Monday, June 13, 2011

White and Green Asparagus - The Difference is Dark.

White and green asparagus are the same. White asparagus is grown completely in the dark, a process known as etiolation, and results in a lack of chlorophyll, the chemical that makes most plants green. White asparagus is supposedly more tender and more mild in flavour compared to green asparagus. There is also a purple variety of asparagus. Originally from Italy, most purple asparagus is a result of the selective breeding resulting in many hardy hybrids. Rutgers, the State University of New Jersey is a producer of many asparagus hybrids such as 'Jersey Supreme, 'Jersey Knight', and 'Jersey Giant'.

Wednesday, June 8, 2011

The parity of 0

Zero is an even number. In other words, its parity—the quality of an integer being even or odd—is even. Coincidentally an even parity is denoted parity 0. Therefore it is true that 0 has parity 0.

Zero fits the definition of an even number:  An even number is an integer of the form n = 2k where k is an integer. It also exhibits all properties shared by all even numbers, including but not limited to:
  • being divisible by 2
  • being surrounded on both sides by odd integers
  • able to be split into two equal groups
Zero also fits the rules for sums and products of even numbers, such as even − even = even, so any alternate definition of "even number" would still need to include zero.

More: Wikipedia

Friday, June 3, 2011

Système international d'unités

The International System of Units, normally abbreviated SI (from the French: Système international d'unités), or more colloquially called "the metric system" has been globally adopted with three main exceptions: Liberia, Myanmar (Burma) and the United States.

Everyone else has caught on...

Thursday, June 2, 2011

Is π any good beyond 39 decimal places?

Visualization of H atom energy level
probability densities

It has been said that π truncated to 39 decimal places is sufficient to estimate the circumference of any circle that fits in the observable universe with precision comparable to the radius of a hydrogen atom.

Back of the envelope time:

The observabe universe has a diameter of about 93 billion light years or 8.79873*10^26m. The circumference of the observable universe (assuming that it is spherical in shape) is therefore π*8.79873*10^26m or about 2.76420*10^27m. An error in π of +/-1.0*10^-39 would result in an error in the circumference of something on the order of +/-1.0*10^-12m (very roughly). The average orbital radius of H is about 5.29177*10^-11m.

So, Is π any good beyond 39 decimal places (even though it has an infinite decimal expansion)?
Answer: Probably not other than for theoretical and computational interests.