Huge Hydrogen Cloud Will Hit Milky Way 220
diewlasing points us to a story about a hydrogen cloud, eleven thousand light-years long, which will collide with the Milky Way in a devastating crossfire of shock waves and star formation...in 20-40 million years. Mark your calendars. At least it will give us something to watch while we're waiting for Andromeda to hit us in a few billion years. Hopefully, it will look at least this cool.
"The detailed GBT study dramatically changed the astronomers' understanding of the cloud. Its velocity shows that it is falling into the Milky Way, not leaving it, and the new data show that it is plowing up Milky Way gas before it as it falls. 'Its shape, somewhat similar to that of a comet, indicates that it's already hitting gas in our Galaxy's outskirts,' Lockman said. 'It is also feeling a tidal force from the gravity of the Milky Way and may be in the process of being torn apart. Our Galaxy will get a rain of gas from this cloud, then in about 20 to 40 million years, the cloud's core will smash into the Milky Way's plane,' Lockman explained."
Hindenstromics (Score:3, Funny)
Shot in the Dark (Score:5, Interesting)
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Probably not so much. The difference is that the Earth is a rigid object, while the galaxy is a swirling pile of unconnected particles. It would take a very long time for tidal locking to redistribute the energy.
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Re:Shot in the Dark (Score:5, Funny)
Re:Shot in the Dark (Score:5, Funny)
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We are a passenger sitting behind the windshield.
Re:Shot in the Dark (Score:5, Funny)
Interesting example. I would have used the puppy vs large wood chipper example.
I don't think it means what you think it means... (Score:5, Insightful)
Does anyone else have a problem with the word "smashing" to describe the contact of two bits of not-quite-vacuum passing through each other?
Re:I don't think it means what you think it means. (Score:5, Informative)
Does anyone else have a problem with the word "smashing" to describe the contact of two bits of not-quite-vacuum passing through each other?
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Gravitation is an interaction force (Score:5, Insightful)
There are four known forces in the universe, the weak and strong nuclear forces are short-range, while the electrical and gravitational forces are long-range, which means they will produce interactions everywhere in the universe.
Electrical forces come in two polarities, positive charges balance out negative charges, but gravitational forces always add up. There's no known way to block gravitation, therefore one can say that any two galaxies in the universe are "close enough for an interaction force to be produced", given enough time.
In the context of the article, I suppose "smashing" means close enough to produce significant distortion in the overall shape of the hydrogen gas cloud.
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I thought that they unified the electromagnetic and the weak force into the electro-weak force.
Re:Gravitation is an interaction force (Score:4, Informative)
The four forces are an entirely different matter. Electromagnetism, the strong and weak forces are summed up in the Standard Model of Particle Physics (in the form of the Electroweak Theory + Quantum Chromodynamics), which is very well tested and in fantastic agreement with experiments. Gravity doesn't fit into the mathematical framework of quantum mechanics, but the theory of General Relativity has been tested experimentally and is almost universally accepted.
So that's basically the reason... You have four interactions for which we have very well tested theories and mathematical tools, while we know almost knothing about Dark Energy except for the fact that we need it to make our cosmological models work
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We can't calculate or predict anything involving Dark Matter / Energy yet, because we know almost nothing about them except for the fact that they are needed at some point to make our mo
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There are fancier dynamical theories of dark energy in which dark energy is due to a new kind of particle (e.g., quintessence), but there it is still ultimately due to the gravitational effects of this new quantum field.
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The electromagnetic and weak interactions are actually already unified, into the electroweak interaction. A theory which unifies electroweak with the strong interaction is called a "grand unified theory" [wikipedia.org], or GUT. A theory which unifies a GUT with gravity is called a "theory of everything" [wikipedia.org] (TOE).
There are a number of GUT candidates out there, basically all of them
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they do (Score:2)
Re:I don't think it means what you think it means. (Score:5, Funny)
I bet quite a number of folks will stock up on gas masks when they'll hear these news...
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Oh come on. By now you should know the only deadly gas is CO2.
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Re:I don't think it means what you think it means. (Score:3, Interesting)
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Two points:
(1) The sun's outer atmosphere is already in the millions of degrees.
(2) Our planet orbits within the sun's outer atmosphere.
Has this happened before - in "recent" times? (Score:5, Interesting)
I don't. (At least not until I find out the relative masses and densities of the gas cloud vs. both the sections of the Milky Way it's about to encounter and the interstellar-gas components of them.)
The cloud may be a very hard vacuum - only slightly softer than the intergalactic space around it. But at galactic scales it still amounts to something quite dense and massive, which will not pass through the interstellar gas and solar winds of our galaxy without interacting repeatedly - let alone through the magnetic fields of the galaxy and the stars and planets that compose it.
I'd expect it to coalesce with the galaxy. That much mass at that much relative velocity will dump enormous amounts of energy into compression and heat at the shock front (similar to the graduation of "falling pebble" to something akin to a bomb when the pebble is falling at cometary speed, or a nuclear bomb when the "pebble" is also a couple miles in diameter). The energy density might be small, but over half the sky the radiant temperature can add up. Over that much matter, even at near-vacuum densities, even fusion events could be non-trivial - especially since magnetic effects could produce concentrations.
In gas clouds I'd expect it, at a minimum, to kick off a round of star formation. Also to sweep the gas and dust out from between existing stars and their planetary systems (and fractionate it), as dense accumulations are accellerated little while gas and dust encounter something of comparable density.
Even if the density is so low that the above effects aren't significant for planetary systems like ours, the passage of the cloud (especially the shock front) would wreak non-trivial havoc on the solar wind and magnetosphere - and thus planetary radiation shielding. Because the solar wind -> radiation shielding -> water condensation nucleation -> cloud cover -> solar heat reflection connection seems to be a major contributor to (geologically) short-term planetary temperature changes, the arrival and passage of the gas cloud could have a major effect on climate. (Even if its impact on the magnetosphere doesn't "stir up" some change in activity on the solar surface or modify the sunspot cycle.)
Which brings up the questions:
- Have similar events occurred in the geologically "recent" past?
- If so, do they have any relation to ice ages and interglacial periods or to mass extinction events?
happens frquently (Score:2)
Re:I don't think it means what you think it means. (Score:2)
Sounds like a smashing good time to me.
Hydrogen economy (Score:5, Funny)
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OK smartypants, go get some
A warming thought (Score:2)
Time to bring out the spaceship and start spreading humanity into the galaxy. :-)
But when the cloud hits humanity will have disappeared and diverted in so many different forms that it's probably not interesting anymore. But is humanity at it's height right now? Inhumanity sure is!
On a geological timeframe humanity is insignificant, and on a universal scale we are merely a static crack. That we still
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That remains to be seen; humanity is very young, but it has the potential of lasting billions of years and spreading across the galaxy.
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fuel for the fire (Score:2, Interesting)
Awesome! (Score:2, Funny)
Sorry about the cloud, guys (Score:4, Funny)
Huge Gas Cloud Will Hit Milky Way (Score:2, Funny)
This is extremely important (Score:5, Funny)
Re:This is extremely important (Score:4, Funny)
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furlongs and donkey forthnights (Score:5, Informative)
suns = 2E30 kg
light year = 1E16 meters
So this cloud has a density of 28 H2 molecules per liter.
That is pretty good vacuum. Actually about a million times better vacuum than "deep vacuum" in outer space here in our solar system, which again is much better vacuum than what is achievable here on earth.
So this "collision" will be quite soft in terms of energy density: One feather landing on an area the size of the earth.
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So this "collision" will be quite soft in terms of energy density: One feather landing on an area the size of the earth.
Right at first, yes. But there will be collisions, there will be gravity interaction.
There also is the fact that (1000000 suns x 2e30 kg = 2e37 kg) of mass coming in at 150 miles/second contain a *lot* of energy...
Some of that mass will combine with the gas in milkyway and push some areas over the threshold into collapsing and forming stars.
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This is why a few new conventions were adopted. A "Solar mass" is indeed a valid measurement of stars, nebulae, galaxies, and black holes. The only difference is the language used to describe such things in press releases, since the public doesn't actually know what a solar mass *is*.
There are also astronomical units, which is the
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You'd think that, but professional astronomers use some seemingly-bizarre units sometimes (though IANAPA). For example, they sometimes use centimeters (obviously with scientific notation). What I don't get is why they don't use the "base" unit of meters, but there you go; it's probably some historical oddity, or who knows, they
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MegaMaid (Score:2, Funny)
Life that one down, Milky Way. (Score:5, Funny)
Don't expect to be invited to too many parties in the 20,002,007AD-40,002,007AD season.
Everyone ... (Score:2)
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Just in time (Score:2)
hudrogen rush (Score:4, Funny)
20 million years? (Score:2, Insightful)
I realize there are probably other ways to keep it from hitting our solar system, but I'd like us all to agree right here and now that a black hole cannon is how we are going to deal with this, just so we're all on the same page and can get our act together in time.
Until this passes... (Score:2)
God's Fart (Score:5, Funny)
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Oh, bugger, that made my day
You wanted hydrogen fuel? Here you go. (Score:3, Funny)
Oblig Douglas Adams Tribute (Score:2, Insightful)
Collision (Score:2)
What next? A Cloud of Oxygen. (Score:3, Interesting)
If a cloud of oxygen of the same size were to come at the Milky Way from the opposite size, would the resulting cloud of water be enough to put out all of the stars?
GBT? (Score:2)
Can someone tell me what the Gay, Bisexual and Transgender study has to do with astrophysics? Or were the astronomers just assuming the cloud was "hetro", and now they understand it better?
Big words (Score:2)
A devastating crossfire of shock waves and star formation
smash into the Milky Way's plane
These are rather heavy words for the fact that a rather rarified cloud of gas is going to seep in between the stars in our galaxy. Even in the highly unlikely event that there are humans around when this begins to happen, we wouldn't notice on a day to day basis. A star system takes long to form, in human terms, in the order of 100,000 to millions of years. Even the collision between two galaxies is not something that anybody would notice in their daily lives.
depends (Score:2)
would this make the earth uninhabitable? (Score:2)
Huge Hydrogen cloud will hit milkyway???? (Score:2)
Re:Shame (Score:5, Funny)
You sure it's intelligence? (Score:3, Funny)
"Oh, like, those Sol guys are, like, soo nerdy, always with their, like, radio-teles-wossnames and their gizmos. And, like, God, they just can't take a hint when they're, like, not wanted. You'd think, like, after they got ignored a dozen times, they'd, like, quit trying to get our attention already. I mean, gah, gag me with a spoon, like I'd ever w
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Who is doing the rectal probing?
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Heh (Score:2)
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Re:Stock Market and Banks (Score:4, Funny)
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And that uranium can be used to create a weapon of incredible power. And that a flood in New Orleans would be really bad. And that travel to the Moon is possible.
Each of those predictions had less consensus than human-aggravated Global Warming does today. Ten years ago, maybe, you could stand by your argument. Not in 2008.
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When they are confronted with it somehow, they either ignore it or pull out some variety of Last Thursdayism: the universe was created with all of the bits already in motion, and the light from distant stars already underway, and the fossils neatly buried. Rationalisations as to the reasons for this range from "test of faith" to "giving us something to look at in the night sky".
Remember: evidence against s
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Mind you, "young earth" is, strictly speaking, an interpretation of the Biblical. An interpretation with which many thoughtful Christians disagree, on the basis that the "young earth" interpretation is shockingly unsupported--contradicted, even--by lots of really good science, and that the Biblical narrative allows for other interpretations that are supported by scientific evidence.
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The "Dinosaurs etc were burried in the flood" argument also holds no water because there is this bizzare trend in the fossil record where the deeper you go the more primitive the organism is. And I don't want to hear any of that "smaller simpler organisms sunk faster" garbage because that's based on density and unless y
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However the scientific arguments for evolution (ie what got us from the first bit of life up to the present day) are so comprehensive and compelling that the only reason I can s
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By all means, show us this marvellous evidence.
Mischaracterisation of the Big Bang.
Lack of understanding of how gravity works
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It's even better if they don't have a good education - faith don't need learnin'!
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never die. How would you prevent boredom? Besides seeding planets
with life, and observing the changes, what else would there be to do?
OK, *beside* waiting for Duke Nukem Forever to be released.
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aka "folks who believe in science"
will start yammering about Galaxy Warming
It's an interesting model... there's a lot of energy in these incoming hydrogen atoms, but adding extra gas between the stars-- especially if some coalesces-- could absorb some energy and keep it from the planet. It makes one wonder what effect it will have, and whether it's happened in the past. A few tens of millions of years is a flashbulb on the geologic time scale. (The amount of time between now and when
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