Why is deuterium so "rare" in Voyager (and Enterprise)?

Discussion in 'Trek Tech' started by Kieran, Aug 21, 2007.

  1. Kieran

    Kieran Commodore Commodore

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    Its just an isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6500 of hydrogen.

    Deuterium thus accounts for approximately 0.015% (on a weight basis, 0.030%)of all naturally occurring hydrogen in the oceans on Earth. Deuterium abundance on Jupiter is about 6 atoms in 10,000 (0.06% atom basis). There is little deuterium in the interior of the Sun, since thermonuclear reactions destroy it. However, it continues to persist in the outer solar atmosphere at roughly the same concentration as in Jupiter.

    On the other hand, antimatter seems so plentiful in all versions of Trek.

    The U.S. has been manufacturing antimatter for more than 30 years... and the sum total produced is a fraction of a gram.

    I understand why deuterium might have been a "rare" find in TOS era of science, but during the Voyager and Enterprise era, exactly what deuterium is, and its relative scarcity, was well known.

    Yep, I'm the first one to admit this is WAAAAY picky, but Trek writers, even back to TOS, were pretty sharp, all things considered.

    By and large, I just enjoy Trek... but I've always been curious about the "scarcity" of deuterium on modern Trek.

    Any thoughts?
     
  2. od0_ital

    od0_ital Admiral Admiral

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    Well, I'm thinkin' that this is a question better suited to the folks down in Trek Tech to tackle...
     
  3. toughlittleship

    toughlittleship Fleet Captain Fleet Captain

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    I remember the crew of Deep Space 9 and the Defiant using deuterium a few times.
     
  4. Timo

    Timo Admiral Admiral

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    It's not that deuterium would be rare as such. It's just that it's fuel. You expect to get it pre-concentrated, refined, ready to be pumped to your tanks. If you don't, you have to get fuel from elsewhere so that you can run your own refinery for getting the deuterium out of the seawater.

    To fill the tanks of the E-D from an ocean, you'd have to pump in something like 45 megatons of seawater and then filter out the desired isotope. Doable, no doubt, but more or less impractical. If your ship is short of fuel, it's probably better to use the remainder in an attempt to find a gas station than to expend it in an effort to get fuel out of the wilderness.

    Anyway, deuterium shortage was only an issue in a single VOY episode, "Demon". Elsewhere in that show and others, the ships sometimes ran out of their dilithium but never of their deuterium - supposedly because those ships never ventured far away from the network of gas stations (which every civilized species has) but sometimes did loiter far away from dilithium vendors (as dilithium indeed appears to be as rare as authentic car spares, and always has to be ordered from afar at top price).

    Mind you, if you already have deuterium, it's easy and cheap to get more: expend it in fusion, power up some artificial gravity plates with the energy, and the D2O is separated from the H2O in a jiffy, after which you can electrocute the results and extract the deuterium. But a fuel-starved ship lost in the Delta Quadrant would have major trouble even pumping in the required megatons of water, let alone filtering and zapping it into useful deuterium.

    Antimatter isn't exactly ubiquitous or easily accessible in the Trek universe, either. It doesn't occur naturally anywhere, and the best Federation trickery can convert deuterium to antideuterium at an efficiency of 1:10 if the TNG Tech Manual is to be believed. That is, if you expend nine units of deuterium in generating energy, this energy can convert the tenth unit into antideuterium in a fancy widget described on pp 71-72. That's a million times more efficient than the best we can do today, and obviously makes antimatter a viable method of storing energy in the Trek universe. But antimatter is still only that - a storage medium, not a mineable or cultivable "primary" energy source. Supposedly the Feds chiefly make antimatter out of solar energy, even though certain starships carry these onboard converters that make it out of artificial fusion energy.

    Timo Saloniemi
     
  5. Christopher

    Christopher Writer Admiral

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    Andre Bormanis's script for "Demon" had Voyager facing a critical shortage of dilithium. But Berman and/or Braga changed it arbitrarily to deuterium because they liked the joke of the ship "running out of gas." Unfortunately, they didn't change the rest of the script to make that credible in any way, and so you have the self-contradictory situation of an isotope of hydrogen being concentrated in the interior of an extremely hot non-Jovian planet, when in reality it would've all escaped to space long ago. Not to mention the conceit of "liquid deuterium" somehow existing on such a superhot planet, when liquid hydrogen can only exist in extreme cryogenic conditions.
     
  6. Cary L. Brown

    Cary L. Brown Rear Admiral

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    Your mostly right, Christopher, but you're misstating that last point.

    Hydrogen exists as a liquid... at "normal" levels of pressure... only at low temperatures, of course. Same with any other material which we think of as a gas. We call gases gases because they exist as a gas at the temperatures and pressures we can exist under. But any material can exist in any of the three phases (solid, liquid, gaseous... plus the fourth phase, plasma, which is basically ionically-dissociated gas)

    However, increase the pressure and hydrogen will exists as a liquid even at very high temperatures. Similarly, water exists as liquid at "normal atmospheric pressure" at 32F to 212F (or 0C to 100C). However, change the ambient pressure and that changes completely. Decrease pressure sufficiently and water boils at room temperature. Increase the pressure and water remains liquid up to many hundreds of degrees.

    So it's by no means unreasonable, scientifically, for you to have extremely hot liquid hydrogen... provided that the pressure is high enough (as you'd expect deep inside of a gas giant).

    The place where Trek, and in particular Voyager, fell down was more a matter of them not acknowledging the extreme pressures we'd be talking about in a way that was clear to the audience. I agree that the show handled this wrong, but just wanted to clarify that point for anyone who might misinterpret the science behind it.
     
  7. Timo

    Timo Admiral Admiral

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    Wasn't it the very point in "Demon" that our heroes discovered things that went against expectations, and couldn't exist without the influence of novel, perhaps intelligent forces?

    They said they went looking for concentrated deuterium. They said their sensors showed some on (or rather, under) that planet. All good and well: geological forces could plausibly "refine" gaseous deuterium for them. When they found out the deuterium was in 12K liquid pools, though, this surprised them mightily. Nothing wrong with that sort of science - as long as it's part of a science fiction plot.

    We can't be quite sure if the deuterium pools were for real. The fake Tom and Harry did deliver some refined deuterium, but it might not have been extracted from any pools. Rather, the pools could have been faked as bait for passing starships, allowing the lifeforms to do their thing and start impersonating the visitors.

    Timo Saloniemi
     
  8. Trekker4747

    Trekker4747 Boldly going... Premium Member

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    Frankly. Those behind the scenes of Voyager where idiots and didn't care to make Voyagers technology credible in the Trek universe, let alone ours. IIRC Voyager's computer capacity was like a million fold times bigger than the Enterprise-D's which just isn't credible. They attatched "giga" infront o 'quad' just to make it sound "kewlyfuturistic" rather than consider what it really meant in terms of treknology.

    Deuterium is abundant as said above you can jump into an ocean and find it. Voyager certainly would've had the ability to scan it, find an ice planet or an ocean and beamed the stuff up by the tons.

    But Voyager's wrtiers didn't care as Christopher said, apparently, Bermaga thought it was "funny" to have the idea of Voyager "running out of gas" so they said deuterium instead of dilithium without even considering what it meant.

    Hell, I think in an episode of Enterprise we even were shown a planet where people where MINING deuterium as if it was a fossil fuel or something. Didn't. Care. And is an earmark in the great book of the downfall of Trek.
     
  9. Cary L. Brown

    Cary L. Brown Rear Admiral

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    Yep. And that's why I keep being so pedantic about what is, and isn't, "real science" even in this forum. You can IGNORE science, but to put out BAD SCIENCE is always a problem and always needs to be addressed. ;)
    Yep, that was one of a great multitude of the "who cares about believability, Star Trek is OURS AND WE CAN DO WHATEVER WE WANT... BWAAAAAHAHAHAHAHAHA!!!" attitude that Berman had (but tried to pretend he didn't), and that Braga had, and was apparently PROUD of (from things I've seen him having said, in public situations).

    Once the people making a show stop respecting their audience, and stop respecting the show themselves, you either end up with failure or a farse. Farses are fine ("Robin Hood - Men in Tights" is a personal favorite of mine in the genre), but basically, under B&B, certainly in the latter years, trek became more farse than drama or adventure. Because they simply didn't CARE.

    Despite all of the negatives that can be said about Mr. Roddenberry and his latter-years weirdness, and his tendency to rob anyone else of credit, one thing that NOBODY can say is that he ever stopped CARING about Star Trek. I always describe him as having been Trek's "domineering mother figure." He may have abused the child, and may have been insanely jealous about keeping other people from having any influence over his child, but even when he did the wrong thing he had the right motives... the well-being of the child (as he saw it). Berman et. al, simply never seemed to have that level of personal attachment... they didn't care. And it showed.

    The idea situation for a Trek production would be to have one person in charge of everything, who only cares about the long-term bottom line (executive producer), plus a permanent line-staff (producers, art director, etc) who are dedicated to making everything be consistent, logical, and FACTUALLY ACCURATE, but with the writers and directors and so forth having NO prior "trek" connections.

    Essentially, set up a situation of conflict... the writers and directors want to tell the best story the can, but they won't care... AT ALL... about what a dilithium crystal is or what "warp factors" are. The permanent production group, who would be equally powerful, would not be concerned with the storytelling, but would have the responsibility of making sure that it remains both fictionally and REALITY-WISE reasonable and practical and consistent.

    These two forces should be literally at-odds... there should be revisions going back and forth, arguments, the whole deal. And when they can't work things out among themselves, that's when the Executive producer makes the judgement call based upon what's in the best long-term financial interest of the show.

    Berman, at least originally, filled that sort of role. Unfortunately, he eventually came to think of the show as HIS (which is probably inevitable) even though he never came to LOVE it like I'm talking about. And with having a "writing staff" and a "directing staff" rather than bringing in the best and the brightest for short-term "tours of duty" or even single episodes, the entire creative staff became stagnant and ... well, "inbred."

    It's inevitable, I think, with any series if you don't really shake things up and have conflicting positions among the production staff.
     
  10. Trekker4747

    Trekker4747 Boldly going... Premium Member

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    I think you really nailed it.

    Bermaga didn't care they weren't doing the show for love or for any "vision of the future" or creative or dramatic showmanship it was just a job for them, a worse than that a job that was just there to be a check/until I get a "real job" it was the Summertime McJob you had to just pass the time and pay the bills.

    Roddenberry had a love for this, in watching the TNG DVD special features people who delt with Gene talked about how he explained to them what the deflector dish/shields where and how they where different from the defensive shields. Gene LOVED the show, his stories, and KNEW what it all meant.

    Bermaga where just like ehh... tetraquads! And mined deuterium!
     
  11. Ronald Held

    Ronald Held Rear Admiral Rear Admiral

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    It is unbeleivable that a ST ship in interplanetary or interstellar space would run out of deuterium, short or being so energy starved as not to be able to collect and refine it.
    As an aside you can use ordinary Hydrogen and Tritium in fusion reactor, as well as Deuterium.
     
  12. Jimmy_C

    Jimmy_C Fleet Captain Fleet Captain

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    I retroconned that the planet which was "mining deuterium" actually just used some unique underground structure and geothermal energy to separate the isotopes of hydrogen that they collected from the star or gas planets around the system.
     
  13. Captain Robert April

    Captain Robert April Vice Admiral Admiral

    We're talking about the same folks who didn't realize that Rigel is a real star and has been known about for centuries.

    Braga may be a good scriptwriter, but he's a scientific moron. And as Issac Asimov said many moons ago...

     
  14. Ronald Held

    Ronald Held Rear Admiral Rear Admiral

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    Very good, Captain!
     
  15. Nebusj

    Nebusj Rear Admiral Rear Admiral

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    Except that in real physics, there's the ``critical point'', the combination of pressure and temperature at which there's no longer a difference between the liquid and gaseous states; it all becomes a gas.

    For hydrogen (and I'm not sure whether this is hydrogen-1, or whether it's a normal mix of normal hydrogen with deuterium; I'd be surprised if there were a substantial difference) the critical point is about 33 degrees Kelvin and about 13 atmospheres of pressure. Above 33 Kelvin, you can't get liquid hydrogen.
     
  16. Deks

    Deks Rear Admiral Rear Admiral

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    If I remember correctly, in 'Void' episode of Season 7, Paris mentioned how deuterium can be found basically anywhere so it would be pointless to steal it (only the Void contained none).

    It is conceivable that in episode 'Demon' the writers wanted to portray Voyager's issue with fuel on such a long journey and that at least those parts of space were not exactly abundant in deuterium deposits ... at least nothing that can be used by Voyagers crew.

    Later on though, the ship didn't experience such issues anymore ... presumably due to the adaptation from the crew to gather necessary supplies in a more efficient manner, plus developing techniques that weren't as taxing on their power/fuel reserves anymore.
     
  17. Cary L. Brown

    Cary L. Brown Rear Admiral

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    You're essentially correct but I think you're "dumbing it down" a little too much... your comment is that it "all becomes a gas." Obviously you "get" this, so I'm assuming you're trying to simplify things for "general audiences," right?

    But the truth is, it's not accurate to say that it becomes a gas under those conditions. In fact, it's probably more accurate to say it's a slightly compressible liquid than it is to say it's a gas. If you want to be accurate, though, the term is "supercritical fluid." (I know that you know this, I'm talking to the "general audiences" right now.) Anybody interested in a "cliffs' notes primer" on supercritical fluids can check this out... it's reasonably accurate. http://en.wikipedia.org/wiki/Supercritical_fluid

    I tend to think of this sort of material more as a liquid, because it has density and viscosity characteristics which are liquid-like, but unlike "true" liquids, it is compressible. Of course, if you place it under sufficient pressure, the compressibility curve levels off and it really is, for all practical purposes, a liquid.

    So, if we want to be "hardcore technically accurate," neither of us was really correct in terms of what we were saying. It's NOT "all a gas" like you said, but it's also not "really" a liquid at any temperature above 33K because it does have compressible characteristics, something that "true liquids" don't have.

    A side note... I was looking for a chart or graph I could stick into this post. I didn't find any that I could use without "hotlinking" to someone else's site... oh well. But I did find a VERY interesting article... something I had never heard about 'til just this morning.

    I've known for some time that certain forms of liquid helium were "superfluids." Nobody's ENTIRELY certain just what superfluids are, though the theory is pretty well-developed. And as it turns out, it appears that a particular "spin configuration" if diatomic hydrogen can behave as a superfluid as well. (Just to clarify... a "superfluid" is unrelated to a "supercritical fluid" as I'm talking about it here.)

    Superfluids are pretty cool... what they are is fluids which have absolutely ZERO viscosity. They are, effectively, the perfect lubricants... having incompressible characteristics (or, in the case of liquid hydrogen... "nearly incompressible" since it's technically a supercritical fluid and not a liquid at the temperatures we're talking about) but having what is essentially zero fluid drag characteristics.

    The theory is that these develop strong repulsive magnetic fields between adjacent molecules (again, the "general audiences" explanation). Kind of like the difference between a regular train rolling on tracks and a "mag-lev" train.

    I wonder if there's a relationship between the extraordinarily low range for "supercritical fluid transition" for these materials and their ability to become "superfluids?"