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Small Black Holes: Cloudy With a Chance of Better Visibility

Soulskill posted about a year ago | from the precipitation-likely dept.

Space 27

Rambo Tribble writes "As reported by the BBC, astronomers are hoping to reap a black-hole-hunting windfall when a giant gas cloud passes through an area within our galaxy thought to contain numerous small black holes (abstract). When the cloud interacts with the black holes, the resultant emission of X-rays should allow scientists to finally confirm their existence. 'The idea is that as the cloud speeds past these small black holes — some slightly more massive than our Sun but just a few tens of km across — gas will spiral around them faster and faster, heating up to millions of degrees and emitting X-ray light. It is a bit like allowing a giant sink to empty through thousands of tiny drains and looking for any evidence of swirling water.'"

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27 comments

First Post (-1)

Anonymous Coward | about a year ago | (#43878131)

FTW!

From TFA ... (1)

Taco Cowboy (5327) | about a year ago | (#43881521)

The G2 cloud is as large as our Solar System, and bound for a "supermassive" black hole at the Milky Way's core.

On the way, it should encounter many black holes just tens of km across.

If I am wrong please correct me ...

From the way TFA is describing it, it's like that's a SUPERMASSIVE BLACK HOLE in the middle, kinda like a HUGE FASHION MALL in the center of the city

The G2 cloud is heading to that supermassive black hole --- kinda like a group of girls are heading to that huge fashion mall

And on the way, the G2 cloud will encounter many, much smaller black holes, some are just tens of kilometers across --- kinda like on the way to that huge fashion mall, the girls would encounter some little fashion shoppes

Black hole sucks, right ?

Supermassive black hole sucks supermassively, right ??

If that's the case, why hasn't that supermassive black hole sucked in the many, much smaller black holes in the neighborhood ???

I'm just a regular geek, I am interested in astronomy but I have to confess that I dunno nothing about the physics of astronomy

Can someone help out, please ?

Thank you !!

Re:From TFA ... (1)

DMUTPeregrine (612791) | about a year ago | (#43881725)

They don't suck. Or, to be more specific, they suck the same as any other body of their mass. So things can orbit them quite nicely, just like things can orbit normal stars, galaxies, etc.

Really? (1)

dragon-file (2241656) | about a year ago | (#43878299)

I heard talks about black holes since I started taking an interest in science when I was 6 (I'm 27now). After 21 years have we still not discovered proof of black holes?

Re:Really? (0)

Anonymous Coward | about a year ago | (#43878499)

This is about confirming the existance of any of several hypothesized small black holes that may be located in the near vicinity of the known super-massive black hole at the center of our galaxy.

Re:Really? (0)

Anonymous Coward | about a year ago | (#43878697)

Still, it sounds like cheating to me. Wait until the cloud gets sucked up or not. Not too long ago, patent clerks had so much time on their hands, they could sit around and theorize this stuff within a shadow of a doubt. Now we soak up the beer with our grant money and " wait for the clouds to get sucked up, dude".

Re:Really? (1)

TapeCutter (624760) | about a year ago | (#43880967)

Still, it sounds like cheating to me. Wait until the cloud gets sucked up or not. Not too long ago, patent clerks...

Three words, "transit of Mercury".

Re:Really? (1)

meglon (1001833) | about a year ago | (#43879073)

http://en.wikipedia.org/wiki/Black_hole [wikipedia.org]

The idea of a body so massive that even light could not escape was first put forward by geologist John Michell in a letter written to Henry Cavendish in 1783 of the Royal Society:

If the semi-diameter of a sphere of the same density as the Sun were to exceed that of the Sun in the proportion of 500 to 1, a body falling from an infinite height towards it would have acquired at its surface greater velocity than that of light, and consequently supposing light to be attracted by the same force in proportion to its vis inertiae, with other bodies, all light emitted from such a body would be made to return towards it by its own proper gravity. —John Michell[4]

In 1796, mathematician Pierre-Simon Laplace promoted the same idea in the first and second editions of his book Exposition du système du Monde (it was removed from later editions).[5][6] Such "dark stars" were largely ignored in the nineteenth century, since it was not understood how a massless wave such as light could be influenced by gravity.[7]

In other equally shocking news, Rome was not built in a day.

Re:Really? (0)

Anonymous Coward | about a year ago | (#43879627)

After 21 years have we still not discovered proof of black holes?

Proven? Well yes. Unless your requirement of proof is for someone to go out and fly into one.

To prove they do not exist, you would still need to explain stuff such as this:
http://www.astro.ucla.edu/~ghezgroup/gc/pictures/orbitsMovie.shtml [ucla.edu]

Plus explain what hubble saw in galaxy NGC4261.
Plus explain the already measured speed, size, and weight of M87.
Plus explain the xrays from Cygnus X-1.

Not to mention explain the past 300 years worth of what we know about gravity.

Doing so would also pretty much disprove a ton of existing fields of science, which means you need to provide alternate theories for all of them.

So it's technically possible to do, just not practically possible for all intents and purposes.

Re:Really? (3, Interesting)

TapeCutter (624760) | about a year ago | (#43880875)

We have had "proof" for a long time in the mathematical sense, what has been more difficult is collecting enough evidence to say (beyond reasonable doubt) they exist in reality (the movie of stars orbiting the milky way's central black hole is my favorite "smoking gun"). I'm 54, when I went to school we were told black holes were "mathematical curiosities" that might exist in reality but nobody was sure, it was also claimed that it was impossible to observe an exo-planet. We live in "interesting times", science in general and astronomy in particular are experiencing a "golden age" that has it's roots in WW2 and is still gathering momentum.

Using maths to predict the existence of unobserved phenomena, and then looking for evidence of that phenomena in the real world is physics in a nutshell [youtube.com]. It's also the reason astronomers no longer laugh at the big bang theory.

Re:Really? (2)

amaurea (2900163) | about a year ago | (#43881373)

No astronomers doubt the existance of black holes. Both black holes with masses comparable to stars, and supermassive black holes with millions to billions of solar masses are supported by a huge body of evidence. However, there is almost no evidence for black holes with masses in between these ranges, so-called intermediate mass black holes. But logically, they should exist - the way we think the supermassive black holes in the center of galaxies form is by a combination of accretion of matter and mergers of smaller black holes. Both of these mechanisms require supermassive black holes to grow from smaller progenitors.

What this article is about is an experiment to test the hypothesis that there is a high concentration of stellar- and intermediate-sized black holes near the center of the galaxy, waiting to merge with the central supermassive hole. So it is a test a model of the galactic structure, not the existance of black holes as such, though it could provide the first solid evidence of intermediate-mass black holes.

Re:Really? (0)

Anonymous Coward | about a year ago | (#43883305)

You're reading the statement:

"When the cloud interacts with the black holes, the resultant emission of X-rays should allow scientists to finally confirm their existence."

wrong.

It will confirm the existence of the small black holes that the cloud would have to pass through. The statement is not referring to black holes generally.

Re:Really? (1)

painandgreed (692585) | about a year ago | (#43883519)

I heard talks about black holes since I started taking an interest in science when I was 6 (I'm 27now). After 21 years have we still not discovered proof of black holes?

Well, they're really hard to study as when we find them, they tend to be wrapped in clouds of dust with only radiation spewing out to study. However, there is enough evidence that if somebody was to show that black holes don't exist, that explaining away all that awkward theory and evidence would require such a large jump in science that they could claim their Nobel and position as this century's Albert Einstein. We're pretty much in the same place with dark matter and some other "controversial" things in physics. It is, however a still recent and growing field of science, as things are far away and the tools to study them are expensive and hard to build.

This is Great! (2)

NEDHead (1651195) | about a year ago | (#43878303)

I have been trying to convince my wife that the dust around the house is an experiment and now I have something to show her!

Re:This is Great! (1)

Anonymous Coward | about a year ago | (#43878583)

Don't forget the giant gas cloud :D

A bit more like 1's than 0's. (5, Funny)

VortexCortex (1117377) | about a year ago | (#43878819)

It is a bit like allowing a giant sink to empty through thousands of tiny drains and looking for any evidence of swirling water.

It's a bit like dusting for fingerprints on a cosmic scale.

It's a bit like tossing handfuls of candy in a class room, then listening for quarreling and munching noises to detect school children.

It's a bit like rolling around in the grass then waiting for stings to discover fire ant mounds.

It's a bit like casting a net made out of fish and counting the holes to detect sharks.

It's a bit like shouting, "You're all fat and ugly" into the woman's bathroom then counting the "Screw You Jerk"s to see if you should wait to clean it.

It's a bit like making a bunch of posts on Slashdot to detect folks with mod points.

It's a bit like observing the expected effect black holes cause in various conditions to further confirm their existence.

Re:A bit more like 1's than 0's. (0)

Anonymous Coward | about a year ago | (#43879777)

This is absolutely my favorite Alanis Morissette song, love it. It's a bit like 10,000 spoons when all you need is a knife. Isn't it a bit like... don't ya think?

How long for the cloud to travel 1 light year? (1)

shoor (33382) | about a year ago | (#43878893)

I would assume that these black holes are still on the scale of light years apart, and this cloud stretches across an area a few times the orbit of pluto. Something doesn't add up.

Re:How long for the cloud to travel 1 light year? (3, Informative)

Anonymous Coward | about a year ago | (#43879213)

I would assume that these black holes are still on the scale of light years apart, and this cloud stretches across an area a few times the orbit of pluto. Something doesn't add up.

The area around the central black hole [wikipedia.org] is very crowded.

The black hole itself is probably about the "size" of the solar system (an event horizon a few light-hours in radius), there are multiple stars within light-weeks of the black hole itself, with orbital periods measured in years/decades, and some of them (S2, S14) come within several light-hours of the black hole, at velocities (relative to the black hole) of thousands of kilometers per second.

Any imaginary probe or lifeform magically teleported into the neighborhood would have one hell of a view in the moments before the radiation fried it to a crisp.

Re:How long for the cloud to travel 1 light year? (1)

slashmydots (2189826) | about a year ago | (#43881015)

Also, it already did happen and we're just seeing it now. So it's not really a "how long until it happens" thing.

Re:How long for the cloud to travel 1 light year? (1)

DMUTPeregrine (612791) | about a year ago | (#43881747)

Not exactly. If we accept that there's no globally valid frame of reference (via General Relativity) then no, it didn't already happen, at least not from our frame of reference. It has happened in some frames of reference, and after we see it happen will still not have happened in yet more frames of reference. But for us, it hasn't happened yet.

Re:How long for the cloud to travel 1 light year? (1)

Urkki (668283) | about 10 months ago | (#43899659)

If we accept that there's no globally valid frame of reference (via General Relativity) then no, it didn't already happen, at least not from our frame of reference.

Second thing does not follow from the first. Light does not travel at infinite speed in any observer's reference frame. So we can actually easily estimate where the light from some event (which then needs to have already happened, or there would not be any light) is now travelling towards us (or not, if predicted event didn't actually happen, which we can't know until the light reaches us).

There may be other reference frames where the event has not happened yet, where the light has not been emitted yet, but in our reference frame, in this case light is already on the way.

All in your source (1)

Anonymous Coward | about a year ago | (#43879833)

Dec. 15, 2011 — The normally quiet neighborhood around the massive black hole
at the center of our Milky Way Galaxy is being invaded by a gas cloud that is
destined in just a few years to be ripped, shredded and largely eaten.
http://www.sciencedaily.com/releases/2011/12/111214135739.htm

I like the way they put it better :}

Here's a 19 second video of stars orbiting a suspected Black hole
http://www.youtube.com/watch?v=c3PeC3bCPKg

I grabbed it from "How the universe works: Black Holes"
to show a friend, it's not much taken out of context.

Many pictures over the course of 10 years were taken to make the video.

cloud speed (0)

Anonymous Coward | about a year ago | (#43880405)

The caption from the pic at the bottom of TFA: "The cloud was spotted in 2011, moving at speeds of millions of m/s".
So is the cloud moving at miles/sec? metres/sec?
The former would imply FTL, while the latter seems a little slow for galactic scale, tho i could be wrong.
If anyone could clarify this...

Re:cloud speed (1)

Anonymous Coward | about a year ago | (#43880435)

Millions of meters per second.

Not relativistic in the sense of anyone would feel the effects of time dilation, but yes, at closest approach, a low-single-digit-percentage-of-c.

Kewl! (1)

woboyle (1044168) | about a year ago | (#43884213)

How neat is this!? :-) Physics at its best. My late father, an astro-geo-physicist (and director of the National Science Foundation), would have been delighted to see this work!
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