Why can't anything go faster than "speed of light"?

There is not limit on the momentum of an object. As you continue to apply force to a mass, its momentum will continue to increase in accordance with Newton's second law.

At non relativistic speeds, an increase in momentum is measured almost entirely as an increase in velocity. If I apply a 1 Ns impulse to a 1 kg object at rest it ends up moving at 1 m/s (within measurable error). It's mass remains 1 kg.

Near the speed of light, an increase in momentum is measured almost entirely as an increase in mass. If I apply a 1 Ns impulse to a 1 kg object travelling at ~c it's mass increases marginally but observably and its velocity remains at c.

In the middle, say at 0.5, increases in momentum are split between small increases in velocity and small increases in mass.

In the end, momentum is conserved and mass-energy is conserved. Momentum, energy, and mass can all be made arbitrarily high (capped only by whatever limits the available resources define). Velocity, however, is capped.

the speed of light is basically defined by a relation between magnetic fields and electric fields. There is no reason why these should work differently in different reference frames. It is a fundamental assumption that any experiment should work the same in any reference frame.
From the fact that the speed of light is constant in all reference frames you can work out that its a speed limit

>relativistic mass
get with the times, no one uses that convention anymore

The speed of light isn't really a speed limit, it's a conversion factor between time and distance.

Faster than light travel pretty much means you're teleporting.

It has to do with the Lorenz group, everything else in this thread is a consequence, not a definition.

Where does that mass come from?

The equations are the explanation you fucking retard.

It would require more mass than exists in the mass-energy of the universe.

[math]E=mc^2[/math] means an object's extra energy becomes its mass.

When an object moves, its kinetic energy adds to its mass.

>[math]
It's [eqn]

Everyone knows E = mc2. What's the explanation for it?

Can't believe there's so much shit in this forum. Special relativity clearly explains this. If you do the maths, you can easily see that: if physics is independent of the frame of reference, AND if we impose the concept of causality - then there HAS to be an upper limit at which information can travel.

That upper limit is shared by all massless particles, and we happen to call it 'speed of light' because light was the first massless particle we found with this behaviour.

You apparently don't know enough to know that E = mc^2 is a generalisation. Just go back to school for fuck's sake.

> Dunning Kruger
> the thread

>As mass cannot be "infinite", never, ever, unless you believe in God or something...
...you can't go faster than the speed of light. you just answered the question yourself.

>As long as your mass is finite, you only require finite energy to accelerate. It is *impossible* to have an infinite mass. Therefore you can breach the speed of light quite easily. Q.E.D.

are you retarded?

that is the process, but why does it stop at 299792458?

Because reality is stupid
>LOL YOU WANNA GO TO LIGHTSPEED
>WELL YOU GONNA NEED INFINITE MASS TO DO SO HEHEHEE

Read "The Science of Mechanics" by Ernst Mach and you'll understand.

>Why can't anything go faster than "speed of light"?

Eternity is currently going faster in the vortex of space than the fucking speed of light?

This: e = m*c^2

Your mother sure goes faster than the speed of light.
I've never seen a body that massive.

Every single person in this thread is retarded except for you. Thank you for pointing out the REAL reason this is impossible. It has nothing to do with infinite mass or infinite energy or any of that bullshit. Those are all consequences of something else, not the cause.

The maximum speed is not governed by light. It's just a coincidence that light happens to travel at the maximum speed of the universe, which is the speed of causality.

Saying you want to go faster than the speed of causality is saying you want to affect events before they happen, which is logically inconsistent and nonsensical.

don't neutrinos go faster than the speed of light?

Nah, neutrinos travel at the speed of light but don't interact with most matter. Photons, on the other hand, interact with almost all matter, so they're slowed down.

It's crazy when you think about it. You'd think if you wanted to go faster you'd just burn more fuel. I mean it would take ridiculous amounts to get to a fraction of the speed of light but it just seems so unreal that you can't.

So as a rocket goes faster does its specific impulse become lower? Sorry for being a brainlet but I seriously can't wrap my head around it.

For most purposes, once something is traveling at 99.99% of c, shooting stuff out the back even at c isn't going to get you past c

It could be possible to go +c with things like the LHC though, because the propulsion is external. you can light the magnets up at +c speeds

If you start walking it doesn't take you much effort.

If you start running at a slow pace it takes you a little more effort.

If you start running fast it takes you quite an effort.

If you start running in sprint you can't barely breath.

So you see, increasing speed requires an exponential effort, and if you look into a exponential graphic the increase of the required effort is so much that it gets into a point where not matter how much spirit you put into it, you simply won't go faster, thats the light speed.

At least thats the most absurdly simplistic explanation I can think of.

Because the speed of light is the speed at which the universe is expanding.

think deceleration from c might be in metres per second per metre

Most retarded post I've seen

>8510322
It would only need to be a 1 / c^2 m/sec/m decel const to kick in hard at c?

Light always goes at c in all frames. So say you move really fast, to you light still goes at c.

Compare this to a train. If you run next to a train as it pulls away, it can be stationary with respect to you.

Light always pulls away from you at the same speed. You cant even get 99% the way there in your frame of reference.

In addition everything moves through space time at c anyway. Our arrow just moves mostly through time. To rotate the arrow so we move through space requires asymptotic energy (as has been explained earlier in thread). This can be visualised as rotating our space-time velocity vector is a hyperbolic rotation, but this stems from the fact that c is the same for everyone (first post)

Finally it is possible for something to exceed c, spatially speaking theoretically. BUT it has to already be going faster than c and would never be able to go slower.

Thats because it cant rotate it's arrow from most space direction to most time, since an asymptote occurs when space speed and time speed are equal.

We have observed such particle however (they are called tachyons)

Why is there a speed limit on causality?

Here's a pic to explain. The 45 degree line represents light speed. If you get faster (move along the hyperbolic curve) it simply approaches 45deg line but never touches.

>that pic
So the more time you have, the more space you get? Makes sense...

Draw a line from the origin to a point on the curve, the gradient is your velocity. Light is at 45 deg. So you see to get their is tricky.

Our definition og meters and seconds is the reason

works out as 1 metre/sec/sec deceleration at c
&
a distance of 9.5 light-years for something travelling at 1 metre per sec to halt with no other forces

OP here.

As of yet, no correct answers have been posted. Lets solve this together guys.

This guy is atm closest to real explanation, although he is wrong about completely. 1% correct, i would say.

Could you expand on what you think it's incorrect. Of course it's simplified but I think fundamentally it stems from
1. C is the same in all frames of reference
2. An object travelling at c has no reference frame

it does not stop at 299792458

A rocket can accelerate as long as it wants, but from Earth's PoV the rocket speed will be approaching to c

Rocket could travel from A to B in 5 minutes, or whatever time, given enough energy. Even if A is Milky Way and B is Andromeda Galaxy. Say, you could go to Andromeda Galaxy and return back to Earth and spend like 10 minutes for this trip. But Earth time will be +5 million years.

When have tachyons been observed? As far as I'm aware they're purely hypothetical.

As far as your explanation about "rotating it's arrow from most space direction to most time", I take this to mean changing the 4-velocity by changing the frame. The 4-velocity always has a squared modulus of c^2, so no matter how you rotate it you will not get a spatial velocity exceeding c.

This is true. However, you will not be going faster than c even in your own frame in that you will not see Andromeda approaching you faster than c. This seems counterintuitive but length contraction and time dilation mean that you can get there in a shorter interval of your proper time than distance/speed of light.

>when you get close to c your mass raises exponentially
what about photons
when do they start moving?
do they accelerate?
what energy does it have?

It's probably just because electromagnetic waves propagate at c and therefore have a diminishing effect on an object as it's speed increases. EM is the only means we have to get anything close enough to c to observe these relativistic effects, so it makes sense that such experiments are bounded by the speed of the acting phenomenon.

>electromagnetic waves propagate at c and therefore have a diminishing effect on an object as it's speed increases

I do not think that this is correct.

kys

space is like liquid

You can use maxwell's equations in a vacuum to get the wave equation for light which gives you the value of c in terms of the permittivity and permeability of free space. The rest of the arguments in relativity mostly follow from the fact that a massless particle travels at c in all reference frames (without any specific reference as to what this value is) and that inertial frames can be chosen arbitrarily.

Realistically, physics doesn't really fundamentally answer questions of "why".

this.

spoiler alert: mass can be created out of nothing i.e. big bang

>are you retarded?

100 years from now, all you speed of light limit cucks will be seen as the retards by history.

Theres a certain point in which the energy to accelerate starts to convert the energy into mass. The upper limit just naturally reaches 300000000m/s. We dont know why that specific velocity is the limit, we have only verified it.
Most of the time, we dont know why the natural laws exist with the values they have. We have only verified them.

Whats really fascinating to me is that in the past, scientists were trying to determine an accurate velocity. Im not sure who it was, maybe maxwell, but one scientist discovered the most accurate way of determining the value. They simply used
c = 1/sqrt(εμ)
which are the constants for electric permittivity and magnetic permeability of free space.

Very cool stuff, good question op.

You could , theoretically , by bending space and time itself. But according to Alcubierre that would need *negative* energy that is equivalent to the mass of Jupiter. So yeah , its pretty impossible with our current understanding of Physics and technology.

Too much Sci-fi shit.

Nobody knows exactly why c is the "limit".

...

Imagine trying to speed up a car by throwing baseballs at a consistent velocity at it. Will you ever be able to get the car going faster than the baseballs?

Your analogy is flawed. The speed of light is constant in all reference frames, meaning even if a stationary observer sees you moving at 0.99c in the same direction as light is moving you will still see light moving at c relative to you in your frame.

Postulates of special relativity:
1. The laws of physics are the same in all inertial frames of reference.

2.The speed of light has the same value c in all inertial frames of reference.

You can do the rest OP.

Tell me, how can you be sure that c is invariant when you can only measure the average round-trip speed of light?

I forgot to include my main point. From my perspective the light approaches me at c, correct? How then can it ever possibly speed me up beyond c? It can't, invariance doesn't change that fact.

Yep. Photons have no rest mass but they do have relativistic mass.

This.

Honestly, I think the nature of constants such as 'c' bolster the theory of the multiverse. The conditions at the start of the Universe, such as physical parameters in the big bang if that's how it happened, give rise to our specific laws of physics. I imagine another Universe with the same generalized laws but different constant values.

It's kind of the entire basis of relativity. I'm sure other people are better at explaining how observation of this fact works. Einstein did propose some decent thought experiments.

Well the thing is, light is always going at c relative to you... the truck analogy is based on the fact that, at some point the truck is moving faster than the ball at which point the ball won't catch up to it and can't impact it to give it energy. But light will always catch up to you and hit you.

I know it's the point, I understand the topic well. I'm just pointing out that there isn't a way to actually test the empirical truth of the matter.

On the second point, my point is that no matter what nothing can go faster than light using light to impart energy to it because it would require light to travel faster than c to do so. Turn it over in your head, it's true regardless of how you look at it.

Because the Lorenz group and motion is continuous

ITT: Brainlets

The main reason is the causality principle. Going faster than the speed of light allows influencing the past basically.

In practice, there is nothing that forbids the existence of ravel faster than the speed of light (see tachyons), but interaction between the world of v > c and v < c is impossible.

I forgot to add that the reason it is impossible is infinite energy requirement mentioned earlier.

[math] \displaystyle
c=\frac{1}{\sqrt{\varepsilon_0 \mu_0}}
[/math]

It could just be a density issue
How much energy does it take to get a feather to break the sound barrier?

~474 J for an average chicken feather, but I'm not sure why you think it's a density issue. It's a basic consequence of SR that it would take an infinite amount of work to accelerate anything with mass to c.

You can tell that someone hasn't actually learned about SR when they parrot off the rest mass energy equation as the reason for everything.

The general case which takes momentum into account is [math]E^2 = m^2c^4 + p^2c^2[/math] btw

>In practice
>Tachyons