lightwave

More odd-shaped rocks that look like something when viewed from afar. Lets pretend that its aliens that shaped the rock/structure and that they are grays and they have fleets of spaceships ready to invade somewhere like, ummm, can't think of a place, oh, yes I can, they are going to invade EARTH! And, we must get ready to receive our new overlords and to work in mines to mine diamonds for them.

Many animals are sensitive to infrasound. Elephants can hear it and they can also feel infrasonic events through their very big feet. Tidal waves (tsunami is not the right word - it means 'harbor wave') produce infrasound (IS) in huge volumes and the IS continues ahead of the tidal wave in the air and under water. Many animals would hear the IS and realize a big frightening event is approaching from the sea, so they'd naturally run from it and that means going inland away from the danger so making safe many animals but the humans would be quite mystified I suppose. Many animals also sense magnetic fields, electric fields and ultrasound. Although I believe humans are able to sense magnetic fields too in the same way that birds do but 99% of us never know or use this. Some people think that there is something 'mystical' about animals sensing tidal waves or there is a 'sixth sense' thing going on. Nothing of the kind. I've been thinking about a simple and cheap way to detect tidal waves and I think I have a method, but cannot try it yet.

It's a good idea. Let us hope it is actually effective in use. Genetically modifying foods can be done in a huge variety of ways and although the greeny-nutter tree-hugging crowd will claim we'll all have three eyes etc., no harm can come of modified foods.

Silkworm is the one who is being petty and being extreme about it. As for Mel Gibson, the topic of this thread. Who cares really what he said about jews. Jews are constantly attacking everybody else, especially Christians but suddenly someone speaks out about jewish attitudes and the jews go ape about it... Ok, so what? Go Mel, you let it all hang out. Ignore the petty twits and go for it.

Get some peltier effect devices. Connected to 12 volts they will cool (or heat) depending on which direction you pass electrical current. You'll need a fan to blow the heat away from the other side of the peltier device. You can easily mount a couple in an insulated box and if you wanted to go real hi-tech you could organise a temperature controller using a simple 555 timer chip and a couple of MOSFET's. Do you sell the plants? What is the value of such plants in the market place?

Thanks lads for your assistance. The blimp is for aerial photography (AP). It's just a modest sized blimp for sailing around during the day to take pics of real estate. It doesn't need to be 15 metres for AP but I intend to put it to other uses. Thanks JCM for that equation... got the equation somewhere in metric too?

I'm designing a blimp - a non-rigid, helium filled airship of about 15 metres (45 feet). Diameter about 3 metres (9 feet). I'd like to know what drag the blimp will produce so I can select the motor sizes and consequently battery sizes - all of which reflects into the payload ability. How can I calculate the drag? I know that it is largely done experimentally using a wind tunnel, but what is the draq equation that I am to begin with? What is a good way to measure drag in a wind tunnel?

All you need is a spring loaded push rod to raise the scoop. You can organize the scoop's push rod to be released with a speed sensor either collected from the speedo or from the wheel sensors. When the pulses rise to a certain frequency the spring loaded push rod is released. To translate pulses (speed) to a suitable output for activating a push rod you could use a simple 555 timer chip (30c) and a few other bits of electronics. See one of your electronics friends for the electronics side of things.

scicop has got it right... patents = lawyers because if you have a patent that is worth anything then someone will steal it and that's when you need the lawyer. If you have an invention, then keep it quiet until you have it patented.

Just a few thousand people would be nice. The planet would be pristine. The worst polluters aren't the biggest consumers, it's the Asians who pollute most. China's waterways and aquifers are mostly polluted, the air is a nasty mess and with 200 million unemployed crime is rampant.

m4rc... very nicely done with your statistics on sea rise.

Gyros have been used to maintain stability in aerial vehicles for many years. Most often they have a rate detector attached which measures rate of rotaton of the gyro body about an axis and that rate data is sent to a navigation computer, always in 3 axis'. But you want to use a gyro and force-turn it's body to bring about a turn in the aerial vehicle. I seem to recall that this was done during WW2 by the Germans for some of their guided rockets. A sensor was attached to a motor which forced the gyro to a new position. The sensor was heat seeking. But the gyro was quite heavy and required quite a bit of electrical energy to run up to speed - about 50,000 RPM.

You could try going to the www.WeDon'tUseAnyThingForEvil.com website

That's nicely thought out Externet and should work to reduce the noise level somewhat. Lengthening each pipe and placing heat absorbing material inside will reduce the final gas temperature and reduce the noise as a result.

Well, you can use a mousetrap to catch a mouse, then train the mouse to crank a propeller and steer an aeroplane. Next inane question please!