Can we travel at the speed of light?

We live in an age with a need for a fast means of transportation.

In that means to that quest, Charles Elwood "Chuck" Yeager in October 14, 1947 put his name in the wall of fame of the daring firsts, when he flew his small rocket-powered aircraft, Bell X-1 at more than the speed of sound (Mach 1).

Today, the legend is 95 and we have aircrafts that travel faster than the speed of sound. Seven and half year later in 1 May 1965, two pilots, Robert L. Stephens and Daniel Andre flew at 3331.505 km/h or 2070.101 miles per hour. This is three times the previous record set by Yeager.

Eleven years later in 28th July 1976 Capt Eldon W.Eldon W Joesz and significant George T Morgan Jr flying the SR-71 "Blackbird" did hit the fastest speed record of an "air-breathing" jet by travelling at 3529.6 km/h (2193 miles per hour).

The record speed for a manmade device was the 390kg NASA's Stardust spacecraft rentry velocity of 46,600km/h (29,000 mph) in June 15, 2006 on its return to Earth after spending 7 years in space.

All these appear insignificant once we realise that the speed of light is 299,792,458 meters/ second (983,571,056 ft/sec).

Can we ever be able to travel at the speed of light?

But before we take a look at that question, here are some fun things that will happen if we finally were able to travel at the speed of light.

If we can move at the speed of light in 1.28 seconds, we will be on the Moon. Getting to the Mars will now take 4.36 minutes instead of the usual number of weeks/months it currently takes.

Getting to the Saturn will be a matter of spending 1.18 hours with Pluto a little short of 6 hours journey at 5.35 hours.

That sounds like something that comes from a science fiction movie. But even at the tremendous speed, getting to the closest galaxy, Andromeda, will still take 2.5 million years.

Travelling at a speed of light will forever revolutionise transportation as we know it. But how possible can this be?

First, let us take a look at Einstein's theory of special relativity. The theory shines a light on an important principle which looks at the importance of frame of reference. The idea of a preferred frame of reference is one the law does not agree with. Everything obeys this which means time is relative.

We have two takeaway from this, first, the laws of physics is same in every changing frmaes of reference.

Secondly, the speed of light is constant irrespective of the motion or light source. In order words, if suddenly you have Flash's ability, and can move at half the speed of light, the speed of light will still be away from you at the same speed.

Remember the famous energy equivalence equation E=mc²? The equation is truly unforgettable. And yes, we still remember it.

Just for the record E= energy, m= mass, and c is a constant which is the speed of light.

Looking at the equation, we could see the relationship between mass and energy is one that is directly proportional. The more energy a body in motion has, the more the mass. That is for an object to accelerate at the speed of light we shall have a mass that is infinite plus a tremendous amount of energy to move this mass.

Almost there

Let us just that pushing things to the speed of light is impossible for now. But that did not stop our good friends, the scientists and engineers at CERN, from trying.

They have successfully pushed trillions of protons around the 27-km Large Hadron Collider's ring at 99.9999991% the speed of light. A mind-boggling 11,245 times per second. That was close, but still some 0.000000900000003% or 2.69813213 m/s off the mark.

The LHC was certainly the most sophisticated of machines ever invented by man for science.

Looking at the physics

Recall that force is required to move an object from A to B

Force (F) from Newtons Laws of Motion is defined by the product of mass (m) and acceleration (a)

That is, F= ma

The Lorentz factor which defines the change in relativistic mass, time and length of a moving object.

It is defined mathematically by

Lorentz factor γ = 1/ √1-(v²/c²)

where the v= relative velocity
the c= speed of light in a vacuum

therefore γ = (1-(v²/c²)^1⁄2

Replacing the Newtonian mass with a relativistic mass m_r(v) we have

m_r = m₀γ = m₀ (1 - v²/c²)^-1⁄2

where m₀ = mass of the object at rest and

From Einstein's energy equation we have

E= mc²

The mass of an object is a function of its energy.

Rewriting the Einstein's equation we have:

E= m₀c² / (1 - v²/c²)^1⁄2

m = m₀( 1 - v²/c²)^-1⁄2 = m₀/ √(1- v/c)²

Again, looking at the formula, it is clear to see that the v, velocity (speed) of an object approaches the speed of light (c), the object's mass tends to become infinitely large. Exceeding the or getting to the speed of light, therefore, proves impossible.

REFERENCE

• ^{Einstein on mass and energy}
• ^{Introduction: The Large Hadron Collider}
• ^{What if you traveled faster than the speed of light?}
• ^{Lorentz Factor}

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