Photographing our own black hole

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#1
There is a fascinating effort underway to photograph our Sagittarius A* - the location of our own alleged black hole; not the first attempt to prove that it exists, but this effort appears particularly promising

http://www.businessinsider.com/image-of-the-century-black-hole-shot-2014-12

Also of interest is the following:

Using the university's [Arizona] powerful supercomputer, they created a black hole that is even more scientifically accurate than the visually stunning black hole in Christopher Nolan's latest film, "Interstellar."

 
Jul 25, 2012
2,556
5
38
NY
#2

BobM

Member
Feb 5, 2014
163
3
18
60
Long Island, NY
#3
it is truly cool to look at the increase in resolution from 1995 to today, showing so many more galaxies. The extreme deep field photo supposedly goes back 13.5 billion years, which is staggering, knowing that every point of light is not a star but a galaxy full of stars.

But to put it all in perspective ... the picture at the end showing the amount of space that was searched, relative to the size of the moon, really puts it all in perspective. This is a pinky-nail size of the sky showing all those galaxies. There is so much more in all other directions.

The true definition of infinity - way more than our feeble minds can comprehend. Makes you wonder how anyone can truly believe that there isn't additional life out there somewhere.
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#4
Jul 25, 2012
2,556
5
38
NY
#5
from ack's article:
If Fb is in the range 0.001 -- 1 then a biotic planet may be expected within 10 -- 100 light years from Earth.


At 4/3pi r^3 (sorry about the lousy notation, but I don't have greek letters and exponents) That's quite a volume of space to go hunting in-- up to 4.17 million cubic light years, it's worse than a needle in a haystack.
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#6
Right, and at this point we can only discuss the probability of extra-terrestrial life, and _hope_ to somehow prove it, much less experience it. But then again, aliens have visited Earth so many times... it's just that they prefer to always land in Roswell for some reason... and as they travel at unimaginable speeds, their landing attempts quickly take them through Areas 48, 49, 50 as they come to a complete stop at 51.
 
Last edited:

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#7
The time to photograph Sagittarius A* is now very near, probably in April http://www.sciencealert.com/scienti...could-photograph-a-black-hole-s-event-horizon and they expect to see a crescent, not a ring

Called the Event Horizon Telescope, the new device is made up of a network of radio receivers located across the planet, including at the South Pole, in the US, Chile, and the French alps.
The network will be switched on between 5 and 14 April, and the results will put Einstein's theory of general relativity through its paces like never before.
The Event Horizon Telescope works using a technique known as very-long-baseline interferometry (VLBI), which means the network of receivers will focus in on radio waves emitted by a particular object in space at one time.
For the black hole, they'll be focussing on radio waves with a wavelength of 1.3 mm (230 GHz), which gives them the best chance of piercing through any clouds of gas and dust blocking the black hole.
And because there are so many of these antennae all tuned in on a single spot, the resolution of the telescope should be 50 microarcseconds. To put that into perspective, it's the equivalent of being able to see a grapefruit on the surface of the Moon
That's important, because the first target will be the huge black hole at the centre of our galaxy, called Sagittarius A*, which is actually only the size of a pinprick in our night sky.

We've never directly observed Sagittarius A*, but researchers know it exists because of the way it influences the orbit of nearby stars.
Based on the behaviour of these stars, researchers predict that the black hole is likely about 4 million times more massive than our Sun, but with an event horizon diameter of just 20 million km (12.4 million miles) or so across.
At a distance of around 26,000 light-years away from Earth, that makes it a pretty small target.
But the Event Horizon Telescope will aim to observe the immediate environment around the black hole, and it should be able to get enough resolution to see the black hole itself.
Depending on what we may or may not see, it may also prove or disprove the notion that black holes have "soft hair" - a research area I've been following for months, and the subject of another thread... We'll know by the end of the year perhaps
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#8

Al M.

VIP/Donor
Sep 10, 2013
4,513
353
83
Greater Boston
#9

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#10
Great article indeed!
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#11
Last edited:

morricab

Well-Known Member
Apr 25, 2014
3,268
430
83
Switzerland
#12
It is highly unlikely life is anywhere near the center of galaxies. Too much radiation and supernovas. Our own Solar system is in a backwater off one arm with a low star density. Close enough to pick up all the elements we need for life (these come primarily from supernovae) but not so close to be obliterated by an explosion. Even then, we still managed to evolve after numerous cataclysmic extinction episodes that were often triggered by large colliding bodies.

We get disruptions every 30 and 100 million years as we pass through the arm we sit off of...this increases risk of extinction.

In a more densely populated region the likelihood of getting this far drops quickly.

Best bets are edges of Galaxies and small clusters I would say...of course this is all assuming all life, whatever it is made from, is as fragile as we are.
 

Al M.

VIP/Donor
Sep 10, 2013
4,513
353
83
Greater Boston
#13
It is highly unlikely life is anywhere near the center of galaxies. Too much radiation and supernovas. Our own Solar system is in a backwater off one arm with a low star density. Close enough to pick up all the elements we need for life (these come primarily from supernovae) but not so close to be obliterated by an explosion. Even then, we still managed to evolve after numerous cataclysmic extinction episodes that were often triggered by large colliding bodies.

We get disruptions every 30 and 100 million years as we pass through the arm we sit off of...this increases risk of extinction.

In a more densely populated region the likelihood of getting this far drops quickly.

Best bets are edges of Galaxies and small clusters I would say...of course this is all assuming all life, whatever it is made from, is as fragile as we are.
Agreed. I think the universe is teeming with microbial life which is more resistant to recurring cataclysmic events, such as asteroid impacts, than higher organisms. Yet even microbial life will likely exist only on edges of galaxies, for all the reasons you describe. Planets with higher organisms like animals and us will be much, much rarer, because of the more sheltered conditions that such life forms require.
 

morricab

Well-Known Member
Apr 25, 2014
3,268
430
83
Switzerland
#14
Agreed. I think the universe is teeming with microbial life which is more resistant to recurring cataclysmic events, such as asteroid impacts, than higher organisms. Yet even microbial life will likely exist only on edges of galaxies, for all the reasons you describe. Planets with higher organisms like animals and us will be much, much rarer, because of the more sheltered conditions that such life forms require.
Its rare to the point that we might consider that, at our level of evolution at least, we are alone...
 

Al M.

VIP/Donor
Sep 10, 2013
4,513
353
83
Greater Boston
#15
Its rare to the point that we might consider that, at our level of evolution at least, we are alone...
Possibly. The famous astrophysicist Martin Rees replied in an interview, when asked if he does not feel an infinitely tiny speck of no significance:

"I don't because the earth, though small in the cosmos may still be a most important part of it. It may be the only place where there's life like us. And so what makes things fascinating is how complicated they are and not how big they are. And for all we know the earth, tiny though it is, could be the centre of the cosmos in terms of complexity."
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#16
https://www.sciencealert.com/our-su...ld-be-pointing-a-relativistic-jet-right-at-us

New science has just come in from the collaboration to photograph Sagittarius A*, the supermassive black hole at the centre of the Milky Way, and it's ponying up the secrets at our galaxy's dusty heart.

The image below is the best picture yet of Sgr A* (don't worry, there's more to come from the Event Horizon Telescope), and while it may look like just a weird blob of light to you, astrophysicists studying the radio data can learn a lot from what they're looking at - and they think they've identified a relativistic jet angled towards Earth.

Above: The bottom right image shows Sgr A* as seen in the data. The top images are simulations, while the bottom left is Sgr A* with the scattering removed.
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#17
https://www.sciencealert.com/black-...c-jean-pierre-luminet-event-horizon-telescope

It looks like we are close to the final picture, but for now, all we can say is that "We don't know what we're going to see; it's possible that the data will only return a few blurry pixels. (If that's the case, more telescopes will join the collaboration, and the scientists will try again.)". The first photo mu post #11 seems like a good candidate.

There do exist simulations, like the one below, off of which Gargantua from Interstellar was modeled; of importance is the asymmetry in luminosity:


A simulation of a black hole from a paper by Thorne and colleagues on the CG techniques used to develop Gargantua. (James et al./Classical and Quantum Gravity)
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#18
 
Likes: slowGEEZR
Feb 8, 2011
21,360
472
83
Vancouver Island, B.C. Canada
#19
Wow, that's a lot of data, and it takes time...and the Internet is too slow to share all the hard drives fast enough...so they are transported by planes.

Where else from other audio forums can we cultivate and expand our brain; nowhere else but here @ WBF.

The other day I was talking with a 75-year old professional lady teacher; she said that learning other languages and listening to music help developing the brain in young students. And starting young is best.

Physics and astronomy can be included later on. I'm in constant need to expand my brain, and I'm still young...between 33 and 99.
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,536
194
63
Boston, MA
#20

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. A place where audiophiles and audio companies discuss existing and new audio products, music servers, music streamers and computer audio, digital to audio convertors (DACS), turntables, phono stages, cartridges, reel to reel, speakers, headphones, tube amplifiers and solid state amplification. Founded in 2010 What's Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals we enjoy learning about new things and meeting new people and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing