Hi All
I like to start a series called "Fameous Experiments", demonstrating some important physical works, replicated with TPT.

1st up, was Ernest Rutherford's gold-foil-experiment from 1911

Part-1: http://static.powdertoy.co.uk/1984482.png
Part-2: http://static.powdertoy.co.uk/1985133.png

The next (When i persuaded the light in TPT to act like a wave) will be the 'double slit' from Thomas young.
Suggestion was from dlaudghks

Completed: The Young Experiment
http://static.powdertoy.co.uk/1986136.png

More ideas for experiments are welcome.

Who said that these experiments must be orthographically correct? :-p

@tptquantum: Puh, that is a tough one. Cause electricity is always related to magnetic fields, or electrolysis.
I will try it.

So, now i have two, to think over: Fermi's Chicago Pile-1, and Discovery of electricity.

Louis Slotin --> The demon core

An experiment that becomes famous by it's human tragedy and the (sorry for the choice of words) stupidity of the executing scientist.
In 1946, the physicist Louis Slotin wanted to trigger the early stage of a chain-reaction, using a Pu-core as reactive mass and two beryllium half-spheres as neutron reflector.
It was calculated that the Pu-core placed in the middle of the half-spheres is subcritical as long as there is space between the half-spheres, but becomes overcritical if the half-spheres are closed.
Normaly a mechanism was preventing the half-spheres from touching each other, but Slotin wanted to "tickle the dragon's tail" using a SCREWDRIVER to decrease the gap between the half-spheres.
Slotin lost control of the screwdriver and the half-spheres clashed together, resulting the Pu-core becomes spontaneous overcritical.
Slotin immediately removed one half-sphere with his bare hands, exposing him to a lethal dose of gamma-rays and neutrons. 7 other people in the room where also exposed to high levels of radiation.
Louis Slotin dies 9 days later as a result of an acute radiation sickness.


Completed: http://static.powdertoy.co.uk/1993498.png

Coming soon: Metallographic appearance of iron-based alloys

Not really a 'famous experiment' but i occupational often have to make microstructual analysis of metals, mainly iron-based.
So i will show you by an little 'artwork' what i see in the optics of my microscope almost every day.

Part one complete. http://static.powdertoy.co.uk/2007132.png
Part two: http://static.powdertoy.co.uk/2007200.png
Part three: http://static.powdertoy.co.uk/2007346.png

Hello together.
I didn't expect such a positive reaction on the microstructures, so thanks to all.
I want to write down a little more background information here, for the people who are interested.

But first: Why is that guy presenting iron-microstructures in TPT?
I'm material-tester, and it's part of my job to check microstructures, and especialy iron-based alloys i alwys found very fascinating cause of it's variety and complexity.

Why checking microstructures?
There are a lot of reasons, depending on the purpose of the material. Normally it's made to see if the heat treatment worked fine, it's the material hardened properly, have the grains the correct size, are there inclusions, and so on. All this has an influence on the mechanical propertys of the material.
Also often microstructual analysis is made for test weldings, to see if the welding process is creating any micro-cracks, which can extend to a critical size.
As part of failure-analysis it's absolute necessary to see the microstructure, because this gives more information about the properties than any other test.

How to see the microstructurte?
First thing is to take a test specimen from the material.
Larger pices can be taken directly to the next step, smaller has to be inbeded for a better handling.
Now the test specimen would sanded to a plain surface.
To remove the grind marks, the test specimen becomes a very fine polish, depending on the alloy and what you wanted to see, the gind size can be going down to 1µm.
Etching the surface is the last step. Which etching medium is used also depends on the specefic alloy, most common are acids like HNO3, picric acid, or a mixture of muriatic acid and picric acid.
A mixture of muriatic acid and Copperamoniumcloride is used to see weldings in detail.
HF is also used sometimes, but it's very unpopular.

Now the test specimen goes under the microscope, and you can see something like the examples i did here at TPT.

Part-4 ready.
http://static.powdertoy.co.uk/2030490.png
Sorry for the delay, i was in holyday.