What is Nuclear Radiation and How Can It Hurt Me?

People get really freaked out about nuclear radiation.

Dude with Awesome Beard, Freaking Out

Since we are all really freaked out by the ongoing trouble with Japan's Fukushima nuclear power plant and the hazards posed to the Japanese population by escaped nuclear radiation, let's figure out what nuclear radiation is, and let's begin by talking about radiation in general.  The word radiation is used to describe any type of particle or wave that is moving through space really fast, which encompasses lots of things.  The kind of radiation that will be most familiar to you is LIGHT, which is a kind of electromagnetic radiation.

Electromagnetic Radiation, so-named because it consists of electric and magnetic waves that fly through space together.

"Where Did Helium Come From?" or "Jupiter & Saturn, Helium Hoarders"

All matter in the Universe is made up of three-quarters hydrogen and one-quarter helium (by weight), with relatively insignificant amounts of all the other elements (not including dark matter, whatever that is).  This crazy abundance of hydrogen and helium has been around in nearly the same ratio from minutes after the big bang over 13 billion years ago.  Wowza!

Hydrogen

Helium.  (see story of Larry Walters)

Cool Chameleons, Cool Carotenoids, Cool Colors

Check out what this chameleon can do!  Understanding how chameleons do this will help you to understand how all life on earth is connected.

"Unexpected Flying Animals" or "Winged Convergent Evolution"

Flying fish become airborne by leaping from the water and spreading their enormous pectoral fins.  They typically fly from 100-200 feet, an adaptation that is thought to have evolved for predator-evasion.  Check it out!

Flying fish have to hold their breath (WTF)!!

Moving from fish to reptiles, the flying snake climbs up trees (not unusual for snakes) and then jumps (unusual for snakes) from tree to tree.  The snake flies (ok, glides) by distorting nearly its entire body into a concave wing-like shape and undulating through the air, in a process that is much more energy efficient and less prone to predation than slithering down to the ground and back up.

Why Animals Migrate

The humpback whale migrates up to 16,000 miles every year, from polar regions to tropical waters and back.

Humpback whale migration routes.

The arctic tern migrates over 44,000 miles every year, from the arctic to antarctic and back.

Bird migration routes. 1-Northern Wheatear, 2-Bluethroat, 3-Eastern Yellow Wagtail, 4-Dunlin, 5-Wandering Tattler, 6-Bartailed Godwit, 7-Arctic Tern, 8-Sandhill Crane, 9-Brant, 10-Smith's Longspur, 11-American Golden Plover, 12-Tundra Swan, 13-Semipalmated Sandpiper.

These are just two examples of the incredible migrations performed on earth every year.  What could possibly motivate these animals to do this?  Well, the exact reasons are slightly different for every migrating animal, but a unifying theme can be found in the video below.  This is a video of "Net Primary Production", which is essentially a measure of the growth of plants.

Why Fire is Cool - entry #4 - Ancient Energy Unleasher

When you heat a can of beans on a campfire, you are transforming the chemical energy contained in the firewood into thermal energy (heat).  As you are in your tent drifting off to sleep and the bean-induced-fart-chorus begins, you may ask yourself where the energy in that firewood came from.  As with most energy sources, the answer is that it came from the sun!  That firewood was once a tree that was merrily pursuing its life's purpose of fashioning itself a body out of carbon dioxide, water, and sunlight, in a process known as photosynthesis.

Photosynthesis requires an energy source (sunlight), therefore the products of photosynthesis (wood, etc) can be thought to contain that photosynthesized energy.  When you burn firewood, you are essentially running photosynthesis in reverse, releasing the energy from the sun that the tree went through so much trouble to absorb.

So, fire is cool because it allows us to unleash energy from the sun in small amounts, whenever we please, regardless of when that energy first arrived on earth.  In the case of firewood, that energy arrived anywhere from a few years to a few thousand years ago, depending on how long the tree had lived.

The Llangernyw Yew, a 4,000-5,000 year old tree.

This same concept applies to anything else we burn, even fossil fuels, which is where things get crazy.

Why Fire is Cool - entry #3 - Ash Ash Baby

When sitting around a campfire I almost always find myself silently staring, mesmerized by the smoldering ashes.  Once I snap out of it, instead of re-joining the conversation with my campfire pals  I often start taking pictures of the ashes.  Though it doesn't live up to the awesomeness of the moment, here is one (notice backlit marshmallow in foreground):

Before we discover the amazing things humans have done with ash, let's figure out what the hell ash is and why red-hot ashes look so awesome.  Once you burn away all of the combustible molecules in wood, the only things left behind (around 1% of the original unburned weight) are the non-combustible nutrients the tree used in order to stay alive.  Ash contains nutrients like calcium (~30% of the ash), potassium (~10% of the ash), and sodium ions (~1% of the ash) along with other metal and non-metal ions (reference).  It is partly these metal ions that make red-hot ashes look so awesome.  As you heat up metal ions in a fire, their electrons will gain energy then lose energy, in a process that results in the emission of light.  Each metal emits light of a specific wavelength, and if you take any substance containing metal ions and put it in a flame you will see this light (this is known as a flame test).