Here's how Albert Einstein came up with his most revolutionary ideas

Albert Einstein, one of the greatest minds of the 20th century, forever changed the landscape of science by introducing revolutionary concepts that shook our understanding of the physical world.

One of Einstein's most defining qualities was his remarkable ability to conceptualize complex scientific ideas by imagining real-life scenarios. He called these scenarios Gedankenexperiments, which is German for thought experiments.

Here are a few thought experiments that demonstrate some of Einstein's most groundbreaking discoveries.

Imagine you're chasing a beam of a light.

This is something Einstein started thinking about when he was just 16 years old. What would happen if you chased a beam of light as it moved through space?

If you could somehow catch up to the light, Einstein reasoned, you would be able to observe the light frozen in space. But light can't be frozen in space, otherwise it would cease to be light.

Eventually Einstein realized that light cannot be slowed down and must always be moving away from him at the speed of light. Therefore something else had to change. Einstein eventually realized that time itself had to change, which laid the groundwork for his special theory of relativity.

Imagine you're sitting on a train.

Imagine you're standing on a train while your friend is standing outside the train, watching it pass by. If lightning struck on both ends of the train, your friend would see both bolts of lightning strike at the same time.

But on the train, you are closer to the bolt of lightning that the train is moving toward. So you see this lightning first because the light has a shorter distance to travel.

This thought experiment showed that time moves differently for someone moving than for someone standing still, cementing Einstein's belief that time and space are relative and simultaneity doesn't exist. This is a cornerstone in Einstein's special theory of relativity.

Imagine you have a twin in a rocket ship.

This thought experiment is a well-known variation of Einstein's light-clock thought experiment, which has to do with the passage of time.

Imagine you have a twin, born at almost the exact same time as you.

But the moment your twin is born, he or she gets placed in a spaceship and launched into space to travel through the universe at nearly the speed of light. According to Einstein's special theory of relativity, you and your twin would age differently. Since time moves slower the closer that you get to the speed of light, your twin would age more slowly.

When the spaceship lands back on Earth, you might be trying to sort out your retirement, while your twin is just trying to get through puberty.