Showing posts with label Geiger counter. Show all posts
Showing posts with label Geiger counter. Show all posts

The Appearance of Man

“Arbitrarily, for the exact date of man’s appearance will never be known, let us estimate that appearance at about one and a half million years ago. Then let us propose a comparison of mankind’s history with a calendar year in which one ‘day’ equals four thousand years of human history.

In this scheme January First would witness the appearance of our Homo habilis ancestors. Homo habilis could walk erect and use the most primitive tools. Hunting in bands, he probably could not talk as we do, though he undoubtedly had some method of communication. Speech, as we know it today, evolved very gradually during the first three months of our year. Man’s evolutionary progress was at best tedious and halting: fire first for protection from the cold and wild animals, and only much later for cooking; tools chipped from stone; the skills of hunting; the slow concentration and evolutions of the cerebral cortex. Summer came and went, and the fall was two-thirds through its course when Neanderthal man finally appeared around November 1st. The first indications of a religious belief can be seen in the burial sites of the later neanderthaloids, around December 17th in our scheme.

By December 24th of our hypothetical year, all the nonsapiens or primitive forms of man had died out or been absorbed by the more progressive and modern Cromagon man. Agriculture began around December 28th and the whole of our historical era, the brief six to ten thousand years for which we have records, is nestled in the last two days of our year. Socrates, Plato and Aristotle were born about 9am on December 31st, Christ at noon and Columbus about 9.30pm. The final hour of December 31st, from 11pm to midnight New Years Eve, embraces all of the nineteenth and twentieth centuries” 
(The Appearance of Man by P. Teilhard de Chardin (New York: Harper, 1956 form the Preface written by Robert T Francoeur)

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Can I use a Geiger counter to test food?

Ever since Fukushima I have wondered about the possibility of radioactive food eventually appearing or even growing the US due to fallout. How will know when it happens? Who will tell us?

This brings up the logical question - Can I use a Geiger counter to test food?

For practicable purposes the answer is no.

There is no Geiger counter out there that can reliably test for radiation in food. It is not a question of accuracy.

The problem is that it only takes a very low amount of radioactive contamination to be dangerous if consumed. The radioactivity of the food will almost always be masked by the normal background radiation (which is usually of a non harmful type).

Example:  If containment is .02 uSv/h and the background radiation is .09 uSv/h, the Geiger will detect contamination but you will not see a spike in readings (which will continue to show .09 uSv/h). It would be like looking for a drop of water in a pond.

The exception of course would be if the food was extremely radioactive. If your background environment for example, varies between .09 uSv/h and .14 uSv/h and the food sample consistently spikes it to .20 uSv/h, you know you have something you better get rid of fast.

The only way to reliably distinguish between low contamination and the normal background radiation is in a lab, where food is placed into a container that isolates it from any background interference. That is the only way.

Next comes the question of how much food. A single piece of food most likely will not give you an accurate reading if any at all. You will need a lot of food. This is because it is very possible that the radiation leaves the sample in such a direction as to miss the tube in your device. The bigger the sample, the better the chance of the device picking it up.

This principle is best explained in the video below. It clearly demonstrates why you cannot accurately measure food.:

Testing food with a Geiger counter overview 



Finally you must remember that a Geiger counter only recordes radiation. It does not tell you what type. Take a banana for example. Bananas naturally give off radiation within a small range of 0.10 uSv/h. Yet bananas however or not harmful at all because they give off potassium – 40, which your body eliminates once it reaches a certain level.


___________________________________________
Attention Writers
Is your setting weak? Is it missing convincing elements? Are you having trouble getting started or filling in the details?
Maybe you just want to learn more about setting or need a few ideas.