Gravitational lensing occurs when things with mass create ripples and dents in the fabric of spacetime, and light has to follow along those lines, which sometimes create a magnifying glass effect. This both sounds and looks like something wild from science fiction, but it’s actually a very important tool in astronomy. The James Webb Space Telescope has been in the news a lot recently for just this: watching how light bends around massive galaxy clusters in space, revealing fainter, further away old galaxies behind them.
Now, Slava Turyshev, a scientist at NASA’s Jet Propulsion Lab, is trying to harness one of these gravitational lenses closer to home, using our sun. In a new paper posted to the pre-print server arXiv, Turyshev computes all the detailed math and physics needed to show that it is actually possible to harness our sun’s gravity in this way, with some pretty neat uses. A so-called “solar gravitational lens” (SGL) could help us beam light messages into the stars for interstellar communication or investigate the surfaces of distant exoplanets.
“By harnessing the gravitational lensing effect of our star, astronomy would experience a revolutionary leap in observing capability,” says Nick Tusay, a Penn State astronomer not involved in the new work. “Light works both ways, so it could also boost our transmitting capability as well, if we had anyone out there to communicate with.”
When it comes to telescopes here on Earth, bigger is definitely better. To collect enough light to spot really faint far away objects, you need a huge mirror or lens to focus the light—but we can really only build them so big. This is where the SGL comes in, as an alternative to building bigger telescopes, instead relying on spacetime bent by the sun’s gravity to do the focusing for us.
“Using the SGL removes the need to build larger telescopes and instead raises the problem of how to get a telescope out to the focal distance of…
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