Theory Of Time

[triplebtalk 0]

Hi all,Yesterday I was thinking about the theory of time which Albert Einstein came up with, and it got me thinking. Since the speed of light is the fastest speed possible, we could never pass a light beam like we could pass a car on the highway. If we can never pass light, how could we even reach the speed of light? My answer to this would be the fact that the speed of light might be relative to the speed you are moving, hence always being unachievable...If you think my idea is completely lunatic please tell me, if you think I might have a good point, please help expand on the idea .Kind Regards,TriplebTalk

[chaos3932 0]

So are you saying that the speed of light is relative to time... That it moves and progresses as time does? Or do you mean it is simply relative to our movements? If that is the case then maybe we could acheive light speed. We simply do not have the science developed yet to be capable of harnassing the power needed to propel objects at such speeds. Maybe we cannot move at light speed on earth. However if we were in space could we possibly propel ourselves in some way?Some people mention G-Force. That we would die if we were placed in a capsule and pushed forward at light speeds. However what if we slowly increased the speed until lightspeed. Just like in a car you feel no oomph when you are driving at 100 miles an hour. Physically you are still and not moving however the car itself is moving you at 100 mph.

[rvalkass 5]

My answer to this would be the fact that the speed of light might be relative to the speed you are moving, hence always being unachievable...

The reason the speed of light is so special is because it is not relative. The speed of light is absolute, and does not vary depending on your speed or position.

 

The reason it is unachievable is because as you approach the speed of light, your mass becomes infinite, and you therefore need infinite energy to move. You could therefore get close to the speed of light, but never actually reach it.

[triplebtalk 0]

Ok, I will close this idea, I thought I was on to something ...

[cyber_electrons 0]

The reason it is unachievable is because as you approach the speed of light, your mass becomes infinite, and you therefore need infinite energy to move. You could therefore get close to the speed of light, but never actually reach it.

rvalkass, do you mind if you give some sources for your post? I am really interested in knowing more about this.

anyway....


Let's imagine. If a thing were to have infinite energy to move at an ultimate speed, what then? If the speed of light is a fixed value, then if you are travelling at the same speed (of light) then light would have a relative velocity of zero. But Einstein did say that you will still see light at light speed. What might the conclusion be?

[rvalkass 5]

rvalkass, do you mind if you give some sources for your post? I am really interested in knowing more about this.

My main source is Prof. Bill Barnes who lectured me in relativity I can also explain it using equations, and can give you some background reading if you want to learn about where they come from.

 

Generally, everyone knows the famous equation E=mc², but this is only half of the equation. The full equation is:

 

E² = m²c⁴ + p²c²

 

where E is the energy of your object, m is its mass, c the speed of light and p its relativistic momentum. Relativistic momentum is equal to:

 

p = (mv)/sqrt(1-(v²/c²))

 

where v is the velocity of the particle.

 

Now, as v approaches c, the number in the square root approaches zero, causing the momentum is increase rapidly, towards infinity as v=c. So, at the speed of light, momentum becomes infinite, meaning the energy of the particle must also become infinite.

 

If any of that made no sense, let me know

[truefusion 3]

If any of that made no sense, let me know

Though this is not necessarily directed to me (and though it did make sense to me), i am still interested in, or curious about, the implications which jump out at me from your following statement:

So, at the speed of light, momentum becomes infinite, meaning the energy of the particle must also become infinite.

I'll admit i've never done any extensive studies concerning light and its interaction with matter, so if you'll be patient with my questioning, it would be appreciated. Though i'll be alluding mostly to how light interacts with matter and is observed through the naked eye, and though i understand that "light" isn't necessarily something visible though in either case will always be energy, if light as you discuss it is defined as electromagnetic radiation, that is, for example, the light emitted by the sun or perhaps even a light bulb, anything visibly bright so to speak, then i am curious at the length it is emitted at or how something that absorbs light (i.e. if light by nature must be an infinite amount of energy) does not become or obtain the same properities of light, for example, like Moses after speaking with God (Exodus 34:29). Following your statement that the speed of light is absolute, it follows that light is always emitted at its speed (obviously), meaning it would require an infinite amount of energy since its (")entrance(") into reality in order to go the speed of itself. I am curious as to how something infinite can change one of its properties (like not being able to be any longer visible to the human eye) yet maintain its infinite, energetic nature. Likewise, how can an object (or matter) absorb something infinite without itself lasting forever, that is, without "practicing" decay?

 

But before answering that question, if the object that is emitting light does not within itself contain an infinite amount of energy, then how is it capable of emitting something that by nature is an infinite amount of energy? Or if the object that emits light does indeed posses an infinite amount of energy, then how, for example, can the sun be "scheduled" for depletion or non-existence? Doesn't it follow that anything that produces something infinite must itself be infinite? And that anything infinite cannot itself become finite (over time)? I am uncertain if your courses' studies include how light interacts with matter, or on perhaps heat, etc, or not, but it would be interesting to see what you have to say about this. I do realize i can just go out and attempt to find an answer to all of these questions, that is, that i can just go and research the matter (pun not necessarily intended ) myself, but this way seems more fun.

[rvalkass 5]

I'll admit i've never done any extensive studies concerning light and its interaction with matter, so if you'll be patient with my questioning, it would be appreciated. Though i'll be alluding mostly to how light interacts with matter and is observed through the naked eye, and though i understand that "light" isn't necessarily something visible though in either case will always be energy, if light as you discuss it is defined as electromagnetic radiation, that is, for example, the light emitted by the sun or perhaps even a light bulb, anything visibly bright so to speak, then i am curious at the length it is emitted at or how something that absorbs light (i.e. if light by nature must be an infinite amount of energy) does not become or obtain the same properities of light, for example, like Moses after speaking with God (Exodus 34:29).

Light itself does not have an infinite amount of energy. The energy of a light wave is equal to its frequency multiplied by the Planck constant. This is all to do with the fact that a photon has no rest mass, no size, etc. yet still carries energy, force and momentum. When something absorbs light, it must absorb the energy of the photon. However, it doesn't have to keep it as energy. Rather like in a nuclear reaction, energy and mass are transferrable, so it can be transformed into mass inside the object absorbing the photon.

Following your statement that the speed of light is absolute, it follows that light is always emitted at its speed (obviously), meaning it would require an infinite amount of energy since its (")entrance(") into reality in order to go the speed of itself. I am curious as to how something infinite can change one of its properties (like not being able to be any longer visible to the human eye) yet maintain its infinite, energetic nature. Likewise, how can an object (or matter) absorb something infinite without itself lasting forever, that is, without "practicing" decay?

The photon has no rest mass, and changes in energy affect its wavelength/frequency. The more energy you give to a photon, the higher its frequency becomes. As the photon is not infinite in energy, an object simply absorbs whatever energy the photon is carrying at the time.

But before answering that question,

Oh well...

if the object that is emitting light does not within itself contain an infinite amount of energy, then how is it capable of emitting something that by nature is an infinite amount of energy? Or if the object that emits light does indeed posses an infinite amount of energy, then how, for example, can the sun be "scheduled" for depletion or non-existence?

Again, the photon is not infinite, so your point is somewhat moot. However, the Sun's demise is due to the nuclear reactions going on within its core, and the depletion of its resources. Once the hydrogen, helium and other light elements are fully used up, the Sun will no longer be able to support itself under its own gravity and will heat up rapidly, causing it to expand into a red giant star. The outer layers will then be lost, leaving a dense white dwarf star and lots of stellar gas. The Earth will likely be consumed by the red giant stage. But don't worry - we've got 5 billion years

[cyber_electrons 0]

What is the answer to this question:If I am holding a mirror, looking at myself, I would see myself when I am still.Will I still see myself when I am travelling at the wavefront of light, looking into the mirror?This is the question in the documentary I saw about e = m c?.If light is a fixed value, then when I travel as fast as light I will not be able to see myself in the mirror as light will never get there. Or is light relative to the speed that I am going? I would still see myself in the mirror even when I am travelling at light speed.What happens if I try to throw a ball in the same direction that I am travelling at light speed?

[Baniboy 3]

What is the answer to this question:
If I am holding a mirror, looking at myself, I would see myself when I am still.

Will I still see myself when I am travelling at the wavefront of light, looking into the mirror?

One question: where you're holding the mirror? If you're holding it when you're "running" with the speed of light in front of yourself,

At first, yes you will, but when you reach the actual speed of light, light that reflects from your face never reaches the mirror. But if you ask me, you'll die before seeing yourself in mirror.

Or is light relative to the speed that I am going? I would still see myself in the mirror even when I am travelling at light speed.

No it's not, radiaton always has one direction and can't move to two directions at the same time, it can't move sidewise when it's moving to it's direction. It has no mass, therefore it can never be moved by mass like a physical object, forexample a ball, when you're running and you through it in the air straight up, it will continue it's movement to where you where going AND it goes up. LIGHT DOESN'T.

What happens if I try to throw a ball in the same direction that I am travelling at light speed?

Well, your mass is relative, you would have to throw the ball faster than the speed of light to even get it out of your hand. And, you can't throw it that hard, it's impossible because nothing can move faster than light. You're already moving with the speed of light, the ball's speed is the same as yours, to throw it, you have to move your hand from back to front and release it, so your hand has to move faster.
Edited March 26, 2009 by baniboy (see edit history)

[jaychant 0]

Wouldn't you be completely unable to do anything while you were traveling at the speed of light anyways?

 

As you approach the speed of light, time slows down, and when you reach the speed of light, time comes to a stop. This would mean that no matter how long it takes, from your point of view, the trip would be instantaneous; the time that it would appear to take would be zero. Therefore, you would not even know that you ever traveled at the speed of light; even if you traveled at the speed of light for 40 billion years, it would seem that the trip took literally no time at all. Because of this, by the time you were able to order your arm to throw the ball, you wouldn't be travelling at the speed of light anymore; the trip would be over.

 

On the other hand, if you were just travelling close to the speed of light, it wouldn't be impossible to throw the ball; however, it would take so much energy, your arm would likely be unable to handle it.

[truefusion 3]

Light itself does not have an infinite amount of energy. The energy of a light wave is equal to its frequency multiplied by the Planck constant. This is all to do with the fact that a photon has no rest mass, no size, etc. yet still carries energy, force and momentum. When something absorbs light, it must absorb the energy of the photon. However, it doesn't have to keep it as energy. Rather like in a nuclear reaction, energy and mass are transferrable, so it can be transformed into mass inside the object absorbing the photon.

 

...

 

The photon has no rest mass, and changes in energy affect its wavelength/frequency. The more energy you give to a photon, the higher its frequency becomes. As the photon is not infinite in energy, an object simply absorbs whatever energy the photon is carrying at the time.

So the particle you mentioned in the area where i quote you in my previous post is not necessarily this photon? And does the adjective "rest" change the meaning or state of "mass" like it appears to be doing? I ask this because "rest," as commonly understood by that word, implies that the photon would not be in motion—that it is "standing" still. However, i also realize that science doesn't necessarily apply commonly perceived definitions to words (e.g. the universe is expanding—"universe" being the keyword). But that would mean that when it is in motion, it bears mass (assuming it can actually stand still in one point in time); and if it bears mass, and if it goes at the speed of light, won't we be back to where we started from? But if "rest" doesn't change the state (or meaning) of "mass," then why is "rest" used? Or perhaps better stated, What would "rest" mean here then?

 

Interestingly enough, if "rest" changes nothing, and if it has no rest mass, applying it to E = mc² would mean E = 0, since anything multiplied by 0 is 0. However, since you state that that equation is only half of the actual equation, E becomes actually something that is greater than zero (which, due to the time required to do the math, i won't even attempt to do the math , but it appears obvious, at least to me, that it would indeed equal something greater than zero, even if it is less than 1). This implies that anyone who doesn't use the full equation is generally in err or not entirely accurate. Of course, this part may become irrelevant if "rest" is defined in a way that affects the state of "mass." But i believe you can see the dilemma anyway if E were to equal 0.

 

In either case, i am finding the whole array of terms interesting, especially within the context they're being used in. That is, i find it interesting that you can give energy to this photon without affecting its rest mass (if i understood it correctly). Also, bearing in mind that a photon is not infinite in energy, supplying it with infinite energy (if at all possible) would, at least in theory, change its state, therefore making it no longer a photon, at least by what can be implied by the definition given.

 

Oh well...

[rvalkass 5]

So the particle you mentioned in the area where i quote you in my previous post is not necessarily this photon?

Not necessarily. The equations can be applied to pretty much anything, from sub-atomic particles to space rockets. A good question is to work out if you have a rocket travelling at 0.8 times the speed of light, and it fires a satellite forward at 0.6 times the speed of light, what speed is the satellite travelling at relative to the earth? The same effects come in to play with anything approaching the speed of light.

 

And does the adjective "rest" change the meaning or state of "mass" like it appears to be doing? I ask this because "rest," as commonly understood by that word, implies that the photon would not be in motion—that it is "standing" still. However, i also realize that science doesn't necessarily apply commonly perceived definitions to words (e.g. the universe is expanding—"universe" being the keyword).

For once science has taken the logical approach. Rest mass does indeed mean the mass of the particle when it is at rest (ie. not moving). This distinction is necessary as the mass of an object is different when it is in motion. Its relativistic mass includes the kinetic energy of the particle, and therefore increases the faster the particle moves.

 

But that would mean that when it is in motion, it bears mass (assuming it can actually stand still in one point in time); and if it bears mass, and if it goes at the speed of light, won't we be back to where we started from? But if "rest" doesn't change the state (or meaning) of "mass," then why is "rest" used? Or perhaps better stated, What would "rest" mean here then?

The rest mass of the photon is zero, allowing it to reach the speed of light. Its relativistic mass includes a contribution from its kinetic energy. To avoid confusion, the terms rest mass and relativistic mass are used to distinguish between the two quantities.

 

In either case, i am finding the whole array of terms interesting, especially within the context they're being used in. That is, i find it interesting that you can give energy to this photon without affecting its rest mass (if i understood it correctly). Also, bearing in mind that a photon is not infinite in energy, supplying it with infinite energy (if at all possible) would, at least in theory, change its state, therefore making it no longer a photon, at least by what can be implied by the definition given.

You can give energy to a photon and not affect its rest mass in the same way that your car does not get heavier the faster you drive. Rest mass is an invariant quantity of an object - it does not change. Supplying anything with infinite energy (hypothetically, as energy is a finite resource) would cause either momentum or relativistic mass to increase to infinity to satisfy the equation. This is logical enough, as we see them increasing along with energy anyway - infinity is just a limiting case of this.

[truefusion 3]

Not necessarily. The equations can be applied to pretty much anything, from sub-atomic particles to space rockets. A good question is to work out if you have a rocket travelling at 0.8 times the speed of light, and it fires a satellite forward at 0.6 times the speed of light, what speed is the satellite travelling at relative to the earth? The same effects come in to play with anything approaching the speed of light.

Why is its relativity to the earth considered?

 

For once science has taken the logical approach. Rest mass does indeed mean the mass of the particle when it is at rest (ie. not moving). This distinction is necessary as the mass of an object is different when it is in motion. Its relativistic mass includes the kinetic energy of the particle, and therefore increases the faster the particle moves.

 

The rest mass of the photon is zero, allowing it to reach the speed of light. Its relativistic mass includes a contribution from its kinetic energy. To avoid confusion, the terms rest mass and relativistic mass are used to distinguish between the two quantities.

 

You can give energy to a photon and not affect its rest mass in the same way that your car does not get heavier the faster you drive. Rest mass is an invariant quantity of an object - it does not change. Supplying anything with infinite energy (hypothetically, as energy is a finite resource) would cause either momentum or relativistic mass to increase to infinity to satisfy the equation. This is logical enough, as we see them increasing along with energy anyway - infinity is just a limiting case of this.

...to avoid confusion. Okay, let's see if i can add these things up. For simplicity's sake, let's stick to the ever-so-common E = mc² equation. Is it safe to assume that m here would = rest mass xor relativistic mass? Assuming it is, that would mean in order for the photon to reach the speed of light it would have to be at rest and bear 0 energy (i.e. E = 0), because anything multiplied or divided by zero is zero. However, you mention earlier that the photon carries energy regardless... But if it is at rest, how can it reach the speed of light? And how can it still have energy though E equals 0? And when it is in motion, in order to reach the speed of light, it would require, as noted earlier, an infinite amount of energy. But, likewise, as noted earlier, energy is a finite resource. Therefore the photon never reaches the speed of light? Or is it that it really isn't the photon moving, but rather something else that is going the speed of light is pushing or pulling the photon (like a person in a vehicle)? Or is it that the statement "in order for the photon to reach the speed of light" is merely theoretical in its nature (i.e. merely allowing it does not necessarily mean any actual moving)? Or is it that m != (rest mass and relativistic mass)?

[Aeon 0]

I believe the answer is more simple than all the scientific examples listed above.If an object/vehicle was capable of traveling faster than the speed of light (note that there is no limit to speed, so it is possible in theory to go incredibly fast).Einstein may have stated that an object was incapable of travailing faster than that speed because of friction (Ie. The thing catching fire and melting the people, cows, monkeys, etc--) But if something were put up which defies the laws of heat, similar to what NASA uses to protect the ship on its reentry into earth-- it is possible to conclude that an object can indeed travel faster than the speed of light.Now, this may or may not mean that time travel is possible. You might just be getting to a very far place at a very fast time. I'd be kinda like saying a vehicle was capable of flying from Africa all the way to LA, California in 1.2 seconds. It's possible, but as far as moving forward, or backward in time-- I do not think it's possible. I believe that the present time and reality is stable, hence-- going hella fast to a certain place wouldn't mean you went 500 years into the future. It would mean you got to some unknown galaxy, or whatever very quickly.I could be wrong-- so it should be noted that my examples were opinion-based.