Thread: Who said....

Einstein said it and proved it (and even NASA agree). Luckily for us all this falls into "Classical" physics which deal with mass, energy, speed and are pretty well established.

All newer discoveries are generally in the the area of quantum physics where things at subatomic levels are now being discovered. It was once believed that atoms were the smallest things to exist but then science decided to find out what atoms were made of, then they looked at what the stuff that atoms were made of were themselves made of etc... which is where the new discoveries are being made.

Funny, I thought it was James T Kirk?

According to Albert Einstein’s Theory of Special Relativity, the speed of light (usually referred to as c) in a vacuum is the maximum speed at which all energy, matter, and information in the universe can travel. This applies to all massless particles and associated fields (including electromagnetic radiation such as light. It is also the speed of gravity (i.e. of gravitational waves) predicted by current theories. Such particles and waves travel at the speed of light regardless of the motion of the source or the inertial frame of reference of the observer. In the theory of relativity, c (the speed of light) interrelates space and time, and also appears in the famous equation of mass–energy equivalence E = mc2.

There are devices on Earth that accelerate atomic particles to high speeds with magnetic fields. You can acelerate a proton to very nearly the speed of light but never exactly the speed of light or above.

What stops a particle going at or faster than the speed of light is that it gets heavier as you approach this speed. In effect it would have an infinite mass at the speed of light. Only massless particles like photons (particles of light) actually travel at exactly the speed of light.

The most recent and well known such device is the Large Hadron Collider.

When running at full design power of 7 TeV per beam, once or twice a day, as the protons are accelerated from 450 GeV to 7 TeV, the field of the superconducting dipole magnets will be increased from 0.54 to 8.3 teslas (T). The protons will each have an energy of 7 TeV, giving a total collision energy of 14 TeV. At this energy the protons have a Lorentz factor of about 7,500 and move at about 0.999999991 c, or about 3 metres per second slower than the speed of light (c).[32] It will take less than 90 microseconds (μs) for a proton to travel once around the main ring – a speed of about 11,000 revolutions per second.

[ame="http://en.wikipedia.org/wiki/Large_Hadron_Collider"]Large Hadron Collider - Wikipedia, the free encyclopedia[/ame]

Time also slows for particles close to the speed of light so that short lived particles live much longer than when stationary.

Originally Posted by KarlB

[FONT=Verdana][SIZE=2] Such particles and waves travel at the speed of light regardless of the motion of the source or the inertial frame of reference of the observer. In the theory of relativity, c (the speed of light) interrelates space and time

A good example of this for a layman to get their head around is to imagine yourself standing at a fixed point. To your left a particle is speeding directly away from you at the speed of light. To you right, off goes another particle at at the speed of light. Each particle is leaving you at the speed of light so what is the speed the particles are parting from each other? Logic would indicate that they are moving, relative to each other, at twice the speed of light: but the speed of light is the maximum velocity, so they are, by relativity, moving apart from each other at the speed of light. Now we start on the wonderful bits of curved space, etc. In the macro universe space (distance), speed and time are not separate, they are the same thing. The faster you go, the slower time gets. So, if you get a worked V8 and continually drive up and down a freeway at 250km/h you will live longer; unless you come to a sudden stop. It's all relative.

E = mc²/√(1 - v²/c²) from Einstein's work

E is energy
m is mass of a body
c is the velocity of light
v is the velocity of the moving body

if v = 0 the body is at rest and the equation reduces to E = mc², the famous equation.

if v = c then the body is moving at the speed of light and so now E = mc² / zero.

Division by zero is not really defined mathematically but some people would say the answer is E = infinity.

Originally Posted by jx2mad

That the speed of light is the absolute maximum speed atainable? How did they prove this to be the case? New discoveries are being made all the time. Or was this just an assumption on some scientist's part? Jim

It depends on your perspective.

Conventional physics dictate that nothing can travel faster than the speed of light, based on Einstein’s theory of relativity: E = mc², where E is energy, m is mass and c is the velocity of light. Based on this formula, as long as an object has mass, even if it consists of a single atom, it needs infinite energy to accelerate to the speed of light, and infinite energy is unachievable.

However, there is a theoretical way to travel faster than light - that is, to create negative mass. The theory is the basis for the theoretical Alcubierre drive - the idea is that you could create a warp bubble that bends the space that surrounds your spacecraft, and surf it like a wave to your destination.

Originally Posted by jx2mad

That the speed of light is the absolute maximum speed atainable? How did they prove this to be the case? New discoveries are being made all the time. Or was this just an assumption on some scientist's part? Jim

You have another theory ?? Do tell