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Gravitational lensing has to be the coolest thing ever. That we can use a black hole as a telescope to see such incredibly distant bodies just leaves me with a
by delecti 8y ago
Gravitational lensing has to be the coolest thing ever. That we can use a black hole as a telescope to see such incredibly distant bodies just leaves me with a childlike giddiness whenever I think about it. What's almost as incredible to me is that someone figured it out before we could prove it.
- Florin_Andrei 8y agoYou can use whole galaxies as gravitational "telescopes". And yeah, it's super-cool.
- Yhippa 8y agoDumb question but does the lensing distort what we would see if there was no lensing at all? Or does that information get compressed as part of the lensing and we need to "stretch" it out to see it?
- roywiggins 8y agoThis is what an Einstein ring looks like, caused by lensing: https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2018/1-imagehubblef.jpg https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hire... Anyway, the test of GR in the actual article does not appear to use or reference lensing at all. It's about looking at the orbit of a star in an extreme gravitational environment and comparing it to what Newtonian models would predict.
- tEMporality7 8y agoWouldn't Newtonian models be off in their predictions for those extreme cases?
- tomrod 8y agoI assume that's the point?
- antientropic 8y agoIndeed that's the point: > The team compared the position and velocity measurements from GRAVITY and SINFONI respectively, along with previous observations of S2 using other instruments, with the predictions of Newtonian gravity, general relativity and other theories of gravity. The new results are inconsistent with Newtonian predictions and in excellent agreement with the predictions of general relativity.
- philipov 8y agoThe conservation of information means that the phase space of a system is incompressable. I believe this is equivalent to saying we can just stretch the image out, within the limits of our ability to resolve detail.
- badosu 8y agoThe sun could be used as well, the problem is that the focus would be outside the solar system.
- Gibbon1 8y agoOne of the early bits of evidence for relativity was it's ability to explain anomalies in the precession of Mercury's orbit.
- nine_k 8y agoIt's also nice that we apparently can "take" a black hole millions of times as massive as our own system, and use it for our purposes. It's likely the single biggest part of a scientific instrument. (Not of an industrial tool... yet.)
- canhascodez 8y agoThere's not really any materials or conditions beyond one's immediate locality that would be worth seeking out in space. Interstellar communication is going to be limited at best, interstellar industry or trade may never be practical, and even if one is willing to accept the idea that there is some purpose for which a black hole is useful, I would still be skeptical that a supermassive black hole would be of more use than a smaller one.
- saagarjha 8y agoThe larger the black hole, the more gravitational lensing there is?
- dylan604 8y agoLarger black hole would mean larger mass. Larger mass would mean a larger bulge/dent/bend in the fabric of spacetime. That would imply to me a larger lensing effect. Not sure if it would be similar to larger primary mirrors for telescopes or not. But in my head, it makes sense. Another movie plot begins...
- brogrammer5 8y agoI agree. I don't think the aeroplanes will ever been able to achieve lift. I'm skeptical of anyone who attempts anything that hasn't been done before.
- zerb 8y agoWe saw birds flying around when we were cavemen. It's always been clear that heavier-than-air flight is possible. We don't currently know of any space-birds flying around black holes. It's also reasonable to assume that more and more extreme physics is going to be harder and harder (if not practically impossible for any future humans) to come up with new gee-whiz uses.
- dylan604 8y agoI agree. I'm also blown away by the programmers that have done the math on how to unbend the light we see to put it back into an actual image.
- Eit4Choh 8y agoThis observation isn't about lensing