Why Does Old Ice Cream Get Crunchy?

This was originally posted on Sustainable Nano, which is my new project.  You should go check it out!  Science Minus Details will live on though! Poop posts will come, have faith!!!!

As with all good meals of information, let's start this one off with ice cream!

In an effort to grow out of my "slim fit" clothes, I've begun an ice-cream-after-every-dinner diet.

Even the cat likes my diet!

An added bonus is that I go through jugs of ice cream so quickly that I NEVER have to deal with old, gross, crunchy ice cream! You know what I'm talking about. You reach into the back of your freezer, find that jug of 6-month-old ice cream, only to discover that it tastes like the perfect mixture of sugar, fat, and sand.

Why Pee is Cool - entry #5 - "How Pee Unites You With Rocks"

From around the 2nd century onwards, many people subscribed to the doctrine of vitalism.  For alchemists, vitalism primarily meant that matter from the inorganic, inanimate world (crystals, rocks, etc) was fundamentally different from matter from the organic, living world (us, kittens, pee, etc).  Specifically, they believed that that non-living matter could not be transformed into living matter.  Vitalists held that the matter of life, the chemicals that compose living things, could be synthesized only by living things themselves.

In 1828 a German chemist named Friedrich Wöhler made a discovery that bridged the divide between living and non-living matter, and the story of how he did this starts of course with pee.

Friedrich Wöhler. German chemist/peepee enthusiast and 1828 blower of minds.

Why Pee is Cool - entry #3 - "Explosive Urination" or "Gunpowder Comes from Pee!!!"

So far we have learned what gives pee its color and smell, and now we will delve into the explosive way pee has changed the course of history.  That's right, pee can be turned into an explosive!

To find out how we have to travel in our minds back to the beginning of human civilization--specifically, the domestication of animals.  One thing that large domesticated animals like horses and cows produce in bulk is urine (pee pee!).  When these animals are kept inside some sort of shelter, their pee seeps into the dry plant-less ground beneath their feet, where microorganisms turn urea into ammonia.  The little pee-digesting organisms don't stop there though, they combine the ammonia with oxygen, eventually giving rise to the nitrate ion, in a process known as nitrification.

Nitrification:

Ammonia + Oxygen →  Nitrates

or

NH₃ + 2 O₂  → NO₃^- + H⁺ + H₂O

or

Nitrification of Ammonia.  Note: animals pee out urea, but  microbes turn urea into ammonia, which then undergoes nitrification.

"Mythical Crysticals" or "Why Crystals are So Awesome"

This past summer, after finishing graduate school I went on a victory lap around the world and stopped by Berlin for some hot eats (döner kebab):

and cool treats (spaghetti eis):

I also stopped by the natural history museum (museum für naturkunde) to check out dinosaurs and stuff: