Relativity
Relavistic corrections:
For speeds such as those that are seen and witnessed in everyday life, Newton's law of motion has worked very well as a model for describing matter. However for speeds far exceeding this, such as speeds approaching the speed of light, Einsteins theory of relativity must be used to describe the motion that these particles undertake. Even though some of these theories seem odd to what we witness in everyday life, a vast amount of experimentation has agreed with Einsteins theories.
The Special theory of relativity is developed from two fundamental ideas:
The speed of light is the same for all observers irrespective of how they move relative to one another
The laws of physicsare the same in any inertial (i.e non accelerated) frame of reference. This means that the laws of physics observed by an imaginary observer travelling with a very fast moving particle would be identical to those observed by someone who is not moving with the particle
Einstein showed that quantities such as mass, length and time must change in order to all obserers to obtain consistent results regardless of the reference frame they were experiencing. Einstein showed that each of the quantities described above is modified by a factor.
For non-relativistic objects mass is constant. However relativity predicts that mass becomes larger and larger as the speed gets closer to that of light.A particle would have an infinite mass if it could reach the speed of light.
If the half life of a large number of particles travelling close to the speed of light was to be measured from Earth it would be found to be much longer than that of a similar sample of stationary particles. The time is 'dilated' or prolonged as a result of travelling at such a high speed. Time like mass needs to have a relativistic correction.
Accompanying time dilation is another relativistic effect with is length contraction. To a stationary observer the length of an object moving close to the speed of light appears to be shorter than if the object was stationary relative to the observer.