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Milky Way Is Twice the Size We Thought

kdawson posted more than 6 years ago | from the everything-you-know-is-wrong dept.

Space 301

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.

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first (-1, Offtopic)

Null Perception (914562) | more than 6 years ago | (#22485286)

first

Re:first (-1, Offtopic)

Trouvist (958280) | more than 6 years ago | (#22485294)

second

Third (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#22485326)

Oh yeah!

Haha (5, Funny)

Anonymous Coward | more than 6 years ago | (#22485290)

Yeah, it comes with "%30 MORE!" now.

Re:Haha (0, Offtopic)

Distortions (321282) | more than 6 years ago | (#22485298)

Oops, didn't mean to post as Anonymous Coward.

Hardly surprising (5, Funny)

oz1cz (535384) | more than 6 years ago | (#22485300)

Obesity is everywhere.

Re:Hardly surprising (3, Funny)

thunrida (950858) | more than 6 years ago | (#22485348)

I knew it was expanding, but I had no idea that is is so fast.

Re:Hardly surprising (4, Funny)

commodoresloat (172735) | more than 6 years ago | (#22485674)

That's what happens when you eat too many Milky Ways

Wikipedia says 1000 (5, Funny)

Aaron Isotton (958761) | more than 6 years ago | (#22485302)

Wikipedia says it's only 1000 light years thick.

Re:Wikipedia says 1000 (3, Insightful)

timmarhy (659436) | more than 6 years ago | (#22485344)

that only confirms that wikipedia is not a reliable source.

Re:Wikipedia says 1000 (3, Funny)

rucs_hack (784150) | more than 6 years ago | (#22485358)

But, but, Voyager only had to cross 70,000 light years to get home....

I mean, you're going to be saying Voyager wasn't real next...

As if..

Re:Wikipedia says 1000 (1)

Bipedal Shark (1210600) | more than 6 years ago | (#22485764)

Thick, motherfucker! 12,00ly thick!

Re:Wikipedia says 1000 (5, Interesting)

I confirm I'm not a (720413) | more than 6 years ago | (#22485448)

To be fair to Wikipedia, they cite their source [wikipedia.org] for that claim. And the source is...

...(drumroll!)...

NASA [nasa.gov]

Other instances of numbers widely off (3, Interesting)

pkphilip (6861) | more than 6 years ago | (#22485648)

What I find disturbing is the fact that a number is this widely off and no one discovered it for such a long time! I can imagine deviation by x % or less where x

The split of Humans from the Apes pushed back by another 6 to 7 million years earlier than previously thought based on molecular genetics. The difference from the earlier estimate of around 5 to 6 million years is therefore over 100%
http://www.news24.com/News24/Technology/News/0,,2-13-1443_2169361,00.html [news24.com]

Re:Wikipedia says 1000 (3, Informative)

Anonymous Coward | more than 6 years ago | (#22485664)

Leave it to wikipedia to cite as a source a NASA edutainment page aimed at grade schoolers.

What the "source" doesn't mention (because it's not meant to give an in depth answer) is that the galaxy is ~1000ly thick on average. It is quite a bit thinner along its edge, and quite a bit thicker in the core.

Monty Python was more accurate than NASA? (3, Funny)

Misanthrope (49269) | more than 6 years ago | (#22485694)


        Whenever life gets you down, Mrs. Brown,
        And things seem hard or tough,
        And people are stupid, obnoxious or daft,
        And you feel that you've had quite eno-o-o-o-o-ough...

        Just remember that you're standing on a planet that's evolving
        And revolving at nine hundred miles an hour,
        That's orbiting at nineteen miles a second, so it's reckoned,
        A sun that is the source of all our power.
        The sun and you and me and all the stars that we can see
        Are moving at a million miles a day
        In an outer spiral arm, at forty thousand miles an hour,
        Of the galaxy we call the "Milky Way".

        Our galaxy itself contains a hundred billion stars.
        It's a hundred thousand light years side to side.
        It bulges in the middle, sixteen thousand light years thick,
        But out by us, it's just three thousand light years wide.
        We're thirty thousand light years from galactic central point.
        We go 'round every two hundred million years,
        And our galaxy is only one of millions of billions
        In this amazing and expanding universe.

        (Animated calliope interlude)

        The universe itself keeps on expanding and expanding
        In all of the directions it can whizz
        As fast as it can go, at the speed of light, you know,
        Twelve million miles a minute, and that's the fastest speed there is.
        So remember, when you're feeling very small and insecure,
        How amazingly unlikely is your birth,
        And pray that there's intelligent life somewhere up in space,
        'Cause there's bugger all down here on Earth.

1000 light years where? (2, Insightful)

uhlume (597871) | more than 6 years ago | (#22485740)

The NASA source doesn't specify at what radius the thickness is measured, leading me to believe that the "1000 light years" figure references an average, or representative, thickness. According to the summary (although curiously unmentioned in TFA) this new discovery seems to pertain specifically to the Milky Way's thickness at the Galactic core, where it is substantially thicker than at points located further down the arms (as illustrated in this side view [usra.edu] ).

Re:Wikipedia says 1000 (1, Insightful)

TapeCutter (624760) | more than 6 years ago | (#22485454)

People who depend on a single source are unreliable.

Re:Wikipedia says 1000 (3, Funny)

B3ryllium (571199) | more than 6 years ago | (#22485514)

I'll need to hear that in triplicate before I believe it.

Re:Wikipedia says 1000 (1)

amRadioHed (463061) | more than 6 years ago | (#22485588)

So which encyclopedia can you recommend that cites multiple sources for every fact?

Re:Wikipedia says 1000 (5, Insightful)

Jugalator (259273) | more than 6 years ago | (#22485598)

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.

Re:Wikipedia says 1000 (1)

TapeCutter (624760) | more than 6 years ago | (#22485690)

"which encyclopedia"

The fact that there is more than one encyclopedia in your question should give you a clue.

Re:Wikipedia says 1000 (4, Insightful)

Jugalator (259273) | more than 6 years ago | (#22485582)

that only confirms that wikipedia is not a reliable source.
This argument is getting sort of tiresome to me. In well written Wikipedia articles, key facts are often referenced today. This then becomes a blanket argument against Wikipedia as a whole, without caring for whether the information was well referenced or not. Often, it is. Sure, often it's not too, but IMHO, one need to check that out first.

This time, you've already received your answer to why Wikipedia had this information, and it's in fact not a long time ago I've had to do the same.

So, please guys, before you bash Wikipedia, check if there's a good reason to the discrepancy of the information. Surprisingly often, especially in articles receiving good attention like the one for our galaxy, there is.

Re:Wikipedia says 1000 (3, Insightful)

Eivind (15695) | more than 6 years ago | (#22485746)

Technically, Wikipedia should never claim any spesific thing. They don't really have an opinion as such on the size of the MW or anything else. Yeah, I know, the article says "The Milky-Way is so-and-so big". But that should really be read as:

"Our sources, given under this article, claims that the Milky-Way is so-and-so big" One could write it like that, but it'd become tiresome real quick.

That information is by nessecity only at best as good as the sources.

Besides; that's the way reality works in general. When somebody claims some fact it ALWAYS means that based on the sources that that person choose to believe (be it his own eyes or a scientific paper, or Fox-news) says so.

Re:Wikipedia says 1000 (1)

toetagger (642315) | more than 6 years ago | (#22485654)

"The disk of the Milky Way galaxy is approximately 100,000 light years in diameter, and, though previously believed to be about 1,000 light years thick[7], has recently been discovered to be roughly 12,000 light years thick[8]."

You may want to check your sources.

Re:Wikipedia says 1000 (1)

ZombieWomble (893157) | more than 6 years ago | (#22485698)

Yes, the helpful editing has now made the article more wrong. The milky way, as a whole, is further from 12,000 light years thick than it is from 1,000 light years thick. The issue is that stating a single thickness for the Milky Way is pretty much impossible - it's much thicker in the center than it is on the periphery, and if you don't bother to illustrate this fact the article is always going to be flawed.

(And before anyone asks, the reason I don't fix it myself is because I don't really care).

what is a reliable source (1)

arse maker (1058608) | more than 6 years ago | (#22485680)

Wikipedia isnt a reliable source? Where on earth is this mysterious relable source? The best you can do is list information while citing sources, but thats not even totally reliable. Id still bet wiki is far more reliable than most the crap you read online about a topic.

Re:Wikipedia says 1000 (1)

wall0159 (881759) | more than 6 years ago | (#22485838)

...and which article will be sooner updated to reflect our new understanding - Wikipedia, or Britannica?

Hell, Wikipedia will probably be updated sooner than NASA!

Re:Wikipedia says 1000 (4, Funny)

kryten_nl (863119) | more than 6 years ago | (#22485346)

Quick, e-mail them! They'll have to retract their article.

Re:Wikipedia says 1000 (5, Funny)

supermari0 (1238518) | more than 6 years ago | (#22485424)

holy astronomy! to the wikipedia edit page... dadadada dadadada!

Re:Wikipedia says 1000 (0)

Anonymous Coward | more than 6 years ago | (#22485528)

Wikipedia says the disk is 1000 ly thick. The article says the bulge at the centre is 12000 ly thick. They are talking about measurements at two different places.

Re:Wikipedia says 1000 (2, Insightful)

Atario (673917) | more than 6 years ago | (#22485538)

Not anymore! Hee hee!

Re:Wikipedia says 1000 (1)

aslvrstn (1047588) | more than 6 years ago | (#22485676)

Yes, but now the entry now says "...though previously believed to be about 1,000 light years thick, has recently been discovered to be roughly 12,000 light years thick." The title for the citation, however, is "The Milky Way is twice the size we thought it was." Clearly, then 1,000 * 2 = 12,000. Quick, someone update the wikipedia entry on multiplication!

Re:Wikipedia says 1000 (1)

Atario (673917) | more than 6 years ago | (#22485742)

Well:

"Previously": adverb. At an earlier time or formerly.
I'm sure at some previous time, it was thought to be a couple of AU thick. Also consider that the "previous" citation is from 1998.

Re:Wikipedia says 1000 (1)

Atario (673917) | more than 6 years ago | (#22485756)

P.S.:

My point was that, rather than bitching about the incorrect information, get in there and fix it. I thought my actions would speak louder than words, but I guess not for some...

Re:Wikipedia says 1000 (1)

amRadioHed (463061) | more than 6 years ago | (#22485568)

My wikipedia says the thickness is 12,000 light years.

Re:Wikipedia says 1000 (1)

anonypus_user (1236548) | more than 6 years ago | (#22485632)

So I guess its already been changed? That was quick. Was the 1000 light years a reference to the thickness of the core or the thickness of the disc though?

2x bigger (3, Insightful)

Feef Lovecraft (1231264) | more than 6 years ago | (#22485308)

So until now everyone was just measuring the radius of the Milky Way?

Re:2x bigger (1)

Ghostalker474 (1022885) | more than 6 years ago | (#22485352)

I was just thinking that.

it's the intelligently-designed choice (1)

User 956 (568564) | more than 6 years ago | (#22485310)

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.

I'm going to have to go with the Biblical numbers on this one and use the 6,000 figure.

Re:it's the intelligently-designed choice (1)

TheLink (130905) | more than 6 years ago | (#22485714)

They used a spreadsheet. Maybe they used Excel 2007, and encountered a minor display error...

A good reminder (5, Interesting)

A beautiful mind (821714) | more than 6 years ago | (#22485314)

This is a good reminder how you're supposed to dig down to the raw data and validate that. I remember reading in one of Richard Feynman's books about a similar case, some conclusion or data appeared well supported, because a lot of the research papers were supportive of the idea, but it turned out that they derived what they said based on a single source.

The case here is similar, it's a good reminder how science is about data, validation and facts not about authority. You're supposed to check your data, check your facts and try to avoid making implicit assumptions.

Re:A good reminder (1)

deathtopaulw (1032050) | more than 6 years ago | (#22485338)

Exactly
and luckily this is just about the thickness of a galaxy, and not nuclear physics or something dangerous

Re:A good reminder (3, Insightful)

bandersnatch (176074) | more than 6 years ago | (#22485374)

because like the internet is like TOTALLY a definitave source mkay?

Re:A good reminder (2, Interesting)

Rocketship Underpant (804162) | more than 6 years ago | (#22485418)

That reminds me of a famous scientist who was mentioning HIV in an article he was writing, and wanted to cite the original source where it was first discovered and published that HIV caused AIDS. He couldn't find it. No one else he talked to could either. It turns out that what is a common assumption (and perhaps true) has never actually been verified and published.

file under pants (3, Interesting)

tinkerton (199273) | more than 6 years ago | (#22485490)

That famous scientist may have allowed himself to get carried away a bit. What it means is that there was no clean breakthrough article. Rather, evidence gradually accumulated. What it does not mean is that the connexion is "perhaps true", certainly not in the current stage where effective medicines exist.

On the other hand it's good practice to have roundup articles that go over the evidence.

Re:A good reminder (5, Funny)

martin-boundary (547041) | more than 6 years ago | (#22485550)

This reminds me of a famous politician who was mentioning WMD in a speech he was having written, and wanted to cite the original source where they were discovered in a certain country or other. He couldn't find it. No one else he talked to could either. It turns out that what was a common assumption (and turned out false) had never actually been verified. So he winged it.

Re:A good reminder (1)

sholden (12227) | more than 6 years ago | (#22485630)

To verify it you would have to have a control group and then the group that you infect with HIV and see if they get AIDS more... Good luck getting that past the ethics board.

There is Blattner et al in '93 looking at three lab workers who were exposed to HIV, http://gateway.nlm.nih.gov/MeetingAbstracts/102203749.html [nih.gov]

And of course Schechter et al in '93, which looked at 715 homosexual men, with about a 50/50 split of HIV positive and HIV negative. All 136 who ended up with AIDS during the study were HIV positive: http://www.ncbi.nlm.nih.gov/pubmed/2112396 [nih.gov]

Re:A good reminder (3, Insightful)

TapeCutter (624760) | more than 6 years ago | (#22485662)

The other reply is correct. It's not that everyone just assumed it's origin it's that everyone was uncertain about the origin. There was a hell of a lot of evidence collected for the CDC, WHO and others. Science is designed like that, nobody is ever 100% certain about anything.

Some religious and political groups (where many claim/demand proof) use this systematic uncertainty to justify their particular perversions of common decency when science presents them with inconvienient evidence. The search for the origin of aids was a good example.

Nobody is immune because nobody can keep up with everything. The comments on slashdot demonstrate that every day. Over the last 7-8yrs there has been a magnificent debate on slashdot over global warming. What once was marked troll is now insightfull, if nothing else I think most of the regulars (including me) know more about the science behind it than they did a few years ago.

Re:A good reminder (1)

Kelz (611260) | more than 6 years ago | (#22485426)

And lets hope that not too much research is completely screwed due to a change in a constant (though what experiments would need to take into account the diameter of the galaxy I do not know).

Re:A good reminder - Disproval of dark matter? (2, Interesting)

Anonymous Coward | more than 6 years ago | (#22485486)

Well, if we're expecting that the universe is actually 75 to 95 percent dark matter based on the
SAME KIND OF FLAWED DATA, perhaps we are underestimating the amount of matter we actually CAN see.

I always wondered how exactly they determined how much matter was in the universe, indirect evidence or not.
Seems like there may be few assumptive leaps there, upon which we build our entire cosmological understanding.

If the 'missing' matter is actually regular matter that we haven't found, or have found and discounted,
the search for dark matter will be even more in vain than it appears to be already. Can we stop looking?

Re:A good reminder (1)

TapeCutter (624760) | more than 6 years ago | (#22485502)

"...it's a good reminder how science is about data, validation and facts not about authority. You're supposed to check your data, check your facts and try to avoid making implicit assumptions."

...and then in your twilight years some smart-arse with a spreadsheet takes all the fun out of polishing your nobel.

Good or bad? (3, Funny)

The Ancients (626689) | more than 6 years ago | (#22485320)

So I read the article (yeah, yeah - I know...I was bored) and I hope the spreadsheet software used wasn't Excel - we all know how well that counts.

Re:Good or bad? (4, Funny)

king-manic (409855) | more than 6 years ago | (#22485336)

So I read the article (yeah, yeah - I know...I was bored) and I hope the spreadsheet software used wasn't Excel - we all know how well that counts.
You mean the radius of the galaxy isn't 65,535 light years?

Re:Good or bad? (0, Troll)

dotancohen (1015143) | more than 6 years ago | (#22485414)

I'm surprised that _spreadsheet_ software was used to calculate this. Once the conclusion was made that the correct width should be twice the accepted size, the numbers should have been verified with Mathematica, or better yet, an open source (peer-reviewed code is just as important as peer-reviewed research) solution such as Maxima.

Re:Good or bad? (0)

Anonymous Coward | more than 6 years ago | (#22485532)

Oic, what bit of software do you use when doing your Ground-Breaking Astrophysics?

This morning, I doubled the size of the galaxy. (0)

Anonymous Coward | more than 6 years ago | (#22485328)

What have you done today?

Re:This morning, I doubled the size of the galaxy. (1)

someone1234 (830754) | more than 6 years ago | (#22485372)

It's slightly more than doubled.

Is this real information? (2, Insightful)

Thanshin (1188877) | more than 6 years ago | (#22485360)

Is there any physical effect where a galaxy ends? Or are we just talking about an imaginary limit.

How hard is it to map the galaxy? If we don't know where the stars are, we can't know the size. If we know, we don't need it; we can describe the actual, real, shape.

Where's the flaw in my logic? (I hope it's in the part about the limit being imaginary, I like limits in Space like the heliosphere)

Re:Is this real information? (3, Informative)

timnbron (1166139) | more than 6 years ago | (#22485460)

They're measuring the sea of electrons between the stars, which they assume stops at the 'edge' of the galaxy.

FTA:
"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. ... If you know the distance to the pulsar accurately, then you can work out how dense the WIM is and where it stops - in other words where the Galaxy's edge is.

Re:Is this real information? (1)

Thanshin (1188877) | more than 6 years ago | (#22485558)

Ok. So there's actually a physical limit: the border between the intergalactic medium (IGM) and the interstellar medium (ISM).

Pretty, pretty Universe.

Re:Is this real information? (5, Funny)

SnowZero (92219) | more than 6 years ago | (#22485510)

Is there any physical effect where a galaxy ends? Or are we just talking about an imaginary limit.
Yes, you pass a sign that says "Now leaving Milky Way galaxy, pop 13.167B". That is soon followed by a sign reading "Ejected star crossing, next 200,000 light years."

How hard is it to map the galaxy?
It's pretty easy actually; We draw the Earth, the rest of the solar system, a few constellations, and a whole lot of "here be dragons[1] (maybe)".

Where's the flaw in my logic?
Asking a serious question on slashdot. At night. Clearly.

[1] Now known to consist of dark matter and dark energy, which is why you can't see them.

Re:Is this real information? (0)

Anonymous Coward | more than 6 years ago | (#22485592)

Dark energy? Hey, that's Mordor!

Re:Is this real information? (1)

kryten_nl (863119) | more than 6 years ago | (#22485580)

I think you can compare it to the height of the atmosphere. While the "size" is debatable based on differing definitions, the important thing is knowing what the state of the medium is at various altitudes.

Re:Is this real information? (1)

Thanshin (1188877) | more than 6 years ago | (#22485696)

I think you can compare it to the height of the atmosphere. While the "size" is debatable based on differing definitions, the important thing is knowing what the state of the medium is at various altitudes.
Yes, but the height of an atmosphere is not arbitrary, it's the highest point where the planet's gravity still manages to keep his surrounding gas. It may vary with time of position, but it's not an imaginary limit.

(After the first post I discovered that the galaxy limit is real: i.e.: the separation between Intergalactic Medium and Interstellar Medium).

Re:Is this real information? (5, Informative)

Siener (139990) | more than 6 years ago | (#22485852)

How hard is it to map the galaxy? If we don't know where the stars are, we can't know the size. If we know, we don't need it; we can describe the actual, real, shape.

It's pretty hard to measure the size and shape of the Milky Way simply because we are stuck in the middle of it. Measuring the size and shape of far away galaxies is a lot easier because we have a better view. Our galaxy is a flat disk with spiral arms where we are in one of those arms - the overall structure is very hard to measure from that perspective. To complicate things further there is quite a lot if interstellar dust that messes up our view in certain directions.

As an analogy - imagine being stuck in a traffic jam. Figuring out the extent of it is very hard from the view you get from your car. A helicopter in the sky has no problems though.

In related news... (1, Funny)

Anonymous Coward | more than 6 years ago | (#22485368)

Snickers is only about half the size

Dark Matter (1, Insightful)

Anonymous Coward | more than 6 years ago | (#22485390)

Does this ruin dark matter? Perhaps our mass estimates for our own galaxy were off by a factor of 2.

skeptical (1, Interesting)

timmarhy (659436) | more than 6 years ago | (#22485396)

have they checked their freely available sources they found on the internets? seriously i'm dubious of everything claiming to use a spread sheet and/or internet sources these days.

Re:skeptical (0)

Anonymous Coward | more than 6 years ago | (#22485780)

Zomg! Someone's skeptical! How bloody interesting!

So... (1)

pahles (701275) | more than 6 years ago | (#22485416)

this is the super size version?

This may cost me my geek card... (1)

SharpFang (651121) | more than 6 years ago | (#22485432)

'cause I think I'm supposed to know but I don't, but how does the tag "montypythonwaswrong" relate to this story?

Re:This may cost me my geek card... (1)

bersl2 (689221) | more than 6 years ago | (#22485462)

I can't remember the exact number, but there was a song in The Meaning of Life that mentioned the diameter of the galaxy. "The Galaxy Song" I think is what the song is titled.

Re:This may cost me my geek card... (1)

great throwdini (118430) | more than 6 years ago | (#22485474)

There was a song in The Meaning of Life that mentioned the diameter of the galaxy. "The Galaxy Song" I think is what the song is titled.

Yes, the "Galaxy Song". Look here now [geocities.com] for the lyrics before GeoCities melts. Second verse: "It bulges in the middle, sixteen thousand light years thick." etc.

Re:This may cost me my geek card... (2, Informative)

Anonymous Coward | more than 6 years ago | (#22485612)

As a public service to the Slashdot community I'm going to blatantly violate copywrite and post the lyrics here so we can all see them after geocities melts down

Galaxy Song

Spoken: Whenever life gets you down Mrs. Brown,
And things seem hard or tough,
And people are stupid, obnoxious or daft
And you feel that you've had quite enough...

Just remember that you're standing on a planet that's evolving
And revolving at nine hundred miles an hour,
That's orbiting at nineteen miles a second, so it's reckoned,
A sun that is the source of all our power.
The sun and you and me and all the stars that we can see
Are moving at a million miles a day
In an outer spiral arm, at forty thousand miles an hour,
Of the galaxy we call the 'Milky Way'.

Our galaxy itself contains a hundred billion stars.
It's a hundred thousand light years side to side.
It bulges in the middle, sixteen thousand light years thick,
But out by us it's just three thousand light years wide.
We're thirty thousand light years from galactic central point.
We go round every two hundred million years,
And our galaxy is only one of millions of billions
In this amazing and expanding universe.

The universe itself keeps on expanding and expanding
In all of the directions it can whizz
As fast as it can go, the speed of light, you know,
Twelve million miles a minute and that's the fastest speed there is.
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth,
And pray that there's intelligent life somewhere up in space,
'Cause there's bugger all down here on Earth.

Re:This may cost me my geek card... (3, Insightful)

piquadratCH (749309) | more than 6 years ago | (#22485710)

As a public service to the Slashdot community I'm going to blatantly violate copywrite and post the lyrics here so we can all see them after geocities melts down

If you violate copyright, do it right [youtube.com] .

Fortunately... (1)

martin-boundary (547041) | more than 6 years ago | (#22485440)

It's only ~ 1.4426 times as big as we thought in log scale...

Monty Python (1)

epsilon720 (307234) | more than 6 years ago | (#22485444)

Historical measurements of the galactic core's thickness by noted astronomer Monty Python resulted in a value of 16,000 light years, much closer to 12,000 than the previously accepted 6,000. The new light shed on this ancient knowledge should remind us all of Eristosthenes' measurement of the of the circumference of the earth, later confirmed to within 1%. Of course, less well known were Eristosthenes' dialogues on the Iberian Inquisition.

Re:Monty Python (1)

epsilon720 (307234) | more than 6 years ago | (#22485464)

Oops, Eratosthenes. I noticed that ff highlighted it as a spelling error, but I figured, there's no way he can be in the dictionary...

Duh (0)

Anonymous Coward | more than 6 years ago | (#22485456)

Perhaps they confused the commonly accepted radius for the commonly accepted diameter:

d = 2 * r

What the F ? (2, Funny)

backslashdot (95548) | more than 6 years ago | (#22485468)

Now you guys tell me!

What the Fudge man, I have been eating Snickers all this time thinking I'm getting more chocolate! Now I find this out?

First measurements were accurate (3, Funny)

Trogre (513942) | more than 6 years ago | (#22485476)

What we're seeing now is middle age spread.

WTF is light year (2, Funny)

jsse (254124) | more than 6 years ago | (#22485552)

Use something a layman could understand OK?

Say, how many Library of Congress, or elephants, have we got here?

Re:WTF is light year (5, Funny)

kryten_nl (863119) | more than 6 years ago | (#22485638)

1 light-year = 4 * (cost of war in Iraq so far) * (mile/$)

I hope that brings it into perspective for you ;)

Re:WTF is light year (2, Informative)

martin-boundary (547041) | more than 6 years ago | (#22485652)

FYI: 1 lightyear = a bit less than 1/39.144 Kessel runs.

The real question (1)

Thanshin (1188877) | more than 6 years ago | (#22485668)

When you say "light year" you mean a "low fat year"? Or it goes all the way to "fat free year".

P.S.: You may want to check your data, a year is a long time to stay under 3 grams of fat per serving.

You're very clever (1)

RuBLed (995686) | more than 6 years ago | (#22485734)

young man, very clever... But it's turtles all the way down...

Re:You're very clever (1)

lbft (950835) | more than 6 years ago | (#22485810)

About 3.5 septillion very small turtles, stacked on top of each other.

Re:WTF is light year (0)

Anonymous Coward | more than 6 years ago | (#22485770)

Libraries of Congress and Elephants don't work as units because they're measures of information and mass respectively. The conversion you're looking for is around 1 million trillion football fields.

Re:WTF is light year (1)

amirulbahr (1216502) | more than 6 years ago | (#22485790)

Its about twice the thickness of our galaxy! no wait....

Monty python (0, Redundant)

Ironweaver (894947) | more than 6 years ago | (#22485554)

"It bulges in the middle, sixteen thousand light years thick, But out by us it's just three thousand light years wide"

Twice the size! (0)

Anonymous Coward | more than 6 years ago | (#22485600)

Being fair at that age it must take quite a while to get an erection.

Does this affect our estimate of the mass? (2, Insightful)

dltaylor (7510) | more than 6 years ago | (#22485628)

The spiral arms are thicker than we've been assuming. Does that mean that there are more stars and gas/dust clouds in the greater volume? If there are more, then the mass of the galaxy is higher, and with the relativistic adjustment recently adopted, there's less need for a "dark halo", or, at least, less of one required to balance the velocity of the outer stars. OTOH, if there's the same amount, then the density is less, which throws off the very measurement technique that they're using to derive the new thickness, since the less-dense interstellar medium will have less effect on the two wavelengths (yeah, I read the article).

Anyone know of an online resource for the American Astronomical Society papers? I'd like to see what, if anything, they say about the density values for the WIM.

This has MAJOR consequences... (2, Funny)

Linker3000 (626634) | more than 6 years ago | (#22485640)

...We are told that the sun's light takes approx 8 minutes to reach us, but now we know that the distance involved is twice as much so therefore the speed of light must be approximately double what we thought! ...if the moon is twice as far away as previously thought, how come astronauts have landed successfully - in theory, they should get 'there' and be in the middle of nowhere ...UNLESS, of course they never went....AH HA!!!

Monty Python knew this years ago (2, Informative)

delibes (303485) | more than 6 years ago | (#22485722)

"Our galaxy itself contains a hundred billion stars. It's a hundred thousand light years side to side. It bulges in the middle, sixteen thousand light years thick, But out by us, it's just three thousand light years wide."

Homer says (1)

blake182 (619410) | more than 6 years ago | (#22485750)

Mmmm. Double-sized Milky Way. aaaaagggggcccchhhh (drools).

Interesting but premature? (5, Insightful)

syousef (465911) | more than 6 years ago | (#22485752)

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?

Monty Python Rules! (1)

PinkyDead (862370) | more than 6 years ago | (#22485820)

It bulges in the middle, sixteen thousand light years thick
Ok, so they were 4,000 light years out, but that's better than 6,000.

Define "edge" (3, Insightful)

Dan100 (1003855) | more than 6 years ago | (#22485826)

To measure the thickness of something, you need to know where it ends. The Milky Way isn't a solid object, so there must be some arbitary definition of the "edge" where the average density drops below a certain value.

Perhaps the differences in quoted thicknesses are the result of different definitions of the edge?

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