Enter the crystalverse

 

In our material science class at Princeton - and in most of the matsci classes that originated from the ASM summer camps, I would imagine - we grow copper (II) sulfate crystals from solution.

It's a fairly easy lab to do, and the students have a high success rate.

For most students, that crystal growing experience is an end, but for others it's just a beginning, a taste of a much richer world of crystal growth.

For those students, crystalverse would be a great resource as it provides instructions for the diy crystal farmer whether they want to grow crystals of copper acetate, monoammonium phosphate, sucrose, alum, sodium chloride, potassium ferrioxalate, or even pyramidal crystals of sodium chloride.

In every case, the procedure is largely the same - make a solution, let the solution cool and evaporate to form seed crystals, continue to let the solution evaporate to grow the seed crystals larger. The great things about the crystalverse website is that it has loads of tips and faqs to help you troubleshoot your growing.

Making salt

Today you get a whole bunch of videos about making salt.

It seems like such a simple thing - talk salt water from the ocean and boil it down - but there's a lot more to the science of making salt including removing the calcium and magnesium impurities, allowing the crystals to grow to the desired size, and sorting those different crystal sizes.

Who knew that the rate of crystal growth would affect the size of the crystals?

More after the jump...

How cooks put their fingers in hot sauce without burning themselves

Heat =/= temperature

Temperature is the average kinetic energy of the particles in a substance.

Heat is energy transferred from one body to another due to a difference in temperature.

Hot things - like boiling water or simmering sauce - conduct energy to cool things - like your finger.

The amount of energy you get from that hot sauce depends on way more than the temperature of the sauce. More mass of sauce that you get on your finger means more molecules with that same average kinetic energy, so more total energy, so more pain.

In this video Adam switches mass out for time in contact with the sauce, but in this case that seems a fair swap.

Don't dunk your finger in hot fryer oil or hot sugar syrup. According to Adam, go ahead and dunk (or flick) your finger in hot, water- or oil-based sauces.

As always, vinegar leg on the right.

How To Accidentally Invent A Color

I've posted about Phoenician Purple before - the dye mentioned in this video as coming from snail shells. That's an amazing story, too.

The early part of this video defines pigments versus dyes. I'll admit that I didn't have any idea there was an actual distinction between those two. I am curious, though, as to whether the insoluble and soluble designation depends on the nature of the solvent. Like are some chemicals pigments in oil but dyes in water-based solutions?

Maybe I'll hunt down that in a different video.