Forces of Nature | Only Four

There are only four known types of force found in nature: Gravity, Electromagnetic, Strong Nuclear, and Weak Nuclear. Each has particular characteristics. This table lists them from weakest to strongest. The last column shows if the carrier of the force was observed by experiment and verified.

Forces

Lederman Science Education Center | Fermilab

Show me more…

Nuclear Options | Dialogue & Planning Needed

This post is a follow-up to one from a week ago. See below the line break for the original.

Thanks to comments by readers, there are three resources to promote which discuss the need for careful, considered dialogue and planning with regard to our nation’s domestic and military nuclear capacity. Readers shoreacres and Jim Wheeler discussed two resources by Thomas Nichols. The third resource is a recent NOVA program about the nuclear option.

First, what if we could rebuild our nuclear weapon forces from scratch? How should it be done?

Second, read the preface and introduction to the Nichols book No Use: Nuclear Weapons and U.S. National Security

Third, the NOVA program Nuclear Option is available for viewing until 8 Feb 2017.

All three urge bi-partisan discussion by all interested parties. One of the reasons hinges on the need for safety and security in our world today. The other reason hinges on the need for a viable solution to the challenges of climate change and global warming.

I believe nuclear energy should play a role in our future. To not examine the ideas and technologies formed in the 50s, 60s, and 70s which brought us to our current position is foolhardy. The world has changed very much since then.


Nuclear Weapons | Do Accidents Happen?

Have there been nuclear weapon accidents or incidents? Yes, there have been many. We are lucky to not have detonations or major spills of radioactive material. An accident near Damascus Arkansas on 18 Sep 1980 illustrates how a simple event can cause a situation of monumental potential for disaster.

Show me more…

Nuclear Weapons | Do Accidents Happen?

Have there been nuclear weapon accidents or incidents? Yes, there have been many. We are lucky to not have detonations or major spills of radioactive material. An accident near Damascus Arkansas on 18 Sep 1980 illustrates how a simple event can cause a situation of monumental potential for disaster.

Local PBS television stations will broadcast on 10 Jan 2016 a program on the American Experience detailing this accident and others. Here is a short preview. Here is a Q&A with the director and the author.

Divider1

Two airmen technicians were servicing a Titan II missile in an underground silo with a hydrogen bomb mounted on top. The bomb had 3x the explosive energy of all the bombs dropped in WWII including the two nuclear bombs dropped on Japan. It was based on the design of this one, the B53, developed during the Cold War. It had a 9 megaton yield.

Show me more…

Radiation Exposure and Dosage in Sievert Units

We all experience radiation exposure. Much of our exposure is from natural sources such as radon, cosmic sources in space, and the soil around us. The rest is from manmade sources like medical procedures, nuclear medicine, and a variety of consumer products such as smoke detectors. This chart from the EPA shows the various sources and percentages.

The reports from Japan and the Fukushima Daiichi nuclear power plant in the weeks that followed the March 2011 earthquake and nuclear disaster thrust many technical terms into the news. A term that is used very frequently is the sievert. What is it? Another link here describes the sievert.

The sievert is a unit used to derive a quantity called equivalent dose. This relates the absorbed dose in human tissue to the effective biological damage of the radiation. Not all radiation has the same biological effect, even for the same amount of absorbed dose. Equivalent dose is often expressed in terms of millionths of a sievert, or micro-sievert.

A unit used in defining the sievert is the Joule/kg. The kilogram (kg) is a quantity of mass of material. It is nearly equal to the mass of 2.25 pounds of ground beef. The Joule (J) is a quantity of energy. It is nearly equal to the energy needed to lift an apple from the floor back up to the kitchen counter against the force of gravity. What the sievert unit does is describe how much energy is deposited in a specific quantity of human flesh by exposure to radiation. The location and nearness of the radiation dosage to vital tissue such as reproductive or intestinal lining are factors that can determine how dangerous the dosage might be.

The deposition of 1 Joule of energy doesn’t sound like much. But, when concentrated on relatively small volumes of tissue, the odds increase for damage to cell structures or DNA genetic material. We all are exposed to radiation doses continuously. These exposures are unavoidable and are quite low in the millionths or thousandths of sieverts (micro-sieverts and milli-sieverts) ranges. Average exposure of U.S. residents from natural and man-made radiation sources is 6.2 milli-sieverts per year.

This video from the University of Nottingham presents the technical definition in understandable terms with some demonstrations of radiation measurement.