FTL Technology

If we found a way to reduce an objects mass, or remove it completely. ( This may be impossible, I know)

1.Can said object accelerate to light speed or beyond?

2. Would said object accelerate or instantly be light speed as soon as its mass reaches 0?

3. If it needs to accelerate, how much power do you need to move an object with no mass?

4. What if we discover in the future that sunlight actually does have mass?

Originally posted by Colossus-Big C
If we found a way to reduce an objects mass, or remove it completely.

1.Can said object accelerate to light speed or beyond?

2. Would said object accelerate or instantly be light speed as soon as its mass reaches 0?

3. If it needs to accelerate, how much power do you need to move an object with no mass?

If it suddenly had no invariant mass it would instantly begin moving at the speed of light. In fact it would be impossible for it to travel at any other speed. I believe there's a proof of that somewhere in special relativity.

Originally posted by Colossus-Big C
4. What if we discover in the future that sunlight actually does have mass?

Mass is a really complicated subject in relativity, there are at least two different kinds and I think one more. Suffice to say no one here would understand anything about the many complicated pages of math that would be needed explain it in a way that is even slightly accurate.

Got it. E = energy; p = momentum; c = speed of light; v = velocity

for a massless particle, assuming p is positive:
E = pc

for all particles:
v = pc^2/E

it follows that for a massless particle:
v = pc^2/pc

which reduces to:
v = c

Again this assumes particles can't have negative momentum and thus move faster than the speed of light but you can rule out such particles on empirical and rational basis.

Originally posted by Symmetric Chaos
If it suddenly had no invariant mass it would instantly begin moving at the speed of light. In fact it would be impossible for it to travel at any other speed. I believe there's a proof of that somewhere in special relativity.

Isn't it "faster than the speed of light" or are you not referring to tachyons?

Also, we can slow light with various methods/mediums. I know you meant 'in a vacuum' and that is almost always understood.

Originally posted by Symmetric Chaos
Suffice to say no one here would understand anything about the many complicated pages of math that would be needed explain it in a way that is even slightly accurate.

I agree: it would take a recent graduate degree in particle physics.

Originally posted by dadudemon
Isn't it "faster than the speed of light" or are you not referring to tachyons?

Also, we can slow light with various methods/mediums. I know you meant 'in a vacuum' and that is almost always understood.

Tachyons are supposed to have imaginary mass rather than zero mass.

Originally posted by Colossus-Big C
If we found a way to reduce an objects mass, or remove it completely. ( This may be impossible, I know)

1.Can said object accelerate to light speed or beyond?

2. Would said object accelerate or instantly be light speed as soon as its mass reaches 0?

3. If it needs to accelerate, how much power do you need to move an object with no mass?

4. What if we discover in the future that sunlight actually does have mass?

Writing a story?

So is it even possible to remove an objects mass/ lower it?

Originally posted by Colossus-Big C
So is it even possible to remove an objects mass/ lower it?

Well, there is speculation about removing the mass mediated interactions which could potentially accomplish that. "Warp fields". But the last I checked, that's magic and not science.

Originally posted by Colossus-Big C
If we found a way to reduce an objects mass, or remove it completely. ( This may be impossible, I know)

1.Can said object accelerate to light speed or beyond?

Originally posted by Colossus-Big C
2. Would said object accelerate or instantly be light speed as soon as its mass reaches 0?

Originally posted by Colossus-Big C
3. If it needs to accelerate, how much power do you need to move an object with no mass?

Originally posted by Colossus-Big C
4. What if we discover in the future that sunlight actually does have mass?

Originally posted by Symmetric Chaos
If it suddenly had no invariant mass it would instantly begin moving at the speed of light. In fact it would be impossible for it to travel at any other speed. I believe there's a proof of that somewhere in special relativity.

E = (m₀c²)² + (pc)² = 0² + 0² = 0.

Not that p is determined by a limit value, and if v < c then p &#8594; 0 for m &#8594; 0.

But then that hinges on what you mean with existence in the first place.

Originally posted by Symmetric Chaos
Got it. E = energy; p = momentum; c = speed of light; v = velocity

for a massless particle, assuming p is positive:
E = pc

for all particles:
v = pc^2/E

it follows that for a massless particle:
v = pc^2/pc

which reduces to:
v = c

Originally posted by Symmetric Chaos
Again this assumes particles can't have negative momentum and thus move faster than the speed of light but you can rule out such particles on empirical and rational basis.

Originally posted by Astner
Negative momentum is just momentum in the opposite direction. 🙄

Well, depending on the "absolute" direction, yes. But I think SC was talking about negative momentum in the absolute direction yet still having negative momentum which is a tad different than moving, say, "left".

Originally posted by Astner
These aren't postulates, so you have a singularity at E = 0.

Okay, I'm not a physicist. Just copying something I found elsewhere.

Originally posted by Astner
Negative momentum is just momentum in the opposite direction. 🙄

Okay, I'm not a physicist.

If you reduce your mass to zero, you'll hit the speed of light, but you won't be able to control yourself or stop because time will stop for you. Also, a tachyon would travel backwards in time.

Originally posted by dadudemon
Well, depending on the "absolute" direction, yes. But I think SC was talking about negative momentum in the absolute direction yet still having negative momentum which is a tad different than moving, say, "left".

Originally posted by Colossus-Big C
If we found a way to reduce an objects mass, or remove it completely. ( This may be impossible, I know)

1.Can said object accelerate to light speed or beyond?

According to the current model; for massless objects light-speed is attainable, but not superluminal-speeds.

So what happens if a massless object at light speed gains back its mass?

It would still be light speed since it doesnt have to accelerate?

wouldn't it have to lose speed to gain mass in the first place? or like, the two things must occur simultaneously?

Originally posted by Colossus-Big C
So what happens if a massless object at light speed gains back its mass?

It would still be light speed since it doesnt have to accelerate?

That said, physics isn't a perfect model fully explaining nature either.

Or is it magically acquired mass? In which case ou can have any answer you want.

Originally posted by Lord Lucien
Or is it magically acquired mass? In which case ou can have any answer you want.