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Yes and no. True, the opposite of an UNDERWATER bubble is an airborne droplet.

However, the opposite of a soap bubble in air drifting on the breeze is an antibubble drifting around underwater.

The part about beer is interesting because it's analogous to blowing soap bubbles on an extremely humid day: the bubbles last longer, or possibly last forever if the air is slightly supersaturated.

An antibubble in beer would collect more and more carbon dioxide into its thin gas layer. If it didn't touch the fluid surface from below, there'd be no reason for it to burst.

Although first observed and studied almost a century ago, no one until now has been able to determine how they form.

Yeah, right. Even little kids have been making antibubbles since that article came out in 1974. If you've tried making them, it's totally obvious how they form. Perhaps what's not totally obvious is why a thin layer of air is stable underwater. But if detergents can stablize an air/water interface in a normal bubble, then this explains both a water film in the air, and an air film underwater.

Antibub trivia: antibubbles have "rainbow" colors, but the rainbows in the opposite place from a soap bubble: they appear at the bottom of the sphere. And of course the rainbows in both bubbles and antibubbles are not rainbows, instead they're antirainbows: dark spectral slots in white light. They're bands of "subtractive colors;" cyan, magenta, yellow.

Make Antibubbles

Yeah? Well I got to work 30 minutes late today because there was an accident. It had been moved well off the road so there wasn't any reason for a slowdown in traffic. Except, of course, the fact that every little shithead had to gawk at other people's misery. *That* is what really bugs me.

I know it's a joke...

But you should tell Sally about Traffic Waves. It's not about gawking, mostly.

Hey, I don't know if you were kidding or not, but your approach is not far from the "correct" one to help reduce traffic jams! Amateur scientist William Beatty has a really interesting page on the physics of traffic jams. Standing waves are a big culprit in causing and keeping traffic jammed. When you rush ahead to cover a gap, hurrying up and to join the jammed cars ahead, you simply perpetuate the life of the standing wave. When you slowly cover the gap, you not only give time for the wave ahead to dissipate, but you smooth out the flow to a pace more suitable to traffic conditions. The result is more than just trading off a continuous, modest pace for hurry-up-and-wait... hard breaking causes ripple effects that actually produce jams.

No, if more people were like him then congested traffic would move a lot more slowly, and people would waste a lot more time stuck in traffic, instead of enjoying it with their families and doing other worthwhile things.

Are you sure about that?

With CPU's operating at or above microwave oven frequencies, maybe Intel is just trying to sheild us from the harmfull radiations.
Hey and since the CPU clock is a square have couldn't it even have highger more dangerous harmonics?

He makes such statements as, "We can't solve traffic congestion by reducing the speed of traffic to 10 KM/Hr" which is entirely false, as anyone who's studied the wave behaviour of traffic can attest to.

Then he makes the assertions, "Nor can we solve obesity by reducing the shelves in the supermarket, or Spam by making it difficult and costly to send e-mail."

Really, if you reduced the number of high-fat foods in super markets and made it so that email did cost more to send, would that not both reduce the fat in most people's diets, as well as make it harder for bulk mailers to send email cheaply? Wouldn't that solve those problems?

This article spends its entire time chasing its own tail around before making unsupported assertions!

An interesting link about traffic patterns: http://amasci.com/amateur/traffic/traffic1.html

Special self-driving vehicle lanes for the highway would be pretty cool - they'd have the potential of running very smoothly, even if they don't move any faster overall than normal lanes. Should be safer, too.

Do your part now. You don't need to wait for automated vehicles.

saw a link to "Airzooka" on /. and decided to investigate more. Found this and from a box of chips and broken condom (no trolling, really!) I built a gun that shoots vortexes of air :)

Very well, Dr. Sample. I accept your expertise in software. Now will you please pay attention to someone with a couple decades of experience as an electrical engineer?

Many researchers have been working since the very beginnings of radio, trying to see if there are any unknown effects that might be RF induced. To date, besides the well known thermal effects, there have been no repeatable experiments suggesting anything else.

Now I know you want to see proof this sort of thing is SAFE. But proof of safety is difficult because the very definition of safety is a political definition, not a scientifically certain group of conditions.

Because of this fuzzy and moving definition, you have to realize that safety is a very individual thing. For example, there are weather conditions in which I choose not to drive to work. However, others might. There are no absolutes in the business of safety.

If you feel, after reviewing at least five decades of serious research, that there are still a few unanswered questions regarding exposure to RF, then you are in a very small minority of experts on this subject. However, if you haven't read this research, and you still feel that there are things that aren't known well enough to make a decision, then I strongly encourage you to please do so before making such uninformed comments.

You have more to fear from your kid sticking these things in to the Microwave Oven than you do from casual use of a cell phone.

I am a father of three myself. Relax. Your child will be weird. All kids start off that way. If you're lucky, they'll get over it when they leave home and strike out on their own. Until then, if you're going to be concerned over trivial stuff like this, I've go this really cool bridge I want to sell to you...

Water in microwaves can be quite dangerous though. Check out the "Coffee Explosion" part on this page.

microwave experiments and links

This is a bit OT, but it sounds like you might be interested in this: Traffic waves

Basically it's a study of traffic as a kind of "fluid dynamics" system, and has some interesting stuff about the ability of one vehicle to affect the behaviour of others, including unblocking traffic jams

Bill Beatty started the conversation on this phenomonon, and the use of antiwaves to cancel it. You can read it and view the animations here

I'm not trying to pass off either of the above sources as remotely scientific, for the record. :)

Here is my recommended recipe for an experiment to demonstrate the effect:

1. Take a 250 ml glass beaker, fill to about 200 ml level with 0.5 molar
(0.5 M) K2CO3 -- potassium carbonate solution

If they were dealing with purely chemical reactions, can you explain how Ohmori and Mizuno ended up with "Hg, Os, Kr, Zn, Cu, Ni, Fe, Cr, Si, and Mg -- with anomalous isotopic content" in the reactor ?

Also, the results of Naudin's experiments show an efficiency of the reactor well above 100% (up to 258%). The reactor boils up much more water than it should given the amount of electricity it uses. Where's all this "extra energy" coming from ? It *may* be from some unknown exothermic chemical reaction, but strangely there are no traces left of this reaction.

I've clicked on this /. article out of curiosity, vaguely remembering "cold fusion" as an outright hoax from several years ago, but I followed the links and changed opinion. I know Mr Naudin for his works on Lifters and electroaerodynamics, and I trust him as a "garage researcher". I firmly believe that there's something happening in these glowing pots full of K2CO3 solution, though I cannot say for sure what it is - nuclear fusion, or something even more exotic ? But it is producing energy, and I'll see if one can harness it into something useful.

Nearly everyday traffic on the 6 lane interstate suddenly comes to a full stop. When you get going again and drive up a little ways, there was no reason to stop, no accident, no debris in the road.

Ah, it's time for a little MLP...
A layman's description of why traffic backs up for no apparent reason and how to stop it.
An article about an actual German study on the the physics of gridlock.

Actually, all you have to do is tap your breaks. In most cases, people follow too closely, so they have to break when they see your lights.

By tapping the breaks and then moving on, you can cause a "traffic wave" of stopped traffic that can last for quite some time.

Visit http://www.amasci.com/amateur/traffic/traffic1.htm l for more information.

He says at one point: When traffic is heavy and unstable, slight braking by a single driver can cause the traffic to freeze into a gigantic crystal. Like Kurt Vonnegut's end of the world story CAT'S CRADLE it's the "Ice Nine" of the highways.

In reading up on vortex rings, I came across this page which has some interesting ideas for building vortex generators as well as some nifty (wierd?) applications. Most interesting is to power the vortex tube with a big loudspeaker, and control the size and spin of the smoke rings by sending it different shaped waveforms.

Please use www.slashdot.com for shit like this.

Please make www.slashdot.org worth looking at.
Smoke ring stuff

Cooler toy stuff

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Please use www.slashdot.com for shit like this.

Please make www.slashdot.org worth looking at.
Smoke ring stuff

Cooler toy stuff

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Please use www.slashdot.com for shit like this.

Please make www.slashdot.org worth looking at.
Smoke ring stuff

Cooler toy stuff

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

Stuff that matters

btw, there's a link in the article, Make one it says.

And he's got the biggest feature of the crank, a martyr complex:

I can give you there an example from my own experience where, when I was still very green and naive, just after the war, I had worked on the theory of hearing: how the inner ear works. As I had just come from wartime radar, I was full of signal processing methods and sophistication and receiver techniques and all that, and there I found myself discussion the physiology of hearing in those terms. I thought it was very appropriate because it is a very fine scientific instrument that we were discussing, the inner ear. But I had to address myself to an audience of otologists - the doctors and medical people who deal with hearing - the only ones who were doing any kind of research in this field. The mismatch was obvious; it was completely hopeless. There was no common language, and of course the medical profession just would not learn what it would take to understand the subject. On the other hand, they sure made their judgments about the matter, without having any basis at all.

I have to suspect that Gold likes to play the contrarian just to avoid dealling with his on collaboration issues.

http://www.amasci.com/emotor/emot1.html

You can use a TV screen as your high voltage source.

I had a variation of this spinning on my office PC a few years back.

Nothing says geek quite like a monitor powered ion motor on your desk.

Is it possible for end-users to easily disable an RFID?

I wonder if an anti-static gun would produce enough voltage to fry them (for the kids: these were used in the Vinyl Ablution Ritual that preceded placing the needle on the record in the old days).

Maybe waving them over a negative ion generator?

What about a serious dose of static electricity? vandegraaff generators anyone?

Possibly this site:

Traffic waves

(Just google for the phrase "antitraffic destroys traffic".)

Too bad more people haven't heard about this.

That site makes a number of interesting points about the way people drive and how just one person can make a difference in traffic jams.

I don't think simulating cities is actually as easy as it sounds. It was only a few years ago that we reached the capability to simulate traffic in cities over a day or so. The actual growth of a city over years could take some big doing, or dumbing down of the simulation detail.

Here's the info on the traffic sim:
Los Alamos gains corporate partner for traffic simulation

Incidently, here's an interesting if not mildly amusing 'amatuer' traffic analysis:
Traffic Waves

And a more thorough site on better driving (which is actually pretty sweet- this should be required reading for drivers):
Big City Driver

Happy trails,
Jason

2.4GHz isn't a "natural frequency of water" -- that's just a legend.

Some discussion of, and experiments using, microwave ovens can be found at that link.

And your laptop will cook your leg through direct heat radiation (and conduction), no microwaves needed.

I don't know whether cell phones and such are safe; I just know that that isn't how microwaves work :-).

-Billy

...people who have absolutely no use for raw data...

I have a use for it, I'd analyse it to death until I have some sort of sequence that matches the dimensions of the Pyramids, preferably also chucking in the orientation of Stonehenge and distance of Easter Island from Atlantis.

Then I'd write a book.

Perhaps I should patent my Business plan first? or is there prior art?

Depends what you mean. Current flow is expressed in Ampere, which is Coulomb/second. Coulomb is a measure of charge; Current flow then corresponds to the physical movements of electrons in a copper wire. Copper contains some 8.5e22 free electrons per cubic centimeter. Now if you know the diameter of the copper wire you can compute how fast the electrons have to move through the wire to establish the current you had in mind. This can be surprisingly slow! E.g. on the order of centimeters per hour is not unusual! See for an example this page.

Of course the electric field (or electromotive force as you call it) travels much faster through the wire, that is probably what you meant with "a little shy of the speed of light".

Paul

this electrostatic motor?

The biggest problem I see in textbooks right now is just how full of errors they are. After that, they have too many pictures, too much white space and rarely get to the point -- they've got fat that needs to be trimmed.

Check out that link. It's a really good source for what's wrong with textbooks.

The biggest problem I see in textbooks right now is just how full of errors they are. After that, they have too many pictures, too much white space and rarely get to the point -- they've got fat that needs to be trimmed.

Check out that link. It's a really good source for what's wrong with textbooks.

Yes, in general, faster traffic causes more accidents and more deaths, but if you are in that faster traffic the worst thing you can do is drive slower than it. Because velocity is relative. If the traffic around you is doing 90, and you're doing 90, your collision speed is nothing, so accidents are less likely. Doing 55 is a combination suicide homicide. (Collision speed of 35 at absolute speed 90! Lethal.)

The best thing you can do for road safety is promote the smooth flow of traffic around and behind you by:

1 - Giving people space to change lanes, and

2 - Driving at the average speed of the traffic ahead, pointedly not following its stop-start rhythm.

The second supports the first, and in combination they serve to smooth the flow of traffic behind you by dampening the compression waves that travel backwards along roads, and to equalise the speed of the traffic around you, which makes you a lot safer at any speed. Traffic is a dynamic system that doesn't respond in any simple way to posted speed limits, and it is irresponsible behaviour for any individual to drive much above or below the consensus speed.

Reference:Amateur Scientist - Traffic Waves

On old TV's it's usually the flywire transformer. Often, you can "whack" it and break the resonance for a short period. As high frequency electricity travels through it, it "whines".
Electricity has lots of properties that can move objects. (Electric motors are an obvious example, speakers and piezo devices are others.) Electricity is pretty good for making sound. High voltage electricity is better. Computer displays and TV's tend to have both.
Electstatic speaker project
I think your TV scans at 15khz and uses big magnets and electric fields. Your old fashioned monitor does the same, but probably at various rates depending on the resolution you've selected.
I often hear the hum of the dispaly on my old Palm III when I turn on the backlight.
When large areas are being redrawn, that just adds another factor that changes what is going on. It might add a beat frequency that you can hear. It might disrupt a resonance that was hiding or exposing a constant state sound. On the other hand, while I play with high voltage regularly and sound occasionally, IANAAE (I am not an acoustics engineer.)

Road traffic works this way too.

Bill Beaty's Amateur Science Pages are a great place for this kind of thing, too... Although his site is a little more aimed at electronics, but there's plenty of physics-related (read: explosive) stuff too :)

Yeah, those are really strong... What are they made of? They seem ceramic, not even metal. Neodymium?

I remember playing with neodymium magnets during physics class. Damn those things were strong. Will stick to anything remotely metal. Very cool.

Cheers

According to this site, the "velocity of propagation" of signals in the blue pair in CAT5 cable is 66% that of "c", the true speed of light. (A few percent of that is because of the twists -- if you completely straightened out the individual wires, they'd stretch longer than the original length of the cable)

Of course there's the difference between the speed of one electron vs. the speed that voltage changes (i.e. information) travel along the wire.

According to this guy, the actual movement of electrons is VERY very slow through a normal wire, on the order of centimeters per hour.

What about superconductors?

I didn't have tons of luck Googling, but I found a message board posting that states that the electron drift rate is much higher in superconductors.

And then there's this physics Q&A about why electrons don't travel at actually the speed of light.

- Peter

Try this for highly dangerous capacitor experiments.

No, I'm not an evil genius -- just a paranoid engineer (having done way too much security work). This guy is an Evil Genius(tm). I especially like the Kindergarten Death Squad and the argon-filled mylar balloon stunts...

It might be easier to build a linear accelerator. It is basically a bigger Van deGraf generator, and (I think) much easier to build than a cyclotron to get a 1MV beam.

If anyone from this morning's traffic jam is listening, learn from the webpage linked above:
On my evening commute on I-5 southbound from Everett there is always a right-lane traffic jam at one of the Lynnwood off-ramps. Close-packed cars must crawl along at 2mph for a very long time. Therefore I intentionally approached that distant jam in the right lane, and started letting a REALLY huge empty space open up ahead of me. By the time I hit the jam, there was maybe 1000ft of empty road ahead of me. Sure enough, my big empty space stopped traffic from feeding it from behind, while the front of the jam kept dissolving as usual. By the time I arrived, the jam was about half the size it had been. Amazing. This wasn't any little traffic wave, yet one single driver was able to take a huge bite out of it.

*gruntle!*

Sounds like you're talking about traffic waves, which have been shown to travel at the speed of stupidity. (I'm not calling the poster stupid, I'm calling the guy in the car in front of me stupid.)

Hey everyone, please get your crackpots straight. Perpetual Motion crackpots just want their devices to keep spinning constantly. Give them a maglev bearing and a vacuum chamber and they're happy forever. It's only the "Free Energy" crackpots who want their devices to keep going faster and faster (or to drive uphill, or to drive against friction, etc.) I should know; I'm a FE crackpot myself. See http://amasci.com/freenrg/fnrg.html

This current inventor is making the usual mistakes: doing everything but PUBLISHING. He seems to start out right: trying to get his idea out into the public. Yet nobody else can build a test model, since the critical parts simply MUST be hidden inside a wooden box... to prevent all the idea thieves from taking the secret and becoming billionaires! :)

So let's see... the goal is to convince the disbelievers. Yet the critical parts must remain secret. So we can show "convincing demonstrations" and give explanations to the experts, but we simply HAVE to keep those experts from ever learning the details, otherwise they'll find out how to build their own version.

Isn't there something wrong with this picture?

If a "free energy" inventor comes up with a genuine discovery, he won't need any oil companies to suppress him as long as he follows the usual path and keeps the critical details a secret.

Note: "pseudoscience" doesn't mean making up your own terminology. After all, most cutting-edge advancements will require some new words to be coined. Pseudoscience means "fake science;" something that gives the surface appearance of science, yet is nothing of the sort. I certainly agree that this battery-car is pseudoscience, since a central goal of a genuine scientist is to teach colleagues how to do it. Hold nothing back. No excuses, no paranoia, no "naive experimenters might hurt themselves." Explain in great detail how the actual device in use was built and adjusted. If there are "idea thieves" trying to steal the device, make damn sure they succeed!

As for me, I don't want the problems with my own demonstrations to be weak wheel bearings. I want to have problems with incoming guided missles as I'm demonstrating my antigravity ideas by buzzing the White House in my plywood/duct-tape flying saucer!