Favorite home experiments

[quadmaster]

Today I've had fun making a homopolar generator out of a very, very much abused hard drive, two brushes from a small motor, and a magnet.

http://www.youtube.com/watch?v=L0E-Na25 ... e=youtu.be

[Jaswinder]

My favorite experiment is using the spectral tubes (glass tubes filled with specific types of gases and lit up by passing an electric current through them) to identify spectral lines and elements in a spectrum. It's my favorite experiment because it's colorful and shiny, and I like shiny things.

[WASwillbe]

Rock Candy. Seriously, growing those crystals and eating them too.

Now, in my Chem Lab, we used a spectrometer to measure the rate of the reaction of Clorox bleach in a solution of food coloring. Honestly, watching the food coloring fade was the highlight of that class

Finally, one I did in high school bio:

Soak an egg in vinegar for 3 days. The acidic vinegar will melt the shell, and then the vinegar flows into the egg through osmosis.
Now, after 3 to 4 days, the egg becomes soft, large, and will even bounce nicely.

But why stop there?
Fill up a jar with pancake syrup, and let the egg soak in there for a while. Through osmosis, all the liquid in the egg (save for the yolk) flows out into the syrup. The egg is now kind of crinkly and gross, and is nothing more than a skin for the yolk.

[idobox]

Not exactly an experiment, but you can use a CD as a diffraction grating to observe the spectrum of light by reflection.
In particular, you can easily see fluorescent light doesn't have a continuous spectrum. Normal CDs work better than CD-R because they are more "white".

[EchoRomulus]

What about good old vinegar and baking soda?

I did that once with little film canisters to make a volcano in a kids summer program...I had to be about 11.

So I decided to pour in the soda, add some vinegar, and put the cap on really fast to see what would happen. This is before I knew the basic principles behind guns, rockets, and other chemical weapons.

The cap flew off as soon as I put it down and hit the classroom light, bouncing to the other side of the room. It was so quick and so quiet the facilitator didn't even see it. My entire table burst into laughter.

10/10 would recommend.

[Cronos51101]

I have two favorite home experiments.

The first is the classic pop can implosion. Put a small amount of water in the bottom of and empty aluminum pop can and heat it to a boil on the stove. Let it boil for a short time, then quickly grab it with a pair of tongs, flip it over, and immerse the top of the can into a pot of cold water. The steam in the can rapidly condenses and implodes the can.

The second is to take a 12V lead acid battery, I used one of those sealed ones for an old UPS and get some alligator clip wires (they must be insulated), some aluminum ( a pie tin, pop can, or aluminum foil works fine), and some 0.7 mm mechanical pencil graphite. You may also want to consider some shaded goggles if you want to do this for any prolonged duration as it bright and will give you weld flash. Something like a #14 should work well.
Just attach your negative lead to your workpiece and grip the graphite rod with your positive lead. You will have to experiment with the length. When you touch the rod to the can, it will heat up, if you do it just right, it will burn through, and if you practice a bit, you can cut shapes out of the metal.
You will find that you can make your graphite rod last longer if you pre-heat it a bit to burn off impurities that may otherwise cause it to burst. You can use different thicknesses of graphite, but if you use the thick stuff from a wooden pencil, you will need to use some heavier wire.

[onoresrts63]

I like experiments on density, acids and bases and water

[tomandlu]

I experimented last night with the burning question of whether having a small buzzing fly lodged against your ear-drum drives you fucking nuts or not. (in addition, I'm deaf in one ear, so the experiment was particularly rigorous)

[Kristen23]

Last week we did this simple experiment at home called 'How to bend a bone with vinegar'. All you need is a jar large enough to fit a chicken bone, a chicken bone (or a drumstick) and vinegar. Just put the meatless bone into the jar and fill the jar with vinegar such that the bone is completely covered in the vinegar. Place the lid on the jar and leave it as it is for 2-3 days. Now try bending it ---- it'll bend just like a rubber bone would! The underlying concept behind this is that vinegar is a mild acid but strong enough to dissolve the calcium present in the bone.

[withinboredom]

If you have a laser pointer and two adjacent fingers on the same hand, you can get single slit diffraction patterns by shining the laser through the gap in your fingers (although aligning everything might take several seconds of practice.) It's about the fastest home experiment I can think of, and it's actually pretty cool to see.

You can also do the double slit experiment with a few pencil leads to create two slits and shine the laser through ... interference pattern appears on wall...

[davidhan]

Here is the issue I am interested.
I didnt read all the posts but did anyone include the emp cannon?
i pulled this one off in middle school(or elementary?...)by wrapping a crap-ton of copper wire around some pvc pipe and hooking that up to 10 lamp batteries with a toggle switch so it went from on to off to negative as the punch or drill bit went through the tube. same idea as rollercoasters; pull, switch to push halfway through.

[davidhan]

This is an issue that I am interested.
for example
This is worth a go...
EXPERIENCE SNOW BLINDNESS
Get a pingpong ball, cut it in half
Lie on your back looking up at a diffused light source (halogen light tube or equivalent)
Place a half of the ball over each eye so that you just see a uniform white surface.
Lie still without moving your eyes and blinking as little as possible
Experience snow blindness
Interrupt the uniform light (wave your hand) and the effect ends

[eternauta3k]

What's the effect?

[Sizik]

That's the Ganzfeld effect, your vision turning off or seeing hallucinations because your eyes aren't receiving any input. Actual snow blindness is like sunburn for your eyes.

[jewish_scientist]

In 10th grade I took a forensic science class (it was awesome). One of the things we learned is that, usually, what a victim is wearing will not effect how insect interact with the body. The teacher bought some meat and had us wrap some chunks of it in cloth and paper towels. Each piece of meat was put into a small cage and chained to a wall on the outside of the building. We checked on it a couple of times and then moved on to other things. About two months later, we go back outside to look at the 'meat'. It was horrible. It was metaphorically and literally what death smells like. The only thing that could have made the experiment better is if we put some meat from McDonald's in on of the cages.

Another fun experiment is basically doing anything with gallium.

[Kalium_Puceon]

I have this old book of home science experiments from 1964, "Science Puzzlers" by Martin Gardner. It's pretty fun to read because it has things like "Ask Dad to blow a puff of smoke into the box" in the Smoke Rings section. because literally everyone smoked.

Yeah, my favourites from there were the "Flaming Sugarcube" and the Playing Card based example of Bernoulli's principle.

For the Sugar, try setting a sugar cube alight with a match. It won't happen at all, it's just too high activation energy. But, rub a small amount of (again) cigarette ash on the cube, and it'll catalyse the burn, allowing it to burn steadily.

With the Bernoulli's Principle one, get a cotton reel, drawing pin and a playing card. Put the pin through the centre of the card. Hold the card underneath the cotton reel with the pin going into the hole in the cotton reel. Blow hard through the top of the cotton reel. The high-speed air moving over the top of the card has a much lower pressure, so rather than falling to the ground, the card stays aloft until you stop blowing.

[Sableagle]

Here is the issue I am interested.
I didnt read all the posts but did anyone include the emp cannon?
i pulled this one off in middle school(or elementary?...)by wrapping a crap-ton of copper wire around some pvc pipe and hooking that up to 10 lamp batteries with a toggle switch so it went from on to off to negative as the punch or drill bit went through the tube. same idea as rollercoasters; pull, switch to push halfway through.

You got my hopes up for a moment there. I was hoping you'd come up with an EMP weapon. You're describing an electromagnetic means of projecting a solid slug. I was hoping for a means of shining a very tight beam of microwave energy in a specific direction without any back- or side-lobes. Just something that'd fry a mobile phone in use in the "quiet carriage" without endangering anyone's pacemaker or similar vital equipment.

[Kalium_Puceon]

Here is the issue I am interested.
I didnt read all the posts but did anyone include the emp cannon?
i pulled this one off in middle school(or elementary?...)by wrapping a crap-ton of copper wire around some pvc pipe and hooking that up to 10 lamp batteries with a toggle switch so it went from on to off to negative as the punch or drill bit went through the tube. same idea as rollercoasters; pull, switch to push halfway through.

You got my hopes up for a moment there. I was hoping you'd come up with an EMP weapon. You're describing an electromagnetic means of projecting a solid slug. I was hoping for a means of shining a very tight beam of microwave energy in a specific direction without any back- or side-lobes. Just something that'd fry a mobile phone in use in the "quiet carriage" without endangering anyone's pacemaker or similar vital equipment.

So there's a few designs for mini-EMP devices which use, like many homemade electrical projects, the capacitors from a disposable camera flash. They can disable most circuits, but they are often unreliable. I stumbled across this design which I have not yet built. The concept seems sound, although the use of a bar as the transformer core is kind of concerning. If anyone builds this, please tell me how it goes!

[InternationalSpaceStation]

Tesla Coil!
Also I'd have to say putting non-Newtonian gunk on speakers is also awesome, but so old school.
And sparking a CRT TV, but I've nearly gotten legit electrocuted from that.
Oh and turning a disposable cam into a taser.
Making sparks with a blanket.
Building a VLF antenna and "listening" for lightning via a digital spectrograph.
Making a tiny plasma speaker via a flyback.

Hey, if I did these all in middle school, I can consider them a "home experiment."
T'was at a time I still wanted to do EE.
I can't major in everything, sadly.
xkcd's already covered that, haha!

[SuicideJunkie]

Visit your local dollar store and see if they have any cheap vanity mirrors.
Drop $5-$20 and you can make yourself a nice solar array.
If you use thin wood such as from a carton of oranges, it will burst into flame quite easily.

Spoiler:

Bonus: drill some holes in the casings and put screws through them for fine adjustments, then arrange them on a portable base and glue the screws in place when it is all well focused. Have a metal post in the middle indicating the focal point.

[tomandlu]

Not exactly a home experiment, but I liked this from Mythbusters:

https://www.youtube.com/watch?v=BLuI118nhzc

[ECK138]

A plasma is an ionically charged gas. You can get a plasma by heating a gas enough to knock the electrons off, as in the sun, OR you can knock the electrons off with electricity, as in a florescent light or those novelty balls, or even neon lights. A quick check to see if it's a plasma is to hold a magnet next to it, it should deflect the plasma. Plasma TVs. The spark you make when you rub your feet on the carpet and touch a door knob.

[jewish_scientist]

Give each end of a slinky to two people sitting on opposite sides of the room. Depending on how they move their ends, you can give a visual example of transverse waves, compression waves, reflections, interference (admittedly, this is a little harder to see) and the property of wave to travel through each other unaffected. What is really cool is when you have a transverse wave meet a compression wave. I suggest doing it on tile instead of carpet in order to minimize the friction.

Along the same line, having a motor spin a rope at different rates to demonstrate the harmonic series is always interesting.

[Himself]

I accidentally found a good demonstration of an exothermic reaction (as well as an acid-base reaction) with safe chemicals.
In my high school chemistry classes, when the teacher wanted to demonstrate an exothermic reaction it would either involve fire or strong acids and/or bases.
Just mix five parts white vinegar with one part milk of magnesia. The mixture will become noticeably warmer and will become clear in about a minute. It's been a while since I've done it but I think it might raise the temperature by about 20°C or so.
Originally I just wanted to show a reaction of an organic acid that wasn't vinegar and baking soda. It wasn't until after trying that I noticed the heat.

[Eebster the Great]

All acid-base reactions are going to be exothermic, so there's nothing special about acetic acid and magnesium hydroxide.

[Himself]

All acid-base reactions are going to be exothermic, so there's nothing special about acetic acid and magnesium hydroxide.

I realize that. But my thought was demonstrations you can do with safe chemicals, considering that the demonstration from my chemistry teacher used sulfuric acid and ammonia.

Though, oddly I tried it again today and the temperature change was not as noticeable as I remember.

[Eebster the Great]

An on-topic bump, how about that!

[Heimhenge]

Visit your local dollar store and see if they have any cheap vanity mirrors.
Drop $5-$20 and you can make yourself a nice solar array.
If you use thin wood such as from a carton of oranges, it will burst into flame quite easily.

Spoiler:

Bonus: drill some holes in the casings and put screws through them for fine adjustments, then arrange them on a portable base and glue the screws in place when it is all well focused. Have a metal post in the middle indicating the focal point.

Kinda like this? http://heimhenge.com/solar-cooking/

[SuicideJunkie]

Vaguely similar. A little more concentrated this way since vanity mirrors focus down two dimensions instead of just one:
(Fixed DNS for images)

[Heimhenge]

I see what you mean, yeah. You're focusing to a "point" and I'm focusing to a "volume". Never calculated a 2D f-ratio before so I had to kinda wing it to even get a number ... probably not meaningful in my case, but I wanted to convey an impression of the extreme aperture / focal length. Still, it won't burn wood like your setup. Nicely boils water though. Made dozens of solar hot dogs during demos.

You ever work out an effective f-ratio for your setup?