If  we  don't  develop

EASY ACCESS TO SPACE
soon,  then  humanity  is  stuffed

No Upper Speed Limit

 Do you hold the widespread belief that no space rocket could ever separate from earth faster than 186,000 miles a second, the speed of light? I believe this view is wrong, and results from a misinterpretation of Einstein’s papers on Relativity of 1905 and 1916. Imagine a spacecraft hurtling away from the earth at fractionally under the speed of light. I believe that if it burns fuel, it will accelerate, but your view means that the laws of physics break down at this point, because it cannot accelerate past the speed of light. This is mistaken, to my mind. 

I have tried to isolate the error in our thinking.  

See the video See the video

In addition, consider these three paragraphs taken from books on the subject, with my comments in italics. 

Gravity Black Holes and the Universe

ONE
 
Mass increase: "In adapting Newton’s second law to fit the Special Theory of Relativity, Einstein found that a further consequence of the theory was that the mass of a body is affected by its motion. The mass of a moving body as judged by a “stationary” observer is greater than its rest mass (i.e. the mass which it would have if it were stationary in the observer’s frame of reference). The closer the body approaches the speed of light, the greater its mass becomes until, if it were possible for it to travel at the speed of light, its mass would become infinite. This implies that no material body can be made to travel at the speed of light, for the amount of energy required to accelerate by even a small increment a massive body which is already travelling close to the speed of light is very high; and an infinite amount of energy would be required to accelerate even the dot on this “I” to the speed of light. Given the resources, the speed of light may be approached as closely as we wish, but it can never be attained. The speed of light is an absolute barrier to the velocities of material particles."

Although lines one to seven relate the speed of light to a stationary observer, from line seven onwards this perspective is abandoned, leading to the blanket statement in the final two lines. 

What the author ought to say is 

The speed of light is an absolute barrier to the velocities of material particles that can be observed by a stationary observer.

This is very different.

TWO 

"The mass-increase equation, then, states that when an object is moving with respect to an observer, the mass of the object becomes greater, the amount of increase depending on the relative velocity of object and observer." 

For the correct statement, strike out the word “becomes” and substitute “appears to become”.


Relativity for The Layman



THREE 

"The only conclusion that can be drawn from all this is that the velocity of light is the maximum possible velocity. Nothing can travel faster than light because, as we have seen, not only does its length shrink to nothing but its mass becomes infinite. And, as a matter of fact, it is more correct to say that material objects with which we are familiar can never even travel as fast as light, because their mass would become infinite, which means that an infinite amount of energy would be required to get them up there. An infinite amount of energy means all the energy in the universe plus a great deal more."

 

 

The first four lines should read
The only conclusion that can be drawn from all this is that the velocity of light is the maximum possible velocity that can be observed. Nothing can be seen to travel faster than light because, as we have seen, not only does its length appear to shrink to nothing but its mass appears to become infinite...
The further point about infinite energy being required compounds the mistake. It would be better to say that it would require infinite energy to produce the illusion of travel faster than light to a stationary observer.

OBSERVATION

All speed is relative. When we say a car is going at fifty miles an hour, we mean relative to the road. But to say a spaceship is approaching the speed of light is meaningless until we add the frame of reference, such as relative to the sun. So the bald statement, “nothing can go faster than light” has no meaning, until the frame of reference is added, which it generally is not in common usage.

 

CONCLUSION
 

In short, whereas the great sleuth Sherlock Holmes admonished his assistant Doctor Watson with the words, “You see but you do not observe,” when it comes to detecting the presence of fast-moving spacecraft, “You observe, but you do not see.”

 

OPINION
 

I believe we will find that there is no upper speed limit in practice, and that one day it will be routine for spacecraft to be separating from earth at many times the speed of light. It will not be possible to observe this, but that won’t prevent it from happening.
Profiles of the Future by Arthur C Clarke

References 

ONE : Iain Nicholson, Gravity Black Holes and the Universe, David and Charles, London, 1981, page 71.

TWO : James A Coleman, Relativity for the Layman, Pelican, Harmondsworth, 1959, page 57 (2nd edition page 58). The second edition was still in print in 1990.

THREE :  ibid page 61 (second edition page 62)
 


Thank you for your interest.
David Pennant, Woking, UK