5 revolutionary physics thought experiments by Einstein

The riding-on-a-light-beam experiment, or the twin paradox, are two of the five thought experiments that led to revolutionary proposals in physics by Albert Einstein, one of the greatest minds of the 20th century.

Illustration of the light-riding experiment. Photo: Darren Arthur/Stringer

Experiment of riding on a beam of light

According toBusiness Insider, this is the experiment that Einstein thought of in 1895, when he was 16 years old. What would happen if you chased and caught a beam of light?

According to Einstein, you would see light frozen in space. But light cannot be frozen, so Einstein realized that light will never slow down and will always move away at the speed of light. Therefore, something else must change. He eventually realized that it was time. This conclusion laid the foundation for his special theory of relativity, which he proposed in 1905.

Experiment on train struck by lightning

Imagine you are riding on a moving train and a friend is standing outside the train watching it pass by. If lightning strikes both ends of the train, the person standing outside will see both events happen at the same time.

As the person on the train gets closer and closer to the lightning in front of the train, he will see the lightning at that end first. This experiment has shown that time is different for a moving person compared to a person at rest, reinforcing Einstein's belief that time and space are relative, simultaneity cannot exist. This is also a foundation of Einstein's Special Theory of Relativity.

Illustration of a train being struck by lightning. Photo: Above Top Secret

According to VNE