Talk:David Criswell

The reality - or - this doctor is a duck (quack quack)

1). even if he could create a dish with an aperture of 2.5 degrees, he would be illuminating the entire earth with microwave radiation.

2). power density of electromagnetic energy attenuates naturally with distance.

in the case of radar (microwave energy) power density in the far field, where:

   Pd = the far field power density in watts per square meter
   R = the range from radiator to target (receiver in this case) in meters
   Pt = Transmitter power
   Ga = Antenna gain

   Pd = (Pt * Ga) / (4 * Pi * (R ** 2))

therefore, and i'll use absurd numbers here to prove a point: I'm unsure the math is correct, but I agree, beaming solar energy The propsal from Geo stationary orbit was a one kilometer parabolic disk supplying a 6 kilometer rectenna from Moon to Earth is extremely impractical even with huge technology advances.

   Pt = 1 trillion watts
   Ga = 60 dB
   R  = 382500000 meters

   Pd = 0.000032634616 watts per square meter at earth (computed by MathCAD 14)

The effective radiated power (ERP) from such an antenna on the moon would be 1,000,000,000,000,000,000 watts (umm, i think that is one quintillion watts (or whatever comes after quadrillion))

This of course ignores the very trivial dielectric constant of the medium of a molecular vacuum, and the very sizable losses due to transit of two magnetic fields and associated wavefront rotation and antenna polarity issues.

In plain english, the above numbers mean that if Mr. Criswell was to transmit ONE TRILLION watts, into a dish antenna with an ABSURDLY HUGE GAIN with the energy traversing the average distance in meters between the moon and earth, you wouldn't have enough energy collected per meter to power a solar powered calculator. In other words, you would have to build a collector here on earth covering 1.532 square kilometers just to power a single red LED (5V 10mA).

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Despite the rules here in relation to biographical articles, I think it would be safe to call the man a quack and use the word incompetent, and possibly con-artist in the body of the article.

The fact that this man was allowed to spout this crap on the National Geographic Channel only shows the kind of fact-checking going on these days on TV.

This man is attempting to obtain taxpayer monies in large amounts in order to pursue something that cannot work, and the fact it cannot work is not a matter of opinion, but a matter of the laws of nature.

Sources: http://www.tscm.com/pwr-dens.pdf , Antennas 2nd Edition by Kraus, Antenna Engineering Handbook 3rd Edition by Johnson, and a nearly endless list of other sources to back up the math here.

71.217.215.181 (talk) 20:58, 18 August 2010 (UTC)

The only problem, man, that loss of radar energy due to distance in your calculations is for near ground atmosphere, so you need to get you calculations once again, and with those figures Criswell provided many times in his calculations ( just search a net - google will suite you ).

He has, after all , spent many years as a director of research institute and did not take a first formula which he encountered and applied to the problem without even considering if it's applicable. —Preceding unsigned comment added by SergeyKurdakov (talk • contribs) 20:07, 25 August 2010 (UTC)

I have other problems with this nonsensical scheme, not least the 2-week day/night cycle (putting receivers into shadow for even longer than terrestrial), moonquakes, & the need to make structures in even Lunar gravity much stronger & heavier than they'd have to be at L4/L5... Which option, I see, is totally ignored.

And while I'm by no means expert in microwave transmission, I have to wonder why relay satellites with their own collector aerials couldn't fly. Which option is actually a really good one even for terrestrial power generation, since it means you can dispense with tens of thousands of km of expensive, hi-loss wires.... TREKphiler ^{any time you're ready, Uhura} 15:00, 7 August 2011 (UTC)

I'm not sure of the math, but I agree, extreemly impractical beaming energy from moon to Earth. The early proposal from GEO orbit was a one kilometer parabolic dish beaming to a 6 kilometer rectenna near the equator of Earth. The moon is 12 times farther so the one kilometer dish becomes a 12 kilometer dish with 144 times the surface area or the rectenna becomes 72 kilometers in diameter. Neither have been demonstrated 1% that big. Much higher frequency, such as infrared reduces the size dramatically, but this has not been demonstrated even medium scale. Worse the illuminated spot becomes eliptical as you move the rectenna away from the Equator and when the moon is close to the horizon. Worse the solar panels on the moon gather max energy only when the sun is straight up, approximently one day per month, except on a high peak near the Moon's North or South pole where the stearable solar panels need to rotate 360 degrees over a 4 week period while facing the horizon 66.177.106.56 (talk) 03:31, 11 June 2012 (UTC)

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Obituary

https://www.hawkinsfuneralhomes.com/notices/David-Criswell

Change Further entertainment section to Further reading

Anybody have objections to changing the Further entertainment section instead to Further reading, consistent with similar pages? Mauricef (talk) 08:13, 6 January 2020 (UTC)

How to put $50 billiion in perspective...

I appreciate the effort made in two previous edits to put in perspective Criswell's estimated $50 billion cost of a demo 1GW lunar-solar power plant. However, with due respect, I don't think either comparison (Gate's personal worth, cost of Iraq war) are relevant to the discussion. Rather, I propose comparing the estimate to the cost of a similarly sized conventional (on Earth) solar plant. Such as the 1GW Kurnool Ultra Mega Solar Park in India. Thoughts? Thanks in advance.Mauricef (talk) 19:42, 21 January 2020 (UTC)