The Book of Experiments (1958) [pdf]
arvindguptatoys.com
arvindguptatoys.com
199. Make your own printed circuit board
You will need: a common kitchen cutting board, a sheet of copper, a roll of electrical tape, a fish tank, and a supply of nitric acid. And whatever electrical components you need to complete your circuit.
All of these supplies are readily available to a third grader, except for the nitric acid which you will have to ask your teacher to source.
First, design your circuit and test it in your mind. Then tape it out - literally - with the electrical tape on one side of the copper sheet and matching tape on the other side.
Pour the nitric acid into the fish tank.
Dip the copper sheet into the nitric acid. Watch it with your teacher as the acid dissolves the copper, except where you have taped out your circuit.
When all that remains are the taped out traces, remove the copper circuit from the acid and rinse it with water.
Peel off the electrical tape and fasten the copper traces onto the cutting board. This is what makes it a circuit board.
Connect the rest of the components and test your circuit.
Go to the science fair, demonstrate the printed circuit, and explain to the visitors how you made it.
Thank you, Mrs. Spencer.
Diluted enough, the nitric could easily be made weaker than your stomach acid but will still eventually dissolve the copper. Its a sort of linear-ish relationship of concentration vs time so you can trade safety for time (as with most industrial processes, LOL)
I would think dilute iron chloride would not taste good, but you could probably chug enough to get sick.
I believe there would be a similar relationship WRT staining skin and clothes, dilute enough HNO3 would not be TOO much more dangerous than letting kids handle a can of Mt Dew unsupervised, but FeCl in any dilution will stain and damage clothes and skin.
If I had to work with maximal concentration solutions of both, I'd agree and definitely prefer the conc FeCl vs fuming nitric.
Mrs. Spencer's Workshop was a class where you could pick out your own projects. She would get you the materials you needed, let you do your project, and help you if you got stuck.
You could say that she was my lab assistant here rather than my teacher.
The other safety question for me is why didn't either of us use eye protection!
26. A flour bomb as a noisy finale to our air experiments
... If you tried to set fire to a small heap of flour you would not succeed. But finely divided flour in a cloud—that can make a completely harmless bomb!
... With a great BANG! off flies the lid of the tin. The finely divided flour has exploded.
It is best to do this experiment out of doors. Not that the explosion is dangerous, but the lid might go through a window or do some damage in the room. It is also important to take care that the lid does not hit you in the face. Given reasonable care this flour bomb explosion is perfectly harmless.
Then again, anything, when suspended in air in significant amounts and the right ratios, will explode. Sugar and flour explode just fine. Sawdust, metal particles, and don't drop that cup of flour next to an open flame if you like your eyebrows.
The Boy Mechanic Volume I: 700 Things For Boys To Do https://www.gutenberg.org/ebooks/12655
The Boy Mechanic, Book 2: 1000 Things for Boys to Do https://www.gutenberg.org/ebooks/44585
One of the transcriber said: Another class of projects illustrate the caviler attitude toward environment and health in 1913. These projects involve items such as asbestos, gunpowder, acetylene, hydrogen, lead, mercury, sulfuric acid, nitric acid, cadmium, potassium sulfate, potassium cyanide, potassium ferrocyanide, copper sulfate, and hydrochloric acid. Many references to these have been highlighted in red.
Projects requiring extra skill and care that involve high voltage, melting metals, or other hazards, have the title highlighted.
My elementary school (1975) library had a copy I devoured.
As good as he was as a theoretical physicist, he was a walking disaster with experiments.
In mechanics there is an experiment where you sit on a chair, with weights in your hands, someone makes you spin and then you extend the arms and the movement is slowed down (conservation of momentum if someone is interested).
He wanted to show this, sat on a chair, extended his arms and asked a student to spin him fast. And then retracted his arms next to the torso. He flew two or three meters away from the chair and fell down, with us jumping to help him (he was something like 70 at that time).
After getting back to his senses he continued with an experiment where you hold a bicycle wheel in your hands by the axis, it spins quickly and you cannot flip it right or left. So he did.
And then he was left with a spinning wheel in his hands, wondered a moment what to do with it and simply dropped it on the floor. It is amazing he managed to squarely hit the audio system of the amphitheatre which did BOOM and we did not have sound anymore.
That was the end of the experiments for that year.
131. Cut glass with. .. scissors!
You will need: bowl of water, pair of scissors, piece of glass.
It is possible to cut glass with ordinary scissors in any shape you wish, provided that while cutting you hold the glass and the scissors as well as your hands completely under water. The water deadens the vibrations which make the glass crack. Yes, under water, glass can be cut almost as easily as cardboard.
It's not mentioned, but I'd assume that the glass thickness would be something like a pane from a greenhouse. Might just have to try this one ...
It is called "Toys from trash". From time to time we go there with my younger daughter and we randomly pick an activity. Compared to the book there is little text, explanations being mostly visual. That makes it accessible to non English speaking children.
https://archive.org/details/GoldenBookOfChemistryExperiments
But then I realized this is just a Book Of Potential TikTok Videos and felt better about it.
Wikipedia: The first documented appearance of the word nerd is as the name of a creature in Dr. Seuss's book If I Ran the Zoo (1950).
I realise it is a typo.
OK. Curious where this is going.
> Where there is a group of people most of whom have a burning cigarette in their hand or mouth, you can play a smart little trick which shows how unreliable our senses are. Without letting anyone see, make a point on a piece of ice with a knife. Dry it well, then press it firmly against the neck of one of your friends. He will be startled and perhaps angry because you, according to him, have held the burning end of a cigarette against his neck.
Yikes! Legitimately so I would think. On the other hand, while finding a gaggle of smokers is harder than it used to be, the subset of adolescent and post adolescent boys who find it amusing to injure, inflict pain and confuse their friends still seems limitless.
> Then it is your turn to be surprised and show him the piece of ice.
Still might get punched.
> Air is easily compressible, water is not.
Not significantly compressible, in the sense of reducing volume, but it is pressurisable (think of pressure at the bottom of the ocean), which is what this experiment depends on.
> The water is not compressed by your called ions) and the chlorine atoms (chlorine ions) of which the salt in solution consists.
Wot?
Thinking about my own experiments as a child, my favourite tools were a 12-volt car battery charger, and fire. Sometimes I wonder that I'm still here :-)
And it's becoming a lost art, like everything's electric, less and less fire in the house for fewer and fewer reasons, fewer smokers smoking less, vaping instead (which I consider good, harm reduction all the way), fewer ways to make fire, offices rarely have incinerators any more, well paper too, fire and paper, another combo. Less metallurgy due to less manufacturing in the States. SF Fire Department actually now do more like...helping the evicteds, because the codes to eliminate fires have worked very well in the regard of preventing fires.
Luckily alcohol doesn't burn at a high temperature, so only all the skin on my hands peeled off. And this is no criticism of the Primus, just wittlessness on behalf of 14-year-old me.
I don't suppose kids get to do this sort of stuff these days?
try explaining how a gas engine works to someone that doesn't understand how vapor burns but liquid doesn't.
My latest "prove something" was taking my brightest flashlight and putting it flush against the bottom of a clear container of peanut butter in a dark room. When you shut off the flashlight, the peanut butter fluoresces. It "glows in the dark" for a short time. really cool.
this whole PDF is whimsically old, but it has some good experiments nonetheless.
Which I think is a great game, or was when I played it, I bought when I had no money, it was I think $40, and was very satisfied. I wanted to play it again see what had changed but Microsoft didn't honor my purchase, they wanted me to buy it again. Obviously not in so many words but dude they have hundreds of UI UX people they A/B test everything. They fucking know. They fucking know. It may have been a mistake (there is literally a 0 probability of this), all the same, I went through the whole protocol, did the backup option, the works. Totally agree that piracy is a service problem. Self-service.
If I feel like playing Minecraft again I won't steal it, wrong word--seize it, take my own property back for myself. I own Minecraft in the specific capacity I agreed to--just a perpetual license for myself, no more than one person playing at a time, no piracy, never even looked it up on all those sites only the Russian search engines can parse.
Yeah that's what "must have happened", someone put a ж in there, it didn't compile, Минкрафт. MS database failure, that's the mistake they didn't make. Yeah that makes sense it's a Russian plant getting children to play indoors only, fake TNT fake water fake fire, play video games and become overweight in elementary, obese in sophomore year of High School. US Army complains about this, all these recruits are busted, nearsighted from screens, fat, flat-footed, everyone has a 1-in-1000000 condition that requires favoritism, never gotten burned, never scraped their knees, nothing.
When I was a kid I had some wound somewhere most of the time. Like they even made the clothing with patches in the elbows and knees not because that would be any protection but to get the clothing to last the year.
Much like alcohol there is no minimum safe harmless amount of current thru the heart, but if you have what by neon transformer standards is a very low current transformer, like limited to 5 mA or so, that might be a low enough current to only kill like 0.0001% of the population or whatever. A kid will probably be fine. An old person with heart problems, maybe not so much.
He would start with a set of wires, some wooden tablets, a few screws and a piece of paper. He would draw how "we" would build, say, a house out of this, moved the pieces around and suddenly was getting from below the table some incredibly complex construction they were supposed to easily reproduce :)