Faster-than-Light the Fantasy You’re the captain of the fastest spacecraft in the galaxy but you and your crew need to get to a faraway planet right away What do you do Power the engines Engage the main thrusters And for goodness sake put your seatbelt on because you’re about to zoom through space faster than light itself But wait could this actually be possible in real life It happens all the time in movies and books You might have heard it called warp speed or hyperspace travel The idea is that we can cover enormous distances by traveling quicker than the fastest thing in the universe light 4
SCI-FI SPACECRAFT Imagine if just like in Star Wars all it took was the press of a button for your spacecraft to reach incredible speeds The stars would hurtle past in a blur In science fiction spacecraft come in all shapes and sizes The Doctor’s spacecraft looks like a police box and travels by disappearing and reappearing somewhere else Science fiction spaceships might even go into warp gates which propel them through space really fast Then they reappear at another warp gate in a completely different star system But all of this seems like a lot of effort right Why would anyone need to go so fast 5
the Universe is Big It is hard to understand just how big the universe is There is a lot more space between planets and stars than you think Venus is usually the closest planet to Earth but even at its closest point Venus is still around 24 million miles 38 million km away To give you an idea of how far that really is Earth’s equator is only 24,901 miles 40,075 km around Venus PROXIMA Centauri Now imagine we don’t want to go to the nearest planet Instead we want to go to the nearest star to our Sun That would be the collection of stars known as Alpha Centauri The smallest star in that collection is called Proxima Centauri and it is 25 trillion miles 40 trillion km away It’s hard to imagine a distance that long Proxima Centauri is a red dwarf star It is much smaller and dimmer than our Sun which is a yellow dwarf star 6
LIGHT-YEARS Now you can see why spaceships have to travel so fast in books and movies If spaceships traveled at normal speeds it would take hundreds of years to visit nearby planets and stars let alone the other side of the galaxy Clearly space is too big to be measured in miles When scientists measure how far away something is in space they use a different measurement called a light-year A light-year is based on the distance light can travel in a year which is 5 8 trillion miles 9 5 trillion km If a star was three light years away it would take you three years to get there if you were going at the speed of light But why do we measure things like this What is so important about light If you were wondering Proxima Centauri is 4 24 light-years away from Earth That’s a much easier number to remember isn’t it 7
