Ultra-Dense Deuterium Produced 355
Omomyid was among several readers writing in about the production of microscopic amounts of ultra-dense deuterium by scientists at the University of Gothenberg, in Sweden. A cubic centimeter of the stuff would weigh 287 lbs. (130 kg). UDD is 100,000 times more dense than water, and a million times more dense than deuterium ice, which is a common fuel in laser-ignited fusion projects. The researchers say that, if (big if) the material can be produced in large quantities, it would vastly improve the chances of starting a fusion reaction, as the atoms are much closer together. Such a D-D fusion reaction would be cleaner than one involving highly radioactive tritium. Many outlets have picked up the same press release that Science Daily printed pretty much verbatim (as is their wont); there doesn't seem to be much else about this on the Web. Here's the home page of one of the researchers. The press release gives no hint as to how the UDD was produced. Reader wisebabo asks: "I can easily imagine a material being compressed by some heavy duty diamond anvil to reach this density, the question is: what happens when you let the pressure off? Will it expand (explosively one would presume) back to its original volume?"
Metallic Deuterium ? (Score:5, Interesting)
There has been a long search for metallic hydrogen [wikipedia.org], which is supposed to be (once made under high pressure) possibly both stable and superconducting [aps.org] at room temperature.
Given that metallic hydrogen is also supposed to be quite dense, I have to wonder if they haven't made metallic deuterium.
Ultra Dense Planet (Score:2, Interesting)
Wasn't there an article a while back about an exoplanet discovered that was so dense the astronomers couldn't even begin to speculate what it was made out of? This would seem to be an interesting candidate for an answer.
Really, stop and think about just how dense this stuff is. Fill a soda can with it and the can would weigh in at 35000 lbs! Even if all you did was burn it or use it in a fuel cell, the volume to energy ratio of this substance is amazing.
The Air Force (Score:2, Interesting)
Not involving tritium? (Score:3, Interesting)
Deuterium + Deuterium = Tritium + Proton (50%) or Helium 3 + Neutron (50%). Must be an unusual definition of "not involving".
Re:Ultra Dense Planet (Score:3, Interesting)
Re:It's also good for practical jokes (Score:3, Interesting)
Re:If they do make a cube... (Score:3, Interesting)
Muon catalysis? (Score:3, Interesting)
If they replace the electrons with muons [wikipedia.org] the nuclei will be much closer together, therefore the matter will be much denser. That's the only way I can imagine this could work.
Re:That's "dilithium" (Score:4, Interesting)
Uh. That was a joke, right?
Nope, he's serious. How many tree-grown products do you eat? I'm betting three or four types of fruit, at most.
Some vitamins do grow on trees, but the rest we need from other sources. Meat isn't easy to get in space, since food animals take up rather a lot of room. And isolated soil culture (what you've got aboard a spacecraft) may not have all the trace elements the plants need to draw upon to sustain us and our would-be food animals.
In a way, for long journeys where there's live and mobile crew to feed, it's almost easier to envision a completely synthetic diet. At least that only requires detailed understanding of our own biochemistry, plus the hypothetical technology to recycle waste indefinitely. Taking all the living things we need to survive with us requires understanding the dynamics of several different biochemistries, and how they all interact, which is no mean feat.
Re:That's "dilithium" (Score:3, Interesting)
I don't know that "most" is accurate, but yeah, people in general probably don't eat enough fruit.
Apricots.
The original commenter has finally responded, so I'll just point you to my response to him [slashdot.org]. Apparently there aren't any fruits which contain Vitamin D, but, regardless, his statement was that "vitamins don't grow on trees", not "some vitamins don't grow on trees".
Correction (Score:3, Interesting)
Running the calculation for our weight yields 101,000 ft/sec., or about 19.2 miles/second.
Except that the Earth's escape velocity (from the Earth's surface) is only 7 mi/sec, so it cannot fall faster than that (into Earth).