Submitted via IRC for TheMightyBuzzard
While focussing on the remains of an exploded star roughly 10,000 light-years away, a team of Japanese astronomers have stumbled across a mysterious cloud of molecules tearing through the Milky Way. So quickly, in fact, they've nick-named [...] the unknown phenomenon the 'Bullet'.
The cause of this cloud's ridiculous speed isn't clear, but so far all signs suggest it's been sent hurtling through space thanks to a rogue black hole.
On account of their light-sucking talent, black holes aren't known for being all that easy to spot. They sometimes reveal themselves by stealing material from a nearby star, heating it up and forcing it to emit X-rays.
If they're wandering alone in interstellar space, however, they tend to remain hidden.
Yet in this case, the shadowy influence of a black hole could explain why a cloud of molecules 2 light-years in size was moving forward at 120 kilometres per second (75 miles per second), and expanding at 50 kilometres per second (31 miles per second).
Weirder still, it was moving against the direction of the Milky Way's spin.
Source: http://www.sciencealert.com/astronomers-find-hints-of-a-black-hole-powered-supersonic-space-cloud
(Score: 1, Troll) by aristarchus on Wednesday February 08 2017, @04:56AM
I see the eds were doing their jobs on this one! All trace of "supersonic" in the description of the cloud has been removed, except in the URL. Super-sonic: above sound. And the speed of sound is? Mach something? Let's see, 120 kilometres per second is about 26,8432 MPH, or about 349.854 times the speed of sound. Or more precisely, Mach 352.6531. (Not sure I trust Google's converters! But, close enough for a Trump Dept. of Education.) I wonder how many parsecs this cloud could do the Kessel run in?
(Score: 0) by Anonymous Coward on Wednesday February 08 2017, @05:37AM
Just call it hypersonic.
(Score: 1, Insightful) by Anonymous Coward on Wednesday February 08 2017, @06:09AM
Mach speed is defined as speed of sound. [wikipedia.org] Ergo, the speed of sound is Mach 1, by definition. How you (or Google) got different numbers when converting "times the speed of sound" to a Mach number, I have no idea :)
Also, converting 120 km/s (two significant digits) to 26.8432 mph (6 significant digits) is... weird. Not to mention that the 120 km/s is only an approximation to begin with...
(Score: 1, Insightful) by Anonymous Coward on Wednesday February 08 2017, @06:34AM
The speed of sound depends on the gas pressure and other parameters (temperature, molar mass). If you don't know those, you can't specify a Mach number.
(Score: 2) by aristarchus on Wednesday February 08 2017, @08:17AM
Well, this cloud is traveling through interstellar space, so the calculations for a Mach number should be pretty easy!
In space, no one can hear you speed!
(Score: 1, Informative) by Anonymous Coward on Wednesday February 08 2017, @12:59PM
That depends on the size of your space ship and the listening equipment. Sufficiently low frequencies (or more accurately, sufficient large wavelengths) can indeed be transmitted in space; it's just that they are far beyond our hearing range.
(Score: 3, Informative) by maxwell demon on Wednesday February 08 2017, @08:39AM
In the milky way: Somewhere between 100 m/s and 100 km/s, depending on where you are. [stackexchange.com]
Assuming it doesn't move through hot ionized medium, 120 km/s is very clearly above the speed of sound. However being a molecular cloud itself, it almost certainly doesn't move through a molecular cloud, which is at the lower range of sound speeds. Assuming the cloud moves through a warm medium, the cloud's Mach speed is at the order of Mach 10.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by The Mighty Buzzard on Wednesday February 08 2017, @11:00AM
Our eds may whip out the Alzheimer's Cock once in a while but changing the quoted text of a story is decidedly outside their mandate.
My rights don't end where your fear begins.
(Score: 2) by driverless on Wednesday February 08 2017, @11:49AM
The cause of this cloud's ridiculous speed isn't clear
It's not travelling at ridiculous speed, it's travelling at ludicrous speed and has recently gone plaid.
(Score: 2) by JoeMerchant on Wednesday February 08 2017, @01:52PM
In space, nobody can hear you scream.
🌻🌻 [google.com]
(Score: 3, Funny) by tangomargarine on Wednesday February 08 2017, @04:16PM
Parsec isn't speed; it's distance. In the EU they explained it as taking a closer route past black holes.
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 0) by Anonymous Coward on Wednesday February 08 2017, @06:26PM
-1 ignorant
(Score: 2) by aristarchus on Wednesday February 08 2017, @06:50PM
+2 Irony! Ah, I love the smell of science in the morning! It smells like, . . . knowedge!
(Score: 0) by Anonymous Coward on Wednesday February 08 2017, @06:31PM
dude - your payment is late
You said, "when I'm downmodded, you upmod me, and I'll keep bitcoin in your wallet"
I've kept my end of the deal, but my wallet is empty.