2010-01-22

Intriguing

http://amasci.com/weird/unusual/e-wall.html

Star Trek forcefields are described as electrostatic . . . but I must say, this one sounds cooler.

2010-01-21

Star Destroyer Mass and Density Guesstimate

While working on an old unfinished page I'd forgotten about, I realized that I really needed a decent estimate of Star Destroyer mass.   Despite not having much to really go on, I decided to make a guesstimate.  

Unless and until we get more information, it's as good as anything else:

So, let us assume that a Star Destroyer is 1600 meters in length.   Now we need an estimate of their density.   We have options here.

1.  We can attempt to use the density of Star Trek vessels.   Star Trek vessels like the Intrepid Class, for instance, have a density of over 1100 kg/m³.  However, we know that the vessels are constructed of different materials and so on, so this is a somewhat dangerous assumption.  There's also the fact that the Constitution Class ships had a far higher density of over 4300 kg/m³.   However, given that the Intrepid can land as most Star Destroyer classes seem able to, the Intrepid density seems the safer (albeit still dangerous) assumption.

2.  We can attempt to use the density of real-world spacecraft.   This is also dangerous, of course, since real-world spacecraft are hardly military vessels.  They are designed to allow people to get to space for a brief period of time, but can hardly be expected to withstand even a single hostile bullet or other decent-velocity impact.

Now, it happens that when Star Trek guru Rick Sternbach was designing the Intrepid Class for Star Trek: Voyager, he intentionally based their stated mass off of an estimate of the ship's volume, calculating the mass via a density derived from an estimate of the Apollo capsule command module.  And indeed, the Intrepid density is within about 10-20% of that value, assuming the Intrepid model used on this site for the estimate is basically the same as his.   However, the command module was basically just the crew compartment and heat shield for re-entry, a single part of the combined Command/Service Module (CSM), with the service module featuring the large engine bell and other machinery that enabled Earth-Moon transit.

Taking that combined vehicle which masses 30 tonnes and ballparking her volume based on her 4m diameter and 8m length (she's actually 11 meters, but between the rear engine bell and conical front section a 'shave' is not out of order for determining ballpark density), the CSM volume is 100m³ and her density is thus 298kg/m³.

That seems a bit light, so we can also compare to the space shuttle orbiter.  Empty, a newer shuttle like Endeavour weighs about 70 tonnes, and she's about 105 tonnes when full.   At about 37.25m long, 23.75m wide, and 17.25 meters tall, she's a big girl.   Determining her density is a little bit of a trick, though, since much of her total empty mass . . . not to mention her width and height . . . is nothing more than wing surfaces.   But since we're ballparking, we can simply take the fuselage as a cylinder and tack on a couple of extra meters for the eyeballed volume of the various atmospheric control surfaces.

So, per estimation from this site, we have the total length of 37.25 meters.   A smidgen of that is the vertical stablizer (the tail fin), but we'll just roll with that figure.  Given that the shuttle fuselage is roughly cylindrical, the height and width values of about 6 meters are sufficient for diameter (the crew area and payload bay are below six meters, the rear fuselage with the engines is over six).   So if we ballpark a 40x6 cylinder, we come up with a total volume of 1130m³.  Given her empty and full masses, the density ranges between 62 and 93kg/m³.

Well, now.   It seems that Rick Sternbach's choice was rather on the heavy side, after all.  The space shuttle tops out at around 100kg/m³, the Apollo CSM 300kg/m³, and the Apollo command module with heat shield by itself is near 1000kg/m³.  And yet the Constitution Class still came in four times more dense than that, and about 40 times denser than the space shuttle!

So where should we attempt to put the Star Destroyers?   Considering that large warships of the Clone Wars era seem to be largely hollow (e.g. the Venators with their extensive landing bay areas, the Malevolence with its massive open center railway areas, and so on), I hardly feel comfortable comparing it to an Intrepid Class ship that has very little empty space by comparison.

On the other hand, given the extensive use of simple steel even for external towers on the Death Star (per the ANH novelization), Coruscant buildings, and similar, it seems unlikely that durasteel or steelcrete will be superdense.   After all, given that a natural stone on Yavin was so dense that no weapon was thought capable of penetrating it, we could be forgiven in believing that Star Wars ships are built strong but as light as possible.

That said, I figure Star Destroyer density probably falls somewhere in the 500-1000kg/m³ range.

Given a calculated volume of about 54,000,000m³ for Star Destroyers at 1600m length, and a density range of 500-1000kg/m³, the mass of a Star Destroyer should fall somewhere between 27,000,000,000 and 54,000,000,000 kilograms.   That's 27 to 54 million metric tonnes.  

If one wants a specific estimate, I'd guess a density of 750kg/m³ and an ISD mass of 40,000,000 tonnes.

Using this density figure elsewhere would give us the following masses:

VesselMass in KilogramsMass in Tonnes (est.)
DS1 (@120km):678525000000000000680 trillion
DS2 (@160km):16080000000000000001.6 quadrillion
Super SD:94844250000009.5 billion
Home One:253978500000250 million
Trade Fed:15208125000001.5 billion
Nebulon-B:138729000140,000
Tantive IV:4856400050,000
X-Wing:2025020
TIE:1125011
Imp. Shuttle:357750360
Millennium Falcon:29377503000

Actual figures could vary significantly, of course, and my rounding above was somewhat haphazard.   I would say that this is especially the case with smaller vessels, but interestingly the X-Wing mass is almost identical to the empty mass of an F-14 Tomcat.  Once missiles and fuel are added, though, an F-14 can mass 33 tonnes.

Also, I don't have volume figures for the Venator or Acclamator.  I'd guesstimate the former at 15 million tonnes and the latter around 8-10, but I really have no clue as to the proper value.  This is just a complete pulled-from-the-posterior guess from memory.

Neuranium in Star Wars

During the Clone Wars, a forged metal called neuranium is, at more than a millimeter's thickness, "impervious to sensors", and standard security scans for items coming into the Republic Senate do not include any sort of gravimetric detection for determining mass-related oddities.  As a result, a neuranium statue made it into the Senate building while secretly containing a weapon.

That's from the RotS novelization.  Considering that no more than a millimeter is required, one wonders why this substance isn't used a bit more often.

2010-01-14

Ferengi First Contact

It's been bothering me for a long while that the Ferengi were such an unknown to Starfleet circa 2364.  Even before Enterprise showed a couple of Ferengi pirates encountering an Earth ship and Ferengi (maybe the same pirates) making contact with Valakians in the 2150's, it didn't make much sense to me.

The Ferengi are traders, first and foremost, and the economy of Ferenginar features markets but seems to be based on a somewhat mercantilist philosophy.   Prior to first contact, Data described them as Yankee Traders in the sense of "the worst quality of capitalists", referring to the principle that the buyer should beware.   In other words, he was associating Yankee Traders with hucksters and shysters.  Hucksters are capitalists only in the grossest possible sense.

At any rate, however, the Ferengi economic system . . . whatever the particulars . . . would seem to be one which favors policies opening up trade.  The Ferengi were, if anything, too interested in opening up trade with the Dominion, for instance.

So the question remains as to why the Ferengi would've been a mystery to the Federation in 2364, despite many years of contact with other nearby powers (like the Cardassians), and despite individuals of their species being well-travelled (as seen by the 2150's Enterprise example, not to mention a Ferengi being assimilated by the Borg circa 1925).   After all, if we're going to compare with Americans, we can't forget Commodore Matthew Perry's "Black Ships" excursion to 'force open' trade with Japan.  The Ferengi ought to have been chomping at the bit to get their sharpened teeth into the succulent Federation trade routes. 

But instead, so far as we know, they were in virtual hiding.  Individual Ferengi were on the very border of the Federation around that time (Quark's bar on Terek Nor in orbit of Bajor supposedly dates from 2363), but the Federation only caught up with them because a Ferengi Marauder was unlucky enough to steal from a Federation outpost that happened to have Picard's Enterprise nearby.  (It's possible that this theft was the form of first contact the Ferengi were going for, i.e. that they were intentionally caught, but that's neither here nor there right now.  Even by this time they'd had at least a couple of decades to make contact, if not more.)

The fact that the Ferengi were so insular in regards to the Federation is perplexing, until one adds in another factor.

The Federation is commonly said to be communist.  It isn't, since communism and capitalism are scarcity-based economic models where scarce raw materials get value added by processing or manufacturing into other useful objects.  The Federation seems based more on a post-scarcity model (though raw materials are still needed of course), and the presence of replicators defeats the concept of value addition by process or manufacture.  When an object's value is not based on its intricacy and the labor to
create it but instead merely on its raw materials or energy content . .
. when an iPod and a cigarette lighter cost the same . . . modern
economics (whether collectivist or capitalist) is turned on its ear.

I would submit that the Ferengi Alliance knew about the Federation and were scared to death of it.   The fact that they knew of the Federation is shown by the statements of the Ferengi landing party during first contact on Delphi Ardu, suggesting some knowledge of Federation policy and disgust with it.   Unlike the Cardassians or other powers they had likely encountered, the Ferengi knew that the Federation's open, egalitarian society and particular economic model presented an existential threat to not only the Ferengi economy, but -- given how tied in their society and economics were, even to the point of religion -- the Federation was an existential threat to the Ferengi way of life.

So, the Ferengi economy might've managed to weather the introduction of replicators and so on, persevering by sheer will despite the obvious implications, and managing to find niche markets.  For instance, whereas something like modern Coca-Cola could be easily replicated, Ferengi Slug-o-Cola features live algae, and thus could not be replicated.  Similarly, latinum cannot be replicated, and when 'pressed' in with gold makes a scarce item useful as a currency.  (Though it seems that latinum was their currency well before replication was discovered . . . might've simply been a nice happenstance.)    Quark's Marauder Mo action figures might've had some sort of anti-replication technique employed.  Those with replicators might've managed to perform some sort of licensing fee for replication of particular objects, though enforcement of this seems complicated. 

There are, in other words, ways for the Ferengi to adapt, but they become increasingly absurd.   And the the closed and militaristic Cardassian Union or other lesser nearby powers, might not've been as big a blow to Ferengi absurdity as the open and charitable Federation.  Hence the existential threat.

And frankly, given what happened to the Ferengi over the course of the TNG era, I'd say that those Ferengi who might've viewed the Federation as an existential threat were right.   Rights for women, Nog as Nagus . . . the fact is, first contact with Starfleet was the death knell of Ferengi society as it existed in 2363.