I can certainly feel the heat creeping up as we sail full steam ahead toward Puerto Rico. The ship is running on full power making it possible for us to get to Puerto Rico in time to stick with the allotted schedule.
I've made it to my second class of Emergency Management after a nice break of liberty. Kim started off the day with an introduction on Natural Disasters. She had the class watch a film that showed how a forest fire can catch and spread within a matter of minutes! Emergency Management does have a huge part in the response to natural disasters, with organizations such as FEMA.
Later on, Arthur discussed Radioactive Materials with the class. He mentioned Alpha, Beta, and Gamma Rays. Alpha rays can simply be blocked by skin or a piece of paper. Beta Rays can pass through both, but will most likely be blocked by a thicker material (six inches of material will block out beta rays). Gamma Rays are the most hazardous because they have no mass and no charge; the only thing that can prevent these rays from passing through is a layer of lead. Think about this: when you go to the dentist, once in a while they take x-rays of your jaw and teeth. They leave the room, but cover you with a heavy vest. That vest has lead in it to protect you and your organs from the radioactive rays emitted from the x-ray machine.
To show how the three rays differ from each other, we used a Geiger Meter and some samples of all three rays (samples are kept in a lead container!). The Geiger Meter counts the particles of radiation being emitted from each sample. There is a stationary meter and a hand held meter. After lunch, Dr. Jop and Kim set off to find a spot on the ship to hide a makeshift bomb. The students were then given a device that would be able to indicate whether or not the bomb was nearby. In a real life situation the meter would detect any radioactive materials being emitted from the bomb. But, since the bomb is fake, the meter picks up radio waves that come from a wire attached to the "bomb". After a long search, the class was successful; the "bomb" was located on the bridge.
Well, cadets are back up on the HELO and Boat decks catching some rays (from the sun!). I must say that I am looking forward to the beach and cannot wait for some of the great excursions that are coming up!
Here are some way that radiation is used in today's technological society.
Radiation in Science
Scientists can label important molecules, called tracers, that pass through living things to allow them to understand the steps that occur in important processes, such as photosynthesis. They can also study paths that different types of air and water pollution take through the environment. Radiation is used to measure the age of ancient objects by a process called carbon dating. Carbon is found in all living things, and a small percentage of this carbon is carbon-14. When a plant or animal dies, it no longer takes in new carbon and the carbon-14 continues the process of radioactive decay. After many years the percentage of radioactivity in the old object is less than when the object was living.
Radiation in Medicine
Doctors administer slightly radioactive substances to patients which are attracted to certain internal
organs such as the pancreas, kidney, thyroid, liver, or brain. A computer can change a non-invasive
scan of the targeted organ or system into pictures on a computer screen or film. This can be used by the doctor to diagnose what is wrong with the patient. Radiation is also used for the treatment of serious illnesses, such as cancer. Treating patients with radiation is called radiotherapy. A beam of radiation can pass through the skin and kill harmful cancer cells without the patient having an operation.
Radiation in Industry
Medical equipment such as bandages, syringes and surgical instruments can be placed in sealed bags and sterilized by radiation. Since the radiation passes through the bags, they can remain sealed until the contents are needed. Engineers use radioisotopes to gauge the thickness of materials and to find defects in many types of metals and machines which would be difficult to detect otherwise. They can be used to check the flow of liquids in machinery and the way various materials wear out. An example is americium-241 which is used inside smoke detectors.
Learn more about radioactive waves and the electromagnetic spectrum
Try this electromagnetic spectrum puzzle. or this quiz
This interactive shows everyday sources of radiation in our enviroment
This activty demonstrates radioactive decay and half life