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Old 8th February 2007, 06:22 PM   #32
maccy
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Join Date: Oct 2006
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Originally Posted by jhunter1163 View Post
IIRC, R.Mackey did some calculations and came up with figures for the amount of energy that would be needed to power such a weapon. This exceeded the power available from various sources (he listed them) by a factor of a million or so.

R. Mackey is my hero. I wonder if he could hook me up with Lisa Nowak.

ETA: For Christ's sake, I'm kidding about the Nowak thing.
This is the post:

Originally Posted by R.Mackey View Post
A mathematician will be quick to point out that any arbitrary surface can be described by a collection of "circles" ("balls," we used to call them) of arbitrary diameter. Unless you can find a single size that fits perfectly, which you can't, you've proven nothing that geometrists haven't known for centuries.

Anyway -- seems we're still thinking about those pesky beam weapons, despite having shown you much less sinister mechanisms that provide the same "round holes," and are in fact completely consistent with the expected building performance. We've also shown you how your Star Wars weapon actually doesn't fit the "evidence" that you (and only you) see.

Still, elsewhere, you've insisted that we treat this as a valid hypothesis. It must be tested, you say.

The test is simple: Do beam weapons of this magnitude exist? No.

Still doubting, eh?

In that case, class, pull up a chair. Today we're going to design our own WTC Killing Beam Weapon of Doom to see just what one would look like. While the beam emitter itself could plausibly be a "black" project, something the Governmint doesn't want us to see, it would be dependent on much more mundane technologies -- launch vehicles, power systems, that kind of thing -- and still restrained by the laws of physics. While we may not know anything about the weapon itself, we can figure out the rest.

So suppose an unsmiling man in a grey suit delivers a magical beam weapon to us, and insists we make it functional. All we know are its requirements. Some of these we can divine from what we saw on Sept. 11th.

1. Orbit

The beam weapon must fire from almost directly above its target, and must do so unseen. If it fired at an angle, the beam -- allegedly capable of destroying the WTC towers -- would have cut through at an angle, leaving a quite interesting damage path, one that was not seen on TV. Likewise, TV cameras did not capture any blimps or dirigibles or large aircraft hovering high above the Towers. Thus, we assume the beam system was orbital.

There are basically two choices for an orbital system: LEO (Low Earth Orbit) and GEO (Geosynchronous) or similar orbits. Both of these orbits have problems.

Recall that not one tower was destroyed, but two. The South Tower fell at 9:59 AM, and the North Tower fell at 10:28. In LEO, the orbital period is a function of altitude, and the spacecraft orbits faster as it gets lower. However, the minimum usable orbit is about 90 minutes long. If the two different firings suggested happened on successive orbits, i.e. 29 minutes apart, the spacecraft altitude would have been below sea level. This is impossible.

If the two firings occurred on the same orbit, we now require a much, much higher orbit. A true GEO orbit won't work either, since you only remain geostationary above the equator, otherwise the spacecraft will appear to oscillate north and south while retaining the same longitude. We need a firing angle that is just about straight down and stays that way for 30 minutes, or 1/48th of an orbit. A GEO track would move by a minimum of 7.5% of peak latitude, or over 1.6o of latitude, which may be unacceptable. So we would need to be much, much higher than GEO.

The high-orbit situation is also impractical for two military reasons. First, high orbits require much larger rockets. Second, it severely limits your options, since it could take hours, days, or even forever to orient this beam on a particular target.

The only practical solution, then, is to have two beam weapon satellites. We will assume these are orbiting in the cheapest orbit possible, i.e. LEO.

2. Beam Energy

The beam must be capable of delivering a WTC-finishing blow in roughly 10 seconds. How much energy are we talking about?

To make this exercise remotely plausible, we will consider a firing energy much lower than the tower destruction itself. For sake of argument, suppose the beam delivers 6.0 x 109 Joules of energy -- a number chosen because it is twice that of the aircraft impact kinetic energy, as calculated in Greening (pg. 10). This is an arbitrary choice but clearly a beam energy higher than the impacts is needed, since the impacts alone finished off neither structure.

We further assume that the beam weapon is 50% efficient, an "ideal" figure (cutting-edge lasers built for efficiency are typically around 16% efficient). This means a total of 1.2 x 1010 Joules of energy must be supplied by the spacecraft, over a period of 10 seconds, or 1.2 x 109 Watts of power. That is the design requirement of our black-box beam weapon.

It should be pointed out that we have neglected many efficiency-robbing problems to arrive at this figure -- attenuation by the atmosphere, for instance, and beam absorption or reflection by the target are both major concerns. In practice I would not be surprised to see an effective beam efficiency as low as 5% under ideal conditions.

3. Energy Storage

As this power figure is roughly equivalent to the output of a commercial nuclear power plant, it is clear that our WKBWD satellite cannot provide this continuously, but must store the energy. This poses a big problem.

The most obvious solution is battery power. The highest energy density rechargeable batteries currently envisioned (and these have not been qualified for space) can supply about 1 MJ / kg of battery mass. To supply the 1.2 x 1010 Joules we require, this means 12,000 kg of battery.

But this figure cannot be trusted. Recall that we require a full discharge in only ten seconds. Batteries don't like this. They heat up, which increases their internal resistance and robs power, and chemical pathways become blocked, making much of its storage unavailable. Given this requirement, our battery size would need to be much larger -- Lithium ion batteries over 20 second peak load are limited to a mere 1500 W/kg. Since our beam requires 1.2 x 109 Watts, we would actually need 8,000 tons of battery.

So batteries are out. What about capacitors? If we assume a spacecraft bus voltage of 1000 Volts (which is unacceptably high for space applications, as arcing would probably destroy our satellite), to reach our total energy requirement, E = 0.5 C V2, thus capacitance C = 24,000 Farads. This can be done with, say, ten tons of capacitors, however the leakage will be much higher -- rather than charging batteries over periods of weeks, the capacitors will require a much more rapid charge cycle, and any weight saved in the capacitors themselves will be lost to solar arrays and thermal management.

The very last possibility is the extreme explosive compression flux generator, basically a one-shot motor that uses explosives to push a magnet and a coil. This is similarly "black" and exciting to Conspiracy Theorists, but not practical here either. While this little gadget can crank out a reported 1012 Watts, it only does so for a few microseconds. To sustain our ten-second beam, we would need about a million small copies of this, and they would have to somehow be shielded from each other. Alternatively, if we convinced the beam weapon designers to change their beam, so that it fired one extremely rapid pulse, we would only need a few thousand of these.

In either case, the beam weapon would have to handle several million Amps of current, and somehow convert this into a useful, collimated beam. If anybody has any ideas how to do this, let me know. The best I can think of is a microwave waveguide -- but the biggest of these is Arecibo, it's four orders of magnitude weaker than we'd need, and it would clearly be seen orbiting the Earth!

We also have a another stealth problem. If we generate a 1.2 x 1010 Joule energy pulse, that means we're setting off much more than 1.2 x 1010 Joules worth of explosives, or 3 tons TNT equivalent, in orbit. This can be done, provided we don't mind creating a flash in the upper atmosphere that would be clearly visible to the naked eye in full daylight, and provided we don't mind alerting the early warning systems of every nuclear-armed government in the process.

4. Launch Considerations

Each of our proposed solutions above requires a satellite that masses over 10 tons for energy storage or generation above. Since the thermal control, solar generation, attitude control, and payload are also assumed to be significant, we may assume the power storage is reasonably close to a standard satellite MEL (Mass Equipment List) breakdown, and is thus around 10-25% of the total satellite mass. We thus estimate our spacecraft minimum mass is around 40 tons.

This exceeds the launch capability of any current launch vehicle -- almost double that of the Shuttle -- although Saturn V could do it.

Needless to say, this also isn't a good consideration for stealth.

Any other launch would require on-orbit assembly, and a rather complicated one at that. The extremely high-power storage and supply would have to be bridged. Pointing on the beam weapon would be critical, requiring utmost precision.

Lastly, this would mean that our astronauts are also members of the conspiracy.

5. Conclusion

Orbital beam weapons, even if the beam technology itself was sound, are not practical as tools of overt domination or covert destruction of land-based targets. There is simply no way to generate the power required to destroy hardened structures, let alone destroy them so thoroughly as to remove evidence of the beam weapon's use. In legitimate studies, beam weapons have only been considered in cases where a much lower power (1 MW or less) can achieve a useful result, such as damaging fragile sensors or puncturing thin-walled critical structures, e.g. the booster of an ICBM.

The fundamental roadblock is the ability to put power on the ground. As we saw above, the only credible approach is to use expendables, viz. explosives. In this case, the orbiting beam weapon offers no advantages over simply putting those same explosives on target. The difficulty and cost associated with the orbiting platform, coupled with the nonexistence of high performance beam emitters to begin with, makes this a complete non-starter.

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Thank you all for your attention. There's a sign-up sheet for my two-week Mad Scientist Camp circulating somewhere near the back.
The whole thread covers pretty much every aspect of the beam weapon hypothesis, it's quite an entertaining read (although it is 23 pages long).

http://www.internationalskeptics.com...ad.php?t=66444
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