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Milky Way Heavier Than Thought, and Spinning Faster
An anonymous reader writes "The Milky Way is spinning much faster and has 50 per cent more mass than previously believed. This means the Milky Way is equivalent in size to our neighbor Andromeda — instead of being the little sister in the local galaxy group, as had been believed. One implication of this new finding is that we may collide with Andromeda sooner than we had thought, in 2 or 3 billion years instead of 5."
At least now we don't have to worry about our sun going nova, we'll all die in an intergalactic traffic accident first.
..on my Zune
Mass != weight
For a while there I was worried it had dropped down to 1 billion years.
One thing that is great about science is that it does have a way of eventually finding errors and correcting them in the face of new evidence.
As far as galactic collisions are concerned, we are in no immediate danger. 2-3 Gy vs 5 is an academic exercise, as the Sun will most likely increase its output sufficiently by then to boil off the Earth's oceans anyway,
Besides, the density of a galaxy (outside of the core) is so low that the chance of a stellar or planetary collision is negligable anyway.
Or, by then, we would have the technology to detect it and either deflect it or GTFO of the way anyhow.
Still, it is nice to know we're not in the pipsqueak galaxy. Hoorah!?!?
Well, that'll show those Andromedans not to attack "smaller" galaxies. Now who's laughing! We will plunder their mass (while watching colateral ejected mass fly out).
oh well.. still leaves plenty of time to debate which is the most robust backup method after all then?
Thought I was drunk.
Good to know it was the milky way spinning all too fast.
NO SIG
But how do you calculate the rate of rotation and mass of a galaxy that you're in? It's mind blowing that we can actually do that.
I dreamed of Freud: What does this mean?
Because it's on youtube. http://www.youtube.com/watch?v=dJRc37D2ZZY
Ugh. Sounds like scientists just discovered my last blind date.
__ Someday, but not this morning, I'll finally learn to use the preview button.
Actually the orbital velocity is (surprisingly) close to constant, as in most spiral galaxies. In fact, it is these "flat" (i.e. constant as a function of galactocentric radius) rotation curves that were some of the earliest evidence for dark matter.
That having been said, my guess is that the velocities quoted in the press release refer to the Sun's (or more accurately the Local Standard of Rest's) velocity around the Galactic center.
Couldn't find the paper on arxiv.org ...
Tell that to the fat guy who got shot with a rifle round. He has a 600,000% weight advantage, yet he's still in ICU on a respirator.
Fat man 0, Remington 1.
I hate printers.
"...the galaxy is rotating at a speed of 965,600 km/h, compared to previous estimates of 804,672 km/h, the astronomers report."
Anyone else think it odd that the previous estimate had six significant digits, yet was apparently off by ~20%?
Whoa, for a moment I thought you said _million_ years. No need to panic, people.
...omphaloskepsis often...
I think my chemistry teacher would have taken off points for that one.
The odd thing is not the estimate (500,000 mph has one significant digit) but its conversion to km/h.
Twice as heavy! Talk about getting it wrong.
It's only a matter of time before the earth's age is readjusted to 6000 years!
I record my sleeptalking
Do you mean there is a problem with gravity in the future?
Fight Spammers!
Thank you, makes much more sense now. Agence France-Presse strikes again. They converted mph to km/hr VERY precisely.
965,600 km/h = 600,000 mph
804,672 km/h = 500,000 mph
Abstract of presentation (10aPT Tue Jan 6, if you are in Long Beach CA) is at http://tinyurl.com/9d5rec.
The visble arms of our galaxy's spiral aren't a fixed buch of stars clustered togther, it's a density wave that travels around the disk. Our solar system will pass in and out of various arms (eventually) as the density wave is travelling at a different speed to the actual rotation.
It seems like whether the Milky Way or Andromeda is bigger changes every couple years, as this paper or that paper claims a measurement showing one or the other is actually a lot bigger than we all thought.
We used to think the Milky Way was bigger (and before that, thought Andromeda was bigger for the longest time), and then recently we got some evidence that Andromeda was actually bigger after all. And then there's this piece about the Milky Way actually be bigger after all.
Me? I'm going to sit back and let the scientists figure it out for a few more decades before deciding. All we really know is that Andromeda and the Milky Way are by far the two biggest galaxies in our Local Group, and they're probably close enough in size to make figuring out which one is really bigger a bit tricky.
Statistically speaking, you will die.
If you don't plan on what happens after that, someone else will (no pun intended).
Planning on something isn't the same as wishing for it.
As for me, WRT "the singularity"? If I could upload "myself", would I? I don't know. Probably. But if you think about it, "you" don't get to go, only your "branch/copy" does. Are you that selfless? What if it costs money? Are you willing to pay for "his" immortality? AFAIK, the first sentence stands alone.
This issue is a bit more complicated than you think.
Precision != Accuracy.
The previous measurement had 6 significant digits of precision.
They just happened to be inaccurate.
Note that the new estimate seems to have *less* precision (assuming that only the first 4 digits are significant), but is claimed, at least, to have more accuracy.
The ringing of the division bell has begun... -PF
Tell that to the fat guy who got shot with a rifle round. He has a 600,000% weight advantage, yet he's still in ICU on a respirator.
Did you see the bullet afterward?
Respect the Constitution
Remember that the reason dark matter supposedly exist is because scientists calculated the weight of the visible matter in the entire universe and said "well that doesn't match up with the energy/gravity" so they make up some imaginary object to make up the difference. And then a couple years later OMG I guess we were 50% off of the mass of the milky way, oops. If they can't even measure our galaxy properly, then dark matter probably doesn't exist because they're just calculating it wrong. Either that or it's literally regular matter that has almost no light bouncing off it cuz it's too far away from a light source.
Google's Super Secret Search Algorithm: SELECT @search_results FROM internet WHERE @search_results = 'good'
Does that mean that we age slower compared to the people in Andromeda?
"It is our choices, Harry, that show what we truly are, far more than our abilities." -- Prof. Dumbledore