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re: The case against dark matter
Posted on 5/8/18 at 11:30 am to rmnldr
Posted on 5/8/18 at 11:30 am to rmnldr
quote:
If gravity bends spacetime, and light is influenced by that spacetime to create an "Einstein ring," so why is there no gravitational lensing (Einstein ring) when S2 (which is travelling at something like 2% of lightspeed when it approaches the black hole on its 16 year orbit) approaches the black hole?
Are you saying that we should see a ring because a star is passing behind the black hole relative to our view of it? If so, we don't because the distance between the star and the blackhole and the size of the star relative to the black hole.
As with the proof of general relativity by Sir Arthur Eddington in 1919, the black hole is bending the path of the star's light so that we "see" it before it's actually clear the of the black hole from our viewpoint. Recall that Eddington used a solar eclipse to show that a star could be seen even while the sun was between the star and the viewer.
This is actually the same effect as lensing but no ring is seen because the object being observed is not big enough for the effect to be realized.
1
Posted on 5/8/18 at 11:34 am to rmnldr
quote:
We can't observe any discernible effects from spacetime besides Einstein basically telling us that mass affects spacetime and spacetime therein affects mass.
You certainly can observe the effects of spacetime. That you have weight and can't leap off the earth shows the gravity effect of spacetime.
Posted on 5/8/18 at 11:38 am to DavidTheGnome
quote:
Emergent gravity,” as Verlinde calls it, is the idea that gravity is not a fundamental governance of our universe, but instead a reaction to the makeup of a given environment
this makes a lot more sense than having a fundamental force that we don't understand what is causing it.
Of course what in quantum physics is causing it to happen? frick if I know.
Posted on 5/8/18 at 11:40 am to DavidTheGnome
I just want to go on record saying that watching the OT, which can't figure out PEMDAS, trying to understand general relativity and its implications is fricking amazing.
This post was edited on 5/8/18 at 11:41 am
Posted on 5/8/18 at 1:57 pm to Kentucker
quote:
No! Recall that gravity is an effect, not a thing. Electromagnetism has a carrier of the force, the photon. There is no carrier for gravity.
That's where the graviton comes in, my friend.
quote:
I recommend Brian Greene's books for you to understand the current view of most scientists views on what spacetime is. You seem to want to understand it based on how classical matter behaves.
Spacetime is what matter and energy of the Universe is expanding into. While we don't know what spacetime is made up of, we know it is something. Something that causes the gravitational effect.
I understand what you and 99% of contemporary physicists/scientists think there is or think what spacetime is. However, I fail to see any proof of there being anything actually there outside of Einstein's general relativity and "Einstein rings" which their existence can be deduced to a simple phenomena like refraction instead of a citing a theory which reinforces the idea of an abstract "thing" which light and mass travels through like a road in space.
If matter influences spacetime and spacetime influences matter, we should probably define what the hell it actually is in this theory instead of just saying it's the combination of X, Y, Z and when it happens. You can't say something is a thing when it's two relative and abstract constructs thrown together, say it's there and exists, then cite the theory itself as proof that it exists.
Posted on 5/8/18 at 2:18 pm to Kentucker
quote:
Are you saying that we should see a ring because a star is passing behind the black hole relative to our view of it? If so, we don't because the distance between the star and the blackhole and the size of the star relative to the black hole.
Objects a massive as a blackhole, and this one is a supermassive blackhole, should have a large gravitational field, or a large "warping of spacetime" surrounding it. That should be sufficient enough for some gravitational lensing to occur.
quote:
As with the proof of general relativity by Sir Arthur Eddington in 1919, the black hole is bending the path of the star's light so that we "see" it before it's actually clear the of the black hole from our viewpoint.
So you're saying we are seeing the effects of gravitational lensing, but there is no ring? Why is there no change then? Why doesn't the star's image jump or have some kind of effect when it passes near the black hole? If general relativity is correct we should see some visible change.
According to general relativity, we should see this:
or at least some form of phenomena from the light being bent by spacetime's "warping"
But we don't. And there's a simple explanation for it if you use simple science:
There is no atmosphere or anything around the black hole to refract light.
quote:
Recall that Eddington used a solar eclipse to show that a star could be seen even while the sun was between the star and the viewer.
That test, as with other examples of "gravitational lensing" can be deduced to refraction, yet again. The sun emits a whole hell of a lot of plasma and light will be bent travelling through it.
quote:
This is actually the same effect as lensing but no ring is seen because the object being observed is not big enough for the effect to be realized.
That makes no sense in regards to general relativity. There should be lensing. The size of the star shouldn't matter. Lensing should happen from any light source passing by or behind any source of gravitational "warping" of spacetime.
Nasa says they can see a distant galaxy with an Einstein ring like this:
In terms of scale that's actually a smaller object (galaxy) behind a much larger cluster of objects (galaxy cluster) at a much further range and they say they'll get lensing due to the massive "warping" of "spacetime" around this cluster.
But we can't see any lensing when there's a much closer object (star that orbits the center of our own galaxy) orbiting an object with far more mass than it (supermassive blackhole Saggitarius A*) that would have an immense "warping" around it, but we can't see it because the star is too small?
Get out of here with that.
If general relativity is correct we should ALWAYS see Einstein rings. In fact, there's so many stars behind other stars or other celestial bodies that actually looking into deep space would be incredibly difficult because of how distorted it all would be. But we don't, It's incredibly rare to see this phenomena.
Later this year that little star orbiting the black hole that we shouldn't be able to see an Einstein ring from is passing near it again. Everyone is going to be looking at this little guy. If there's no Einstein ring, I'm sure they'll use your explanation. If there is, I'll gladly come here, find you, and eat crow, and change my views.
Posted on 5/8/18 at 2:19 pm to Kentucker
quote:
You certainly can observe the effects of spacetime. That you have weight and can't leap off the earth shows the gravity effect of spacetime.
Does it? Or it could just show that gravity itself exists.
You're citing the theory to prove the theory is correct.
Posted on 5/8/18 at 2:36 pm to TigerstuckinMS
quote:
I just want to go on record saying that watching the OT, which can't figure out PEMDAS, trying to understand general relativity and its implications is fricking amazing.
Posted on 5/8/18 at 3:55 pm to rmnldr
quote:
That's where the graviton comes in, my friend.
That's old science. There's no evidence that gravity is a force.Posted on 5/8/18 at 3:59 pm to rmnldr
Wow, you seem stuck on refraction as an explanation for gravitational lensing. I encourage you to research gravitational lensing from the viewpoint of some leading researchers in the field. You'll see that your logic is faulty.
Posted on 5/8/18 at 4:04 pm to rmnldr
quote:
You're citing the theory to prove the theory is correct.
No, I'm citing indirect evidence of the same sort that we cite for the confirmation of dark matter. Even though we can't detect spacetime directly, we can experience its effects. Gravity is one of those effects. Another is the increasing rate of the expansion of the Universe.
Posted on 5/8/18 at 6:19 pm to Kentucker
And recently the detection of gravitational waves by LIGO is further evidence of general relativity and the warping of spacetime.
Posted on 5/8/18 at 7:15 pm to DavidTheGnome
quote:
Dark matter and dark energy are the prevailing stand-in answers for this problem, but they are, as of yet, merely stand-ins.
WTF, science? Get it together.
Posted on 5/8/18 at 7:27 pm to DavidTheGnome
Yes, every challenge to Einstein's Theory of General Relativity has failed. There may never be another human with the skills of that man. Without his genius we might still think Newtonian gravity is the limit of knowledge about it.
Posted on 5/8/18 at 7:44 pm to DavidTheGnome
quote:
And recently the detection of gravitational waves by LIGO is further evidence of general relativity and the warping of spacetime.
I've gotten drunk with an astrophysicist who works at LIGO a few times. We drink at the same establishment. Weird dude. Deep conversations.
This post was edited on 5/8/18 at 7:44 pm
Posted on 5/8/18 at 8:01 pm to Houma Sapien
I am so jealous.
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