Keeping the blogosphere posted on the goings on of the world of submarines since late 2004... and mocking and belittling general foolishness wherever it may be found. Idaho's first and foremost submarine blog. (If you don't like something on this blog, please E-mail me; don't call me at home.)

Wednesday, February 23, 2005

'Dark Matter' Galaxy Found

OK, this isn't sub-related, but I think this stuff is really cool. I expect A. E. Brain will have a more substantive post on this later, but this Yahoo report on a possible 'dark matter' galaxy is really fascinating. An excerpt:

"Theorists have long said most of the universe is made of dark matter. Its presence is required to explain the extra gravitational force that is observed to hold regular galaxies together and that also binds large clusters of galaxies.
Theorists also believe knots of dark matter were
integral to the formation of the first stars and galaxies. In the early universe, dark matter condensed like water droplets on a spider web, the thinking goes. Regular matter -- mostly hydrogen gas -- was gravitationally attracted to a dark matter knot, and when the density became great enough, a star would form, marking the birth of a galaxy.
The theory suggests that pockets of pure dark matter ought to remain sprinkled across the cosmos. In 2001, a team led by Neil Trentham of the University of Cambridge
predicted the presence of entire dark galaxies."

I've been fascinated by the fast pace of potenial breakthoughs in physics for the last couple of years, particularly with "superstring" or "M-theory" that has a chance of unifying quantum mechanics and general relativity. If you ever get a chance to see the NOVA special "The Elegant Universe" I would urge you to do so, or even read Brian Greene's books. (I'm re-reading The Fabric of the Cosmos now...) To me, it all just makes sense; the universe ought to operate by consistent laws, and having all matter and energy have the same basic form, varying only by it's vibrational energy, is all very elegant; after all, as a nuke I know that mass and energy are easily converted between each other...

Going deep...

Update 0941 24 Feb: I was right! Continuing on with my thoughts on the "new cosmology" that's been discussed in the last few years, especially inflationary expansion. I always wondered how, if everything is limited to the speed of light, how we could be seeing objects 13 billion light years away if our galaxy were not moving at at least half the speed of light (which we clearly are not) -- as we would have had to be to get that far from another object in the 13.7 billion years since the Big Bang. The proposed answer now is that space itself expanded rapidly very soon after the Big Bang; there's no limit on how fast space can expand, and light still moves at the same speed through the space in which it exists; it's just that that space has gotten relatively bigger. Now, we're finding out that the universe is actually increasing in its rate of expansion, meaning that there's some kind of "anti-gravity" at work at trans-galactic distances; many scientists postulate that this is due to as yet undiscovered "dark energy" that they theorize makes up more than 70% of the total energy in the universe. Anyway, it's fascinating to me...


Blogger ninme said...

What a dumb article. There's no pictures.

2/23/2005 6:54 PM

Blogger Bubblehead said...

You know, it took me a few seconds to catch on to your comment, there...

2/23/2005 7:50 PM

Anonymous Anonymous said...

John McCain, as Secretary of Defense will do more of what he has been doing since 1988... ...minimize submarine force funding. He loves the Libs because they heap self-serving
praise on him. He feigns support for Bush because of his Keating 5 culpability (the singular Republican)
Any thoughts on this building
stupidity? The Old Hand

2/23/2005 7:51 PM

Blogger Andy said...

The reason for the fast pace in physics breakthroughs is due to the governments introduction of alien technologies into our nations R&D efforts....

God i love alien conspiracy theories.*grin*

2/23/2005 10:36 PM

Blogger Bubblehead said...

I always figured Einstein was an alien myself, or at least a time traveler; now, with all of these 11-dimensional models they're coming up with, I figure it either is aliens or much better pharmaceuticals...

2/24/2005 5:02 AM

Anonymous Former NavET said...

Bubblehead, ever thought of commenting on China's recent Nuke ambitions? Check out their progress on Pebble Bed reactors. or

Former NavET

2/24/2005 9:55 AM

Blogger Bubblehead said...

To be honest, I've always been kind of an optimist with respect to U.S.-China relations in the short term (21st century); the men running China are nothing if not realists to whom "the long term" means a couple of hundred years, not 15 years like it is for us. I think they recognize that they have more to gain by splitting up the East Asia/Pacific sphere of influence with the U.S., Japan, and Australia rather than fighting for it, and hope that the U.S. collapses economically and/or morally so they can pick up the pieces. Regarding the reactors, I think that pebble bed is the wave of the future, and I'm glad someone is doing it, since I think it would still be politically impossible to build a new commercial reactor of any type in the U.S. for probably the next 20 years (or until oil hits $100/bbl).

2/24/2005 12:25 PM

Blogger ninme said...

But how can China get many pebble-bed reactors, when the primary thermal exchange medium is helium, which is an element with a finite supply and only two known natural sources at the planet? At some point, won't market forces intervene, making helium recognized as the strategic element it is? Wouldn't it be easier, given the unlikelihood of the Chinese finding a helium deposit, for them to just drill deeper for more oil?

2/24/2005 2:00 PM

Blogger ninme said...

What, no one wants to know how I woke up this morning an expert on nuclear power plants?

2/24/2005 5:51 PM

Blogger Bubblehead said...

Ninme, I was actually just trying to research your question to come up with an acceptable answer. While He gas is indeed the moderator/coolant of choice (due to it's relatively low atomic weight and chemical unreactivity) I think that since any Helium used would be recycled, so the actual amount required might be relatively low. Additionally, Helium is basically an alpha particle; they could collect the alpha radiation from a big pile of uranium, add electrons, and voila! Instant Helium! (I know this doesn't make actual technical sense due to the amount of Uranium, which has a 4.5 billion year half life, you'd need to make a usable amount of gas, but it almost sounds plausible, and I couldn't let Ninme thing she'd stumped me...)

2/24/2005 6:16 PM

Blogger ninme said...

Yes, but no one is saying whether helium would form radioactive helium isotopes the way water in similar situations forms radioactive hydrogen isotopes when in the presence of radioactivity. Helium is relatively stable, but what about under long-term neutron bombardment? And helium can leak through much tinier pores than water vapor can.

2/24/2005 6:52 PM

Blogger Bubblehead said...

The microscopic cross section for neutron absorption of Helium is essentially negigible; and, since He-5 decays to He-4 in a few femtoseconds, this wouldn't be a concern. The porosity of standard containment vessels would be a bigger concern; helium is even more leakable than hydrogen gas, since it is monatomic rather than diatomic.

2/24/2005 8:14 PM

Blogger ninme said...

Which is my point. You couldn't simply recycle the helium ad nauseam, you'd have to pony up for more, which would make the savings versus oil negligible.

2/24/2005 9:49 PM

Blogger Zoe Brain said...

When in doubt, look at the numbers.

Let's assume that a pebble power plant requires helium equal to a cube 100 metres on a side. That's 1 million cubic metres. I suspect that's a slight over-estimate, but is probably OK within an order of magnitude.

Further, assume that it all leaks away in the course of a year. This I'm sure is a gross over-estimation, with 10% being a more likely figure, and possibly less than 1%.

Even further, let's assume that we build one plant per year for the next 100 years, so there's more pebble plants operational than all current commercial plants put together.

In 100 years, we'd need 100 million cu metres per year.

Current US production capacity is 152 million cubic metres per year ( source)

Unless there's a new Renaissance in Zeppelins, or a millionfold increase in deep sea diving using trimix (O2,N2,He), I don't think we'll need to build new plants - there's already more He production capacity than we can use.

Summary : it's not a problem.

2/25/2005 3:08 AM

Anonymous Former Navet said...

Upcoming helium shortage reported by the UN (see link)

Thats a lot of Kids birthday party balloons. ;-)

Former NavET

2/25/2005 8:52 AM

Blogger ninme said...

Alright, he's here, I fold. I knew it was only a matter of time. I can't pretend to be smarter than Alan.

Well, Hong Kong has endorsed a three child policy to battle falling birth rates, and Europe needs to ah, increase production. But Asia and Africa are going to need to put the brakes on the baby makers, if China wants 1000 reactors to bloom. Either that or start bombing florists and party supply stores across the globe.

2/25/2005 12:49 PM

Blogger Bubblehead said...

I was glad he showed up; I was running out of plausible-sounding answers...

2/25/2005 1:57 PM

Blogger ninme said...

Darnit, I was enjoying my notoriety. Stumping a nuclear engineer.. Oh well, I knew it couldn't last.

2/25/2005 3:03 PM

Blogger Zoe Brain said...

But...but... but... all I did was do a few sums, and a bit of Googling.

Look, I have a very high opinion of myself (but you knew that). My ego's so big it goes through the doorway at least half an hour before I do.

But I didn't get to be a Rocket Scientist by pretending that there wasn't a heck of a lot I know nothing about, nor that there weren't vast numbers of people smarter than me.

I do a lot of listening, and a lot of reading.

Please don't puncture my balloon by cutting off the sources I plagiarise from - er, make that "research from".

Besides which, ninme's original post was dry wit at its finest, something I could never equal.

Also please have some consideration : like many certifiable, no, certified geniusses (legends in their own mind), I have more tha a touch of Asperger's. So please insert <sarcasm> tags next time, huh?

2/26/2005 7:52 AM

Blogger ninme said...

Oh Alan, you're too modest. You're going to have to accept that you're the smartest one in the room.

Is asperger's that form of autism? We were talking about it today, because it occurs so frequently here in the silicon valley because of all the computer geeks getting together and procreating.

And no one's asked me yet how I woke up an expert on nuclear power. I was a design and merchandising major, for heaven's sakes!

And I'm glad Alan thought my first comment was funny. I thought it was hilARious, and was hoping I wasn't the only one laughing.

2/26/2005 10:40 PM

Anonymous Anonymous said...

I betcha there are *lots* of slightly aspie types in Navies these days, especially in the nerdy rates like Nukes and Sonar.

3/04/2005 5:13 PM


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