Physics Question Within

[Ex-User (5841)]

What, if anything, prevents large objects from moving at the speed of light (Or faster. I believe, it's been theoretically shown that moving at a speed just a teensy bit faster than the speed of light is possible?) in the vacuum of space?

Is it related to atomic mass (or whatever its equivalent is at the subatomic scale)? If so, how, exactly? (<-nothing TOO complicated plz).

Are these or similar forces present on the smallest of scales (particle physics)?

 

[Felan]

The amount of energy necessary to accelerate large objects is beyond the means of the so far observed most energetic events of the universe.

No particle has yet been observed travelling faster than the speed of light. There was a brief experimental error that raised the question, but it was eventually found to just be an error.

 

[Etheri]

Simply said, the amount of energy required to accelerate an object to the speed of light is infinite. The more energy you add to a moving object, the faster it moves, the closer it gets to the speed of light. But as long as this object has finite mass, it will never reach this speedlimit, being the speed of light in vacuum.

As an answer to why it works this way, special relativity and lorentz transformations should suffice to answer that question... But that'd take a while to explain, and I have more studying to do.

Edit : Felan is right, there has not been any correct measurements showing anything faster than the speed of light. If we'd find any, this would require a major change in our understanding & physics.
Also, it has nothing to do with the atomic weight. It has to do with actually having a nonzero mass.

 

[Nick]

Here's some reading for ya!

http://en.wikipedia.org/wiki/Speed_of_light#Faster-than-light_observations_and_experiments

 

[Ex-User (5841)]

It has to do with actually having a nonzero mass.

OKAY! So this is what I was looking for.

Can anyone give me the specifics?

Here's some reading for ya!

http://en.wikipedia.org/wiki/Speed_of_light#Faster-than-light_observations_and_experiments

Ugh. Such drudgery...

*starts reading*

 

[Felan]

OKAY! So this is what I was looking for.

Can anyone give me the specifics?

Ugh. Such drudgery...

*starts reading*

As you move faster and faster your mass increases and as has been pointed out approaches infinite. This is why only very light things (like nuetrinos) approach the speed of light.

Some people do get confused by the fact that two distant stars can be moving away from each other faster then the speed of light but Einstein's theory just says that no one thing can get from point A to point B faster than the speed of light.

 

[Etheri]

Some people do get confused by the fact that two distant stars can be moving away from each other faster then the speed of light but Einstein's theory just says that no one thing can get from point A to point B faster than the speed of light.

Wowowow, take it back one step. I'm not a physics student or professor, but I'm fairly certain that :

No object can surpas the speed of light, in any frame of referance. This means that the theory says a LOT more than 'getting from point A to point B faster than the speed of light'. In fact, it says that two distant stars CANNOT move with a relative speed higher than c. They can however move away from eachother faster than the speed of light, but only when you're looking from a third frame of referance caught in between the two separating objects. (I think?)

 

[Felan]

Wowowow, take it back one step. I'm not a physics student or professor, but I'm fairly certain that :

No object can surpas the speed of light, in any frame of referance. This means that the theory says a LOT more than 'getting from point A to point B faster than the speed of light'. In fact, it says that two distant stars CANNOT move with a relative speed higher than c. They can however move away from eachother faster than the speed of light, but only when you're looking from a third frame of referance caught in between the two separating objects. (I think?)

Relativity says nothing about the space between two seperate objects. It just says that one object cannot move through space faster than the speed of light.

From Earth it has been observed that two distant stars are moving away from each other faster than light can move between them. If you are were in orbit around one of those stars, you wouldn't be able to see the other. It's a bit of misnomer though because it's not so much that the objects themselves are moving through space that fast but that the space between the objects is expanding (and still accelerating) that fast.

As billions of years pass we will lose sight of more and more stars as the space us and them moves away from expands between us faster than the light of their existance can get to us. Eventually all the celestial sky will just be the local collection of galaxies that happen to be travelling in same general direction.

 

[BigApplePi]

What, if anything, prevents large objects from moving at the speed of light

If we ask that question but for a bit short of light speed, I believe there are objects in space that shoot out enormous mass at that speed. I forget what they're called. Check "quasars" but I'm not sure if that's the correct name.

 

[Buck Shane]

Tachyons.
(Faster than light)

 

[Felan]

Tachyons.
(Faster than light)

The are thus far only a mathematical prediciton. Which isn't to say they don't exist, just that we don't know them to exist.

 

[Felan]

If we ask that question but for a bit short of light speed, I believe there are objects in space that shoot out enormous mass at that speed. I forget what they're called. Check "quasars" but I'm not sure if that's the correct name.

There is the Oh-My-God Particle which was believed to have a proton or nuetron moving at nearly the speed of light. Galactic black holes are the leading contender as the source of them.

 

[The Introvert]

As you move faster and faster your mass increases and as has been pointed out approaches infinite.

Why does this happen?

Does it have something to do with friction between matter and the space it moves through at ever-increasing speeds?

I have next to no actual knowledge of physics, despite it being of profound interest to me. I'm looking forward to taking some classes next semester

 

[Ex-User (5841)]

Okay, so I'll cut to the chase here. I'm thinking of how it might be theoretically possible to measure something smaller than Planck length (PL). The general idea is that if you have a window with a diameter of 1 PL (likely coupled with other windows of 2-20 PL, with replicates of each, to use in an algorithm), then within a spherical enclosure with a known volume, the rate of particle intersection after they're set in motion by a known energy input combined with the known mass of the contents of the vacuum, reveals particle size.


For example, say you have a vacuum sphere covered in 4 unit diameter circular windows. Particles that are less than 4 units are invisible, yet they are contained within the sphere. The idea is that every time a set of particles come together in an arrangement > or = to 4 units long, something appears for a brief instant. If small particles move faster than large ones, then the rate of intersections, if tracked for a long enough period of time for each window, identifies the trajectory of the invisible particles and when formulated into an algorithm results in a total number of particles of each size.


Known drawbacks:
-This assumes that any particle smaller than Planck length is perfectly spherical. Oddly-shaped particles = FUBAR.
-I assume collisions between invisible particles can be factored into the trajectory equation with a large enough sample size.
-I doubt such an apparatus could actually be built. Having said that, let's build it.

 

[Etheri]

Okay, so I'll cut to the chase here. I'm thinking of how it might be theoretically possible to measure something smaller than Planck length (PL). The general idea is that if you have a window with a diameter of 1 PL (likely coupled with other windows of 2-20 PL, with replicates of each, to use in an algorithm), then within a spherical enclosure with a known volume, the rate of particle intersection after they're set in motion by a known energy input combined with the known mass of the contents of the vacuum, reveals particle size.


For example, say you have a vacuum sphere covered in 4 unit diameter circular windows. Particles that are less than 4 units are invisible, yet they are contained within the sphere. The idea is that every time a set of particles come together in an arrangement > or = to 4 units long, something appears for a brief instant. If small particles move faster than large ones, then the rate of intersections, if tracked for a long enough period of time for each window, identifies the trajectory of the invisible particles and when formulated into an algorithm results in a total number of particles of each size.


Known drawbacks:
-This assumes that any particle smaller than Planck length is perfectly spherical. Oddly-shaped particles = FUBAR.
-I assume collisions between invisible particles can be factored into the trajectory equation with a large enough sample size.
-I doubt such an apparatus could actually be built. Having said that, let's build it.

I just totally lost you. What does plank length have to do with special relativity? D: (inb4 universal theory of everything.)

As for the rest of the post, I have no idea what you're saying or trying to prove... But I had serveral glasses of wine, so it might be my own stupidity.

 

[Felan]

Why does this happen?

Does it have something to do with friction between matter and the space it moves through at ever-increasing speeds?

I have next to no actual knowledge of physics, despite it being of profound interest to me. I'm looking forward to taking some classes next semester

Since the speed of light is the limit as you add energy to something approaching that speed that energy can not be expressed in a way that means it goes faster. Still it has more energy.

With light there is no mass so the energy is expressed as increasingly energetic photons, which leads to red shift.

Matter and energy are interchangable. When something that has mass approaches the speed of light, one of two things have to happen: it has to become more energetic (red shift) or it's mass has to increase. So crudely speaking you either become a form of electromagnetic radiation or your mass increases.

 

[Ex-User (5841)]

I just totally lost you. What does plank length have to do with special relativity? D: (inb4 universal theory of everything.)

Universal theory of everything = Systems Theory.

As for the rest of the post, I have no idea what you're saying or trying to prove... But I had serveral glasses of wine, so it might be my own stupidity.

I'm trying to coagulate this myself during a brief-I-hope bout of apparently infectious scatterbrainiosis. I'm feeling pretty fruity. Brainstorm and reflect and visualize and stuff.

So you've got a 4x4 square window in front of you and there are 1x1x1, 2x2x2, and 3x3x3 blocks moving randomly in all directions behind it, and they're invisible because they're smaller than the window. But every once in a while, they randomly line up to form something 4x4 wide or larger, which makes them visible.

i.e. something with a width of 2 can't be seen, but 2+2=4, so they'd be visible if they lined up. Same deal for a 1 and a 3.

I probably just confused you more...

 

[Ex-User (5841)]

This whole thing is sort of like a total solar eclipse, but in reverse. Instead of being hidden by a shadow when everything lines up correctly, something appears from the shadows instead. Just briefly. Very briefly.

 

[Felan]

Since the speed of light is the limit as you add energy to something approaching that speed that energy can not be expressed in a way that means it goes faster. Still it has more energy.

With light there is no mass so the energy is expressed as increasingly energetic photons, which leads to red shift.

Matter and energy are interchangable. When something that has mass approaches the speed of light, one of two things have to happen: it has to become more energetic (red shift) or it's mass has to increase. So crudely speaking you either become a form of electromagnetic radiation or your mass increases.

Adding a bit more here. The thing about relativistic mass is that it depends on something else. If we are travelling near the speed of light we would not feel a mass or energy increase. Nor would people travelling at the same speed and parallel to us.

However in order to accelerate mass requires a force. You will have relativistic mass against that force (which is going in the opposite direction). So as you approach the speed of light the push you need to go faster gets bigger and bigger.

 

[Ex-User (5841)]

Matter and energy are interchangable. When something that has mass approaches the speed of light, one of two things have to happen: it has to become more energetic (red shift) or it's mass has to increase. So crudely speaking you either become a form of electromagnetic radiation or your mass increases.

So theoretically, adding enough of an energy input could increase the size of something smaller than Planck length to an observable size, and the amount of energy required to do so would predict said particle's true size?

 

[Felan]

I'm trying to coagulate this myself during a brief-I-hope bout of apparently infectious scatterbrainiosis. I'm feeling pretty fruity. Brainstorm and reflect and visualize and stuff.

So you've got a 4x4 square window in front of you and there are 1x1x1, 2x2x2, and 3x3x3 blocks moving randomly in all directions behind it, and they're invisible because they're smaller than the window. But every once in a while, they randomly line up to form something 4x4 wide or larger, which makes them visible.

i.e. something with a width of 2 can't be seen, but 2+2=4, so they'd be visible if they lined up. Same deal for a 1 and a 3.

I probably just confused you more...

A planck length window is way smaller than anything we observe even now. An electron is
2.81794033×10^-15 meters
A Planck length is
~~ 1.616×10^-35 meters
So to be honest we can't even see the windows much less whether something lines up behind it.

 

[Ex-User (5841)]

A planck length window is way smaller than anything we observe even now. An electron is
2.81794033×10^-15 meters
A Planck length is
~~ 1.616×10^-35 meters
So to be honest we can't even see the windows much less whether something lines up behind it.

Wouldn't the same idea apply regardless of window size, with a longer observation period to allow for more frequent random alignments at that given size?

 

[Felan]

Wouldn't the same idea apply regardless of window size, with a longer observation period to allow for more frequent random alignments at that given size?

I think you are just trying to create your own universe and want to know if you'll be able to detect it and next you'll want to know if you can slip into it when you detect it.

My answer is you'll have to do a lot more dieting.

 

[Ex-User (5841)]

I think you are just trying to create your own universe and want to know if you'll be able to detect it and next you'll want to know if you can slip into it when you detect it.

My answer is you'll have to do a lot more dieting.

Nah, just curious mainly. Now when it comes to larger, more tangible systemic components, a la ecosystems and social institutions, then yes.

And... dieting?

Spoiler

Strawmanning, eh?

 

[Felan]

Nah, just curious mainly. Now when it comes to larger, more tangible systemic components, a la ecosystems and social institutions, then yes.

And... dieting?

Spoiler

Strawmanning, eh?

Nah just failing at humor.

 

[Felan]

Wouldn't the same idea apply regardless of window size, with a longer observation period to allow for more frequent random alignments at that given size?

I think the main problem is the scale. An electron is closer in size to human than it is to a Planck length. What you are proposing to do would be worse than trying to visually detect a random spontaneous collection of electrons by walking around a human sized set of windows constructed as you propose. Physics of the small also behaves differently then physics of the large.

To have any hope I would think you would you need something much closer to a Planck length in size that you could still detect and measure (through machinery or some such).

 

[Ex-User (5841)]

To have any hope I would think you would you need something much closer to a Planck length in size that you could still detect and measure (through machinery or some such).

So you're saying it's theoretically possible!

Spoiler

http://www.youtube.com/watch?v=KX5jNnDMfxA

 

[Felan]

So you're saying it's theoretically possible!

Spoiler

http://www.youtube.com/watch?v=KX5jNnDMfxA

LOL

 

[The Introvert]

Adding a bit more here. The thing about relativistic mass is that it depends on something else. If we are travelling near the speed of light we would not feel a mass or energy increase. Nor would people travelling at the same speed and parallel to us.

However in order to accelerate mass requires a force. You will have relativistic mass against that force (which is going in the opposite direction). So as you approach the speed of light the push you need to go faster gets bigger and bigger.

Ok, I kind of understand. I'm assuming the interchangeability of mass and energy is consistent with Einstein's equation?

This may be an obvious question (or maybe not at all, and impossible to answer) but why is it that light is the fastest moving thing we have found in the universe? Why can't other particles that have no mass move equally as fast?

Another possibly unrelated question: how is the speed of light constant if rays of light can be bent? To explain further: If you are measuring the speed of light as a unit of distance/time, wouldn't a bent ray of light get to point A slower than a normal one? Wouldn't this make the speed of light not constant? Or am I just misunderstanding here (completely possible)

Spoiler

Probable, actually...

 

[Felan]

Ok, I kind of understand. I'm assuming the interchangeability of mass and energy is consistent with Einstein's equation?

This may be an obvious question (or maybe not at all, and impossible to answer) but why is it that light is the fastest moving thing we have found in the universe? Why can't other particles that have no mass move equally as fast?

Another possibly unrelated question: how is the speed of light constant if rays of light can be bent? To explain further: If you are measuring the speed of light as a unit of distance/time, wouldn't a bent ray of light get to point A slower than a normal one? Wouldn't this make the speed of light not constant? Or am I just misunderstanding here (completely possible)

Spoiler

Probable, actually...

E = mc^2 ... yep interchangability of mass and energy

There are others particles with zero mass that can travel the speed of light. Photons are electromagnetic energy (light). Gravitons are unconfirmed yet but expected to be zero mass and travel at the speed of light, I believe it has been observed that the effect of gravity is a wave that propogates at the speed of light.

Gluons are strong nuclear energy which is stronger than electromagnetic energy in the small, it's this force that lets the nucleus (nuetrons and protons) of an atom stick together rather than fly apart because of the repelling electromagnetic effect of the same charge protons. Unfortunately gluons can't exist in isolation like photons can, so if they aren't gluing stuff together they cease to exist.

Light is always going in a straight line. The perception of it bending is a result of gravity deforming the geometry of space/time. The bending of space doesn't slow light down, but it may make the journey longer as the light has to traverse some extra stretched-out space.

 

[BigApplePi]

@thehabitatdoctor,Felan.

I once asked someone on this very forum why couldn't there be something smaller than the Planck's length. Something to do with the Heisenberg Principle or string theory. The reply must not have been satisfactory because I don't remember who I was talking to or the answer.

Later:
Here ... I found something:
Re: Movement Paradox

 

[The Introvert]

Light is always going in a straight line. The perception of it bending is a result of gravity deforming the geometry of space/time. The bending of space doesn't slow light down, but it may make the journey longer as the light has to traverse some extra stretched-out space.

So, if I'm understanding correctly...

Bending space does not slow time, but rather shifts the distance it must travel.

Does this imply that light will then reach point A from point B more slowly if space is stretched as opposed to if it is not?

I guess the question is: If I were able to manipulate space in a way that makes the journey of light longer, would it take longer for light to make that journey?

 

[Felan]

So, if I'm understanding correctly...

Bending space does not slow time, but rather shifts the distance it must travel.

Does this imply that light will then reach point A from point B more slowly if space is stretched as opposed to if it is not?

I guess the question is: If I were able to manipulate space in a way that makes the journey of light longer, would it take longer for light to make that journey?

If you can stretch out the space before light reaches it then yes it will have a longer journey then if the space hadn't be stretched out.

If you can shrink the space before light reaches it then it will have a shorter journey. I'm not aware of anything that shrinks space though.

 

[Reluctantly]

What causes light?

 

[Etheri]

So, if I'm understanding correctly...

Bending space does not slow time, but rather shifts the distance it must travel.

Does this imply that light will then reach point A from point B more slowly if space is stretched as opposed to if it is not?

I guess the question is: If I were able to manipulate space in a way that makes the journey of light longer, would it take longer for light to make that journey?

Actually, I think time dilatation (time ticking slower) and length contraction (lengths getting shorter) are both effects of moving at higher speeds.

However, light ALWAYS moves with at lightspeed (in vacuum atleast), and since the relative speed is constant, the length is constant aswell, so the time it requires is constant too. (= you can't 'bend space' when related to light)... I'm not too sure about this last part, i'm decently sure about the rest of it D:

 

[Reluctantly]

Actually, I think time dilatation (time ticking slower) and length contraction (lengths getting shorter) are both effects of moving at higher speeds.

However, light ALWAYS moves with at lightspeed (in vacuum atleast), and since the relative speed is constant, the length is constant aswell, so the time it requires is constant too. (= you can't 'bend space' when related to light)... I'm not too sure about this last part, i'm decently sure about the rest of it D:

What I think about Time Dilation:

Time dilation is probably related, but sort of a different monster. If a ship blasts away from Earth at near lightspeed and comes back in say 15 Earth Years, but comes back thinking only 5 years have passed on the ship, why does the ship time slow down, but not the Earth?

Someone could argue that the Earth is moving away from the ship and that its time should slow down instead, but then not the ship. There's a way to explain the discrepancy though; the Earth is quite massive compared to the ship and arguably has a larger effective mass. The ship has some effect on the Earth, but so does the Earth have an effect on the ship. As the ship moves away from the Earth or the Earth away from the ship, they each will have a lesser effect on each other. The Earth's time will slow down, as well as the ship. However, the Earth has a greater effect on the ship (larger effective mass), creating a subjective difference in time from the viewpoint of the Earth, slowing down time on the ship.

What's interesting is that if you consider light to be a measure of the effect particles have on one another in spacetime, then as the Earth and Ship move away from each other, not only does it take longer for each particle to effect one another (because effects, being light, would travel at the speed of light), but that effect becomes weaker as they move away. The difference in time would start to make sense; it would also make sense that satellites orbiting the Earth would have a slower time as well (and they do).

Does that make sense?