I love this entry form XKCD!!!!!

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How should we tackle sentences with the following structure: “If X, then Y”
This simple logic statement can be seen as 2 parts:

X is the hypothesis/premise/evidence
Y is the conclusion

At any time, 4 situations can happen:

X is true - If X is true, then Y is true
Y is true - If Y is true, we know nothing [...]

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Probability A and B

P(A) + P(A’) = 1
P(AUB) = P(A or B) = A union B
P(A?B) = P(A and B) = A intersect B
P(AUB) = P(A) + P(B) – P(A?B)
P(AUB) = P(A) + P(B)  for mutually exclusive events

Probability A and B and C

For 3 sets A, B, and C:
P(AuBuC) = [...]

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Focal length of a camera lens system is a measure of how strongly it converges (focuses) light. A photographic lens is used in a camera to make images of the opbjects on the film or other image sensors.
Some links…

wiki: focal length
wiki: photographic lens
photoxels: Focal length
focal length

Measurement of focal length is done in mm. nowadays:

Wide-angle lens 18mm, 20mm, [...]

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I want this water powered clock! Yes, really… this clock is powered by only water. Here’s how…
The internal converter simply extracts electrons from water (or other liquid) molecules and provides a steady stream of electrical current acting as a fuel cell to generate power to the clock.
Check out this and a lot other eco-friendly gadgets [...]

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I found a neat website, that tells us the daily day and night times… as this is important while travelling to new cities.

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Book Title: Surely You’re Joking Mr. Feynman!
Author: Richard P. Feynman
Year written/published: 1985
Book Source: Google Books, Library
Summary: Colletion of very short stories about Feynman’s adventures of being an inquisitive person.
My Comments: This book is so humorous that instead of being in the physics section of the library, it must be in the  fun section. Through these [...]

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some short forms…

AM - Ante Meridiem, before noon in Latin
PM - Post Meridiem, after noon in Latin
UTC - Cordinated Universal Time
GMT - Greenwich Mean Time
DST - Daylight Saving Time/Summer Time [map]

Time zone  and a map of the world. Lastly, the times for many cities around the world.

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Today we use many units that were actually once the surnames of eminent scientists… examples from this site includes a list of units scientists and engineers use everyday

A ampere André Ampère
C  coulomb Charles-Augustin de Coulomb
°C degree Celsius  Anders Celsius
F  farad  Michael Faraday
Gy  gray Louis Harold Gray
H  henry Joseph Henry
Hz  hertz Heinrich Rudolf Hertz
J  joule James [...]

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fantastic video i thought … about 10 dimensions…

and part 2…

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Another classic problem solving question - Konigsberg Bridge! To put it simply: People tried to find a way to walk all seven bridges without crossing a bridge twice, but no one could find a way to do it… until Euler came to explain why! And his analysis on this problem was the first of Graph [...]

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to denote very small numbers or very large numbers, we use standard prefixes… 

1,0E+24 yotta- Y

1,0E+21 zetta- Z

1,0E+18 exa- E

1,0E+15 peta- P

1,0E+12 tera- T

1,0E+9 giga- G

1,0E+6 mega- M

1,0E+3 kilo- k

1,0E+2 hecto- h

1,0E+1 deca- da

1,0E-1 deci- d

1,0E-2 centi- c

1,0E-3 milli- m

1,0E-6 micro- µ

1,0E-9 nano- n

1,0E-12 pico- p

1,0E-15 femto- f

1,0E-18 atto- a

1,0E-21 zepto- z

1,0E-24 yocto-  y

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 To transfer and rebuild the tower around one of the initially empty pegs such that:

only one ring be moved at a time
no ring must rest on a smaller ring

2^n -1 gives the value of the number of turns where n = number of rings
 

picture credit here

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with the recent series of earthquakes, i decided to refresh my memory about the plate tectonics and the boundaries of these plates on the surface of the earth…

picture credit
and some links about what a plate tectonic is all about…

Wiki

platetectonics.com

causes of earthquake

and others from google search

Earth’s crust is constantly being reshaped from the time of Pangea… [...]

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I thought this list in Wiki is rather interesting… it has the list of unsolved problems in mathematics and some problems include…

Goldbach’s conjecture
infinitely many Fibonacci primes
Twin prime conjecture
existence of odd perfect numbers
infinitely many prime quadruplets

some of these are really easy to understand especially the ones under number theory, but nobody has been able to prove [...]

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Book Title: The Universe - A Biography
Author:John Gribbin
Year written/published: 2006
Book Source: Amazon, Library
Summary: From Big Bang, the birth of the Universe to the future - how will the universe end?
Some extracts:
Scientific model…

In fact, all scientific models have restricted applicability. None of them is ‘the truth’. The model of an atom as perfectly elastic little sphere [...]

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So what is the fundamental unit of all matter? Long ago, it was the molecules, then it was atoms… and then it was the electrons, protons and neutrons.
Well, now there’s something evern smaller - quark. There are 6 flavours of quark and by the names, we surely know that phsycists are very imaginative and amusing:

up
down
top
bottom
charm
strange

Example, [...]

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So we could see the entire earth and it was already awesome for me… the next is the Google Earth SKY!!! Imagine you can zoom into the night sky … zoom zoom zoom and see all the stars, galaxies, constellations and the beautiful nebulae and star bursts. Yes it can all be done now due [...]

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Mobius Strip is a surface with only one side. It’s mind-boggling and yet it’s so simple to make it with just a piece of paper strip…

picture credit: wikipedia
Another surface will be the Klein bottle which also has only one side!

picture credit: wikipedia

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CERN - French Conseil Européen pour la Recherche Nucléaire, or European Council for Nuclear Research - is the particle physics laboratory.
Some facts…

it has the world’s largest particle accelerator
it can accelerate particle nearly to the speed of light
it’s members include 20 European nations

other links…

info.cern
webcast.cern
high school teachers at CERN

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