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Science in the Microwave

michael posted more than 12 years ago | from the it's-alive dept.

Science 95

Sunda666 writes "I have just hit this site which describes in detail how to build an one-atmosphere plasmoid using ordinary stuff and a microwave oven. Interesting thing, i'll try it as soon as I get a spherical glass vessel like that ;-)"

cancel ×

95 comments

Props to all dead Frank Zappas (-1)

Carp Flounderson (542291) | more than 12 years ago | (#3172572)

Dreamed I was an eskimo
Frozen wind began to blow
And my mama cried
And my mama cried
Dont be a naughty eskimo

Watch out where the huskies go
and dont you eat that yellow snow
Watch out where the huskies go
and dont you eat that yellow snow

Well right about that time, people
A fur trapper
Who was strictly from commercial
Strictly commercial
Had the unmitigated audacity to jump up from behind my iguloo
Peek-a-boo,
woo-woo-woo.

Then he started into whipping on my favorite baby seal
with a lead filled snow shoe
That got me just about as evil as an eskimo boy can be
So i bent down
and i reached down
and i scooped down
and i gathered up a generous mittenful of the deadly...
yellow snow
The deadly yellow snow from right there where the huskies go

Where-upon i proceeded to take that mitteful of the deadly yellow snow crystals and rub it all into his beady little eyes with a vigorous circular motion hitherto unknown to the people in this area
Here it goes now,
the circular motion
Rub it.

And then in a fit of anger I...
I pounced
and I pounced again
Great googly-moogly
Well he was very upset
as you can understand
And rightly so because
The deadly yellow snow crystals had...
deprived him of his sight

And he stood up
and he looked around
and said...
Well,
Oh-no,
Now I can't see!
No, No, No, No, No, No, No, No, No, No, No, No, No, No, No, No!

He took a dog-doo snow cone and stuffed it in my right eye!
He took a dog-doo snow cone and stuffed it in my other eye!
And the huskie wee-wee, I mean the doggie wee-wee has blinded me,
and i cant see,
temporarily.

Not the first post! (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#3172578)

So don't moderate like it was a first post!

You don't need a "vessel" and this is old news (5, Informative)

a3d0a3m (306585) | more than 12 years ago | (#3172583)

This has been done before, and posted to slashdot before. You can do it without the glass vessel. There's an old quickies here [slashdot.org] that shows how to do it without the vessel.

Adam

Re:You don't need a "vessel" and this is old news (1)

bleak sky (144328) | more than 12 years ago | (#3172607)

The link in the quickies is broken, and in any case, JLN labs are the source for both this one and the one you mentioned, so it's likely to be exactly the same.

John

Re:You don't need a "vessel" and this is old news (5, Informative)

garglblaster (459708) | more than 12 years ago | (#3172613)

Here is another page which has been around for a few years now:


the "funny things to do with your microwave oven" [utwente.nl] page

I like the one with the CDs !!

Re:You don't need a "vessel" and this is old news (2)

DNS-and-BIND (461968) | more than 12 years ago | (#3185653)

I rather like the Unwise Microwave Oven Experiments [eskimo.com] page, myself.

Umm (1)

red5 (51324) | more than 12 years ago | (#3172619)

You seam to know what this is all about.
Mind explaining to me what the hell this is?
Thanks.

Re:Umm (3, Informative)

Alsee (515537) | more than 12 years ago | (#3172843)

explaining to me what the hell this is?

When air gets hot enough it turns into a plasma which is conductive. This means it adsorbs microwaves which drives up the temperature and keeps it in the conductive plasma state. You get a ball of plasma, as long as you keep pumping in microwave energy.

The flame itself is nowhere near hot enough to create plasma to get the process started, but after a few seconds the flame, microwaves, and I think the burning object (conductive carbon) combine to trigger a little high temperature spark which can get the process going.

-

Re:You don't need a "vessel" and this is old news (4, Informative)

BlueUnderwear (73957) | more than 12 years ago | (#3172682)

You can do it without the glass vessel.

Yes, but without a glass vessel, the ball lightning will be too short-lived. Indeed, due to higher temperature, it raises up, and as soon as it reaches the metal ceiling of the nuker, it collapses. The glass vessel makes sure that it can get to the metal, and hence it will stay longer (contact with glass doesn't make the plasmoid collapse, because glass doesn't conduct electricity).

I just wonder whether the shape is important, or whether an inverted drinking glass would also do the job.

Beer glass (0)

hochwald (551915) | more than 12 years ago | (#3175259)

Sam Barros has used a beer glass [powerlabs.org] to contain his plasma.

My experiment using a glass jar [tripod.com]

The problem when you don't use something to contain the plasma in the oven is that it can get sucked throuygh the vents by the fan, or sometimes it floats near the magnetron and destroys the mica covering.

Sci-Home (2, Interesting)

linuxator (529956) | more than 12 years ago | (#3172587)

Rules :)
How many CD's have you burned in your microwave oven? And have you build your own Tesla trafo? If not, then give them a try also...

Don't Forget Kids... (5, Funny)

Greyfox (87712) | more than 12 years ago | (#3172588)

This is extremely hazardous and should never be tried at home. That's what the microwaves at work are there for!

Re:Don't Forget Kids... (1)

AlaskanUnderachiever (561294) | more than 12 years ago | (#3172753)

I also encourage you to use your local University Cafeteria microwave. I mean you ARE paying those student fees for a reason and this is sorta educational. . . not like that silly flaming pop tart thing. . .

What if you DON'T heed the warnings... (2, Interesting)

Calrathan (114381) | more than 12 years ago | (#3172589)

The page has a bunch of warnings saying that you shouldn't keep the microwave on for more than 10 seconds because the glass container is getting hot... If you do and it melts the glass, will it attack the ceiling of the microwave itself next? =)

Anyone have a spare microwave they don't mind sacrificing to see what happens if you just keep it going? :) (don't forget to document and give us a link!)

Re:What if you DON'T heed the warnings... (2, Funny)

j3110 (193209) | more than 12 years ago | (#3172601)

yeah... just before you do it, give us your name, so we can link to your darwin award! :)

7-11 (3, Funny)

BCoates (512464) | more than 12 years ago | (#3172626)

There's always a funky-looking microwave in 7-11s for cooking your burritos and whatnot...

Re:7-11 (0)

Anonymous Coward | more than 12 years ago | (#3172669)

and for starting plasma experiment fires?

Re:7-11 (0)

Anonymous Coward | more than 12 years ago | (#3172691)

University canteens also have those, because the food is almost always too cold...

A friend of mine once started a small fire inside one by trying to microwave bread. Chocolate apparently works too (leave it long enough...). Those items have the advantage of "plausible deniability"...

Re:What if you DON'T heed the warnings... (1)

skinfitz (564041) | more than 12 years ago | (#3172636)

...it knackers your microwave! True! (you DONT want to know how I know this)

Re:What if you DON'T heed the warnings... (2)

Detritus (11846) | more than 12 years ago | (#3172649)

Running a microwave oven with no load (food or water) can damage the magnetron.

Re:What if you DON'T heed the warnings... (2)

BlueUnderwear (73957) | more than 12 years ago | (#3172684)

That's why they suggest also putting a small glass of water inside, along with the experiment.

Re:What if you DON'T heed the warnings... (1)

Physics Dude (549061) | more than 12 years ago | (#3173263)

The Plasmoid IS a load on the microwave... just where did you think all that light and heat was coming from anyway? :)

Re:What if you DON'T heed the warnings... (3, Informative)

BlueUnderwear (73957) | more than 12 years ago | (#3172705)

If you do and it melts the glass, will it attack the ceiling of the microwave itself next? =)

No. Actually, as soon as the plasmoid touches a conductive (metal) surface, it shorts out and just collapses. The purpose of the glass vessel is not to protected the ceiling of the microvave oven, but rather to protect the plasmoid ;-)

Re:What if you DON'T heed the warnings... (1)

SpamSlapper (162584) | more than 12 years ago | (#3178229)

We tried this during a mate's buck's night last week. Works just fine with a candle and a beer glass! We stopped after the beer glass shattered.

Sec0nd First P0st (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#3172590)

This is the second First P0st, so please do not moderade me down nooooo please not, don't do it!

btw what is this lamenessfilter everyone is talking about? does not seem to work...

Re:Sec0nd First P0st (0, Offtopic)

Anonymous Coward | more than 12 years ago | (#3172641)

btw what is this lamenessfilter everyone is talking about? does not seem to work...

Try posting some ASCII art like this [goatse.cx] , and you'll get bitchslapped by the filter.

Re:Sec0nd First P0st (0)

Anonymous Coward | more than 12 years ago | (#3172778)

No, actually the original poster is right, it still does not seem to work.

2nd post! (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#3172591)

What what?!!

GDP thruster? (1)

bleak sky (144328) | more than 12 years ago | (#3172595)

I watched the video after reading the article, and I must say I'd be getting the hell out of there when it flashed that bright blue... Seriously, it's quite an interesting experiment, though I'd be afraid to put anything other than food in my own microwave.

Their article on their GDP thruster design is also pretty interesting - does anybody know how viable this would actually be?

Re:GDP thruster? (2, Informative)

Anonymous Coward | more than 12 years ago | (#3172698)

...though I'd be afraid to put anything other than food in my own microwave.

Who said you had to use your own? 7-11's, university canteen's, your workplace, etc. all have "public access" microwave ovens which are perfect for this purpose...

Other items of interest:

  • eggs (you said you were only concerned about putting non-food items inside...)
  • pencils: they'll burn pretty quickly
  • pencil mines: they get so hot that they can melt glass...
  • soap: if you try this, make sure your microwave oven is very big (or only use a rather small filing of soap
  • the newest MSDN CD's from work (perfect for doing in the office kitchen!). Those make great office ornaments, but it's probably best if your boss and/or colleagues don't see them... Microsofties are known for their lack of sense of humor, and might not appreciate it...
  • chocolate, bread (again, if you're concerned about putting non-food items inside...)

Re:GDP thruster? (2, Informative)

Sunda666 (146299) | more than 12 years ago | (#3173019)

GDP thrusters are a very kewl concept, but I think they might be very poluent.

Man, that site is full of cool research, check it out, especially the lifter experiments.

Just as much fun... (4, Interesting)

Deltan (217782) | more than 12 years ago | (#3172596)

Take a non conductive container and fill it part way with water. Take your standard every day 60 Watt light bulb and submerge the threaded end into the water. Put the container into the microwave & turn it on.

Fun light show...wheee!

Re:Just as much fun... (2)

William Tanksley (1752) | more than 12 years ago | (#3173471)

Quite true! It's interesting that the resulting light show is _not_ monochomatic, as you might expect -- it flashes through many colors. Definitely worth doing.

I'm not sure whether it matters that the threaded end is submerged (or even touching the water), though. I've always had it that way, but only because that's how the bulb sits. Maybe I'll have to try...

-Billy

Re:Just as much fun... (3, Informative)

Deltan (217782) | more than 12 years ago | (#3173695)

If the threaded metallic end is not submerged the metal will spark in the microwave and you might blow up the whole works.

Re:Just as much fun... (2)

William Tanksley (1752) | more than 12 years ago | (#3173981)

I've sparked metal in the microwave before (aluminum foil or an old CD). What's the danger? What exactly is going to "explode"?

True, you don't want to do it heavily or with an otherwise empty microwave; the magnetron has enough heating problems anyhow (hear that noisy fan?); but that's why you also use a dish of water, to give the microwaves something to be absorbed by. Note that the water isn't conductive (we're not adding salt), so there's no reason for it to innately prevent sparks.

I'm going to have to try this with my spare microwave. While hiding behind a concrete wall, holding a panic switch. I'm a pyro, not an idiot :-).

-Billy

Re:Just as much fun... (2)

Deltan (217782) | more than 12 years ago | (#3174437)

Well.. the first time I tried it the tip wasn't submerged the whole way and the bulb exploded in the microwave. I'm not sure if that was the reason it happened but after fully submerging the threads it just gave me a pretty light show.

Re:Just as much fun... (2)

William Tanksley (1752) | more than 12 years ago | (#3174601)

Facinating! I'll have to try to recreate that. Was there any microwave damage?

I know that I've done it before without complete submersion -- perhaps I was just (un)lucky, or perhaps only the tip matters, or maybe it only hurts if there's sharpened metal (that's a general rule with MWs -- area doesn't matter, only edge).

Thanks for the pointers -- and I think I'll have to say that newbies should start by submerging their threads. At least until we figure out why yours exploded.

Anyhow, this is probably my favorite demonstration; quick, easy, cheap.

-Billy

Seen this before, be carefull! (5, Informative)

j3110 (193209) | more than 12 years ago | (#3172598)

I was going to try this a year ago, but decided that I didn't really need a darwin award :) You can do it with any glass bowl and anything that burns in any microwave that you feel safe doing it in :) The brown gas you see, NO2, is toxic and is found in cigarette smoke. Be careful, it's arguably the most harmful substance in cigarettes. Not good for the atmosphere either :) I really don't think there is that much in cigarettes, and I would urge anyone foolish enough to do this (like me after a few drinks) to NOT breath the funky air! :)

You have been warned! :)
http://www.epa.gov/oar/aqtrnd95/no2.html
bad stuff really :) when it dissolves in your lungs, it's likely to make nitric acid, which is like to make your lungs liquid if you breath too much.

Re:Seen this before, be carefull! (5, Funny)

The Bungi (221687) | more than 12 years ago | (#3172633)

bad stuff really :) when it dissolves in your lungs, it's likely to make nitric acid, which is like to make your lungs liquid if you breath too much.

Dear Sir,

I smoke 3 packs a day of unfiltered Camels. Does that mean I can try your experiment with alacrity?

Please respond to me immediately.

Sincerely,

satamarnayananamayanapan guchanda
sat@hotmail.com

Re:Seen this before, be carefull! (0)

Anonymous Coward | more than 12 years ago | (#3172672)

We're sorry. All smoking your brains out gets you is higher insurance rates. hahaha.

Re:Seen this before, be carefull! (1)

DickScratcher (566134) | more than 12 years ago | (#3172694)

I tried rolling a camel once but it kept going out. Please advise. Regards, Mr Scratcher

Re:Seen this before, be carefull! (3, Funny)

Alsee (515537) | more than 12 years ago | (#3172869)

NOT breath the funky air!

Is that kind of like "Don't eat the yellow snow"?

-

Not a goatse link (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#3172604)

Interesting Britney Spears trivia (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#3172640)

  • Initially Britney used padded bras because it was decided she would get breast implants eventually (consequence: you see curves but no skin)
  • Then she got a boob job
  • Now she can exhibit more skin around her breasts.
Anyone has more info on this?

That's why I love consumer electronics (1)

Inthewire (521207) | more than 12 years ago | (#3172615)

The cavity magnetron was a state secret [radarworld.org] during the Second World War.
Now it's the centerpiece of an, oh, maybe $80 toy [dealtime.com] , destroyed in the name of junk science.

y'all don't do enough drugs (0, Flamebait)

sister_snape (552198) | more than 12 years ago | (#3172620)

to have an excuse to not remember that this story is OLD news on slashdot. Even I remember that much. Or was it just a s-l-o-w day and you needed the filler?

More microwave experiments (5, Informative)

eram (245251) | more than 12 years ago | (#3172621)

Some other potentially dangerous experiments with CD:s, light bulbs and other objects in microwave owens can be found here [utwente.nl] . Looks interesting, but I personally wouldn't do that in my own kitchen.

Re:More microwave experiments (1)

Ptolemarch (11506) | more than 12 years ago | (#3172854)

I just tried the lightbulb. It was quite impressive: no results for about two seconds, then some very pretty colors, though I was slightly worried that somehow the radiation produced would be unhealthy. I hope not. After a few seconds (10 or so), it exploded, with little bits of glass coating the bottom of the microwave.

Oops.

Good thing I was already planning on doing some cleaning today.

Tons of interesting stuff (1, Interesting)

Anonymous Coward | more than 12 years ago | (#3172639)

There's tons of interesting research on that site,
like field effect propulsion and antigravity.
Check http://jnaudin.free.fr/advpmnu.htm

care to explain it? (0, Redundant)

Johnny00 (213878) | more than 12 years ago | (#3172643)

This is all good, but IANAP (I am not a Physicist), can someone explain how this is working or point me to an explaination?

Re:care to explain it? (1)

trl (561794) | more than 12 years ago | (#3175545)

*shrug* your post is marked 'insightful' though... makes you wonder...

Search engines all over this (1)

automag_6 (540022) | more than 12 years ago | (#3172645)

I read the article. It looked kinda nifty, but I wanted to know more, since I was still very fuzzy on exactly what the heck a plasmoid was. I searched on google, and that page was the #1 result, and it was #5 on Ask Jeeves.

I kinda like asking Geeves questions "Hey Jeeves, old buddy, do you happen to know what the heck a plasmoid is?" It's so much more conversational than barking orders like "plasmoid" at google. *grin*

Marshmallows: poor man's plasma (5, Informative)

Oink.NET (551861) | more than 12 years ago | (#3172654)

For an even quicker thrill, try putting marshmallows in the microwave.

For those too lazy to actually get up, find marshmallows and find microwave, use this applet [colorado.edu] to cook them virtually, or check out this time lapse video [angelfire.com] .

For those craving more of an intellectual thrill, find the speed of light with marshmallows [bowlesphysics.com] using a microwave.

Please don't link directly to angelfire videos (0)

hochwald (551915) | more than 12 years ago | (#3174880)

Try going here [angelfire.com] instead, then you can download the video, as sites like angelfire want to pay for their their bandwidth by showing ads.

what exactly is 'plasma' (2, Interesting)

haedesch (247543) | more than 12 years ago | (#3172655)

i may have missed something in the article, but when does a substance qualifies to be a 'plasma'?
It sure looks nifty but that can't be a criterium, right?

Plasma: (2)

Hektor_Troy (262592) | more than 12 years ago | (#3172845)

An electrically neutral, highly ionized gas composed of ions, electrons, and neutral particles. It is a phase of matter distinct from solids, liquids, and normal gases.

Re:what exactly is 'plasma' (2, Informative)

Ozan (176854) | more than 12 years ago | (#3172852)

Often gas that is emitting light is being falsely named plasma, but the atoms are only being stimulated by heat or light and emit light. A real plasma is a gas which is stimulated so high that the atoms are ionized and free electrons are floating between them.

Nice Blue flash (0)

Anonymous Coward | more than 12 years ago | (#3172662)

If he could see it with his eyes shut, or in the next room with the door shut, he might be onto something.

Re:Nice Blue flash (1, Interesting)

Anonymous Coward | more than 12 years ago | (#3172701)

A blue flash? Like this guy [lavitt.ca] ?

this page is not wide enough (-1, Troll)

Anonymous Coward | more than 12 years ago | (#3172720)

this.page.is.not.very.wide.i.like.wide.pages.i.lik e.the.work.that.klerck.does.to.make.pages.wide.it. brightens.up.my.otherwise.miserable.day.to.come.to .slashdot.and.see.those.nice.wide.pages.just.goes. to.show.how.lame.cmdr.taco.and.co.are.they.cant.ev en.fix.a.simple.page.widening.bug.and.they.accuse. microsoft.coders.of.being.lame.let.he.who.is.witho ut.sin.cast.the.first.stone.or.something.like.that .Whats.happened.to.egg.troll.recently.i.miss.egg.t roll.he.was.one.of.the.good.trolls.now.we.are.left .with.fuckwits.like.robo.troll.arrg.

Re:this page is not wide enough (-1, Troll)

BlueUnderwear (73957) | more than 12 years ago | (#3172743)

You need to put a space before the dots, or else slashdot will break the lines:

this .page .is .not .very .wide .i .like .wide .pages .i .like .the .work .that .klerck .does .to .make .pages .wide .it . brightens .up .my .otherwise .miserable .day .to .come .to .slashdot .and .see .those .nice .wide .pages .just .goes . to .show .how .lame .cmdr .taco .and .co .are .they .cant .even .fix .a .simple .page .widening .bug .and .they .accuse . microsoft .coders .of .being .lame .let .he .who .is .without .sin .cast .the .first .stone .or .something .like .that .Whats .happened .to .egg .troll .recently .i .miss .egg .troll .he .was .one .of .the .good .trolls .now .we .are .left .with .fuckwits .like .robo .troll .arrg .

Maybe you also need to put it into a link; unfortunately, I have no IE to test it...

Moderidiots on crack! (-1, Flamebait)

Anonymous Coward | more than 12 years ago | (#3172766)

Parent is informative, not a troll. Indeed, it conveys useful information, which parent-of-parent can use.

Manufacturer Warnings of Old (5, Funny)

MyNameIsFred (543994) | more than 12 years ago | (#3172724)

30 years ago my father owned an applicance store, back when microwave ovens were becoming popular. GE told the store owners about some neat tricks to impress the customers.

Nothing draws them in like putting light bulbs in the microwave and letting the magic turn them on.

Not too long after they told us how to do the tricks, GE yelled STOP. It's scaring the bejebbus out of the public. We're getting frantic calls about the death rays.

How times have changed.

Suck my pussy (-1, Troll)

Anonymous Coward | more than 12 years ago | (#3172726)

this.page.is.not.very.wide.i.like.wide.pages.i.lik e.the.work.that.klerck.does.to.make.pages.wideit.b rightens.up.my.otherwise.miserable.day.to.come.to. slashdot.and.see.those.nice.wide.pages.just.goes.t o.show.how.lame.cmdr.taco.and.co.are.they.cant.een .fix.a.simple.page.widening.bug.and.they.accusemic rosoft.coders.of.being.lame.let.he.who.is.withut.s in.cast.the.first.stone.or.something.like.tha.What s.happened.to.egg.troll.recently.i.miss.egg.troll. he.was.one.of.the.good.trolls.now.we.are.left .with.fuckwits.like.robo.troll.arrg.

Re:Suck my pussy (-1, Troll)

Anonymous Coward | more than 12 years ago | (#3172758)

Man, you both fucking suck, and it doesn't even cme close to widening the page.

Why not just go back to your porn collection?

Re:Suck my pussy (-1, Troll)

Anonymous Coward | more than 12 years ago | (#3172773)

You're right. On a web browser, it doesn't widen the page. However, on Internet Exploder, it's does... Thus, these are not trolls, but rather educational tools to show users how to behave on the internet.

Re:Suck my COCK (0)

Anonymous Coward | more than 12 years ago | (#3174416)

Well, I'm using Exploder and the page sure ain't wide. Seems like Taco & Co. got around fixing the stupid page widening bug.

Easier way (2, Interesting)

vossman77 (300689) | more than 12 years ago | (#3172738)

We used to build plasmoid balls as physics demos for kids. My professor said it isn't bad on the microwave either.

Instead of building that complex machinery list at the webpage all you need is a standard 2-liter bottle of soda (pop for Midwesterners, coke for Texans). Cut the bottom off and discard the top (usually about 3-4 inches should do) poke hole in the side for airflow.

Now you need something to hold the match upright e.g. a.b.c. gum or a cock like them.

Light the match close the door, start the microwave. Eventually your 2-liter will melt causing even more fun.

vossman

Re:Easier way (2, Funny)

JonWan (456212) | more than 12 years ago | (#3172774)

Now you need something to hold the match upright e.g. a.b.c. gum or a cock like them.

I think I'll pass on that one.;-)

Tune in next week when we will show you how to build a hydrogen fusion containment vessel using your bath tub.

Old story (0)

Anonymous Coward | more than 12 years ago | (#3172818)

I have seen this on Slashdot a while ago. How come you call these old reruns news?

Big deal (2)

Syberghost (10557) | more than 12 years ago | (#3172820)

You wanna make plasma? Light a match.

Re:Big deal (3, Informative)

XNormal (8617) | more than 12 years ago | (#3173197)

The flame of a match is just hot gas, not plasma. The flame's light comes from incandescent particles of carbon, not ionized atoms.

Re:Big deal (2)

Graymalkin (13732) | more than 12 years ago | (#3176252)

Hot flames most certainly are ionized which is why this experiment doesn't work well with candles because the flame is too cool. The ionized carbon from the toothpick burning is what is causing the light in this shmoo. Another experiment is to ionize water and spray it out of a mister, if you light a match or other moderately hot flame and put a paper card between the mist nozzle and flame the water will go under the card and extinguish the flame. There's a sprinkler system designed for data centers which instead of normal sprinklers uses ionized misting nozzles to spray a sort of ionized fog which is attracted to the flame and snuffs it out.

Same sort of result but generated a different way? (1)

zytheran (100908) | more than 12 years ago | (#3172858)

The first description on the website below on generating ball lightning using a Tesla coil seems to use the same concept for an ignitor and relies on carbon soot for ball formation.
http://www.amasci.com/weird/unusual/bl .html
Whats the link's here people? A fair bit sounds the same. Now if you could get ball lightning inside your microwave, the sort that goes through glass....

Re:Same sort of result but generated a different w (0)

Anonymous Coward | more than 12 years ago | (#3173728)

the sort that goes through glass....

Even if it went through glass, this wouldn't help it to get outside, as it needs the microwaves to get its energy. And, what's more: the metal lining in the front door would stop it.

The "humming" explained (3, Informative)

Alsee (515537) | more than 12 years ago | (#3172902)

If you look deeper into the website you'll see that the author goes into detail analyzing the sound produced. The humming sound is simply the frequency of the microwave electronics. The plasma itself would normally be silent. It is acting as a "speaker" based on the varying energy it gets from the microwave oven. If you take a look here [google.com] you'll see projects that use the plasma effect as an extremely high quality tweeter.

-

Re:The "humming" explained (2)

XNormal (8617) | more than 12 years ago | (#3173190)

The 250Hz sound is the 5th harmonic of the mains power (electricity in France is 50Hz). If you look carefully at the spectrum you will also see a small peak at the 3rd harmonic (150Hz). The glass vessel and/or the microwave oven itself act as a resonant cavity that emphasizes these frequencies. The fundamental frequency (50Hz) is so weak that it drowns in the noise. There are no even harmonics because the waveform is symmetrical.

My email to Jean-Louis Naudin (0)

hochwald (551915) | more than 12 years ago | (#3175173)

your site at this address mentioned a buzz produced by
the plasma, this is produced by the cheap voltage
doubler setup used in most microwaves. An explanation
can be found here:-
http://www.mtt.org/miscellany/fiftyanniv/c p_01intr o.htm

Also many sites that talk about the repair of
microwave oven's
such as
http://www.bithose.com/serfaq/REPAIR/F_micfaq. html
and
http://www.gallawa.com/microtech/double r.html
detail the action of the doubler

Just tried it out... (4, Informative)

BlueUnderwear (73957) | more than 12 years ago | (#3172906)

Having no suitable sperical vessel ready, I used a sawed-off plastic mineral water bottle. Having no tooth-picks ready either, I just stuck the match itself into the cork. As recommended in a previous Slashdot story about the subject, I removed the revolving plate, and put a glass of water into the back.

First attempt: the match always went out before it could produce any plasma ball. D'oh

Second attempt: rather than using a match, I stuck a long pencil mine into the cork, and set the oven to thirty seconds. 29 seconds of nothing. Then a loud whizz, and the time ran out before it could get any more interesting (should've set it to a minute). However, this one second of action was enough to fill the bottle with a mysterious thick white fume. Question: is this the nytrogen oxyde that the article speaks about, or was it only the plastic burning (other than the fumes, there were no obvious traces of burn on the bottle). Worrying that the fumes might be toxic, I didn't repeat the experiment.

Re:Just tried it out... (3, Interesting)

BlueUnderwear (73957) | more than 12 years ago | (#3173358)

Ok, curiosity was stronger than worry:

Third attempt: more or less same setup as previously, but a little less water in the "load" glass, and using a larger cork, so that the mine could stand upright without leaning against the bottle. A spark appeared already early on in the experiment, but didn't cause a ball. However, the same candle-flavored fumes started appearing again. Then it hit me: they came from the cork, which was heated by the pencil mine stuck into it. Indeed, the cork had small traces of burn. Still no plasmoid, alas.

Fourth attempt: Figuring that strength of microwaves might depend on orientation, I broke a small piece off the mine, and stuck it into the cork, horizontally, rather than vertically. Soon indeed sparks, and then a ball of fire appeared, but unfortunately the pleasure was rather short-lived: the plasmoid set fire to the plastic bottle, and thus I had to stop the mess. Ok, I'll have to hunt for a suitable glass vessel.

Re:Just tried it out... (-1)

real_b0fh (557599) | more than 12 years ago | (#3174715)

jeezus christe, be cheap, use a water cup or something, but a plastic bottle? haha

Re:Just tried it out... (2)

Deagol (323173) | more than 12 years ago | (#3174870)

Ok, I'll have to hunt for a suitable glass vessel.

Go to Home Depot or any home improvement store and go to the lighting department. You can get glass globes for light fixtures for a couple of bucks. I can only assume they are heat tolerant, as lightbulbs get prety hot.

big fun time (2, Interesting)

68030 (215387) | more than 12 years ago | (#3172953)

I've tried this several times with varying
degrees of sucsess. For those of you with
plenty of time, try repeating the experiment
with a glass container not given enough
ventilation. When the plasmoid ignites
(lights? is born? stabilizes?) it radiates
a lot of heat. Without proper ventilation
the glass vessle will jump upwards with a
satisfying bang. The flash is quite impressive
for the easily amused.

As for the sound, there is some sound produced
other than the low pitch hum of the microwave
itself, sort of a buzzing noise.

I once saw a page describing this experiment,
but this person had taken the magnetron tube
out of the microwave, mounted it in a very
sexy looking raygun type configuration. It
looked exceedingly dangerous. I'm sure all the
reflected radiation was an excellent
stimulation to his fertility.

Such wonderful toys.

Re:big fun time (1)

Jabroni54 (320749) | more than 12 years ago | (#3173111)

To quote my conversation with my roommate who wished to reproduce the results of his experiment one of the first time this showed up on Slashdot.

Me: So what are you going to do after you are done, i.e. made the Plasmoid Fireball?

The Roommate: We'll just open the door and let it go free like nature intended.

Eheheheh.

Re:big fun time (2)

Renraku (518261) | more than 12 years ago | (#3173443)

I made a microwave gun in electronics. Proper shielding, power, everything. I was..16 maybe? I made sure it was safe on me. My first experiment was to aim it at a computer. Insta-bluescreen/reboot. That was cool. I also told the people around me not to step in front of it, but apparently they had more things to worry about than the thermal integrity of their flesh/organs/pocket contents.

HPM's DEW's etc. (0)

hochwald (551915) | more than 12 years ago | (#3175094)

Someone reassembling their microwave [swbt.net]
Sam's site with his remounted magnetron he has used for making plasmas [powerlabs.org]
I can't find the Hootenanny site right now, but it used to detail the contruction of a DEW with microwave parts and a horn. They used to upset the operation of some computers.
Slava's site detailing the use of a magnetron, capacitors and horn to make a HPM [svbxlabs.com]

The classic way (1)

billsf (34378) | more than 12 years ago | (#3173473)

While I think the concept of this method is sound, the classic method works well too. Take enough "steel wool" (the real stainless stuff works best) and spread out to about 25^2cm. Finely grind some charcoal and place a couple grammes on the cleaning pad. Place this whole thing on a ceramic surface that can take *extreme* tempatures. Turn the nuker on high (600W is wimpy -- use a dual-magnetron 2000W model for best results) and watch the show. Beware it gets very hot, so when the plasma really gets going, its time to quit.

It is fairly safe, but the oven should be 'expendable'. AFAIK, no toxic fumes are produced as in the case of CD's and if you don't destroy your oven, you can still warm over your food.

It's baaaaack ... (1)

JoeGee (85189) | more than 12 years ago | (#3173490)

Hey Johnny, want a neat project for science fair? Here's how you trash mom's microwave, make toxic gases, and endanger your reproductive future all in one simple experiment.

This same page was posted a year or so ago. It's neat, it's fun, it has geek-appeal, and it's mildly dangerous in an MTV "Jackass" sort of way. :)

Forget the microwave: Aircraft plasma propulsion (2)

schmaltz (70977) | more than 12 years ago | (#3173678)

The greater context [jnaudin.free.fr] of this guy's site is a series of experiments aimed at using plasma generators to provide thrust for a new generation of aircraft. With one type of thruster, they've achieved accelerations up to 480 m/s (for the liquid medium, not the aircraft, not yet.)

This was news to me, and I'm finding the concept and science [jnaudin.free.fr] behind plasma thrusters fascinating (this is a link off the microwave page.)

Plus, there's a far more interesting experiment, where he shows you how to build your own plasma panel [jnaudin.free.fr] .

Re:Forget the microwave: Aircraft plasma propulsio (-1)

real_b0fh (557599) | more than 12 years ago | (#3174901)

more than that

check that flying capacitors (the lifters)

kicks butt.

new pain (0)

Anonymous Coward | more than 12 years ago | (#3175252)

Wow, think of how i can hurt myself now!

Kind of safe and very fun (1)

spike hay (534165) | more than 12 years ago | (#3176035)

I've done this. Take lit matches and put them in the microwave. They will make blue or white bursts of plasma. It's great fun!! Also try steel wool.It makes all sorts of sparks. If you take a paperclip and bend it so the two ends are about 3 cm away from each other, you can make a great arc that can melt stuff.

The plasma thing with the match works because the flame is plasma. Plasma absorbs microwaves. The microwave energy heats the flame more, superheating air around it, and it makes a big burst of brillianltly bright plasma, sometimes. Ive had huge bursts that go up to the top of the microwave out of a little burning match.

It is completly safe to you. Absolutely safe. Once the microwave is off the plasma/arc/whatever instantly dissapears since it's power source is cut off. It may not be safe for your microwave.

To be safe with you microwave, take these steps:

1. Have a cup of water off in the corner of you microwave.
This prevents your magnetron from overheating by absorbing excess microwaves. Yes, it may reduce the intensity of the plasma a little, but it saves your microwave. If you do this, there is no real way of hurting your microwave. The magnetron can't be fried if you got some water in there. The worst that could happen is you could get scorch marks in your microwave.

2. Limit the time to about 20 secs. The cup of water should prevent anything bad from happening. Just to be safe though.

Also, use matches, not a candle. A candles' flame is not hot enough to absorb enough microwaves to make a good plasma.

Cheap spherical glass vessels (1)

shpoffo (114124) | more than 12 years ago | (#3181136)

Go to you local home improvement store - in the lighting section you can buy clear glass covers for external post lamps. Be care when using them to experiment with microwave plasmoids - the glass is cheap and will easily crack under the intense heat of a plasmoid.

also, beware that plasmoids produce 'real' heat that will keep the glass hot for a longer period of time (as opposed to the 'fake' microwave heat that seems to quickly dissipate)

-shpoffo
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