We know the universe is and always was expanding, but we’ve never really known just how fast it’s happening. That is, until now. Researchers have used gravitational lensing to and watched a star die 5 times to better understand just how fast our universe’s expansion is happening.
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00:00We know the universe is and has always been expanding, but we've never really known just how fast it's happening.
00:10That is, maybe, until now.
00:12According to a pair of new studies, experts say they were able to use novel techniques to watch a star die not once, not twice, but five times.
00:20Researchers use what's called gravitational lensing, or when you use the gravitational well surrounding massive objects in the cosmos, like a galaxy cluster,
00:27and use the curvature of space time where light bends around it as a lens to look further into time and space.
00:32This can result in light from the far reaches of the universe reaching our telescopes via multiple routes,
00:37meaning we can effectively watch an event, in this case a supernova, happening multiple times.
00:42So by looking at the gravitationally lensed image from multiple routes, experts were able to calculate the travel time of the light to Earth,
00:48using that data to then calculate just how much the universe expanded in the amount of time it took the light to get to our instruments.
00:54So how fast is it expanding?
00:56Well, you might need a degree in astrophysics to even understand the answer to that.
01:00According to the new data, it's expanding at a rate of around 46 miles per second per megaparsec,
01:06which is a distance of around 3.26 million light years.