Black Holes

[Danny M2ZParticipant @dannym2z]

I was nicely surprised when the first pictures of a black hole were published **LINK**

I waited a day but no posting from our esteemed Neil, he's probably still getting over the excitement

How fascinating that Albert Einstein could have predicted such mysterious things so long ago. We still live in interesting times.

My current black hole is my workshop – Things randomly disappear if I drop them so my workshop floor is my own 'event horizon'.

30 years ago my first black hole was my desk, or rather the computers that came and went from it's surface although my first home built Z-80 PC still survives from 1983 in working condition (with it's green screen).

* Danny M *

[Danny M2ZParticipant @dannym2z]

[John HaineParticipant @johnhaine32865]

Certainly an amazing discovery. Actually it was a clergyman called John Michell who first suggested them in 1784! He just observed that a massy enough star would have an escape velocity faster than light. And it seems that Einstein actually didn't predict black holes himself though other people did using his theory shortly after it was first published – details in that Wikipedia link.

The Event Horizon Telescope has a website which has a load of excellent information on the system and how it works, well worth browsing.

[larry phelan 1Participant @larryphelan1]

I too have a black hole,into which everything I want to use seems to vanish,sometimes never to be seen again.

Ex A box full of 6mm nuts,never taken out of the workshop, where did they go ??? Where indeed,that was six months ago.. Spanners,magnetic pick-ups 6 " rule ———-ect,ect.

All ideas welcome !

[nigel jones 5Participant @nigeljones5]

Every 10mm socket comes with its own free black hole.

[Thor 🇳🇴Participant @thor]

Danny, you are not the only one with a workshop floor that acts like a black hole

Thor

[Neil WyattModerator @neilwyatt]

I spent a lot of time trying to understand the image, which is not well explained by the media, especially as they think it is a light not radio image.

I finally saw an explanation. It's the light from the accretion disk BEHIND the black hole being bent around the event horizon at 2.6 times its diameter. The edges of the black circle in the middle are actually a circular image of the centre of the far side of the black hole… now that mangles your brain cells!

So Harry Potter's invisibility cloak is probably woven from black holes…

Purely by coincidence (it really didn't occur to me at the time) I photographed M87 on Wednesday night. It's the large blob at bottom left. The curved line of galaxies is known as Markarian's Chain. There are about five dozen glaxies visible in this image, all part of the Virgo Cluster, itself part of the Virgo Supercluster which also contains our 'local group' of galaxies.

[JasonBModerator @jasonb]

How do we know it's a black hole and not an orange ring?

[Boiler BriParticipant @boilerbri]

I am with Jason on this. Its thats far away it could be anything. Thats if it still exists? Too many people are out to get into the history books these days and make a name for themselves.

[Boiler BriParticipant @boilerbri]

Sorry. Had a bad week. 😳. I know that space is a good subject for some people.

Bri

[Sam Longley 1Participant @samlongley1]

Posted by Boiler Bri on 12/04/2019 18:43:42:

Sorry. Had a bad week. 😳. I know that space is a good subject for some people.

Bri

Spot on. Space has been a big subject in our house for some time.

I have been trying to get my wife to let me build another 3 feet onto the end of my shed for ages

It is all relative really

[VersabossParticipant @versaboss]

Posted by Neil Wyatt on 12/04/2019 18:03:19:

… It's the light from the accretion disk BEHIND the black hole being bent around the event horizon…

Hi Neil,

Isn't the word 'light' in the sentence above a bit misleading? Afaik a radio telescope doesn't see 'light' in the sense we usually use that word. I suppose the black hole picture is a computer generated picture from whatever electromagnetic waves they received.

If I'm wrong, I am eager to learn more…

Regards,
Hans

[Enough!Participant @enough]

This was the best explanation I saw.

[Author]

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