Light-years are the measure of distance light travels in a year, and it's an incredibly long way. Light moves at an incredible speed of 186,000 miles (300,000 kilometers) per second and 5.88 trillion miles (9.46 trillion kilometers) per year. But, is it possible for humans to travel such a vast distance in a single lifetime?Dr. Phil Lubin has done calculations that suggest it is possible to reach speeds of up to 20% of the speed of light.
While we don't yet have a plan to slow down such a spacecraft, reaching the nearest star in a single human lifetime is within the realm of possibility. To put this into perspective, there are about 31,500,000 seconds in a year, and if you multiply that by 186,000 (the distance light travels every second), you get 5.9 trillion miles (9.4 trillion km) - the distance light travels in a year. The Spore Drive, from Star Trek Discovery, opens up a new possible mechanism for traveling faster than light that may be even higher than the Warp Drive. However, even if we could travel at the speed of light, it would still take us more than 100 years to travel 100 light years - longer than a human life. The most likely way that humans have in their foreseeable future arsenal of launching a macroscopic spacecraft over interstellar distances is to use powerful arrays of phased lasers that can reach gigawatt power levels. This has the potential to accelerate non-living objects to speeds close to the speed of light, making interstellar travel possible in a single human lifetime. Voyager 1 is currently the farthest object ever launched by humanity and it's still thousands of times away from traveling 4 light years.
At the speed of the fastest space probes humanity has ever sent out of the Solar System (the Voyager 1 and 2 spacecraft), covering the distance to the nearest star would take approximately 80,000 years. While interstellar travel may not be possible for humans anytime soon, it's still exciting to think about what could be out there and how we could explore it one day.