[HN Gopher] Astronomers witness energetic switch on of black hole
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Astronomers witness energetic switch on of black hole
Author : wglb
Score : 45 points
Date : 2023-07-14 17:59 UTC (5 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| dathos wrote:
| "Very Large Telescope", I love this name. Any better ones out
| there?
| ProAm wrote:
| There is the "Very Large Array" too! the VLA. I love these
| naming standards. Way better than any startup or open source
| project name
| willis936 wrote:
| Potentially inspired by Very Large Scale Integration.
| ck2 wrote:
| Go read about the solar gravitational lens telescope proposal
| by physicist Slava Turyshev
|
| It is the most mind blowing thing that could actually be built
| someday by humans imho, well if we decide to stop blowing all
| our budget on killing other people
|
| https://google.com/search?q=solar+gravitational+lens
|
| It would be able to image exoplanets, 10 square kilometers for
| objects 100 light-years away.
| floxy wrote:
| >solar gravitational lens telescope
|
| Here is a great video about it:
|
| https://www.youtube.com/watch?v=NQFqDKRAROI
|
| ...and a paper:
|
| https://arxiv.org/abs/1802.08421
| nonameiguess wrote:
| Astronomers are great at this. Three postulated categories of
| dark matter include:
|
| * WIMPs: weakly interacting massive particles
|
| * MACHOs: massive compact halo objects
|
| * RAMBOs: robust associations of massive baryonic objects
|
| There's also the HERO (hyper extremely red object), which isn't
| quite dark, but close.
| mecsred wrote:
| The checklist is accurate: https://xkcd.com/1294/
| hinkley wrote:
| The OWL was cancelled?
|
| Can we propose the Obnoxiously Large Telescope to replace it?
| throwaway7868 wrote:
| Is the "final telescope" massive enough to be its own black
| hole?
| etra0 wrote:
| Now they're building the ELT -- Extremely Large Telescope.
|
| They're great with names haha.
| FredPret wrote:
| They should build one ten times the size of the next largest
| one, and call it the Quite Sizeable Telescope
| cyberax wrote:
| Don't forget OWL: Overwhelmingly Large Telescope (
| https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope
| ).
| OldGuyInTheClub wrote:
| Or, "Once Was Larger"
|
| "The ESO specialists expect resolutions from OWL that are
| up to 40 times higher than those of the Hubble Space
| Telescope. If the 100-meter mirror cannot be financed, a
| 60-meter variant is being planned. The name OWL would
| remain the same. Because then the project is jokingly
| called >>Once was larger<<."
|
| https://www.itespresso.de/2006/04/17/groesstes-
| observatorium... --> Google Translate
| moffkalast wrote:
| Still waiting for the Stupendously Gigantic Telescope.
| dmvdoug wrote:
| Big Ass Telescope?
| pengaru wrote:
| What, no BFT?
| denton-scratch wrote:
| What does it mean for an AGN to "turn on"?
| treeman79 wrote:
| It ate a star.
| ars wrote:
| But that would take infinite time (as we perceive the event)
| because of time dilation.
|
| You would not see it "turn on", you would see a slowly, very
| slowly, changing signal.
| willis936 wrote:
| You'd be hard pressed to ever directly observe something
| that is astronomically tiny and emits extremely low
| frequency radiation, if any at all.
|
| When an accretion disk is actively ripping apart a
| celestial body the plasma is some of the hottest material
| in the current universe. It's extremely violent and bright.
| You're seeing a gravitational well converting a huge
| quantity of mass to energy.
| deepspace wrote:
| Yes, as I understand it, the "turn-on" effect is from the
| plasma generated while the star is falling into the
| gravity well. The bit of the star that passes the event
| horizon would be tiny.
|
| Moreover, I believe that the radiation from an object
| falling into a black hole is redshifted so rapidly, that
| it effectively disappears from view in a very short time.
| An outside observer would not see anything "lingering"
| near the event horizon.
| ithkuil wrote:
| Yeah, the redshift and the slowing down due to time
| dilation are exactly the same phenomenon.
|
| If the wavelength is a million longer, any event that
| would take 1 second to happen, appears to us as it took
| 12 days.
| drojas wrote:
| I think this is good evidence in favor the plasmoid model
| from Eric Lerner as a replacement for black holes. Some key
| differences.
|
| * Instead of a black hole eating a star, a plasmoid is
| having an increased load. * Black holes are "gravitational"
| machines while plasmoid are "electromagnetic" machines. *
| With the plasmoid model there is no time dilation * With
| the plasmoid model, the load is any source of plasma, not
| necessarily a star
|
| https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=eri
| c...
|
| https://www.google.com/books/edition/The_Big_Bang_Never_Hap
| p...
| post-it wrote:
| > With the plasmoid model there is no time dilation
|
| But there _is_ time dilation, so the plasmoid model isn
| 't very good at explaining observations.
| 01100011 wrote:
| It confused me too. At first I thought it meant that a
| collection of matter became dense enough to form an event
| horizon and become a black hole. Instead, from
| https://www.livescience.com/space/black-holes/gargantuan-bla...
|
| > If J221951 is indeed a supermassive black hole, its sudden
| burst of brightness has two possible explanations, according to
| the researchers. First, the black hole could have pulled an
| orbiting star into its clutches, stretching and tearing the
| star to shreds in a messy process called a tidal disruption
| event or "spaghettification." The second, more mysterious
| possibility is that the black hole could have shifted states
| from dormant to actively feeding, as it suddenly began gorging
| on the fast-moving disk of gas that surrounds it.
| SomeRndName11 wrote:
| Today they witness energetic switch, tomorrow - energetic router.
| [deleted]
| civilitty wrote:
| Followed by a wireless gamma ray burst. Aimed right at us.
| mrtksn wrote:
| And still no reception in the kitchen.
| SomeRndName11 wrote:
| kitchen must be beyond the event horizon.
| pixelpoet wrote:
| That's because of the CMB (cooking microwave in the
| background)
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