Slashdot Mirror
Milky Way Is Twice the Size We Thought
Peter writes to tell us about a research group at the University of Sydney in Australia, who in the middle of some calculation wanted to check the numbers everybody uses for the thickness of our galaxy at the core. Using data available freely on the Internet and analyzing it in a spreadsheet, they discovered in a matter of hours that the Milky Way is 12,000 light years thick, vs. the 6,000 that had been the consensus number for some time.
Ironically, Wikipedia is one among few encyclopedias that do this. Not for all facts, far from it, but for a fair number of facts. For example, Wikipedia has three references for the mass of the Milky Way, and you can also see which referenced were used for that sole claim. You won't be able to see that by using Britannica.
Beware: In C++, your friends can see your privates!
From TFA with commentary:
Proving not all science requires big, expensive apparatus, Professor Gaensler and colleagues...downloaded data from the internet
No, this actually proves that you can reuse data gathered with large expensive apparatus. There's a difference. They couldn't have done this without expensive infrastructure that just happened to cost them nothing (or close to nothing) - ie. The original instruments and the Internet.
The University of Sydney team's analysis differs from previous calculations because they were more discerning with their data selection. "We used data from pulsars: stars that flash with a regular pulse," Professor Gaensler explains. "As light from these pulsars travels to us, it interacts with electrons scattered between the stars (the Warm Ionised Medium, or WIM), which slows the light down.
Well now wouldn't you want to explore why the data differs so much, before declaring your answer to be the correct one just because you verified your calculations are correct?
My first thought is: Did they use some standard or average value for the density of the WIM? Could the discrepancy be because the WIM itself is not uniform through the thickness of the galaxy/
This is definitely an interesting result and worth following up but rather than declare victory the real question is why is there such a large discrepancy with other data?
These posts express my own personal views, not those of my employer
How is this modded "insightful"? Scientific models and methods improve, often building upon earlier models and methods. This isn't an indication of incompetence or malfeasance in the earlier science; it just means that we're getting better at it.
Additionally, the revised estimate of the point of divergence of humans from primates as a result of newly-discovered fossil evidence isn't even remotely relevant to a case in which existing data has been re-interpreted to form a new conclusion.
SIERRA TANGO FOXTROT UNIFORM
Read the best of all of Slash: seenonslash.com
I guess I should clarify. I have no problem with amateurs editing Wikipedia. But I do have problems with, as you say, stupid, fucking amateurs editing Wikipedia.
For example, at the moment Wikipedia says:
The disk of the Milky Way galaxy is approximately 100,000 light years in diameter, and is believed to be about 1,000 light years thick (average thickness),[8] with the center bulge's thickness recently discovered by University of Sydney researchers to be about 12,000 light years, contrary to the previously thought 6,000.[9]This is not correct. The Wikipedia editors have decided somehow that the 12,000 light year measurement refers to the center of the Milky Way (even though it does not state this anywhere in the U Sydney Press Release). As I said above, the 12,000 light year measurement refers not to a location but to a component, the Warm Ionised Medium or WIM.
My point is simply that the quality of Wikipedia is only as good as the effort that editors make to understand a subject and edit appropriately.
I can easily understand that talking about 'how thick the galaxy is' is a lot like the 'is Pluto a planet' dispute -- it's just shorthand for more complex issues that you could elucidate. For example -- you could provide a brief paragraph describing the controversy, and how different elements lead to different measures of a galaxy's thickness, and give those measures. You'd be, you know, educating. If you both care enough and know enough about a subject to be bothered by the Wikipedia article, that's a sign you should be improving it.
Read the best of all of Slash: seenonslash.com
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton