Black holes

[Olaf Hart]

Thought this piece from the Australian ABC might be interesting to some.

The video is useful.

https://www.abc.net.au/news/science/201 ... s/10993112

[JoeP]

Ha! It's a purposely blurred photo of a Krispy Kreme glazed doughnut sitting in used motor oil! It''s all a fake I tell ya! A deep state conspiracy!





Actually pretty damn fantastic.

[BeauV]

Looks like the Eye of Sauron to me!

[kdh]

One of my colleagues is an astronomer. Perfect pedigree. Harvard, Yale PhD, post-doc at Cambridge in Stephen Hawking's group. For some reason he wanted to work for us after that.

I asked him about the result yesterday, and he thinks it's significant.

Given my background I was interested in the methods used to build the image. My understanding is a phased array the size of the planet was used at radio frequencies, by combining signals received at various sites on our planet. The result was a sparse-data image that in combination with what I would call a Bayesian prior led to a reconstruction. Right up my alley.

[Ken Heaton (Salazar)]

Thought this piece from the Australian ABC might be interesting to some.

The video is useful.

https://www.abc.net.au/news/science/201 ... s/10993112

As Olaf said the video (the one at the bottom from 'Veritasium') explains what we see in the photo very well. There is a companion video to that which is at least as interesting: https://www.youtube.com/watch?v=S_GVbuddri8

[BeauV]

I've always wondered if folks who are falling in towards a black hole know they're falling. After all "speed" is relative, so how would one know? My simple-minded theory as a kid was that as one went over the event horizon all the stars would wink out, but that's not right. The light traveling towards you would be bent to follow you over the event horizon. So, how do we know???

Maybe we're falling into a black hole right now and don't know, don't care, party on!!

[kimbottles]

A world sized phased array, as an antenna guy it just does not get any better that that.
I was impressed with that VLA in New Mexico we visited last year, but it pales by comparison.

[kdh]

I've always wondered if folks who are falling in towards a black hole know they're falling. After all "speed" is relative, so how would one know? My simple-minded theory as a kid was that as one went over the event horizon all the stars would wink out, but that's not right. The light traveling towards you would be bent to follow you over the event horizon. So, how do we know???

Maybe we're falling into a black hole right now and don't know, don't care, party on!!

As long as we're on a generalized straight line in space-time, which can be curved, we'll remain oblivious.

Space station astronauts orbiting round and round don't feel any centrifugal force, as the earth has warped space-time for them.

Our local physicist said something interesting the other day--that space and time didn't exist before the big bang.

[JoeP]

A world sized phased array, as an antenna guy it just does not get any better that that.
I was impressed with that VLA in New Mexico we visited last year, but it pales by comparison.

Just think of the future when phased arrays can be as big as the solar system or perhaps larger if they could intercommunicate via laser or some type of quantum device (???).

[kimbottles]

A world sized phased array, as an antenna guy it just does not get any better that that.
I was impressed with that VLA in New Mexico we visited last year, but it pales by comparison.

Just think of the future when phased arrays can be as big as the solar system or perhaps larger if they could intercommunicate via laser or some type of quantum device (???).

I was thinking same thing; first we add an antenna on the moon, the get a couple orbiting ones added, then Mars, etc.....computers can keep track of time distance etc to get them all synced together.

On a MUCH smaller scale I have used various phased arrays in Ham Radio. They tend to be good antennas, but sometimes complicated, especially way back when we phased them with lengths of coax. I have friends right now who use phased verticals on 80 and 160 with good results. Usually top loaded.

[Rob McAlpine]

A world sized phased array, as an antenna guy it just does not get any better that that.
I was impressed with that VLA in New Mexico we visited last year, but it pales by comparison.

Our son rewrote a bunch of the control code for the VLA. That little joint in Datil, the crossroads just west of the VLA, has some of the world's best cheeseburgers. Saturday is Mexican food night there and also superb.

[BeauV]

Our local physicist said something interesting the other day--that space and time didn't exist before the big bang.

I love it that you have a "local physicist" in the way we all have a local plumber.

[BeauV]

Someplace near Los Banos, CA there is a US Gov phased array of pretty substantial size, I think SRI built it for some spooky stuff. My recollection is that it's about 10 miles square with an antenna every 50 feet or so.

[kimbottles]

Someplace near Los Banos, CA there is a US Gov phased array of pretty substantial size, I think SRI built it for some spooky stuff. My recollection is that it's about 10 miles square with an antenna every 50 feet or so.

There is also another one off of Highway 395 south of Topaz Lake where it crosses the CA/NV border.

[Ken Heaton (Salazar)]

Another interesting video.

"At the heart of the Milky Way, there's a supermassive black hole that feeds off a spinning disk of hot gas, sucking up anything that ventures too close -- even light. We can't see it, but its event horizon casts a shadow, and an image of that shadow could help answer some important questions about the universe. Scientists used to think that making such an image would require a telescope the size of Earth -- until Katie Bouman and a team of astronomers came up with a clever alternative. Bouman explains how we can take a picture of the ultimate dark using the Event Horizon Telescope."

I understood everything up to about the mid point. after that I had to watch it a couple of times before I began to understand what she was explaining to us: https://www.youtube.com/watch?v=BIvezCVcsYs

[JoeP]

Another interesting video.

"At the heart of the Milky Way, there's a supermassive black hole that feeds off a spinning disk of hot gas, sucking up anything that ventures too close -- even light. We can't see it, but its event horizon casts a shadow, and an image of that shadow could help answer some important questions about the universe. Scientists used to think that making such an image would require a telescope the size of Earth -- until Katie Bouman and a team of astronomers came up with a clever alternative. Bouman explains how we can take a picture of the ultimate dark using the Event Horizon Telescope."

I understood everything up to about the mid point. after that I had to watch it a couple of times before I began to understand what she was explaining to us: https://www.youtube.com/watch?v=BIvezCVcsYs

Thanks for that Ken. It''s pretty cool that their predictions and simulations look very much like the final picture. What i'd really like to know is how in the world an elephant got to the middle of the universe.

[Olaf Hart]

That’s interesting Ken, but I wonder if we are missing something because it’s not like anything else we can experience.

Sort of like the unconscious unconscience

[JoeP]

Good point.

[kimbottles]

She did a very good job explaining how they did it.
(I love TED talks videos.)

[SemiSalt]

The first picture of an astronomical object is always blurry.

The asteroid Pallas:

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