b3ta.com qotw
You are not logged in. Login or Signup
Home » Question of the Week » Home Science » Post 1703432 | Search
This is a question Home Science

Have you split the atom in your kitchen? Made your own fireworks? Fired a bacon rocket through your window?
We love home science experiments - tell us about your best, preferably with instructions.

Extra points for lost eyebrows / nasal hair / limbs

(, Thu 9 Aug 2012, 17:25)
Pages: Popular, 5, 4, 3, 2, 1

« Go Back

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.
(, Tue 14 Aug 2012, 13:30, 19 replies)
I think all dynamos were shite.
They may work nowadays due to rare-earth magnets or something.
(, Tue 14 Aug 2012, 13:34, closed)
Maybe the Large Hadron Collider will help us out?

(, Tue 14 Aug 2012, 13:36, closed)
I want a Casimir Effect generator.

(, Tue 14 Aug 2012, 14:46, closed)
Negative energy! You'll kill us all!
Although I like the analogy to what I (and a young Mr Vagabond) were trying to do!
(, Tue 14 Aug 2012, 15:49, closed)
Just realised I wasn't clear. I meant, of course, they may work to light a bike not defy the laws of physics.
(, Tue 14 Aug 2012, 21:12, closed)
Doomed from the start.
The only real source of free energy is the Large Buttered Cat Array.
The LBCA will harness the energy of a huge number of cats with buttered toast strapped to their backs which are then thrown into the air to hover and spin -defying gravity, friction and several skeptical physicists.
(, Tue 14 Aug 2012, 14:32, closed)
You know what, The Infidel?
I do like the stuff you come up with.
(, Tue 14 Aug 2012, 14:43, closed)
Not mine of course, but I do love the idea.
(, Tue 14 Aug 2012, 15:16, closed)
I was discussing and refining this with a doctor at the weekend.
We concluded that four cats strapped back-to-back would be more efficient, but in order to build a monorail to run on such, you'd have to decide whether or not you wanted to get off the train before you knew where your station was, because of Schrodinger's theories &c.
(, Tue 14 Aug 2012, 14:47, closed)
Good point.
and because obviously only a live cat would try to land on its feet, if one of the cats in the array died then the whole thing would spin out of orbit, so you'd need one of Schroedinger's boxes to house the feline generator, to ensure that we had some kind of stability in the system.
As long as nobody looked inside to see how it worked then it would work.

This still doesn't solve the problem you have proposed though.

I just haven't thought this through properly and now my head hurts.
(, Tue 14 Aug 2012, 15:12, closed)
Now mine does too.

(, Tue 14 Aug 2012, 21:07, closed)
Yep - pretty well point for point what did, though the explanation from my dad was simply
"Entropy increases."


*is handed dictionary of science*

*sees it's a nice day*

*goes and plays outside*
(, Tue 14 Aug 2012, 14:45, closed)
He he! You got the advanced thermo explanation.
My old man's coming up to retirement and he's messing around with heat engines and the like.
(, Tue 14 Aug 2012, 14:57, closed)
I first read this, as your dad loves a disco biscuit while jumping around in some woods.

(, Tue 14 Aug 2012, 17:35, closed)
Are you 'Tyres', by any chance?

(, Tue 14 Aug 2012, 17:56, closed)
work better now if you use LED lighting and a battery charging circuit to keep the light on when you've stopped moving.
(, Tue 14 Aug 2012, 17:36, closed)
There you go, evolution!
It was always a good idea, glad to see it's moving on!
(, Tue 14 Aug 2012, 17:57, closed)
I like this , it reminds me of trying to "levitate" as a kid by sitting on a chair and trying to lift it from underneath.

(, Tue 14 Aug 2012, 21:08, closed)
What used to really piss me off
was how it would always get quite dark going uphill but burn like a thousand ficking suns on the downhill run.
(, Tue 14 Aug 2012, 23:43, closed)

« Go Back

Pages: Popular, 5, 4, 3, 2, 1