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The Milky Way's Black Hole Is Not So Quiescent

kdawson posted more than 6 years ago | from the long-ago-in-a-galaxy-right-nearby dept.

Space 152

esocid writes in with a followup to the recent discussion about the possibility that our galaxy's central black hole could reignite. "Using NASA, Japanese, and European X-ray satellites, a team of Japanese astronomers has discovered that Sagittarius A* let loose a powerful flare three centuries before the time at which we are observing it (i.e., 26,000 years in the past). X-ray pulses emanating from just outside the black hole take 300 years to traverse the distance between the central black hole and a large cloud known as Sagittarius B2, so the cloud responds to events that occurred 300 years earlier. 'By observing how this cloud lit up and faded over 10 years, we could trace back the black hole's activity 300 years ago,' says team member Katsuji Koyama of Kyoto University. 'The black hole was a million times brighter three centuries ago.'"

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IS that an astrophysics term for (-1, Flamebait)

Anonymous Coward | more than 6 years ago | (#23080962)

HIV positive ?

Re:IS that an astrophysics term for (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23081374)

that (t, t)
pron. pl. those (z)
1.
a. Used to refer to the one designated, implied, mentioned, or understood: What kind of soup is that?
b. Used to refer to the one, thing, or type specified as follows: The relics found were those of an earlier time.
c. Used to refer to the event, action, or time just mentioned: After that, he became a recluse.
2. Used to indicate the farther or less immediate one: That is for sale; this is not.
3. Used to emphasize the idea of a previously expressed word or phrase: He was fed up, and that to a great degree.
4. The one, kind, or thing; something: She followed the calling of that which she loved.
5. those Used to indicate an unspecified number of people: those who refused to join.
6. Used as a relative pronoun to introduce a clause, especially a restrictive clause: the car that has the flat tire.
7.
a. In, on, by, or with which: each summer that the concerts are performed.
b. According to what; insofar as: He never knew her, that I know of.
adj. pl. those
1. Being the one singled out, implied, or understood: that place; those mountains.
2. Being the one further removed or less obvious: That route is shorter than this one.
adv.
1. To such an extent or degree: Is your problem that complicated?
2. To a high degree; very: didn't take what he said that seriously.
conj.
1. Used to introduce a noun clause that is usually the subject or object of a verb or a predicate nominative: "That contemporary American English is exuberantly vigorous is undeniable" William Arrowsmith.
2. Used to introduce a subordinate clause stating a result, wish, purpose, reason, or cause: She hoped that he would arrive on time. He was saddened that she felt so little for him.
3.
a. Used to introduce an anticipated subordinate clause following the expletive it occurring as subject of the verb: It is true that dental work is expensive.
b. Used to introduce a subordinate clause modifying an adverb or adverbial expression: will go anywhere that they are welcome.
c. Used to introduce a subordinate clause that is joined to an adjective or noun as a complement: was sure that she was right; the belief that rates will rise soon.
4. Used to introduce an elliptical exclamation of desire: Oh, that I were rich!
Idioms:
at that
1. In addition; besides: lived in one room, and a small room at that.
2. Regardless of what has been said or implied: a long shot, but she just might win at that.
that is
To explain more clearly; in other words: on the first floor, that is, the floor at street level.

Black(hole)box joke. (5, Funny)

suso (153703) | more than 6 years ago | (#23080982)

has discovered that Sagittarius A* let loose a powerful flare three centuries before the time at which we are observing it (i.e., 26,000 years in the past)

That's a bit of a confusing sentence but I think I understand. What they really meant to say is that if Sagittarius A's flare produces a 26,000 Hz tone, it
will interfere with GT&T's subspace carrier signal and allow you to send free messages to the gamma quadrant.

Re:Black(hole)box joke. (1)

molecularaz (1066042) | more than 6 years ago | (#23082270)

Now we just need the folks at CERN to create a giant red box and then we can have free messaging to anywhere in the universe. Of course it will break down on the first attempt at using it

Sounds like the Brown Note? (2, Funny)

AnomaliesAndrew (908394) | more than 6 years ago | (#23083160)

"let loose a powerful flare"...

"26,000 Hz tone"...

Sounds like the Brown Note [wikipedia.org] ...

Re: open letter to the universe (0)

Anonymous Coward | more than 6 years ago | (#23084010)

My Open Letter to the Universe: .Knock and it shall be opened-Seek and ye shall find.. I ask for winning numbers on next lottery ticket purchase. Although I am solvent, I need to help family members. Would like for my #s as purchased to be selected. Thanks for previous favors granted too. I am at peace & wish to share good fortune that comes my way. TRY YOUR OWN OPEN LETTER TO THE UNIVERSE!!

A million times brighter than black? (3, Interesting)

jomegat (706411) | more than 6 years ago | (#23080994)

How bright is a million times brighter than black?

Re:A million times brighter than black? (5, Informative)

explosivejared (1186049) | more than 6 years ago | (#23081094)

The stuff that the black hole is sucking in is under great pressure and will often ignite, which is what this article is talking about. The pressurized gas being consumed by the black hole gives off very visible radiation, not the black hole itself. The black hole gives off Hawking radiation which is not with this is talking about though.

Re:A million times brighter than black? (3, Informative)

drerwk (695572) | more than 6 years ago | (#23081156)

It does not 'ignite' by any sense of the word. It does get very hot through friction, and emits black body radiation. But it does not burn.

Re:A million times brighter than black? (2, Funny)

Anonymous Coward | more than 6 years ago | (#23081218)

It does not 'ignite' by any sense of the word. It does get very hot through friction, and emits black body radiation. But it does not burn.

Burning requires oxygen, but everyone knows there is no oxygen in space!

Why else would the space-men wear those funny hats?

QED

Re:A million times brighter than black? (1)

interiot (50685) | more than 6 years ago | (#23081860)

Why else would the space-men wear those funny hats?

Otherwise the helium would make their voices squeaky, and having squeaky voices over the radio isn't very manly [wikipedia.org] .

Re:A million times brighter than black? (4, Informative)

evanbd (210358) | more than 6 years ago | (#23081798)

In astonomy and astrophysics, ignition usually refers to fusion, rather than a chemical process.

Re:A million times brighter than black? (1)

drerwk (695572) | more than 6 years ago | (#23082456)

I'm not recalling that the accretion disk is supposed to sustain fusion, I don't think it is dense enough, nor do I think that the x-rays we see from AGN suggest that the are hot enough to support fusion. So including that definition I don't think we have ignition, just blackbody friction induced radiation.

Re:A million times brighter than black? (1)

Evil Pete (73279) | more than 6 years ago | (#23082880)

Warning: vague half-baked memory retrieval detected. So I'm not certain about what follows.

I seem to recall that in some circumstances, eg very large black holes, some fusion in the accretion disk is possible. Though probably not much. Sorry haven't got a reference for that.

Re:A million times brighter than black? (1)

vajaradakini (1209944) | more than 6 years ago | (#23083108)

Fusion can occur in the accretion disks around neutron stars (for example [harvard.edu] ), why not black holes?

Granted, it may not be the sort of long sustained fusion reactions one usually thinks of, but jamming some extra protons and neutrons into some nuclei can still get energetic.

Re:A million times brighter than black? (2, Interesting)

wattrlz (1162603) | more than 6 years ago | (#23082072)

It does not 'ignite' by any sense of the word. It does get very hot through friction, and emits black body radiation. But it does not burn.
Well, in a few senses [reference.com] of the word it does. The American Heritage® Dictionary of the English Language, Fourth Edition 2nd definition of ignite as a verb includes to make luminous with heat and the 2nd definition as an intransitive verb is to begin to glow.

Re:A million times brighter than black? (1)

drerwk (695572) | more than 6 years ago | (#23082532)

Oh, sure, use a dictionary against my Wikipedia definition. And beaten only with the second definition. Ok, in no sense of the word as I'm familiar with it from college physiscs 20 years ago.

Re:A million times brighter than black? (1)

UncleTogie (1004853) | more than 6 years ago | (#23082874)

Ok, in no sense of the word as I'm familiar with it from college physiscs 20 years ago.

...and 20 years ago, it was thought that no information ever escaped a black hole, either...

Do keep up, dear boy...

Re:A million times brighter than black? (3, Informative)

evanbd (210358) | more than 6 years ago | (#23081786)

Black holes of this size do not give off meaningful amounts of Hawking radiation. Their temperature is far, far below the cosmic microwave background temperature -- so even if they didn't capture matter, they would grow by absorbing background radiation. A one solar mass black hole is at only 60 nanokelvins; heavier black holes are colder. Perfect black bodies at that temperature glow very, very dimly.

Re:A million times brighter than black? (1)

Evil Pete (73279) | more than 6 years ago | (#23082828)

Black holes don't give off much radiation but the accretion disk around it usually gives off plenty.

Re:A million times brighter than black? (1)

electricbern (1222632) | more than 6 years ago | (#23081124)

blackish?

Re:A million times brighter than black? (1)

Gilmoure (18428) | more than 6 years ago | (#23082428)

Would make a great album cover.

Re:A million times brighter than black? (1)

mikael (484) | more than 6 years ago | (#23082644)

Like this? Scientists make Darkest material ever made [physorg.com]

Re:A million times brighter than black? (1)

Gilmoure (18428) | more than 6 years ago | (#23082746)

I dunno, but it better be played at 11.

Re:A million times brighter than black? (1)

Barryke (772876) | more than 6 years ago | (#23083490)

The darkest material ever made?
Frankly I always accredited that to TellSell, Idols, Big Brother, The Bold and the Beautifull, among various others on the earth timescale.

Re:A million times brighter than black? (2, Informative)

xPsi (851544) | more than 6 years ago | (#23081346)

I think he's right, there is something about this, that's...that's so black, it's like; "How much more black could this be?" and the answer is: "None, none... more black." Seriously, though, the term "black hole" is descriptive in some ways, but is not to be taken literally. There are a lot of interactions which radiate near the event horizon. In short Black holes aren't so black [physorg.com]

Re:A million times brighter than black? (1)

An ominous Cow art (320322) | more than 6 years ago | (#23081512)

The answer is 'none'. None more bright.

Re:A million times brighter than black? (4, Funny)

ArcherB (796902) | more than 6 years ago | (#23081674)

How bright is a million times brighter than black?
Dark Gray

Re:A million times brighter than black? (1)

bryce4president (1247134) | more than 6 years ago | (#23082184)

Well if black is the absence of all color... then in numeric terms black = 0. So 0 * 1,000,000 = 0. I'm guessing...black? Or if black is the absence of color and the number of colors are n. Then you are talking about -n * 1,000,000 which would be less than 0... So it would be "REALLY black"?

Re:A million times brighter than black? (3, Informative)

ozbird (127571) | more than 6 years ago | (#23083306)

How bright is a million times brighter than black?

Since it's a million times brighter in X-rays, not much as far as your eye is concerned.

Re:A million times brighter than black? (1)

Colonel Korn (1258968) | more than 6 years ago | (#23083328)

How bright is a million times brighter than black?
Yeah, those Pioneer Kuros have great contrast ratios.

Re:A million times brighter than black? (1)

newgalactic (840363) | more than 6 years ago | (#23083486)

"...but it goes to 11"

"300 years ago" (3, Informative)

l2718 (514756) | more than 6 years ago | (#23080998)

Warning: that expression does not quite meant what it seems to. The "timeline" under discussion here is from our point of view as light from that area arrives here, after about 26,000 years. On the other hand, that doesn't quite mean that the events actually happened "26,300 years ago" -- there's no good global notion of time that is applicable here.

Re:"300 years ago" (5, Informative)

Beryllium Sphere(tm) (193358) | more than 6 years ago | (#23081956)

There's only a tiny fraction of c relative velocity between us and the center of the galaxy. For practical purposes we're in the same reference frame, and in any one reference frame you can do a clock synchronization algorithm that gets everybody to agree.

The weird effects that relativity is famous for come into play when you're comparing clocks between two reference frames that are moving relative to each other at relativistic speeds.

(Physics degree speaking here).

Re:"300 years ago" (0, Redundant)

Barryke (772876) | more than 6 years ago | (#23083268)

"The weird effects that relativity is famous for come into play when you're comparing clocks between two reference frames that are moving relative to each other at relativistic speeds."
No offense intended, but i am amazed at something sounding really profound to me in a scientific way actually more resembles the average political speach. I beleive to fully understand what you meant, and wonder if my "plain english" interpretation be a correct translation by your standards;

"Comparing the whole situation on moment A, would work. It would also work on any moment B. When one wants to compare the comparisons of moments A and B, it gets more complicated."

Well that sounds pretty straight forward, if not stupid. Its like saying "Slicing a bread on more than one unique axis is more difficult."

Re:"300 years ago" (4, Interesting)

Roger W Moore (538166) | more than 6 years ago | (#23083626)

There's only a tiny fraction of c relative velocity between us and the center [sic] of the galaxy.

True but not really relevant. Unless the readership of Slashdot is wider than I'm aware of the only frame of reference of relevance is that of the Earth. Hence that is the only frame you need to concern yourself with is that one.

The weird effects that relativity is famous for come into play when you're comparing clocks between two reference frames that are moving relative to each other at relativistic speeds.

Not actually true: they are larger at those relative speeds but are certainly present and noticeable at far lower velocities e.g. atomic clocks on Concord, GR corrections to GPS satellite clocks etc.

(Physics degree speaking here).

Physics professor speaking here :-).

Astronomy 300 years ago (0)

Anonymous Coward | more than 6 years ago | (#23084250)

That point prompted me to add that simply because Sagittarius-A was more active 26,300 years ago than it currently is, does not put it on equal footing with the distant galaxies that have supposedly re-activated after maturity. The last discussion was focused heavily on possible threats to earth if Sagittarius-A should do the same.

In fact, we know that the level of activity 26,300 years ago was no indicator of the safety of the earth from a dramatic re-start like the last discussion covered, because there were people around 300 years ago who not only were not visibly affected by it, but apparently didn't even see it, or at least left no records if they did.

Now I'm completly lost (0)

The_Angry_Canadian (1156097) | more than 6 years ago | (#23081002)

This has me confused...

The black hole was a million times brighter three centuries ago.

We are talking of a BLACK hole here, correct ?

Re:Now I'm completly lost (3, Funny)

lottameez (816335) | more than 6 years ago | (#23081254)

You may refer to it as "the hole who so recently was known as black".

Ni.

Re:Now I'm completly lost (1)

beckerist (985855) | more than 6 years ago | (#23081696)

...you racist.

(I'm kidding! Better than my first Michael Jackson joke...)

Re:Now I'm completly lost (5, Funny)

protolith (619345) | more than 6 years ago | (#23081916)

The term black is offensive to some, We say African American Holes

Re:Now I'm completly lost (1)

Kozz (7764) | more than 6 years ago | (#23083066)

Glad to see you've reformed your ways, Mr. Imus.

Re:Now I'm completly lost (5, Funny)

The End Of Days (1243248) | more than 6 years ago | (#23084440)

That's one of my favorite movies.

Re:Now I'm completly lost (3, Informative)

l2718 (514756) | more than 6 years ago | (#23081286)

We are talking of a BLACK hole here, correct ?

The black hole itself is, indeed, black for all intents and purposes. However, matter falling into the black hole (but still outside the horizon) heats up as it accelerates, emitting thermal radiation, typically in the X-ray spectrum. Thus one talks about "brightness", the brightness of the region right around the black hole.

An illustrative example: for an outside observer, the "temperature of the sun" can mean the temperature of the part one sees, that is the surface temperature (roughly 6000 kelvin). This is not the same as the core temperature of the sun (roughly 1.5x10^7 kelvin).

Re:Now I'm completly lost (1)

TexVex (669445) | more than 6 years ago | (#23083172)

The black hole itself is, indeed, black for all intents and purposes.
And this would also be a rare time when you could get away with saying "for all intensive purposes". :)

Other deadly core issues? (3, Informative)

CRCulver (715279) | more than 6 years ago | (#23081008)

In Larry Niven's old Known Space story "At the Core" (collected in Neutron Star [amazon.com] , he conjectures that because the stars at the core are so close together, one supernova-ing could cause a chain reaction that would bring killing radiation to all reaches of the galaxy. What do astrophysicists today think of this possibility? All the hype now seems to be on black holes.

Re:Other deadly core issues? (0)

Anonymous Coward | more than 6 years ago | (#23081496)

I thought nivens point was more that the central supermassive central black hole(s) would eventually become so massive as to disturb the outer layer of stars to the point that that causes a chain reaction of novae for.

been ages since i read anything that was all about the Galactic Core Explosion though, so whatever =D

Re:Other deadly core issues? (4, Informative)

HiThere (15173) | more than 6 years ago | (#23081668)

No, Niven wrote before we knew that the Milky Way *HAD* a central black hole. He was assuming that there were a whole bunch of really large stars hidden behind the gas clouds (that we couldn't see through from ground level).

At the time he wrote it, it was plausible. Now he'd probably write about a huge gamma burst instead. Not quite as destructive. Or he could write about a cluster of stars that had been merged into the accretion disk, and were now feeding into the central black hole.

Don't try to make what he wrote then match with current possibilities. It doesn't mesh. If you want to find really blatant mismatches, look at his really early stories that take place within the solar system, and before the interstellar drive. (More particularly, before the "Gil the Arm" stories.) Try "Becalmed in Hell".

Niven made reasonable guesses given what was known at the time. Don't try to stuff his guesses into what was later discovered. They don't fit.

Re:Other deadly core issues? (1)

UncleTogie (1004853) | more than 6 years ago | (#23082970)

Now he'd probably write about a huge gamma burst instead. Not quite as destructive

Tell that to THIS guy... [wikipedia.org]

Re:Other deadly core issues? (3, Funny)

meringuoid (568297) | more than 6 years ago | (#23081618)

he conjectures that because the stars at the core are so close together, one supernova-ing could cause a chain reaction that would bring killing radiation to all reaches of the galaxy. What do astrophysicists today think of this possibility? All the hype now seems to be on black holes.

It's not thought likely. Supernovae are triggered by the collapse of a star's core; external phenomena don't have a great deal to do with it. However, active galactic nuclei have been known about for quite some time. Perhaps when Niven was writing, the idea that active galaxies were powered by chained supernova swarms was current in the literature.

The contemporary model for such phenomena is that the gas swirling around the black hole is heated by friction and by compression as it moves inward. Consider: you're dropping thousands of solar masses through the deepest gravity well in the universe. That releases an awful lot of energy. It makes little difference to Niven's nightmare scenario: it's entirely possible that our Galaxy was active in this way in the past, may become so again in the future, and may even be a little bit active right now. If anyone were to go to the galactic core today in a General Products #3 hull with a quantum-II hyperdrive and discover that the X-ray flux was way, way higher than it ought to be... then we'd better start making plans to run to Andromeda, now.

Re:Other deadly core issues? (0)

Anonymous Coward | more than 6 years ago | (#23081688)

I doesn't really work that way. Supernova explosions don't cause other stars to go supernova. Even in the case of a binary star system where one of the two stars blows up, the other star will survive (at worst, it might lose some mass from its outer layers). There are known remnants of such systems, ie. binary pairs where one of the bodies is a presumed black hole or a neutron star. At true interstellar distances, the physical effects of a supernova won't affect a star in any way whatsoever; it's just a quick flash of radiation.

Re:Other deadly core issues? (1)

Beryllium Sphere(tm) (193358) | more than 6 years ago | (#23082050)

There are several lines of evidence that point to a large black hole being at the core. The speed of things orbiting it points to so much mass being in so small a space that it would be a black hole.

I don't know what astrophysical thinking would be, but one of the reasons to doubt the possibility of a supernova chain reaction is that it takes thousands of years for energy to travel between the core of a star and its surface. The core of a star might never know that a supernova had happened outside it.

Re:Other deadly core issues? (1)

Barryke (772876) | more than 6 years ago | (#23083366)

"The core of a star might never know that a supernova had happened outside it."
Also that in my interpretation in a infinite dense object time would stand still. I'd even go on to say that mass is rejected from to time, a.k.a. gravity.
One could also state mass is attracted to less time.

Remember you saw it here first, history here i come.

Re:Other deadly core issues? (1)

majorgoodvibes (1228026) | more than 6 years ago | (#23082738)

i don't know but i'm still building my ringworld at right-angles to galactic center.

just in case...

Phrasing? (1)

teasea (11940) | more than 6 years ago | (#23081020)

'The black hole was a million times brighter three centuries ago.'

What is it about this phrase I just can't wrap my mind around? Black hole...Brighter?

Re:Phrasing? (1)

Oxy the moron (770724) | more than 6 years ago | (#23081086)

I am by no means an expert here, but couldn't that mean that one million times more light was escaping before?

yet more evidence of human interferance (4, Funny)

CodeMunch (95290) | more than 6 years ago | (#23081072)

"'The black hole was a million times brighter three centuries ago.'"

Damn global warming!

Re:yet more evidence of human interferance (1)

Mr. Beatdown (1221940) | more than 6 years ago | (#23082226)

I think it's even more likely the fault of terrorists.

dup (1)

Bob-taro (996889) | more than 6 years ago | (#23081098)

Already posted [slashdot.org] a few days ago.

Re:dup (1, Troll)

esocid (946821) | more than 6 years ago | (#23081382)

/Fail.
RTFA next time before shouting wolf. I mean dupe.

Re:dup (1)

Bob-taro (996889) | more than 6 years ago | (#23082266)

Sorry, I'll be more careful in the future.

Matter ingestion (1)

redelm (54142) | more than 6 years ago | (#23081106)

IANA astrophysicist, but a black hole might be said to be bright if it gives off radiation outside it's event horizon.

I suspect this mostly happens when normal or superdense (neutronic) matter nears and passes the event horizon. The bigger/better question is: Any estimate on the amount of matter ingested to produce the fireworks? How many solar masses? Just what is going on around that drainhole?

Re:Matter ingestion (2, Informative)

explosivejared (1186049) | more than 6 years ago | (#23081212)

This [physorg.com] is what I think you are looking for. The black hole is essentially working as a particle accelerator. The article I linked to mentions that the forces involved can can produce rays in the trillions of electron volts.

Re:Matter ingestion (0)

Anonymous Coward | more than 6 years ago | (#23083002)

that's nice, but what's really important is the GP's misuse of it's

The Two Things Rule (5, Informative)

Anonymous Coward | more than 6 years ago | (#23081126)

To all those confused about black holes being bright - you need to learn the "two things rule" proposed by a colleague of mine - it runs like this:

There are two things you need to know about black holes: They're not black, and they're not holes.
There are two things you need to know about parallel universes: They're not parallel, and they're not universes.
There are two things you need to know about the big bang: It wasn't big and it didn't bang.

Sadly it extends way beyond just physics, but it does give an insight into why physicists have trouble communicating with the public - names come from the very early days of an idea and as often as not end up being misnomers.

Re:The Two Things Rule (1)

teasea (11940) | more than 6 years ago | (#23081238)

My issue is not with blackness or holeness. As I have learned, light does not escape black holes. Therefore, the misnomer here is the term 'brighter.'

ooof. I think I pulled a neuron. I need a nap now.

Re:The Two Things Rule (1)

frith01 (1118539) | more than 6 years ago | (#23081738)

Only material / energy which is beyond the "Event Horizon" of a black hole no longer radiates back out. Matter / Energy which is in the process of being consumed is quite bright, due to the accelleration / compression process, and friction with other items being consumed. If all local matter had been consumed, then the black hole will not be "bright". If additional material in on the path towards the black hole, we will see the hole 'brighten' once the material starts to accellerate / compress as it reaches near the event horizon.

Re:The Two Things Rule (1)

MightyMartian (840721) | more than 6 years ago | (#23081896)

Light that crosses the event horizon does not escape (or at least in classical physics). However, the matter and energy that is falling into the black hole does give off radiation as it accelerates and compresses, and it is this radiation (ie. light) that can be seen.

Re:The Two Things Rule (1)

Barryke (772876) | more than 6 years ago | (#23083460)

ooof. I think I pulled a neuron. I need a nap now.
You mean comatose for a few hours, hallucinate vividly, and then maybe suffering amnesia about the whole experience?
I hate it when that happens, never understood why people want to do that when they do not experience lucent dreams.

Re:The Two Things Rule (4, Funny)

sm62704 (957197) | more than 6 years ago | (#23081290)

Sadly it extends way beyond just physics

Pogo said it best: Nuclear physics ain't so new, and it ain't so clear.

Recursion (0)

Anonymous Coward | more than 6 years ago | (#23081350)

There are two things you need to know about the two things rule: It covers more than two things, and it is not a rule.

Re:The Two Things Rule (0)

Anonymous Coward | more than 6 years ago | (#23081468)

Perhaps it should be called the "n Things rule". n being the number of words in the thing that you're talking about.

Re:The Two Things Rule (1)

fitten (521191) | more than 6 years ago | (#23081534)

Kind of like the:

"There are X number of people in the world", followed by a list? ;p

Re:The Two Things Rule (1)

HasselhoffThePaladin (1191269) | more than 6 years ago | (#23081574)

I always thought that was called the "Linda Richman Rule", proposed by Mike Meyers.
"I'll give you a topic: a black hole is neither black, nor a hole. Discuss!"

Re:The Two Things Rule (0)

Anonymous Coward | more than 6 years ago | (#23082372)

That really sucks for connoisseurs of Big Tits monthly.

Re:The Two Things Rule (0)

glitch23 (557124) | more than 6 years ago | (#23084388)

There are two things you need to know about black holes: They're not black, and they're not holes.

They are black as far as the visible spectrum is concerned which is all the public cares about. Those who are questioning how a black hole can be brighter are in the middle between the general public and a physicist otherwise they would either know the answer or they wouldn't even know otherwise to ask "how can a black hole be brighter?" because they wouldn't be reading this story in the first place.

There are two things you need to know about parallel universes: They're not parallel, and they're not universes.

Then what are they? Perpendicular worlds?

There are two things you need to know about the big bang: It wasn't big and it didn't bang.

I don't know about you but I think it was pretty big (i.e. important) if it caused something to come from nothing (unless we are debating that now too to avoid the use of a Creator) and also big (i.e. vast) if it created the entire universe. And if it didn't bang then what did it do? It's all well and good to say all this stuff is wrong but it doesn't do readers any good if you don't say what these things really are if what readers thought they were is all wrong.

I'm dumb (1)

sm62704 (957197) | more than 6 years ago | (#23081206)

In the original subject, IRTFA and came to some stupid conclusions. Blame having a bubble in my eye and being stoned on endorphins from the pain in my neck and back from holding my head down.

Anyway, I didn't say that we're safe because the black hole is fifty thousand light years away and if it started spewing radiation, whatever was left of humanity (whether already wiped out, anything like ourselves, or what we may have evolved into would see the result.

However, the thing could have exploded fifty thousand years ago, and there's no way anybody could tell. Its radiation could reach us tomorrow.

However, I'm still more scared of being squished by an SUV than from the black hole. Hell, an asteroid strike is probably more likely.

-mcgrew

Re:I'm dumb (1)

Vectronic (1221470) | more than 6 years ago | (#23081854)

"...the pain in my neck and back from holding my head down"

huh... couldnt suck your own dick either eh?...lol /kidding

Re:I'm dumb (1)

sm62704 (957197) | more than 6 years ago | (#23082406)

Heh, there's a cartoon about a guy jealous of his dog ;)

But I had a vitrectomy [slashdot.org] and had a gas bubble in my left eye, had to keep my head down 50 minutes out of every hour. Literal pain in the neck! And back as well.

OB Billy Joel reference (1, Funny)

Anonymous Coward | more than 6 years ago | (#23081488)

We Didn't Start the Fire...

Re:OB Billy Joel reference (1)

Farmer Tim (530755) | more than 6 years ago | (#23082218)

Billy Joel...???

There's a thing called "it", which, it is my sad duty to impart, you are not and never will be with.

of course a black hole can give off light (2, Interesting)

pclminion (145572) | more than 6 years ago | (#23081660)

Anything within the event horizon of the hole, by definition, cannot escape to the outside universe again. But that doesn't mean that matter OUTSIDE the horizon, falling into the hole, doesn't get heated up unbelievably hot and radiate like hell.

I suppose you could make a pedantic argument that it isn't the hole glowing, it's the matter falling into it, but it's certainly the hole which causes it.

Re:of course a black hole can give off light (1)

What me a Coward (875774) | more than 6 years ago | (#23082048)

That's not true

    Anti matter radiates out from the center of the black hole caused by matter being annilated by the black hole inside the event horizon of the black hole. Hubble photos of black holes have shown this IE the hubble space photo of the black hole in the center of the andromoda galaxy.

    Black holes also shed mass slowly when not active.

    So it's not true that anything within the event horizon cannot escape out into the universe again when it has been shown quite clearly that anti matter for one has.

Re:of course a black hole can give off light (1)

pclminion (145572) | more than 6 years ago | (#23082250)

You are wrong. Hawking radiation arises when a virtual particle/antiparticle pair pops into existence very near the horizon. One particle is inside the horizon and falls in. The other particle is outside, and escapes. Had the virtual pair come into existence entirely within the horizon, both particles would have fallen in and no radiation would have escaped. Nothing, not even a virtual particle, can escape the event horizon of a black hole. Hawking radiation is "strange" but it cannot defy the basic physics of the event horizon.

Also, you seem to believe that Hawking radiation is composed solely of antimatter. This is also completely untrue. Hawking radiation is composed of any and every particle type up to an energy limit dictated by the area of the hole's horizon. The rule is, "anything that can radiate, will radiate."

Re:of course a black hole can give off light (1)

vikhik (984981) | more than 6 years ago | (#23083924)

For starters, neither of them mentioned Hawking radiation (which is DIFFERENT, and you are correct) secondly, What me a coward (above you) is.. well.. how shall I put it nicely.. a tard? Because antimatter particles are still attracted by gravitons, therefore his theory doesn't make sense (and I haven't seen it elsewhere, so I'm guessing it's something he's made up or mis-interpreted) This means black holes don't *lose weight* by sitting around in front of their comp.. some people could learn from this!

Re:of course a black hole can give off light (1)

pclminion (145572) | more than 6 years ago | (#23084308)

The OP's description sounded roughly like Hawking radiation, so I just assumed that was what he/she meant. If not, then I have utterly no clue what they are talking about.

Re:of course a black hole can give off light (1)

snaz555 (903274) | more than 6 years ago | (#23082138)

Anything within the event horizon of the hole, by definition, cannot escape to the outside universe again.


But it can still be observed in some ways, no? Matter inside the horizon exerts gravitational pull on matter outside - so matter inside the horizon still in the process of accreting should produce gravitational effects that can be observed in the matter still outside. We should be able to observe what goes on inside, in some ways. Similarly, a star cluster getting sucked in should be able to cause measurable wobble in the location, and some sort of tidal effects inside?

Re:of course a black hole can give off light (1)

pclminion (145572) | more than 6 years ago | (#23082292)

Matter inside the horizon exerts gravitational pull on matter outside - so matter inside the horizon still in the process of accreting should produce gravitational effects that can be observed in the matter still outside.

No. The key is, "Black holes have no hair." What this means is that there are only three properties which can be distinguished for a black hole: Electrical charge, spin, and mass. Once a piece of matter or energy has penetrated the event horizon, the only observable effect on the hole is a change in one of those three variables. Period. Obviously, when something falls into a black hole, the hole becomes more massive. But you cannot determine anything else.

26,000 years? (1)

Jedi Holocron (225191) | more than 6 years ago | (#23081802)

26,000 years? Isn't this equal to the Mayan Calendar that predicts the end of time in 2012?

Re:26,000 years? (1)

19thNervousBreakdown (768619) | more than 6 years ago | (#23082120)

wut?

Re:26,000 years? (1)

esocid (946821) | more than 6 years ago | (#23082122)

That is just a misinterpreted end-time theory. Scholars have been trying to figure out the Mayan calendar in Gregorian terms for a long ass time. I've heard it best described as odometer like. When it hits the "end" around Dec. 21st 2012 it will roll over and begin a new "era" of the calendar, ending 1/5 (5,125.36 years) of the Platonic Year (about 26,000 years), which measures the length of the procession of equinoxes. Their calendar was all about mapping cycles, and on Dec. 21st 2012 there will be a pretty impressive event when the Sun conjuncts with the Milky Way and the ecliptic [wikipedia.org] .
whew. Anything else you'd like to know about it?

Re:26,000 years? (1)

Colonel Korn (1258968) | more than 6 years ago | (#23083364)

The adjective is actually "Maya" not "Mayan." Mayan is a language spoken by the Maya people.

Relative Time (1)

Thyamine (531612) | more than 6 years ago | (#23081910)

I always find the idea of the time/distance involved to be amazing, and it really kinds of gives you a good perspective on how big things are (small you are). Like a friend who pointed out that the half moon you could see in the sky was because of the shadow _of the earth_. That's just crazy talk, and even more interesting as it sinks in.

This type of thing though is interesting in how it may have already reignited. Maybe just this morning, maybe 20000 years ago. We have no idea, it's not as easy as just looking out a telescope to know. Perhaps massive waves of radiation or solar flares or cosmic rays have been headed to the earth for thousands of years and we could all die tonight, or maybe it'll happen tomorrow and our great^10 grandchildren will be the ones to see it happen. I'm rambling, sorry about that. Too much afternoon coffee.

Re:Relative Time (1)

lionforce5 (1033490) | more than 6 years ago | (#23082348)

Perhaps massive waves of radiation or solar flares or cosmic rays have been headed to the earth for thousands of years and we could all die tonight, or maybe it'll happen tomorrow and our great^10 grandchildren will be the ones to see it happen.
Or maybe, just maybe, we'll all be infused with the power cosmic, enabling us to stretch our bodies in ways previously thought unimaginable, or crush cars with our rocklike hands, or ignite the heavens with a mere thought. I mean...think of the possibilities!

Re:Relative Time (0)

Anonymous Coward | more than 6 years ago | (#23083842)

Um, the half moon you could see in the sky is because of the shadow of the *moon*.

Passing Gas (1)

street struttin' (1249972) | more than 6 years ago | (#23082160)

Sagittarius A* let loose a powerful flare
Woah, Sagittarius A*, open a window!

New extinction event hypothesis? (2, Interesting)

PoliTech (998983) | more than 6 years ago | (#23082288)

Consider the hypothesis about the layer of enriched iridium in rocks formed at the boundary between the Triassic and Jurassic geologic periods and the associated extinction event... 200 million years ago.

And the similar hypothesis about the layer of enriched iridium in rocks formed at the boundary between Cretaceous and those of the Tertiary periods and the associated extinction event ... 65.5 million years ago.

Could that suggest an alternative to the "impact from an asteroid or comet" hypothesis? Could this actually be the observance of a 100 million year "or so" natural galactic cycle?

If that is indeed the case, we should expect our local galactic black hole to go "milky white" in 15 to 35 million years or so.

Keep your sunglasses handy!

BTW, if you couldn't already tell ... IANAAP and IANAPG

Re:New extinction event hypothesis? (0)

Anonymous Coward | more than 6 years ago | (#23084526)

Consider the hypothesis about the layer of enriched iridium in rocks formed at the boundary between the Triassic and Jurassic geologic periods and the associated extinction event... 200 million years ago.

And the similar hypothesis about the layer of enriched iridium in rocks formed at the boundary between Cretaceous and those of the Tertiary periods and the associated extinction event ... 65.5 million years ago.

Could that suggest an alternative to the "impact from an asteroid or comet" hypothesis? Could this actually be the observance of a 100 million year "or so" natural galactic cycle?

Two words: Great Flood. And if you want to dismiss this then just read my signature first. Whether you like it or not, the Great Flood did happen. That isn't up for questioning because there is evidence of huge deposits of mud at the right depth to show a Flood. If we trust the layers for an asteroid strike by seeing iridium there shouldn't be any reason to not trust it for the Great Flood, unless we decide to pick and choose what to believe based on biases. However making an assumption that iridium had to come from outer space is just that, an assumption, with no proof either. Scientists take it on faith that iridium came from space to fill the holes in their theories with the asteroid idea to explain dinosaur extinction. It's hard keeping the nest of lies straight and logical once 1 builds on another which builds on another and so on. Uncover one of those lies and the whole thing comes crashing down. It requires scientific faith to prevent that from happening since there is no proof of an asteroid strike among other things. I find it hard to believe that after millennia of continual plate movement and formation that the 'crater' from the killer asteroid still looks enough like a crater for us to be duped, not to mention that after plate movement the location of the strike wouldn't be in the same place geologists say it is in at present (Yucatan peninsula).

Quiescent... (1)

brennanw (5761) | more than 6 years ago | (#23082978)

... oy. Why choose a word that means both "being at rest; quiet; still; inactive or motionless" and "Having the power or quality of acting; causing change; communicating action or motion; acting" for the news headline? (Dictionary.com Definitions [reference.com] )

Friends (1)

Barryke (772876) | more than 6 years ago | (#23083392)

I really like the fact that this one thread contains more friends and fans than any other i ever read.

Its a worthy subject and article.
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