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A Strange Black Hole Is Shooting Out Wobbly Jets Because It's Dragging Spacetime:
Some 7,800 light-years away, in the constellation of Cygnus, lies a most peculiar black hole. It's called V404 Cygni, and in 2015, telescopes around the world stared in wonder as it woke from dormancy to devour material from a star over the course of a week.
That one event provided such a wealth of information that astronomers are still analysing it. And they have just discovered an amazing occurrence: relativistic jets wobbling so fast their change in direction can be seen in mere minutes.
[...] V404 Cygni is a binary microquasar system consisting of a black hole about nine times the mass of the Sun and a companion star, an early red giant slightly smaller than the Sun.
The black hole is slowly devouring the red giant; the material siphoned away from the star is orbiting the black hole in the form of an accretion disc, a bit like water circling a drain. The closest regions of the disc are incredibly dense and hot, and extremely radiant; and, as the black hole feeds, it shoots out powerful jets of plasma, presumably from its poles.
[...] "We think the disc of material and the black hole are misaligned," [astrophysicist James] Miller-Jones said. "This appears to be causing the inner part of the disc to wobble like a spinning top and fire jets out in different directions as it changes orientation."
[...] It's a bit like a spinning top that starts to wobble as it's slowing down, the researchers said. This change in the rotational axis of a spinning body is called precession. In this particular instance, we have a handy explanation for it courtesy of Albert Einstein.
In his theory of general relativity, Einstein predicted an effect called frame-dragging. As it spins, a rotating black hole's gravitational field is so intense that it essentially drags spacetime with it. (This is one of the effects scientists hoped to observe when they took a picture of Pōwehi.)
In the case of V404 Cygni, the accretion disc is about 10 million kilometres (6.2 million miles) across. The misalignment of the black hole's rotational axis with the accretion disc has warped the inner few thousand kilometres of said disc.
The frame-dragging effect then pulls the warped part of the disc along with the black hole's rotation, which sends the jet careening off in all directions. In addition, that inner section of the accretion disc is puffed up like a solid doughnut that also precesses.
"This is the only mechanism we can think of that can explain the rapid precession we see in V404 Cygni," Miller-Jones said.
[...] the team had to [take] 103 separate images with exposure times of just 70 seconds and [stitch] them together to create a movie - and sure enough, there were the wibbly wobbly spacetimey jets.
A video explaining the activity is available on Vimeo.
A rapidly changing jet orientation in the stellar-mass black-hole system V404 Cygni, Nature (DOI: doi:10.1038/s41586-019-1152-0)
(Score: 3, Interesting) by Gaaark on Friday January 03 2020, @01:33AM (9 children)
except they don't DEPEND on dark matter for an explanation:
1. QI also explains it: https://physicsfromtheedge.blogspot.com/2012/12/undue-wait.html [blogspot.com]
2. https://physicsfromtheedge.blogspot.com/2016/03/mihsc-wins-in-dwarf-galaxies.html [blogspot.com]
3. https://physicsfromtheedge.blogspot.com/2013/09/anomalies-at-low-acceleration.html [blogspot.com]
4. https://physicsfromtheedge.blogspot.com/2015/03/dark-matter-contradicts-itself.html [blogspot.com]
https://physicsfromtheedge.blogspot.com/2017/06/evidence-from-early-galaxy.html [blogspot.com]
5. https://physicsfromtheedge.blogspot.com/2014/11/a-love-of-anomalies.html [blogspot.com]
6. Are you asking Galaxy formation structure?
"There is no experimental evidence for dark matter, and for each different galaxy the dark matter has to be added by hand in such a way as to make general relativity work. This means dark matter is ad hoc and not predictive and so we may as well attribute the rotation to lingering poltergeists. In contrast, MiHsC predicts galaxy rotation without any 'fiddling'."
https://physicsfromtheedge.blogspot.com/2014/11/the-present-crisis-in-physics.html [blogspot.com]
7. Not enough data yet: https://physicsfromtheedge.blogspot.com/2013/02/the-bullet-cluster.html [blogspot.com]
8. How does this depend on DM? They, possibly, aren't consistent in being 'standard candles'.
9. I don't see how this DEPENDS on DM at all.
10. I don't see how this DEPENDS on DM at all.
11. I don't see how this DEPENDS on DM at all, either.
New list:
1. Dark matter can't explain Wide Binaries (AT ALL!) but QI can.
2. Renzo's rule
3. Milgrom's acceleration cutoff
4. Globular clusters
5. The cusp-core problem
https://physicsfromtheedge.blogspot.com/2017/10/dark-matter-does-not-exist.html [blogspot.com]
I need more "real science"!
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by FatPhil on Friday January 03 2020, @11:02PM (8 children)
Damn right that response doesn't have enough data.
In no way is the thing that doesn't even address the question a better answer than the thing that addresses the question with an answer in agreement with other things we know about DM.
Just because we don't know what it is doesn't mean we can't know it exists from what it does. *No* scientist is saying they know what it is, and you appear to be using that honesty as a stick with which to beat them. But that's not how science works. We knew the planets go round the sun a long time before the concept of a gratitational field was hypothesised. That's not a flaw, that's piecing together larger theories bit by bit. If you deny the evidence, such at planets going round the sun, you're quite likely going to *slow down* the progress of science.
Keep an open mind, but don't let your brain fall out.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by Gaaark on Saturday January 04 2020, @12:51AM (7 children)
I AM keeping an open mind: I'm not saying QI IS the answer and no other, la la la my ears are plugged....
...what I'm saying is DM is a kludge to save GR that kept evolving new parameters (can't think of the word I want) until it worked.
It is not scientific, it has magical qualities (theres the word) brought in to make it work.
I hate magic...I open my mind to science like QI.
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by FatPhil on Saturday January 04 2020, @03:08AM (6 children)
[* No, I will never put an apostrophe in "ones", there's no historical precedent for it, and it's an ignorant modern change that complicates things. Posessive pronouns ("his", "hers", "its", "theirs", "yours", "ones") do not have apostrophes as *nothing was apostrophised*. Ockham, motherfucker.]
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by Gaaark on Saturday January 04 2020, @03:33AM (5 children)
Well, see, I see QI as the simplest Ockham solution, "mother fucker".
Has a formula, is predictive and isn't arbitrary: much simpler than o formula to work with, predicts nothing and is arbitrary as hell!
Ockham, "mother fucker".
And, it's easy to balance a slice of cucumber and you don't need magic!
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by FatPhil on Saturday January 04 2020, @03:46AM (4 children)
DM has been tested, and supported with evidence. Everything that cannot be explained simply without it supports DM.
QI has not been tested to any comparable extent. And the last thing I heard, last year, was that it had suffered an embarassing failure.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by Gaaark on Saturday January 04 2020, @04:27AM (3 children)
QI has not been around as long but is now getting funding and testing and seems to me to be supported by more real evidence than DM!
And what, pray tell, is this embarrassing failure?
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by FatPhil on Saturday January 04 2020, @01:31PM (2 children)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by Gaaark on Saturday January 04 2020, @02:22PM (1 child)
It wasn't disproved:
First measurement campaigns were carried out
with both thruster models reaching thrust/thrust-to-
power levels comparable to claimed values.
However, we found that e.g. magnetic interaction
from twisted-pair cables and amplifiers with the
Earth’s magnetic field can be a significant error
source for EMDrives. We continue to improve our
measurement setup and thruster developments in
order to finally assess if any of these concepts is
viable and if it can be scaled up.
---https://www.researchgate.net/publication/325177082_The_SpaceDrive_Project_-_First_Results_on_EMDrive_and_Mach-Effect_Thrusters
They say further improvements to setups are needed to disprove.
Ooopsy!
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by FatPhil on Saturday January 04 2020, @04:36PM
Keep cheering for them, by all means. We scientists need something to laugh at.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves