite velocity. Which is infact a no brainer!!
Some people still think that Einstein's barrier is a proven fact. What a bunch of morons! If Newton's laws of motion could be challenged, no theory is unchallengable. Physicists might have bowed to Einstein but nature does not give a shit on Einstein's words.
All you need to do to decrown a bird's head of too big a crown is spot a signal, (NOT AN OBJECT) shooting just even slightly faster than c such that it relay information. You disembowel relativity! There is practically nothing left! Why? Simple, consider the extreem case. We have a rocket shooting at relativistic speed. Take your telescopes ready all we need to do is observe a moving clock but using signal s which is propergating exceedingly faster than c so that it relays to me a clocks reading nearly instantaneously. The clocks will be observed to tik nearly at the same rate!!
Of course Einsteins work has been challenged and will continue to be challenged. We've even found times where he was wrong, in the quantum world. In this particular case, however, (speed of light being a speed limit) there have been no successful challenges.
Speed of light is independent on the observer??? Then what happened to the "objectivity" in science?
What they should say is, speed of light is independent of the source.
Then we have an example - sound. The speed of light is also independent of the source. Why? Like sound, light is not also on the source. Some object on a speeding source take the speed of the source because the object picks up the speed of the moving source owing to the fact that both has same speed, as one is 'on' another. So when somebody throws the object, its speed will be = speed of source + speed at which it is thrown.
But for light and sound they are not on the source to pick up the speed of the source.
So the inference - both are waves. The difference, sound is supra-atomic, so we know the medium, light- subatomic, so we do not know the medium.
One area I am suspicious in is gravitantional waves if any. The assertion that they will propergate at c seems suspicious for gravity is still a different phenomenon from electromagneticsm. Why the majical equality? Perharps they shoot faster than electromagnetic waves. This of course would mean that the whole of GR is on its way to dust pin!! So I warn those guys looking for gravitantional waves to be sure that they measure very well. It will be ridiculus if the waves are infact undulating in a different medium than EM waves which alows them to shoot faster which is likely for there is no known interaction between gravity and electromagnetism. Infact if the Gwaves shoots excedingly faster than EMwaves, Newton's law of gravity was more correct than Einstein's!!
Gravity may work instantaneously - we don't know. It may be a wave, or not - we don't know. While we can correctly predict the pull of gravity, that is about all we can do in that field. Unfortunate as it may be the key that holds everything together in the world of physics and cosmology.
The effects of gravity are instantaneous. I think this is usually demonstrated during total eclipses and the bending of light as it passes the sun. String theory is based on the idea that gravity is the string holding all atoms together. If you pull on the string at one end, the effect will be felt immediately at the other end no matter how long the string is.
Mmm. I had not come across any proof that gravity was instantaneous - I'll have to check that out. It doesn't seem right to use an eclipse as the moon is slowly moved into position, but I'm probably missing something.
Thanks for the tip.
The moon actually has no affect on the phenomena other than allowing the light being bent by the sun's gravity to be observed because of the eclipse. Is this what you mean?
I remember a few years ago hearing about some type of identical "dangling" particles or something similar. If one of the twin particles were placed across the universe from the other and one was moved, the other particles would move at the same time, no matter the distance.
The scientists announcing this discovery claimed it had been tested somehow. I've never heard anything about it since. The scientists claimed it would enable super fast computers and instant radio messaging to spacecraft even light years away. Anyone know anything about this?
Very little. It's a part of string theory, and my understanding is that it has indeed been verified. It involves changing the spin of subatomic particles rather than moving them, though.
Thanks, Wilderness. I just remember them being referred to as "dangling" particles or something similar. I don't know if this would prove the instantaneous gravity theory, but it would seem to have some bearing on it.
Or it may show that the space between two "linked" particles has disappeared as far as they are concerned. That they are actually touching somehow. Through the infamous "subspace" maybe.
I don't know - this stuff is beyond me.
It is that. It usually leaves me shaking my head in confusion, but is fascinating nevertheless.
I watched a report on an experiment the other day where individual photons were being shot at a target. They acted as a wave instead of a particle, but ONLY when no one was watching. If an observation detector was turned on they reverted to acting like particles. Turn off the detector and they were waves.
Things like that just baffle me.
I could be wrong in what I said. I was thinking that the position of a visible star which would otherwise be obscured by the sun (if it wasn't for the bending of light through gravity) would still be obscured if the effect of gravity also travelled at the speed of light. But that doesn't seem right thinking about it.
I also seem to remember reading somewhere that there is gravitational attraction between all matter in the universe, even matter from which light has not reached us yet. Must look it up!
You could well be right on gravity too far away for light to reach us. I have never seen any limiters on the G equation for attraction between two masses.
Doesn't mean it's not there, and doesn't meant that it shouldn't be there, but I've never seen it.
First of all - the speed of light isn't constant. So when you speak of the speed of light - you aren't talking about a constant speed.
I certainly realize that the speed of light used to be thought to be constant - but that's the past.
No, it isn't. Continually more accurate instruments and methods have shown that it does vary by medium and, I think, local gravity. Although that could be due as much to relativity as anything.
Interesting - thanks. I didn't realize we had produced such a low temperature that we had slowed light to anything like that.
All they did was dump the photons into a Bose-Einstein condensate and made copies of the original photons. So what?
The speed of light is invariant, in other words, it does not vary. If it is moving through mediums other than space, then it will interact with whatever is present in the mediums giving the appearance that it has slowed, but it nonetheless interacts with whatever is in the medium at c.
So if the car is traveling at the speed of light, what happens when you turn on the headlights?
Seriously though, if a fly was in the back of the car and flew to the front seat--in a hypothetical sealed interior, of course--would the fly be going faster than the speed of light?
According to our understanding, you can't go the speed of light. The amount of energy needed to accelerate you that quickly doesn't exist in the entire universe.(without turning you into pure energy, at least).
The more energy you put into accelerating, the more 9's you add on to your 99.9999% the speed of light figure.
If, however, you are going 99.9999999% the speed of light and turn on your headlights, you will measure the light travelling away from you at the speed of light. Someone standing still outside your window would also measure the light travelling away from you at the speed of light... not faster than the speed of light as you would expect.
Maybe it's just me but all these article which talk about traveling at the speed of light is talking about particles lighter then air but some reason we think someone weighing more then air can sail through the universe at light speed-like I said maybe it's just me-I don't know?
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