1.5 Flashcards
What is time dilation?
The difference in elapsed time between two clocks due to a difference in relative velocity.
Why does less time pass for a person travelling on a space shuttle close to the speed of light relative to an observer on Earth?
The speed of light is a constant, so as an object nears the speed of light, time will change for the moving person/object. Due to time dilation caused by the shuttle’s relative velocity, a clock on the moving shuttle will measure a shorter time than a stationary clock on Earth.
Break down the equation
t’ = t/square root1 - v^2/c^2
t’ = stationary observer (s)
t = moving observer (s)
v = velocity (ms^-1)
c = speed of light (ms^-1)
What is a consequence of time dilation?
The observed time in the stationary frame of reference t’ is always greater than the time experienced in a moving frame of reference.
What is length contraction?
When the length of a moving object close to the speed of light is observed to be shorter than its true length measure when the object is at rest.
When observing a space shuttle travelling near the speed of light from Earth, the observer notices that the length of the shuttle appears contracted. Why is that?
The speed of light is constant, and so the length of the travelling shuttle must change as it nears the speed of light. Therefore, the length of the moving object will appear constricted to the object at rest.
Break down the equation
l’ = l square root 1 - v^2/c^2
l’ = statonary length (m)
l = moving observer length (m)
v = velocity (ms^-1)
c = speed of light (ms^-1)
