We know that there are worlds much like our own. There might even be other “Earths” that are able to support life. But how do we get there? Right now interstellar travel for humans is a long way off. But that doesn’t mean we aren’t working on it!
The universe is vast, there is much to see and explore.
There are more than just a few roadblocks in the way of traveling to the stars. The most obvious one is the distance.
The fastest speed humanity has ever achieved was with the Helios 2. This craft achieved an amazing speed of 240,000 kilometers an hour. That’s fast enough to circle the entire Earth in 10 minutes. But even going at that speed it would still take us about 19,000 years to reach the next star closest to us.
Will Interstellar Travel Ever Be Possible?
Almost a hundred years ago, Albert Einstien saw a problem that awaits those who seek to travel to the stars. He produced his theory of relativity which was about time and how we experience it.
In general, we view time as a constant. Relativity proved that the passage of time is determined by how fast something moves in relation to its surroundings. The faster you go the more your perception of time changes. This is time dilation.
Interstellar Travel and Time Dilation
If you traveled close to the speed of light, time will pass much slower for you. By the time you returned to Earth your friends will have aged much more than you have.
Let’s pretend light speed was possible and you decided to take a trip to the star closest to us, Alpha Centauri. This star is about 4.37 light years away. Traveling at this speed would take you about eight to nine years to get there and come back.
Or it would from the point of view of the friends and family you have on Earth. But for you, the trip would only take a little over a year. Because you are both experiencing time differently.
We all experience time differently based on how fast we are moving. Sloths move very slowly, how do you think they experience time?
Can We Even Reach Lightspeed?
Albert Einstein also said that objects of mass could never reach the speed of light. This is because it would require an infinite amount of energy to achieve this speed. But despite this, scientists still try to figure out how we can get beyond the speed of light. So far, only science fiction has achieved it.
How Close are We to Interstellar Travel?
Interstellar travel is going to be very hard to achieve but that doesn’t mean it will never be possible. Some of the world’s brightest minds, which included Stephen Hawking, believe that interstellar travel is possible. In fact, one team of scientists has started a project called Breakthrough Starshot which aims to achieve it soon.
These scientists want to send small spacecraft to the closest star system. They claimed that lasers are now advanced enough to help launch tiny space probes. Researchers can currently produce phased laser arrays. These are rays built up by fairly modest laser amplifiers. They can connect together to make a single powerful laser.
Eventually, the team plans to build a laser that is about 50 to 70-gigawatt laser array. When launched into orbit around Earth this array could send light to a very small spaceship. This spaceship could be as small as a mousetrap, the weight of an eraser with a small sail. Scientists theorize that lasers could send the tiny craft at more than 25% the speed of light. This speed could get the tiny spacecraft to Mars in half an hour and to Alpha Centauri in about 20 years.
Current Obstacles to Interstellar Travel
There are still some challenges. This same system could send a full-sized spacecraft to Alpha Centauri but it would take about 2,200 years. We would need a much larger array in the future. But with these new technologies, interstellar travel might be closer than we think.
Just because we can’t go ourselves doesn’t mean we can’t see any of it. We can send satellite probes to take pictures to send back to Earth.