## Relativity of Simultaneity

Let’s assume there is a light source in the middle of the train and sensors on both sides to detect the light. From the point of view of an observer inside the train, the two light sensors are the same … more

Twin Paradox Twin paradox started as a contradiction in ‘time delay’ in Special relativity. The Twin Paradox goes something like this: (Contents vary depending on the media.) One of the twins stays on Earth, and the other leaves Earth in … more

## Special Relativity: Length Contraction

CAUTION: Read the following instructions to the end to get the result that the moving object appears to be constricted in length. (It is difficult to explain ‘Special Relativity’ only with the above simulation.) The meanings of the symbols used … more

## Special Relativity: Time Dilation

The meanings of the symbols used in this simulation are as follows. L = Distance that light travels in a stationary state, (=ct｡) c = Speed of light (≒ 299,792,458 m/s) t｡ = The transit time of light observed inside … more

## Gravitational Lensing

Space-time warpage Einstein, famous for the theory of relativity, thought that the mass of an object warps space-time. The larger the mass, the greater the degree of time-space warp. He explained that an object’s falling or planet’s revolution is a … more