Odds and ends

[Mark]

A faster start with the advantages of no spark plug and the up-the-tailpipe ignition system, to be fair.
http://youtube.com/watch?v=N9fZqqt0Q3c

But then again ... note the flames in the face. Oh!
http://youtube.com/watch?v=xiobEXzgl4M&feature=related

[Mark]

Today I hefted my old diamond saw and motor out on the back porch and sawed some of my thicker quartz tubing. It's just mounted on a flat board which makes it awkward to lift, and hard on my back. ha
It slings a little bit of oil even though there is a guard over the diamond saw blade. I really don't think it needs a big heavy motor, it could do with something smaller I'm sure to run the belt and pulley.
So I cut the meter length of quartz in 3 pieces, the two longer ones I hope to use for a Schmidt type pulsejet. I thought it might be nice to have a short piece too, to dink around with, maybe make a very tiny jam jar perhaps. But I got to toying with some thinner quartz tubing I had previously sawed into 3 pieces some time ago and came up with this trombone arrangement. It's neat in that the thinner quartz is darn near a perfect seal against the inner walls of the thicker tubing. The two pieces remind one of playing with a glass syringe, the springiness is the same if you plug both ends and pull or push, it fights you like a magnet. I blew into one end and couldn't in the least hear any air hissing or leaking out so the two pieces sleeve/seal very well.
Now the strange thing is that I put a wafer thin copper cap in the smaller tubing and then sealed both pieces of quartz with a rubber stopper. I'm glad that I bought every size of solid and holed stopper because it was such a hassle to have to find something to make do for such experiments. Stoppers come in handy when I spray/mist tubes with methanol and then "bark" them to see which length barks best for some certain diameter, a lighting of the tail reaction. ha
Anyway, with both ends of the trombone stoppered and the copper cap sleeved inside the smaller diameter tubing, I started to piston the two pieces of quartz, pulling them and pushing them about an inch in either direction rapidly, feeling the piston effect. The little copper cap isn't a perfect air tight fit but it still struck me as strange that it doesn't move in the least relative to the larger diameter tubing which is sleeved over the thinner tubing. I put the tip of my finger at the exact spot of the copper cap and actuated the two pieces of tubing and yet it remains stationary even though the thinner piece it is riding in moves rapidly back and forth an inch in play as I have mentioned. It behaves as if it is relative/affixed to the wider diameter tubing. I guess it's nothing really, but I find it curious.
I wonder too if some kind of jam jar or pulsejet action could use the principle of a sliding piston within a piston? I wonder this because I am probably crazy. ha

[Mark]

Go full screen and you can click on the controls at the bottom to speed things up or if you are having problems sleeping just watch it at the slow pace. ha
http://www.nikon.com/about/feelnikon/un ... ndex_f.htm

[Mike Everman]

wow, that was a good one.

[Mark]

I wonder if something like this http://tinyurl.com/4y6bce and something like this http://www.afcinternational.com.au/site ... 3_tech.htm could be used to make a short-lived pulsejet? I think it would be fun to launch a pulsejet like a bottle rocket and have it rev up for just a few seconds and perhaps reuse it again upon falling to earth safely. Maybe have a little rubber/foam nose cone on it for impact. I think about my little Logan how easily it starts if you mist/prime the inside with methanol and light the tail. It would be nice to make a light/thin-walled and stiff facsimile of some small pulsejet/missile and let her fly with just enough fuel for a few seconds of ear-shattering noise. ha
I once used a few layers of aluminum foil for the top of a stainless steel spice jar/jam jar and held it on with a rubber band. After it stopped running it made a dart/candle flame about 10 inches long for a few seconds. I attributed the dart to the peculiar flexing of the lid, allowing the flame not to be extiguished after jam jarring. The steel tape might make for a quick jam jar lid on some jar you don't have a lid for too.
http://www.right-tape.com/html/prod_hc4260.html

[Mark]

Some old stuff/topics from 1665 augmented/illustrated with a youtube post. The gods of resonance and kadency appear sympathetic. ha

"In 1665, the great Dutch scientist Christiaan Huygens, inventor of the pendulum clock, wrote to the Royal Society of London to tell them of his discovery of an "odd kind of sympathy"
"Just what was this insensible motion? Huygens thought at first that tiny air currents were causing the interaction between the two pendulums. But when he blocked the flow of air, the pendulums still swung into synchronization--or rather, antisynchronization. He eventually concluded that the effect was due to "imperceptible movements" in the beam from which the clocks were suspended—an explanation that is quite correct, according to Kurt Wiesenfeld and Michael Schatz, the Georgia Tech physicists who led the newly published study."
http://www.americanscientist.org/templa ... etid/14766
http://www.youtube.com/watch?v=W1TMZASCR-I

[Mark]

Another thing to dwell upon from the same article.

"Coupled oscillators are even more ubiquitous in nature, showing up, for example, in the synchronized flashing of fireflies and chirping of crickets, and in the pacemaker cells that regulate heartbeats. "The theme of synchronization between coupled oscillators is one of the most pervasive in nature," Strogatz says."
http://www.americanscientist.org/templa ... 4766#17939

[pezman]

Self synchronizing systems, especially synchronized chaotic systems, are one of my favorite mathematical topics. If anyone is interested in the topic, a good search phrase is "synchronization manifold". Some of the math is surprisingly accessible.

A closely related topic is the Ott-Grebogi-Yorke (OGY) control strategy for chaotic systems. You can actually control a chaotic system (within certain limits) by gently nudging it at the right time in the right direction. The idea is a little like juggling, or carpentry in the pre-industrial age, where one exploited wood's traits rather than running it through machines that essentially render it a purely dimensional material -- i.e. one can exercise control over the system as long as the control objectives are consistent w/ what the system already "wants" to do.

Topics like quantum entanglement appear to be related to synchronization manifolds. The "Falaco" soliton, a physical oddity that you can make in your very own swimming pool, may be related as well http://www.youtube.com/watch?v=PyjwZ39EDmw

[Mark]

Some sort of praxis philosophy I was reading in the New York Times book review magazine at work yesterday. ha
"The more we believe success is derived from information rather than the mixing of our hands and labor with concrete things, the more we distance ourselves from the very essence of what it is to be human."
http://www.nytimes.com/2008/05/04/books ... ref=slogin

[Mark]

"Rated as the top solar appliance in the world."
http://www.sunoven.com/usa.asp

[Mark]

I was looking at some Bedouin women dressed in black in a children's science book on heat at the library. It seemed an odd color for the desert, but I wonder if the heat radiated is greater than the heat absorbed? I would like read more on the subject. I wonder how well a zebra-striped cloth would do? ha

I found this tidbit on the topic too. Getting back to nature. ha
“Their tents are made of goat hair and are very loosely woven. They are beautifully lit inside and, as the outside of the tent gets hot, it causes an updraught that sucks air through the loose weave. If you open the tent flaps, the air comes screaming in, even though there is no breeze. It's brilliant. If it rains, the goat fibres swell up and the tent gets tight as a drum. And, because it's black, the tent shows no dirt. And the factory that made the tent follows you around, eating anything you can't and converting any form of biomass into meat, butter, cheese, fur, leather and wool.”
http://answers.yahoo.com/question/index ... 242AAGhovK

[Mark]

Anyone for a pulsejet tattoo? Maybe I'll get a jam jar done on my ankle. ha
http://carlzimmer.typepad.com/sciencetattoo/

[Mark]

The other day I was thinking what if you put a jam jar on a record player and spun it up so that the methanol would climb the sides of the jar? This might protect the jar from cracking, keeping any sharp heat gradients from forming.
Another thing to try might be injecting a tiny stream of methanol that swirls down the sides of the jar and is led out at the bottom of the jar at a specific rate to have some sort of optimum fueling and recirculate the methanol back up to the top of the jar, perhaps cooling it before reintroducing it again at the top. The tubing could have a fairly small diameter I think.
I wonder if a snorkeled jam jar with two Hero's steam engine arms could spin itself on a freely rotating stand and that too would make the methanol climb the sides of the jar, a Reynst Hero Methanol Jam effect.
Yet another option might be to put a magnetic stirrer in your jam jar.
All this in an effort to get away with using ordinary glass for a jam jar; everyone in the class would be happy then. ha
Or what if you could valve and bleed off some pressure inside your jam jar to do the methanol pumping for you, providing a constant alcohol bath to cool the sides of the jar. Maybe if you perfected it, you could get away with using a clear, stiff plastic jar for all but the lid or exhaust/intake hole where the breathing occurs.
Here is a gravity feed system that might somehow if modified keep a jar from cracking perhaps, although eventually the system stops of course.
http://physics.kenyon.edu/EarlyApparatu ... ntain.html
Too, a very long, simple thistle tube high above the jam jar using gravity to fuel and cool a jam jar might work, only feeding in just enough fuel/methanol to sustain the engine and cool the walls, a sort of ablative cooling.
http://www.newton.dep.anl.gov/york/thistletube.html
Some other spinners for inspiration. ha
http://physics.kenyon.edu/EarlyApparatu ... ngine.html
An old post of a plastic balloon cooled with water ...
It even crossed my mind to try and make a jam jar balloon, because I am way off the deep end in some never-ending jam jar odyssey adventure. I thought to try and create some sort of invagination of the balloon to create a cavity for combustion with the external walls filled with water, a real stretch of the imagination I know/admit.
http://youtube.com/watch?v=EExri5yxTkc
PS This makes me think of something else. I have some "exotic" iced tea glasses that make me nervous to drink out of really because the glass is so thin. Maybe a very thin-walled ordinary glass could be externally cooled with water just as the balloon is, a rapid transfer of heat effect.

[Mark]

http://tinyurl.com/3m4axy
http://www.amazon.com/The-Ten-Most-Beau ... B00164X2UO

This was too funny, especially at the end. Those who have buzz coils have all been there. ha (Click on the George Johnson clip at the bottom of the page) ( I can't direct link it)
http://www.comedycentral.com/colbertrep ... eId=167537

[Mark]

http://www.news.com/8301-11128_3-9916858-54.html