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ASTRONOMERS CRUNCH NUMBERS, UNIVERSE GETS BIGGER
Ohio State University ^ | 03 August 2006 | Staff (press release)

Posted on 08/03/2006 12:52:54 PM PDT by PatrickHenry

That intergalactic road trip to Triangulum is going to take a little longer than you had planned.

An Ohio State University astronomer and his colleagues have determined that the Triangulum Galaxy, otherwise known as M33, is actually about 15 percent farther away from our galaxy than previously measured.

This finding implies that the Hubble constant, a number that astronomers rely on to calculate a host of factors -- including the size and age of the universe -- could be significantly off the mark as well.

That means that the universe could be 15 percent bigger and 15 percent older than any previous calculations suggested.

The astronomers came to this conclusion after they invented a new method for calculating intergalactic distances, one that is more precise and much simpler than standard methods. Kris Stanek, associate professor of astronomy at Ohio State, and his coauthors describe the method in a paper to appear in the Astrophysical Journal (astro-ph/0606279).

In 1929, Edwin Hubble formulated the cosmological distance law that determines the Hubble constant. Scientists have disagreed about the exact value of the constant over the years, but the current value has been accepted since the 1950s. Astronomers have discovered other cosmological parameters since then, but the Hubble constant and its associated methods for calculating distance haven't changed.

"The Hubble constant used to be the one parameter that we knew pretty well, and now it's lagging behind. Now we know some things quite a bit better than we know the Hubble constant," Stanek said. "Ten years ago, we didn't even know that dark energy existed. Now we know how much dark energy there is -- better than we know the Hubble constant, which has been around for almost 80 years."

Still, Stanek said he and his colleagues didn't start this work in order to change the value of the Hubble constant. They just wanted to find a simpler way to calculate distances.

To calculate the distance to a faraway galaxy using the Hubble constant, astronomers have to work through several complex steps of related equations, and incorporate distances to closer objects, such as the Large Magellanic Cloud.

"In every step you accumulate errors," Stanek said. "We wanted an independent measure of distance -- a single step that will one day help with measuring dark energy and other things."

The new method took 10 years to develop. They studied M33 in optical and infrared wavelengths, checking and re-checking measurements that are normally taken for granted. They used telescopes of all sizes, from fairly small 1-meter telescopes to the largest in the world -- the 10-meter telescopes at the Keck Observatory in Hawaii .

"Technologically, we had to be on the cutting edge to make this work, but the basic idea is very simple," he said.

They studied two of the brightest stars in M33, which are part of a binary system, meaning that the stars orbit each other. As seen from Earth, one star eclipses the other every five days.

They measured the mass of the stars, which told them how bright those stars would appear if they were nearby. But the stars actually appear dimmer because they are far away. The difference between the intrinsic brightness and the apparent brightness told them how far away the stars were -- in a single calculation.

To their surprise, the distance was 15 percent farther than they expected: about 3 million light-years away, instead of 2.6 million light-years as determined by the Hubble constant.

If this new distance measurement is correct, then the true value of the Hubble constant may be 15 percent smaller -- and the universe may be 15 percent bigger and older -- than previously thought.

"Our margin of error is now 6 percent, which is actually pretty good," Stanek said. Next, they may do the same calculation for another star system in M33, to reduce their error further, or they may look at the nearby Andromeda galaxy. The kind of binary systems they are looking for are relatively rare, he said, and getting all the necessary measurements to repeat the calculation would probably take at least another two years.

[Co-author info and funding sources omitted from original article.]


TOPICS: Culture/Society; Philosophy
KEYWORDS: astronomy; cosmology
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Like it says: "... the universe could be 15 percent bigger and 15 percent older than any previous calculations suggested."
1 posted on 08/03/2006 12:52:55 PM PDT by PatrickHenry
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To: VadeRetro; Junior; longshadow; RadioAstronomer; Doctor Stochastic; js1138; Shryke; RightWhale; ...
SciencePing
An elite subset of the Evolution list.
See the list's explanation at my freeper homepage.
Then FReepmail to be added or dropped.

2 posted on 08/03/2006 12:54:19 PM PDT by PatrickHenry (The Enlightenment gave us individual rights, free enterprise, and the theory of evolution.)
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To: PatrickHenry
Does Algore know about this Global Expansion?

I'm waiting on the edge of my seat to find out how mankind has caused it...

3 posted on 08/03/2006 12:54:44 PM PDT by C210N (Bush SPYED, Terrorists DIED!)
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To: PatrickHenry

You know why this is... its global warming causing the universe to expand and... I think this President's administration is behind it but no one was available to leak it to the NY Times yet....developing ;)


4 posted on 08/03/2006 12:56:27 PM PDT by getbillnow
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To: PatrickHenry


"... and Leon's getting larger!!"
5 posted on 08/03/2006 12:58:26 PM PDT by PackerBronco
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To: PatrickHenry

Interesting. Science changes as new information is found. What a novel idea....oh, wait, thus has it always been.


6 posted on 08/03/2006 12:59:30 PM PDT by MineralMan (non-evangelical atheist)
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To: PatrickHenry

In two years, the universe will be older still, and they will have to start over.


7 posted on 08/03/2006 1:00:50 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: KevinDavis

Ping


8 posted on 08/03/2006 1:01:46 PM PDT by raygun (Whenever I see U.N. blue helmets I feel like laughing and puking at the same time.)
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To: PatrickHenry

So if the universe expands, wouldn't that create universal cooling?


9 posted on 08/03/2006 1:02:58 PM PDT by Toby06 (True conservatives vote based on their values, not for parties.)
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To: PatrickHenry


Same thing happens with our state budget deficit every year.


10 posted on 08/03/2006 1:03:02 PM PDT by Fido969 (Don't tread on me.)
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To: PatrickHenry

I have a naive question : ) If by Universe they mean everything outside our Galaxy how could it possibly be defined by size? Are they only speaking of the portion of the Universe that we can either see or measure from Earth or by other means? I've always considered the universe to be infinite. Am I missing something?


11 posted on 08/03/2006 1:03:07 PM PDT by labowski ("The Dude Abideth")
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To: PatrickHenry
getting all the necessary measurements to repeat the calculation would probably take at least another two years.

Job security.
12 posted on 08/03/2006 1:05:34 PM PDT by UnbelievingScumOnTheOtherSide (Give Them Liberty Or Give Them Death! - IT'S ISLAM, STUPID! - Islam Delenda Est! - Rumble thee forth)
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To: betty boop; Alamo-Girl; cornelis
[ ASTRONOMERS CRUNCH NUMBERS, UNIVERSE GETS BIGGER ]

Bigger than what?...

13 posted on 08/03/2006 1:08:06 PM PDT by hosepipe (CAUTION: This propaganda is laced with hyperbole..)
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To: C210N

I'm waiting on the edge of my seat to find out how mankind has caused it...


Not mankind...only Americans!


14 posted on 08/03/2006 1:10:06 PM PDT by camofilly (The penalty good men pay for indifference to public affairs is to be ruled by evil men.)
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To: PatrickHenry
Gheez!

Of course it is! Even blondes know that!

Didn't they tell us that the universe is expanding?

Well, it probaby's been a coupla months since they last checked.

15 posted on 08/03/2006 1:10:38 PM PDT by Publius6961 (overwhelming force behaving underwhelmingly is a waste.)
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To: PatrickHenry

Very cool.

Thanks for posting this.


16 posted on 08/03/2006 1:12:10 PM PDT by Skooz (Chastity prays for me, piety sings...Modesty hides my thighs in her wings...)
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To: PatrickHenry

We're gonna' need a bigger boat.


17 posted on 08/03/2006 1:12:58 PM PDT by Dilbert56
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To: PatrickHenry

Science is an intellectual dead end. It's a lot of little guys in tweed suits cutting up frogs on foundation grants.


18 posted on 08/03/2006 1:14:45 PM PDT by MilesMonroe
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To: PatrickHenry
"... the universe could be 15 percent bigger and 15 percent older than any previous calculations suggested."

Yes, just plug new constants in the model whenever you have a problem.

If it could have been off that much, it could be off by 100% or 1000000% or whatever. The fact is, we don't know how big the universe is or even if it is infinite.

19 posted on 08/03/2006 1:14:57 PM PDT by robert jones
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To: Toby06

I think the boundary conditions need to be considered.


20 posted on 08/03/2006 1:14:58 PM PDT by doc30 (Democrats are to morals what and Etch-A-Sketch is to Art.)
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