Slashdot Mirror
Scientists Find Doublehelix at Center of Milky Way
An anonymous reader writes "Astronomers report an unprecedented elongated double helix nebula near the center of our Milky Way galaxy, using observations from NASA's Spitzer Space Telescope. The part of the nebula the astronomers observed stretches 80 light years in length."
You will see a large, light absorbing, black monolith - howling Ligeti - in the center of the nebula.
"Speaking the Truth in times of universal deceit is a revolutionary act." -- George Orwell
Maybe that's why he calls himself "BadAnalogyGuy".
Here is the Nature article abtract:
"A magnetic torsional wave near the Galactic Centre traced by a 'double helix' nebula"
The magnetic field in the central few hundred parsecs of the Milky Way has a dipolar geometry and is substantially stronger than elsewhere in the Galaxy, with estimates ranging up to a milligauss (refs 1-6). Characterization of the magnetic field at the Galactic Centre is important because it can affect the orbits of molecular clouds by exerting a drag on them, inhibit star formation, and could guide a wind of hot gas or cosmic rays away from the central region. Here we report observations of an infrared nebula having the morphology of an intertwined double helix about 100 parsecs from the Galaxy's dynamical centre, with its axis oriented perpendicular to the Galactic plane. The observed segment is about 25 parsecs in length, and contains about 1.25 full turns of each of the two continuous, helically wound strands. We interpret this feature as a torsional Alfvén wave propagating vertically away from the Galactic disk, driven by rotation of the magnetized circumnuclear gas disk. The direct connection between the circumnuclear disk and the double helix is ambiguous, but the images show a possible meandering channel that warrants further investigation.
Maybe in order to understand mankind we have to look at that word itself. MANKIND. Basically, it's made up of two separate words "mank" and "ind." What do these words mean? It's a mystery and that's why so is mankind.
Jack Handey
Deep Thoughts
Haha, he makes me chuckle
According to the story, the magnetic field has energy equivalent to 1,000 supernovae, although it's overall magnetic field is 1,000 times weaker than the sun. Therefore this magnetic field must cover an immense volume, if the sun was as powerful as a supernovae (which it's not, so think even larger than this figure...), then that would mean that this magnetic field is coming from a volume 1,000,000 times larger than the sun (something like that anyway, it sounds pretty good :P). Sure there's much, much bigger things in the universe, but, as already stated by others, you can't just say "oh, it's so big!" that's all relative. So, yeh, I could say that it's a really big thing and be shot down by someone telling me it's not so big, or I could give you a figure.
A magnetic field in the middle of the galaxy over 1,000,000 times the volume of the sun. That's big :P
To answer my own question, here is the link.
You can't think of something incomprehensibly fast in terms of something incomprehensibly large and say you understand it.
If anything, the fact that it takes a measurable amount of time to traverse the earth-moon distance by something so fast it seems instantaneous to us is just an indication of how far the moon really is away. (385000 km, about ten times further than the circumference of the earth.)
And the circumference of the earth is a bloody long way. 40000 km. If you were to try walking this distance, it would take you more than a year of continuous walking (no sleep)
As said, the moon is about ten times further away than that, 385000 km, about ten years of walking.
The sun is one astronomical unit away. (150 Million kilometers) 4280 years of walking. You'd have to have started walking about the time the first pyramid was built to get there by today.
The nearest star to the sun is just over 4 light years away (40 Million Million km) One thousand million years of walking. I'm running out of timescales to compare this to now, because human experience doesn't date anywhere near as far back. This timescale now compares roughly to the age of life on earth, and even the age of the earth itself is only about four times as large.
The nebula in the article is about ten times that size. Ten thousand million years of walking. If you wanted to walk that distance, you'd have to start at a time where neither earth nor sun existed, or would exist for billions of years. The solar system around that time would probably be little more than a localised gravitational aggregation of spinning gas.
You're right that one could keep going for quite a lot longer. Once one starts considering the distances in the universe, you can think of them only in numbers, they're so huge. The upshot of this is that in a universe where all mayor distances are unimaginably huge, this one is one of them.
But if you're interested in experiencing these speeds and distances, I'd suggest you give Celestia a try. It's a 3d simulation that puts you smack bang into the middle of our solar system, and you can whiz around, visit nicely textured planets and even leave and visit other stars, other galaxies. Really beautiful graphics. You can actually move from the earth to the moon at walking speed, or at light speed.