At 1% the speed of light, going from Los Angeles to New York would take a little over a second.
, with a top speed of 7,000 mph . That sounds impressive, but it’s still only 0.001% the speed of light.
The fastest human-made objects are spacecraft. They use rockets to break free of the Earth’s gravity, which takes a speed of 25,000 mph . The spacecraft that is traveling the fastest is NASA’s . After it launched from Earth in 2018, it skimmed the Sun’s scorching atmosphere and used the Sun’s gravity to reach 330,000 mph . That’s blindingly fast — yet only 0.05% of the speed of light.What’s holding humanity back from reaching 1% of the speed of light? In a word, energy. Any object that’s moving has energy due to its motion. Physicists call this kinetic energy. To go faster, you need to increase kinetic energy. The problem is that it takes a lot ofto increase speed.
For example, to get a teenager who weighs 110 pounds to 1% of the speed of light would cost 200 trillion Joules . That’s roughly the same amount of energy that 2 million people in the U.S. use in a day.Solar sails, the thin shiny square seen in this artist’s rendition of the Japanese IKAROS spacecraft, could propel a spacecraft to 10% the speed of light.It’s possible to get something to 1% the speed of light, but it would just take an enormous amount of energy.