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Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

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Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#31

Post by resource0x »

stareatgoats wrote: post #20

Quite OT, but these phenomena always reminds me of how wrong (popular understanding of) Einstein actually is. Whereas gravity according to that understanding warps the fabric of space itself, these pictures prove that gravity actually only appears to warp space. I.e. our intuitive, euclidean concept of space is actually the most correct, albeit an abstract, inferred phenomenon.

We certainly need the concept of Euclidean space in order to make sense of the phrase "warped space". Fortunately, our "everyday" space is almost Euclidean, so this condition is met. If we lived in a different place in Universe, not sure what our concepts could have been. But I think same applies to just any concept we derive from our observations. E.g., we would never be able to form a notion of ice if we lived near some star. But I can't see how your statement about "real" vs "apparent" follows from here.

Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#32

Post by stareatgoats »

resource0x wrote: post #31
stareatgoats wrote: post #20

Quite OT, but these phenomena always reminds me of how wrong (popular understanding of) Einstein actually is. Whereas gravity according to that understanding warps the fabric of space itself, these pictures prove that gravity actually only appears to warp space. I.e. our intuitive, euclidean concept of space is actually the most correct, albeit an abstract, inferred phenomenon.

We certainly need the concept of Euclidean space in order to make sense of the phrase "warped space". Fortunately, our "everyday" space is almost Euclidean, so this condition is met. If we lived in a different place in Universe, not sure what our concepts could have been. But I think same applies to just any concept we derive from our observations. E.g., we would never be able to form a notion of ice if we lived near…

"Real" vs "apparent" simply follows from what we can infer from the picture, i.e. the galaxies appear to be several because of the light-warping effect of gravity, in reality they are not.

Further, I don't think space (or time for that matter) are comparable to the notion of ice, but let's keep it simple for now :-)

Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#33

Post by resource0x »

stareatgoats wrote: post #32
resource0x wrote: post #31

Earlier quoted context omitted.

We certainly need the concept of Euclidean space in order to make sense of the phrase "warped space". Fortunately, our "everyday" space is almost Euclidean, so this condition is met. If we lived in a different place in Universe, not sure what our concepts could have been. But I think same applies to just any concept we derive from our observations. E.g., we would never be able to form a notion of ice if we lived near…

"Real" vs "apparent" simply follows from what we can infer from the picture, i.e. the galaxies appear to be several because of the light-warping effect of gravity, in real ity they are not. Further, I don't think space (or time for that matter) are comparable to the notion of ice, but let's keep it simple for now :-)

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 - look no further than quantum mechanics, which is an example of what happens when we cross the boundaries of the 'oasis'. We still can write formulas, but we don't understand the meaning. I personally believe that just everything we "know" - applies only in the vicinity of our habitat. Won't be surprised if all our observations about the Universe turn out to be illusions resulting from infinite warping of just everything :)

Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#34

Post by 8bitsrule »

One ( SDSSJ0146-0929) of 37 objects in a program to image strong lensing fields with Hubble.

http://www.stsci.edu/hst/phase2-public/13003.pro

"The fundamental unit of star formation in the Universe is neither a star, nor a galaxy, but a star forming region with a typical scale of at most 100s of parsecs."

More interesting stuff at: http://www.stsci.edu/

Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#36

Post by sp332 »

sp332 wrote: post #2

I'm getting cross-domain errors on the images on this page. The main one of the ring has this URL https://img.purch.com/h/1400/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1... and if you base64-decode the last part you get http://www.space.com/images/i/000/075/580/original/hubble-te... Here's the first video https://videos-f.jwpsrv.com/content/conversions/xTYS7F8k/vid... Second video https://videos-f.jwpsrv.com/content/conversions…

Edit: The cache tokens have expired so the video links don't work anymore, but the site seems to be working better now.

Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#38

Post by roywiggins »

stareatgoats wrote: post #29
kowdermeister wrote: post #26

Earlier quoted context omitted.

No, this phenomenon actually proves that space really is warped, otherwise you wouldn't see the light from behind a galaxy cluster because light follows a straight line.

Even the concept of 'warped' space itself indicates that the intuitive, euclidean concept is correct, the light does in fact not travel in a straight line, it follows a 'warped' line. The difference between the two is that the 'warped' space is what we observe (because observing is an electromagnetic process, subject to gravity), 'real' space is something we can only infer (or observe in photos like in the linked art…

I don't think that's quite right. You can theoretically detect the local curvature of space by measuring the angles made by a sufficiently exact triangle. If space is flat, such a triangle will have interior angles that sum to a half turn. If it's curved, it will deviate from that. And that's something you can do more or less entirely locally and is a property of the space you're inhabiting.

We can know the Earth is round without any reference to Euclidean space or Euclidean coordinates- just trace out a big triangle and you could observe that the interior angles will sum to more than 180 degrees.

Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#39

Post by roywiggins »

stareatgoats wrote: post #24
MereInterest wrote: post #22

Earlier quoted context omitted.

I'd be interested to hear how you came to that conclusion, as these pictures show the complete opposite to me. In a vacuum, light takes the shortest distance between two points. That light is bent by gravity shows that gravity is changing what it means to be the "shortest distance". That is, space itself is being warped by the presence of mass.

Sure, maybe this explains better: The picture shows how light from a galaxy or galaxies from behind the galaxy cluster SDSS J0146-0929 are bent around it. It makes it "seem as though the galaxy is in several places at once". The key word is "seem", which means that the light-bending characteristic of gravity make space seem like something it is not. Hope this helps.

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 (even if it's basically flat and Euclidean, the geodesics are different).

So it seems to me that you can have warped spacetime that produces illusions like duplicate galaxies.

Re: Hubble Telescope Discovers a Light-Bending 'Einstein Ring' in Space

#40

Post by downer59 »

kowdermeister wrote: post #26
stareatgoats wrote: post #20

Quite OT, but these phenomena always reminds me of how wrong (popular understanding of) Einstein actually is. Whereas gravity according to that understanding warps the fabric of space itself, these pictures prove that gravity actually only appears to warp space. I.e. our intuitive, euclidean concept of space is actually the most correct, albeit an abstract, inferred phenomenon.

No, this phenomenon actually proves that space really is warped, otherwise you wouldn't see the light from behind a galaxy cluster because light follows a straight line.

No, it proves that the path of the visible photons we're detecting have been altered by forces of attraction.
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