Have you seen comments on this article on the original site? What is wrong with those people?
Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
51–60 of 60 posts
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#52Does this mean time travel is possible ?
I think that this one answers the question pretty good: https://xkcd.com/209/
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#53Have you seen comments on this article on the original site? What is wrong with those people?
Well, I've seen worse, at least no one gets threatened. But it doesn't suprise me one bit. About 6 years ago I started to abandon comment sections altogether, because every second poster or so had some agenda politically, religiously or some esoteric nuthouse BS. This directly affects the quality of the other (genuineley interested) postings, because they started to argue with the trolls and shills. What once were intersting fora of conversation became snake pits. Not everywhere, but to a significant degree.
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#54It never, ever ceases to amaze me how right Einstein was without the ability to test his hypotheses. At the time it was all groundbreaking theoretical work yet it mostly holds up to empirical studies.
Einstein was the first to truly grasp James Clerk Maxwell's work. If Maxwell hadn't died in 1879 at only 48, then I like to imagine he would have produced Special Relativity – most of it is there in his famous equations.
Einstein also had the benefit of knowing the null result of the Michelson–Morley experiment (1887), and Hertz's experimental confirmation of electromagnetic waves moving at the speed of light (1889) predicted by Maxwell.
Einstein, of course, explicitly recognised Maxwell and kept a picture of him on his office wall.
While Einstein's theoretical work is fabulous, it was Maxwell who first broke away from the mechanical model; something that even his illustrious contemporaries struggled to understand.
If you appreciate Einstein, yet know little of Maxwell, then The Man Who Changed Everything[0] is a great introduction.
[0] https://www.goodreads.com/book/show/29442.The_Man_Who_Change...
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#55Earlier quoted context omitted.
So, here's an example. Suppose you're in a toroidal space. It's an Asteroids world: you're in a cube, and if you pass through one wall you find yourself passing back into the cube from the opposite one. If you look in the right place, you will see the back of your head- several times! So there's an illusion of seeing yourself in several places at one time. But toroidal space really is different from normal space (eve…
Yea thanks, that is exactly my point; warped space produces illusory concepts of reality. So, an apparent illusion of disagreement seems to have occurred ;-)
Right, but you seemed to be arguing that illusory images meant that the curvature itself was illusory, whereas in my toy universe space really is toroidal, and anyone using the existence of multiple images to suggest otherwise would be wrong (because I set up the universe that way). In fact, such images would be convenient evidence that space was actually toroidal. I don't see how Einstein rings are any different- they can't be evidence against actual curvature of actual spacetime. You'd expect double and triple images if spacetime was curved.
One prediction of GR is that if there were enough mass in the universe, the global curvature would be positive everywhere and the universe would close in on itself and be connected more like a sphere than a plane. If you moved in a straight line you would eventually return to your starting point. That doesn't seem to be the universe we live in (as far as anyone can tell, it's flat) but that certainly seems like a prediction about the actual curvature of actual spacetime.
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#56Earlier quoted context omitted.
Yea thanks, that is exactly my point; warped space produces illusory concepts of reality. So, an apparent illusion of disagreement seems to have occurred ;-)
Right, but you seemed to be arguing that illusory images meant that the curvature itself was illusory, whereas in my toy universe space really is toroidal, and anyone using the existence of multiple images to suggest otherwise would be wrong (because I set up the universe that way). In fact, such images would be convenient evidence that space was actually toroidal. I don't see how Einstein rings are any different- th…
I don't seem to be able to get my point across, but thanks for playing anyway. I really believe this point is of some philosophical and ultimately scientific value, however still largely misunderstood, but didn't really expect a forum comment (albeit on HN) to make a significant dent. Have a good day!
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#57Earlier quoted context omitted.
How about this: we live in a rare oasis in the Universe where the things are more or less 'stable', and due to this, we can form more or less consistent concepts (not 100% consistent, but enough for most practical purposes). Beyond this oasis - who knows, maybe the notions of space and time themselves become fuzzy (not unlike ice, by the way - though you objected to comparison). And this view is not that far-fetched…
yes, I actually subscribe to this view too. We are observing things at the borders of the capacity of our instruments that is so far removed from our natural habitat as humans that we may never understand much more. I don't think we should give up however, and the distinction between appearances and reality is fundamental to proceeding further IMO. To clarify, it seems to me probable that real space itself (and time…
I'm not so sure about this exemption. It's just very difficult for us to reason about it. And even formulating a counter-argument in a meaningful way requires some notions we don't have. Tangentially related: http://www.paradise.caltech.edu/cook/Workshop/Physics/QMQues...
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#58It never, ever ceases to amaze me how right Einstein was without the ability to test his hypotheses. At the time it was all groundbreaking theoretical work yet it mostly holds up to empirical studies.
Einstein was the first to truly grasp James Clerk Maxwell's work. If Maxwell hadn't died in 1879 at only 48, then I like to imagine he would have produced Special Relativity – most of it is there in his famous equations. Einstein also had the benefit of knowing the null result of the Michelson–Morley experiment (1887), and Hertz's experimental confirmation of electromagnetic waves moving at the speed of light (1889)…
Thanks for that, I wasn't aware of Maxwell, I'll have to do some reading.
Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space
#59It never, ever ceases to amaze me how right Einstein was without the ability to test his hypotheses. At the time it was all groundbreaking theoretical work yet it mostly holds up to empirical studies.
In a way, that's pretty disappointing. Einstein's general theory of relativity is a theory that essentially only describes gravity. The standard model describes everything but gravity.
And there is zero common ground between them. The standard model says, in a way, that gravity cannot exist (because gravitons are impossible, nothing in the standard model could carry the gravity force), and the special theory of relativity says nothing about anything other than gravity and spacetime. Or we should say, it describes spacetime, but not what's in it.
And yet there are ridiculously obvious empirical links between both of them. There's many, such as the famous e=mc2 equation, or the speed of light that can be measured in both theories using vastly different theoretical underpinnings, yielding the same value. And yet, theory says they have nothing to do with eachother. The speed of light could very well be very different, it would not be a problem, so why does it match ?
But my favorite is that inertia only exists in the standard model. Gravitic attraction only exists in relativity. But they are determined by the same property. We know that to a factor of about 1e-50 there is no difference between inertial mass and gravitic mass ... and yet all our theories say that there is no link whatsoever between them, that that's just another amazing coincidence.
And half of the physics of the 20th century can be described as "ah ! problem with relativity. Oh wait no. But ! Problem found ! Nope. Found it ! No. Here there might be a flaw in relativity and that would explain all these ... nope, no flaw".
In many ways, if we had found a huge problem with general relativity, we could have been much further in our understanding of the universe than we are now.