[HN Gopher] Magnetic launching of black hole jets in Perseus A
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Magnetic launching of black hole jets in Perseus A
Author : raattgift
Score : 20 points
Date : 2024-02-04 19:07 UTC (3 hours ago)
(HTM) web link (www.mpifr-bonn.mpg.de)
(TXT) w3m dump (www.mpifr-bonn.mpg.de)
| ttul wrote:
| If my math is right, the angular resolution of the EHT is such
| that you could image an object just 99m across on the surface of
| the moon. Or a 2in object could be resolved from a low earth
| orbit satellite. Not bad.
|
| They are imaging an object 0.6ly across at a distance of 250M ly
| or so. Just insane.
| pomian wrote:
| I thought the jets emitted were made of anti matter? (Anyone?)
| Interesting principle, as I understood it, was that the jet
| diameter to turbulent transition to laminar flow length held to
| similar principles as (roughly), gaseous (which would include
| liquids) in practical day to day physics. (Compare a jet from a
| propane torch.) Meaning diameter to length ratios, affected by
| velocity(pressure) and density. Of course that is a
| simplification, but relative to such distance observations, seems
| to fit accepted models. Very interesting that now we can study
| The magnetic fields on such a large scale. Which then raises
| another deep hole to climb into (pun intended), how do those
| ratios (proportions) compare to those we see in our physical
| world, at the molecular level.
| pfdietz wrote:
| How could they possibly be made of antimatter? They can contain
| antimatter (particularly positrons), but what physical process
| could possibly create antimatter and then separate it from
| matter?
| jiggawatts wrote:
| As an aside, the intersection of certain "cultural" aspects of
| different groups and the Internet always fascinated me.
|
| Scientists, and especially astronomers, had to publish high-
| resolution digital images when their distribution over the
| nascent Internet and its 2400 bps links was a challenge. So they
| got into the habit of using a thumbnail for the article and a
| list of "download high resolution image" links at the bottom --
| presumably for journalists to print at full quality in colour
| magazines or whatever. Meanwhile today my phone takes pictures
| with higher resolution and can send about a hundred of them per
| second over 5G! I can send an image with higher resolution than
| any screen in an instant, there is no need for a "workflow" of
| additional manual steps to download it in the background while we
| go out and have a coffee.
|
| Similarly, up until very recently, most science was published as
| PostScript (.ps) files instead of PDF files, even though the
| latter is basically the same and much easier to open on a wide
| variety of platforms. It's just that science publishing needed
| high-resolution typesetting early when only PostScript was good
| enough, and they got into a habit that was hard to break even in
| the era when practically nobody actually prints the papers out
| any more.
|
| I'm not picking on scientists in any way here, lawyers do the
| same type of thing with their courier fonts and layout they
| emulates the properties of typewriters so that they can annotate
| documents with pens in an era of source control systems and cloud
| collaborative editing.
|
| I just suddenly had a pang of nostalgia for the era when I had to
| wait patiently for the latest Hubble photo to download oh-so-
| slowly over a dialup modem.
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