
Chapter 1
The neighborhood is too big
Chapter 2
Einstein's absolute speed limit
Chapter 3
The ridiculous fuel bill of interstellar travel
Chapter 4
Space is actively trying to kill us
YOUR GOAL
Master of Why we might never leave our solar system
Ch 2 · Einstein's absolute speed limit
artiteacher Einstein's Absolute Speed Limit
When you speed right up, your mass climbs high, it takes infinite energy.

artiteacher High-speed space travelers would return to find their loved ones on Earth have aged decades more.

artiteacher A diagram shows how time warps as a spacecraft approaches the speed of light.
Fun Fact
Light speed: A beam of light could circle the Earth's equator about 7.5 times in just one single second.
Glossary
speed of light (noun)
The speed at which electromagnetic radiation propagates in a vacuum, measuring approximately 299,792 kilometers per second. Albert Einstein established this cosmic boundary in 1905 through his theory of special relativity.
The speed at which electromagnetic radiation propagates in a vacuum, measuring approximately 299,792 kilometers per second. Albert Einstein established this cosmic boundary in 1905 through his theory of special relativity.
Quiz
According to Einstein's 1905 theory, what happens to an object's mass as it accelerates?
Quiz
Why is infinite energy required to accelerate a spaceship to the speed of light?
Quiz
Which of Einstein's theories, published in 1905, established the speed of light limit?
Quiz
What is the scientific term for time slowing down for an object in rapid motion?
Quiz
If an astronaut travels at 99% light-speed to Proxima Centauri, how much time passes for them?
Quiz
How heavy would a 100-ton spaceship behave if accelerated to 90% the speed of light?
