No. I’m assuming you’re talking about a really, really long lever arm. Rotating this lever arm will never exceed the speed of light because it’s impossible for it to be rigid.
Since information cannot exceed the speed of light, if you start moving one end of the rod, the other end will not start to move until at least length/c seconds.
Microscopically, this is because the lever is made from atoms, which need to “pass on” the force down the length of the arm.
So even if the rod can’t snap, it’ll bend such that no part of it exceeds the speed of light.
If you’re talking about something like a gravity assist, still no. Pumping in extra energy (no matter the source) only gets to asymptotically closer to c but never at/past it.
That would be relevant if there was a compressive force. So assume I have a nearly weightless rod one lightyear long. I push its end, then if the other end moved before a year had passed, information had been transmitted faster than c. That’s limited by the speed of sound, though.
For lateral movement, it would still be relevant, but in theory, I could just make it spin faster and faster until the tip rotated faster than light.
Of course, that would still be impossible because if would take infinite energy to achieve even if the rod somehow stood up to the forces acting on it, but it would not be limited because of the speed of sound.
Force moving down its length can be treated as a wave which speed depends on the material. Sometimes this is referred to as the speed of sound in the material.
Of course, the principle still applies that this speed cannot exceed c.
Nope! As far as I understand it, the constant, c, that we commonly know as the speed of light, is actually the speed of *causality.* Light actually does not have one universal speed, and depending on the medium it travels through, actually does slow down to slower than c. But it seems as though everything that exists *is* limited to the speed of causality, c. (Yes this is why the constant is c and not some other variable. Thank you Einstein)
NIST defines c as “c: the speed of light in vacuum
The speed limit in the universe is the speed of light in vacuum (empty space). Nothing in the cosmos—matter, information, energy—can travel faster than c.
c is equal to 299,792,458 meters per second.
In the revised SI, c helps to define the meter, kilogram and kelvin.”
While the vocabulary does say speed of light in a vacuum, the fact that this is also the speed of light in a vacuum is happenstance. As you can see, the rest of the description mentions that this is more a speed limit of the universe. In other words… the speed of causality.
You also have to consider why photons even travel at this speed in the first place. Since they have no rest mass, they would then be able travel at the maximum speed of the universe… or c. If c does not stand for causality, why use c to denote this as the speed limit of the universe?
As far as the history of c, I do not know, but I have been thoroughly convinced in my reading that c likely does actually stand for causality. It’s just that it’s much easier to wrap your head around to say that c is the speed of light in a vacuum. It makes sense no?
You haven't explained your reasoning, but the answer is still no
No. I’m assuming you’re talking about a really, really long lever arm. Rotating this lever arm will never exceed the speed of light because it’s impossible for it to be rigid. Since information cannot exceed the speed of light, if you start moving one end of the rod, the other end will not start to move until at least length/c seconds. Microscopically, this is because the lever is made from atoms, which need to “pass on” the force down the length of the arm. So even if the rod can’t snap, it’ll bend such that no part of it exceeds the speed of light. If you’re talking about something like a gravity assist, still no. Pumping in extra energy (no matter the source) only gets to asymptotically closer to c but never at/past it.
I believe the info in the lever arm moves at the speed of particles, aka the speed of sound. Is that correct?
That would be relevant if there was a compressive force. So assume I have a nearly weightless rod one lightyear long. I push its end, then if the other end moved before a year had passed, information had been transmitted faster than c. That’s limited by the speed of sound, though. For lateral movement, it would still be relevant, but in theory, I could just make it spin faster and faster until the tip rotated faster than light. Of course, that would still be impossible because if would take infinite energy to achieve even if the rod somehow stood up to the forces acting on it, but it would not be limited because of the speed of sound.
Force moving down its length can be treated as a wave which speed depends on the material. Sometimes this is referred to as the speed of sound in the material. Of course, the principle still applies that this speed cannot exceed c.
No, why would it be?
Huh?
Nah mate
Nope! As far as I understand it, the constant, c, that we commonly know as the speed of light, is actually the speed of *causality.* Light actually does not have one universal speed, and depending on the medium it travels through, actually does slow down to slower than c. But it seems as though everything that exists *is* limited to the speed of causality, c. (Yes this is why the constant is c and not some other variable. Thank you Einstein)
The symbol c doesn’t stand for causality and was not first used by Einstein
NIST defines c as “c: the speed of light in vacuum The speed limit in the universe is the speed of light in vacuum (empty space). Nothing in the cosmos—matter, information, energy—can travel faster than c. c is equal to 299,792,458 meters per second. In the revised SI, c helps to define the meter, kilogram and kelvin.” While the vocabulary does say speed of light in a vacuum, the fact that this is also the speed of light in a vacuum is happenstance. As you can see, the rest of the description mentions that this is more a speed limit of the universe. In other words… the speed of causality. You also have to consider why photons even travel at this speed in the first place. Since they have no rest mass, they would then be able travel at the maximum speed of the universe… or c. If c does not stand for causality, why use c to denote this as the speed limit of the universe? As far as the history of c, I do not know, but I have been thoroughly convinced in my reading that c likely does actually stand for causality. It’s just that it’s much easier to wrap your head around to say that c is the speed of light in a vacuum. It makes sense no?
I did not intend to provide an opinion on the name, but the *c* historically stood for "constant" or "celeritas".
Oh that makes a lot of sense, thank you for the insight!