# Recent content by poor mystic

1. ### My amplifier -- why did this capacitor blow in my guitar amp?

Your capacitor probably failed due to age
2. ### Source strangulation for an instant water heater?

As an electronics tech I suggest actually measuring the resistance of the plumbing. I’d use a static test of pressure with no water flowing, and a further measurement with the tap fully ON. Does that make sense to the fluid dynamics guys?
3. ### DB scale misunderstanding

Attenuation is measured in dB; so that for example a level of -10dB is the outcome when a signal at a level of 0dB is attenuated by a factor of ten. :)
4. ### I Number of gravitons detected

So gravitational waves are waves of electromagnetic energy which come from some direction, weakly interact with matter, and move on. You'd think that a massive sphere (say a planet) would focus gravitational waves much as a glass sphere focuses visible light, so that at some distance a...
5. ### I Why do rockets turn horizontally so soon after launch?

Possibly, the fact that the Earth is rotating away from the rocket's launch point makes it seem to turn to the horizontal, when it's actually moving in a straight line.
6. ### I A perfectly stiff wheel cannot roll on a stiff floor?

Hi :-) This question reminds me of the problem that ancient mathematicians had with Achilles and the Tortoise, because their problem required the expansion of mathematical understanding to encompass the calculus - in other words the paradigm within which they attempted to get a grip on the...
7. ### What are the 'best of the best' textbooks to help me learn math from the ground up?

I really liked those books too. The "College Algebra, with 1720 solved problems" if I remember correctly, was such a big help.
8. ### What are the 'best of the best' textbooks to help me learn math from the ground up?

Hi :) I have found that the best teaching resources are at New Zealand/Australian "4th Form" level. Almost any modern book will do. Usually, the most trouble people have is learning the meaning of division. Good luck, and feel free to PM me if you have any further questions. Mark
9. ### Lazer but with sound?

maybe this could be done with powdered or gaseous chemistry
10. ### Coherence distance in lasers

Thanks for your question Ranger Mike :) I have very little money, being a pensioner. The design I'm using is one I cooked up for myself in the olden days (ended last week) when I believed that lasers just continuously lased, and did not continually restart as seems to be the case.
11. ### Coherence distance in lasers

Hi people :) I want to build an interferometer. In the course of looking for a suitable light source for my instrument I have been advised to check the 'coherence distance' of the sources; it is clear to me that this distance places practical limits on the design of the machine. However...
12. ### How to get teh closest Metal object

Hi Litup! :-) are you still looking for ideas? I suggest ultrasonic 'radar'. You could pulse a burst of 40kHz sound, time the received signals, and locate the nearest item using Arduino. I hear that the Arduino platform is very good for this kind of work, and is very cheap. There will be a...
13. ### Any ideas how I could fill a steel tube with pellets?

... or the pellets could be swept up from the bottom of the tube by air moving towards a partial vacuum at the top, or Lester's "2)" could use air pressure instead of a ramrod
14. ### Recording sound without microphone

I have heard that there are often conflicts when a soundcard is used for both input and output simultaneously. I might look for a way to resolve those conflicts or include a second soundcard. I found this: http://chipmusic.org/forums/topic/638/lsdj-to-mp3/ which may help... :-D
15. ### Monochrome interference microphone

Further question: I've been turning this over and over in my mind and I just don't see why a laser should be required. It seems to me that a Young's double slit should work just as well, with no dangerous lasers. Perhaps I got that wrong?