The Big Flying Fox
Well, this isn't science as much as Civil Engineering. back in the early 1970's, my BFF Wayne had this bright idea. We had already build ourselves a treehouse in a big gum tree in the side yard of his place, maybe 15 feet high. Climbing up and down the ladder was a pain, so Wayne decided that the easy way down was to build a flying fox, from treehouse platform level to the ground. All we needed was a suitable rope, with a pulley on it.

So, we scrounged the anchor line from his father's fishing dinghy - about 40 feet of wire rope, with an anchor on one end. This anchor was not a substantial affair- just a four pronged device made from bent (mild) steel. We put the anchor through the fork of a convenient tree, maybe 30 feetout from the treehouse. The other end was attached to the trunk of the tree a few feet above the treehouse platform, and a suitable pulley put on the wire. We made a seat, attached that to the pulley, and we were ready to go.

Wayne, as chief engineer, tested if first. Woosh - he went zooming down the flying fox, and landed gracefully on the ground below. I pulled the "fox" back to the treehouse level, and then it was my turn. More fun that sex! So it was Wayne's turn again. As soon as he pushed off from the platform, ARRRRGH!!!! and CRASH as the wire rope pulled away from the tree at the far end, and Wayne flew like a brick, straight down at a great rate of knots.

Our weight (as little as it was) was too much for the mild steel boat anchor - it had pulled out from between the tree trunks, and what was originally four curved flukes, designed to hold his father's fishing dinghy at anchor were now straight. The rest of the afternoon was spent re-bending the anchor back into a shape resembling its original appearance, before his father came home from work and saw what we had done.

Needless to say, both of us were misguided enough to initially attempt careers in engineering....
(Maclir, Wed 15 Aug 2012, 16:28, Reply)

Cillit Bang vs. Kill It, Bam!
Back "when we woz studends", around 2005, Cillit Bang spokesperson "Barry Scott" was an internet craze for some bizarre reason. At least, until people got sick of the made-up marketing device.

Anyhoo, we discovered that our 99p store stocked what we believed was a cheap knock-off of Cillit Bang called "Kill it, Bam!". In the interests of science, we decided to perform an experiment to find out which was better, using the cleaning test of choice - old pennies. The results may surprise you. Or possibly not, as we got featured in a b3ta newsletter that week.

Interestingly, after we got featured in the newsletter the people who made "Kill it, Bam!" got in touch with us. It turns out they're the same people who make "Astonish" which I vaguely remember being advertised on late night TV once. Anyway, their email was a little bit sarcy as apparently they felt their product was above merely cleaning pennies (And in fact they informed us that Tomato Ketchup does an even better job - which it actually bloody well does) but they did have the good grace to send us a shitload of various cleaning products, such as de-limescaling tablets for the toilet and feather dusters.

Being students, we didn't really use any of it for anything productive like cleaning, but it was still bloody nice of them.
(Kushan just wants to fit in..to your mum, Wed 15 Aug 2012, 15:51, Reply)

I'm working on a faster than light engine.
I'm about halfway finished. Pretty sure I'll have it done by 1995.
(apeloverage committed the vile act of onanism on, Wed 15 Aug 2012, 13:25, 11 replies)

Kitchen Science Experiments are part of my job*
And one of my favourites is being able to crush a can with steam. It's easy, fairly safe and good to do at bbqs.

You will need:

Empty drinks can (without a widget)
A source of heat (gas/electric hob, BBQ, fire)
1 bowl of cold water
Something to pick the can up with - BBQ tongs or similar work well

What to do:

Take the empty beer/soft drink can, pour in a double shot of water (you shouldn't need more than that) and place it on your heat source. After a few minutes you should hear thew water inside boiling vigorously.

Now, grab your bowl of cold water (you don't need to bother with ice, cold tap water is fine) and put it close to the now very hot can.

Using your tongs (not your toungues, unless you're into that sort of thing) pick up the hot can and rapidly turn it upside down and plunge into the cold water.

The can will instantly be crushed, usually with a very satisfying sound.

Here's the science bit:
When you're heating the can, the water is boiling off into steam. This fills the can, displacing the air that was inside. When you then cool the can, the steam rapidly condenses back into water. This takes up less volume, creating a vacuum in the can. The air pressure around the can is therefore much higher than the pressure inside, and makes light work of the flimsy aluminium structure.


<sub>* - No really, they are. Have a look here for more.

Spammy plug: I'll be doing some home science demos on BBC Radio 5Live on Sunday 19th August, 7-10pm, in case you're interested in that sort of thing.</sub>
( TheAlmightyBeev, Wed 15 Aug 2012, 13:22, 24 replies)

I once tried to tell my schoolfriends that I had invented an invisibility cloak
I even took it to school to show them, but it didn't work, they saw straight through me.
(username failed moderation, Wed 15 Aug 2012, 13:21, 3 replies)

Home Etching Device
Being into electronics when I was younger, I decided early on that standing next to a tray of etching fluid with a PCB in it just so I could tip it back and forth for 20 minutes was boring as hell.

So I set about thinking up designs for an etching machine.

After several attempts to build a motorised tray agitator from lego (I still have Technic lego with orange stains on to this day), my attention turned towards bubble etching.

Not having a suitable thin tank to place the pcb in, I found the biggest glass jar I could (Nutrasweet jar I think).

Now, the bubbles would be provided by a 12V car screen washer pump and some plastic tubing from Halfords. All I needed was a basket to put the pcb in and lower into the jar full of etching fluid.

Whilst at Halfords, I noticed a pack of aluminium mesh, the type used for car bodywork repairs. Purchased, and off home to sculpt a basket. After hours of careful cutting, folder and stitching together, the basket was ready.

The time came to try out the Mark II etching machine. Parents out that evening, PCB laid out with transfers, into the basket and etching fluid at the ready. I lowered the basket into the jar full of etchant, closed the lid and turned on the pump.

WOW! Look at all the etchant fizzing up - it's working great.

Hang on, the fizz is up to the lid, what happens if it keeps going?

Simple, the pressure build up causes the etchant to force its way through any channel it can find around the lid, out over the table top and start pooling up! Shit! Mop it up, mop it up. Why won't it stop?? Bollox, how do I get this out of the house?

I disconncted the tubing, dumped the smoking/fizzing bottle of brown acid onto a tray, covered it in newspaper, ran outside and dumped it in an inconspicuous area of the garden.

The cleanup job was hard enough, the smell quickly removed by opening doors and windows, and on the parents' return they knew nothing.

Next day, I awoke to the sound of my dad in the garden...bollox! Later on, he asked if I knew what the hell the glass jar of brown sludge in the garden was. I explained it was a PCB I was etching, but left out a lot of the detail!

On closer examination, the aluminium basket had completely etched away - all that was left inside was my PCB, perfectly etched.

So now I know, etching fluid isn't just for copper - it's also for 14yo kids to mix with raw aluminium in a sealed jar for potential explosive fun.
( brown-wings Made with three kinds of butter, Wed 15 Aug 2012, 12:30, Reply)

A better robot.
When I was a kid I could be regularly found in my ‘secret lab’ situated behind my wardrobe. With all the troubles in the World I had been pondering what I could do to help mankind better itself. I had recently watched Robocop and thought a cyborg policeman would be pretty awesome but I had to chuck that idea away as I had no half dead person on hand. I then considered the other star of the film ED209, now if I could make my own version but one that could actually navigate stairs without going arse over tit then I would be onto a sure-fire winner.

So I drew up the schematics, got the relevant materials I needed and got down to work. It took me several weeks of hard grafting but in the end I was triumphant and my BoB486 was ready. It stood in my lab all gleaming and looking quite awesome, I picked up the remote control all set to give it its first test run.

With much anticipation I slowly started to press the button that would start up BoB486 when ‘BOOOOOOM’ it exploded into a gazillion pieces. I was rooted to the spot startled, “What happened?” I said to myself barely able to conceive what I had just witnessed. My beautiful creation, gone, destroyed in a matter of moments. How could this be?

Then I heard it.

The laugh.

The girly laugh.

I realised that I should’ve known the moment BoB had exploded.

I turned round and there by the self destruct button I had made just in case BoB ran amok stood my sister.

“DEE-DEEEEeeeeee” I yelled.
(ParaSitius is an Optimistic Pessimist, Wed 15 Aug 2012, 11:20, 14 replies)

Using your sister's new toy electric blender to make an "everything you can reach in the cupboard" drink
is a great way to spend an afternoon vomiting copiously.
( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 15 Aug 2012, 11:20, 5 replies)

Bet you can't rip a tissue
Taken from a book aimed at kids so if any of the internet shut-ins try this their massive right arms may prove too much for the experimant and end up with salt all over the floor.

What you will need
1 x Kitchen roll tube
1 x broom handle
1 x elastic band
1 x tissue (an ordinary 2-ply tissue should suffice)
Table salt

Method
Cover one end of the tube with the tissue and hold in place with the elastic band. Carefully pour in about 8-10cm salt. Hold the tube upright and ram the broom handle into the tube and try and tear the tissue. It won't.
The salt absorbs the impact of the broom handle and the tissue remains intact.
(TitanLX, Wed 15 Aug 2012, 10:48, 1 reply)

Time to shoehorn this one in....
As I think this must be someones own home science project

A few weeks ago I was cycling home from work through one of the more rough-and-ready- parts of the village I live in (where all blokes read the Sun/Daily Sport believing every word and women all aspire to appear on Jeremy Kyle). In an effort to make it look like they aren’t spending all the public’s tax money on expenses the local council have spent the last few months rebuilding the front walls of most of the houses, complete with metal gate and matching metal fence. I was sat at the traffic lights* when I heard the following exchange between two blokes (Neil and Dave) about Daves new garden improvement, a wooden fence added to the top of this wall built by the council that made the view into the garden impossible to anyone under 5 foot 5**:

Neil: Hey Dave, whats with the wooden fencing? Looking for a bit more privacy, because if you are that isnt going to work its too small?

Dave: No mate, we use the back garden mostly, this stuff is to keep the pedophiles out.

(Mon thinks WTF, did he just say what I think he said)

(Neil runs his hand over the cheap plywood/ bamboo type surface and nods)

Neil: Good thinking Dave, good to see you used the right paint for it too

Dave: You have to use this stuff, I made it thicker than recommended though cause the wife hated the first coat and the thicker it is the better it works against pedophiles

Neil: Haven’t your kids moved out?

Dave:Yeah but it’s always best to be safe, you never know, the grandkids could come up and they could be gone like that (snaps fingers)……. dirty buggers those Pedo’s

Neil: Yeah dirty buggers…..

Thankfully the lights changed so I had to leave before I burst out laughing and was beaten up by two dolescum blokes and their specialised fencing.

Now what the hell? Has this bloke built this special defense mechanism himself or does B & Q have a specialized section containing repellant for slugs, vermin and sexual deviants?

*Im not one of those twattish cyclists that jumps lights via the pavement

** Translated from local Barnsley dialect so all can understand
(mon bison powered by magnets, Wed 15 Aug 2012, 10:35, 5 replies)

Science = Fire, Sex lube and pickle cakes
Here are three tales of woe from my attempts to be all sciencey as a wee one.

When I was 12 I thought I would bake a cake as a surprise for when my mum got home from work. Found a recipe which called for cream of tartar. Being a stupid kid, I found some tartar sauce in the fridge and presumed that was what the recipe meant. Admittedly, the acidity in the sauce made the cake rise, but the powerful taste of pickle and the sharp smell which now permeated the kitchen made this endeavour less than successful.

When I was 14, I had a dirty pound coin. I decided to clean it by soaking it in methylated spirit. This did sod all, so I thought lighting the spirit on fire would speed up the fabled cleaning reaction. I then knocked the tin can I was using to the floor and set my bedroom carpet alight.

Finally, when I was 16, I found a recipe for home made sex lubricant online which was basically flour and water. A few months later when some friends and I were making use of my parents not being home for the weekend to enjoy some drinking time, we thought it'd be hilarious to make it. So I whipped it up and promptly forgot about it until an hour later I smell burning and find a nice half chalky/half sooty concoction clinging irremovably to my mum's expensive pan. I just threw it away and pled ignorance to the location of said pan.

This is why I studied a BA at uni.
( B.T., Wed 15 Aug 2012, 10:34, 3 replies)

Maxwell's Fishpond
makes ripples in water stop spreading out and refocusses them. Always. Wherever they start.

I made the first prototype at home using a circular chocolate box, some borrowed plasticine (thanks, haberkids!), and printed cutouts as guides for depth. Astoundingly, given how crude it was, it mostly worked.

See a description and a discussion of a proper version here: Intro with links to paper & video ...


Edit: apologies for the lack of explosions and/or poisonous chemicals.
(haberman is singing in the changes, Tue 14 Aug 2012, 22:51, Reply)

The last of the oven experiments
Like many other posters, during my teenage years, I enjoyed extracurricular chemistry experiments. This particular one involved popping into sainsburys and wilkos on the way home from school in order to buy icing sugar and sodium chlorate weedkiller. As others have noted, the weedkiller available was only about half sodium chlorate; the other half was sodium chloride, to act as a fire suppressant and spoil our fun. Sodium chloride was a very good choice in that it is really quite difficult to separate chemically, however there had obviously been a breakdown in communication somewhere as whoever had mixed the two had forgotten to make the grains the same size. A trip to the kitchen drawer later I possessed a separation system that was seemingly considered beyond the logistical capabilities of the IRA: a tea strainer.

After a merry half hour or so sieving the weedkiller, I mixed it with some icing sugar (my science teacher was surprisingly helpful in helping me do chemical equations with molecular masses in order to get the quantities correct). Piling the mixture up and lighting it had en effect similar to a flare- bright yellow light and clouds of smoke. The next step was to try and make a version of the "smoke pellets" somewhat less shit than the joke shop sold. My utterly foolproof plan was based around the fact that the sodium chlorate would not chemically decompose until it reached 250C; I could put the mixture in the oven at around 200C thereby melting the sugar, which would bind everything together when I let it cool and set.

Satisfied with the genius of my plan I put the mixture in an old bean tin and placed it in the oven. As a teenager with a short attention span I wasn't going to stand around in the kitchen waiting, so went and shut myself in the back room and messed about on the internet. It wasn't long before I was disturbed by my mum screaming something that roughly translated as "what the buggering fuck is my house full of smoke so thick I can't see a bastard thing". I learned two things that day: a bean tin half full of weedkiller and sugar makes rather a lot of smoke, and no amount of protestations that the thermostat in the oven is to fault will reduce the bollocking metered out for putting such a mixture in the oven. From that day forward I was banned from putting anything non-food based in the oven (well, for a few years; I recently got away with cooking old microwave transformers as part of an unrelated project to build my own welder).
(madsporkmurderer, Tue 14 Aug 2012, 22:24, 6 replies)

Did you hear the one about the mobius strip that crossed...no, wait.

( The Awful Puppy Bakery is still bored, Tue 14 Aug 2012, 21:25, Reply)

Magnets
Earlier stories about dynamos remind me of when I pressured my dad into making me a dynamo. I had collected the magnets from old TVs dumped on waste land - this was the early 70s so the B&W TVs had a pair of circular beam focussing magnets around the neck of the tube. The yoke coils provided the copper wire for the armature windings and he knocked up a neat commutator for it from bits of a tin can using snips. We hooked it up to a torch bulb.

It made perfect sense at the time to have the armature spinning through the hole of the circular magnets with the net result of nothing, zilch not a flicker.

I'll let you figure out why it didn't work and it wasn't the insulation on the wire.

I did get a reputation in the neighbourhood as the boffin and became the go-to guy when dumped telly screens needed a bricking. Very satisfying implosions would result.
(karnuvap, Tue 14 Aug 2012, 20:15, 5 replies)

Food dye is indestructible.
Of recent times I've been clearing out my house and workspaces of old things I will likely never use- old metal things I will never weld into anything, odd chunks of glass I don't immediately need, neon tubing that I don't have the time to work on... loads of stuff has gone to the landfill.

It's hot, sweaty work, and after a recent load I stopped at the gas station for a drink. Gatorade was on sale, so I got two bottles of electric blue sugar water with electrolytes. I drained them before I got back to the house.

The next morning as I went through my usual morning routine, I discovered that food dye does not break down in the digestion process.

I had shat out an entire clan of Smurfs.
( The Resident Loon Not a demographic. Do not measure., Tue 14 Aug 2012, 20:15, 3 replies)

A while ago I read about medical devices that would stimulate nerves into firing with laser light
so thought I would experiment. Now, seeing as laser pointers that are legal in this country are usually 1mW or less, that wasn't usually going to do the job and get through the dermal layers to tickle the nerve itself. However eBay seems to have no problem selling ons from Hong Kong which, by my estimate must be at least 10mW, to the point that while it doesn't burn or hurt when directed at the skin, you can definitely 'feel' it.

So what to do next? Well, I found the principle was much better demonstrated with spider legs. Flash the laser at their legs while they're walking and they stagger about like a drunken stag night, turn it off again and it's creepy crawly service as usual.
( Rotating Wobbly Hat That's not a banana. THIS is a banana., Tue 14 Aug 2012, 17:47, 3 replies)

Unobtanium with a McGuffin in it
makes a cheap fuel for a plot device.
(apeloverage committed the vile act of onanism on, Tue 14 Aug 2012, 17:08, Reply)

Five, Four, Packet of three
As a yoof I was into model rockets, as many here seemed to be. One particularly scientific one - which actually made it into a book on the subject - squirted ink out of the nosecone as it took off, so you could examine the flow patterns over the surface after it had completed its flight.

To do this, it was in two sections, with a bag of ink between them. The thrust pushing up compressed the bag and squirted the ink out of a row of holes around the nose. Now, after much experimentation, I discovered that the perfect way to make these bags was to use the teat at the end of a condom.

All was fine until my mum discovered the left-over condoms. After explaining why I had them, I think she didn't know whether to be relieved that there was a good reason, or sad because her son was such a sad geek that he'd probably never need them otherwise...
(moon monkey is busy making memories worth repressing, Tue 14 Aug 2012, 16:12, 3 replies)

Because it went faster than light.

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Tue 14 Aug 2012, 15:20, 7 replies)

2nd Law
I must have been about 9 or 10 when this happened. My dad, who's always had 'techno joy', got me a dynamo light set for my bike ('to save on batteries'). I'm not sure what they're like now, but back in the eighties, they were a bit rubbish (well mine was) so after a few weeks it was left rusting in the garage.

I can't remember what I'd watched/read, but I got the idea that, if you turn the wheel on the dynamo it makes electricity and my battery operated Lego motor needed electricity to turn round, so I hooked them together. 'Wicked' I thought, 'if I then hook up the motor so it turns the dynamo, it'll go on forever!'.

Anyway, unsurprisingly, I was having a bit of trouble making this work and I mentioned it to my dad. I thought he'd be really proud, but instead of the expected 'well done son', I got a grilling on the 2nd law of thermodynamics, which my dad summarized as 'you don't get aught for naught'.

Git. I got him back though, by laughing at his home made 'wind farm' many years later.
(Jimbojames Wishing every day could be like today, Tue 14 Aug 2012, 13:30, 19 replies)

Can of Lynx Africa and a Zippo
Endless home entertainment, also useful for making chemical burns on other peoples hands and lighting farts. Not to mention the scores of woman attracted to the manly smell.
(Shamelesspendant Better dead then smeg., Tue 14 Aug 2012, 13:10, 3 replies)

I went to a Catholic school for a couple of years.
One of the priests was some kind of mad scientist looking bloke and all he kept on about was a strange compound with Iron, Carbon and Potassium. I never did work out what it was for, and couldn't make it myself, but I hear he was retired to an island parish in Ireland and still goes on about it to this day.
(Me, I'm not... in any way intoxicated, Tue 14 Aug 2012, 12:29, 11 replies)

Home experiments with electricity
I wondered as a kid what would happen if I put my finger on the sparky bit that lights the gas stove & pressed the ignition button...

Wow! It makes your finger feel like it's gone massive for a second, then it's all tingly.

Further experimentation was halted however, when I got my little brother to try it. He cried & told our mum
(Professor Kenny Martin Hmm? What?, Tue 14 Aug 2012, 11:50, 2 replies)

I mixed Oxygen, Arsenic, Iodine and Sulphur
It was shit.
(Captain Placid 24/7 ball gags, brownie mix and clown porn, Tue 14 Aug 2012, 11:39, 2 replies)

Don't mix sulphur, helium and darmstadtium.
It'll just get you in trouble.
( BraynDedd Natasha Kaplinsky's labia majora, Tue 14 Aug 2012, 11:15, 3 replies)

I make jewellery from a copper/tellurium alloy
It's CuTe
(Captain Placid 24/7 ball gags, brownie mix and clown porn, Tue 14 Aug 2012, 11:09, Reply)

That pun about acid really burns.

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Tue 14 Aug 2012, 10:47, 2 replies)

I would make another lame joke based on the periodic table
but it would be fucking shit
(Darth Foxtrot A one-man army dedicated to making fetch happen, Tue 14 Aug 2012, 10:42, 1 reply)