Re: thanks
Posted by Pasti on Jan 07, 2004 at 09:41
(67.69.240.121)Re: thanks (danno might)
>I think you would pick a frequency which the >atmosphere is transparent. We have ground based >radio telescopes which can see very minute >signals. A 100 watt transmitter on Mars can be >detected from the earth so how much attenuation >is there?
I am not exactly sure that the transparency windows of the atmosphere are in the microwave domain of the spectrum, but never mind that.
I am afraid you did not get my point.Your problem is not detection of minute signals,but quite the opposite.You need high power "signals", not some puny 100W.And the major problem is not exactly the atmosphere,but interstellar dust particles.
And don't forget that the transmiter on Mars is a RADIO ransmitter,i.e. the waves correspond to a differnt spectral domain, and the physics is slightly different when it comes to propagation.>But such corrections and suggestions is why I >came to this site. I read a lot. Unfortunately I >also fall into the same patterns of >reinforcement and negliect others practice - one >reads and credits more info that supports their >own opinions and discounts or ignores >information that disagrees with cherished >beliefs.
Well,what can I say, reading is good, and reading a lot is even better.The problem is acquiring the right knowledge and info.Unfortunately, this involves a bit more than reading,namely learning.
>I will look for some more info on this, if you >have a couple of links to help steer me, it >would be appreciated.
I take it you are not exactly on the scientific side of the fence.
For lasers and masers,take your pick on Google.Or get Pedrotti and Pedrotti's "Optics", if you actually want to start understanding the stuff.Propagation of light, again, Google can be useful, but even more useful would be if you could read Born and Wolf's "Principles of Optics" (don't be fooled by the title). Good description on propagation on various spectral domains is in Jackon's "Electrodynamics".>I knew of the wave diffusion issue and there is >also the rotational problem of Earth, Luna and >Sol requiring a set of reflectors (which cuts >into the power generated) but the power source >large solar cell farms on Luna) is free and >power loss is only a consideration if the >diffusion somehow threatens other resources. >Some of something (especially a continually >renewing resource like solar power) is a whole >lot better than all of nothing.
I am not exactly sure what you read, but try to understand that microwaves have their own specific problems, radio waves their own specific, and so on and so forth, for each spectral domain.
Moreover, if you are talking about solar energy conversion on the Moon,it is OK as long as you don't exactly require a lot of power.Solar pannels are known for their poor efficiency, so if you want power with solar pannels,you need a huge surface covered by these pannels;you do see the problems, right? Not to talk about micrometeorites that impact the surface of the Moon, and which would turn your pannels inoperative on large scale.>The selection of the Earth sites would depend on >atmospheric influences to some extent. I would >think dust would play a larger role than water >vapor but maybe I need to review that too.
For the atmosphere you are right, but the atmosphere is just a few hyndred miles thick, compared to the ~200,000 miles of open space with intergalactic dust
>I still think it could be done but the distance >relaying problem would be a challenge. The sites >in Nev with acres of receptors would probably be >the best to catch most of the power of a beam >from a geostationary reflector.
Of course it could be done, in the end that is not the issue.But remember that you don't want to test the validity of a principle, you want an effective and efficient system, and there is where your problems are.The principle itself is valid, but not efficient at this stage...
Follow Ups:
- Re: thanks victor 19/1 22:45 (0)