January 02, 2011

Scientists say it well

There are several ways a single thing can be explained.  But there are times when you look at some explanation and go wow.  I am gonna list some really cool explanations that I have heard.
  • The first such explanation I remember was given by a MySQL trainer.  He was talking about different data types and gave the best explanation I have heard of why floating point data in computers can be inaccurate.  He said that every data type in computers is finite, and there are infinite numbers between any two fractions, say 0.1 and 0.2.  So floating point representations hop through the interval including some values and skipping several values.  For instance, one implementation of float type might be able to only represent 0.1, 0.12, 0.14, 0.16, 0.18, and 0.2.  You simply cannot represent 0.17 using such a type.  (When using such a type, your computer cannot differentiate between 0.1734 and 0.1748; it will treat them as two equal numbers!)
  • Someone told me sometime back that if you keep applying the brake, it would eventually fail.  I looked it up on the web, and I found a curious explanation (I don't remember the source).  It said that while applying brake, we transform the kinetic energy from the wheel into heat energy.  When there isn't any more kinetic energy left to move the vehicle forward it stops.  (If we keep applying the brake, the brake will get so hot it cannot take any more heat from the wheel.  Since no energy is taken off the wheel the vehicle keeps moving.)
  • The Dancing Wu Li Masters says that no one has ever seen an atom.  To see if science has improved since then or still atoms cannot be seen, I did a Google search and found an answer Argonne National Laboratory's site.  The answer is more than 17 years old now, but the way scientists answer questions is interesting.  Arthur Smith of ANL says that atoms cannot be seen because all atoms are thousands of times smaller than the smallest light waves we can see using our eyes.  It conveys the idea directly that we don't see objects, but all we see is light.

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