Asymmetrical Capacitor Lifters seem to be a popular "anti-gravity" concept and for fun I thought that I might experiment with them. An asymmetrical capacitor is a capacitor that has one electrode larger than the other one. If the insulating dielectric between the electrodes is a gas there is a small thrust that is generated in the direction from the small electrode to the larger one. This thrust is sometimes referred to as the Biefeld-Brown effect and at other times it's considered to be a mysterious anti-gravity effect. Some experiments have seen a thrust generated in a vacuum as well as an ion wind. I'm not going to comment on the presence of any anti-gravity effect other than to say I don't know what the exact definition of anti-gravity is. If a hot air balloon is floating is it defying gravity? My understanding is that there is still a gravitational attraction between the balloon and the earth it's just countered but the force of the hot air trying to get up above cooler air. Does that count as anti-gravity?
|Asymmetrical Capacitor Lifter Test - it's arcing in this picture|
The experiment that I decided to try was to build a small asymmetrical capacitor and photograph it in my Schlieren setup to see if I could detect any airflow. From what I have read to get some kind of force you need to have a high voltage DC potential across the electrodes. I don't have a really high voltage purely DC supply right now. The closest thing I have is a 28,000 volt DC supply that is pulsed at 15kHz. Since that is all I have, that is what I used.
I decided that I didn't want to make something that was actually going to 'lift off' and fly around because it wouldn't be too easy to photograph. With that in mind I stuck two toothpicks into holes in a piece of wood and stretched a couple pieces of wire across them. The toothpicks are 2" apart. The lower wire has a square piece of aluminum foil folded in half and draped over it making an electrode that is 2" X 1". The upper electrode is a 0.005" diameter stainless steel wire. The upper electrode wire is fixed at the top of the toothpicks and the lower wire is just wrapped around the toothpicks making it easy to slide and adjust the gap between them. For the experiments the gap was about 1/2" and I adjusted it down until I didn't get any arcing. The toothpick, wire and foil construction if this capacitor is based on the plans that you find on the internet for lifters.
One thing that I want to mention and I'll write about later is that I'm using a new and improved Schlieren setup for this test. Instead of having a light source that is offset from the camera I'm using a beam splitter and the light source and camera are coaxial. This seems to give much better results and much more sensitivity. It's also much easier to set up.
For fun I set the gap between the electrodes a little close so that there was a lot of arcing and I filmed it with the Sony video camera that I have. I tried it with the IR 'night shot' and also in regular light. You can see the difference in the first part of the video that I made below. Once I got tired of the arcing and the ozone smell I adjusted the foil electrode down in small increments until there was almost no arcing. then I switched the high voltage on and off and observed the airflow in the area of the gap between the electrodes. There is a subtle but noticeable airflow from the top wire electrode toward the lower foil electrode. It might be a little hard to see in the video after youtube compresses it and degrades the quality but it is there.
I don't think there is any real discovery here because the 'thrust' effect (or ion wind) is pretty well understood. You can click on the links above to read more about it if you are interested. Also a google search for "asymmetrical capacitor lifter" gives a lot of results. Leave a comment of send me an email at firstname.lastname@example.org if you want more details about my little experiment. In the meantime have a look at the video and let me know what you think.
Messing around with this has given me some ideas of more things to try with high voltage and the Schlieren setup. First thing I need to do is get a high voltage DC poser supply that isn't pulsed and repeat this experiment. Another fun thing to do might be to make a series of capacitors and see if I can get a more pronounced 'wind' blowing by feeding one capacitor with the output of another one.