## What Happens When Things Go Near the Speed of Light?

#### Challenge Home - Online Resources - Challenge - Assessment - Site Index

Taking Special Relativity into account, the particles travel much farther than you might expect!
• You perceive that particles have longer lifetimes when they move near the speed of light. And the closer they get to the speed of light, the greater the increase in their lifetime and the farther they travel.

• What does this mean for detector design? Physicists need to understand how far a particle will travel before decaying so they can design a detector that will observe the decay. They might build a detector that is too short or too long.

• Be careful when applying what you have learned based on your experiences to new situations. It can be dangerous if you:
• assume nature's laws are the same in all situations.
• don't check.
• aren't prepared for surprises.

• And back to Superman . . . if you watch Superman fly near the speed of light, you think he has gone farther than he thinks he has gone. For example, if you could stand still on the ground and watch him fly from New York to Los Angeles in one fiftieth of a second, you would see him travel 2485 miles. Superman, on the other hand, would only think that he had gone 1434 miles.

So, using D = vt doesn't work for velocities near the speed of light. So, how do we calculate a distance? You can use the Fermilab data to find the correct relationship! Advanced Analysis