Showing posts with label diagrams. Show all posts
Showing posts with label diagrams. Show all posts

April 15 – Happy Birthday, Leonhard Euler

Posted on April 15, 2014

He's considered one of the greatest mathematicians of all times!

He's considered by most to be THE greatest mathematician of the 18th Century (the 1700s)!

In his own time, Euler was so famous among scientists and mathematicians that one of the greatest, Pierre-Simon Laplace, told students, “Read Euler, read Euler; he is the master of us all.” 

Euler is also considered a physicist. Here are fields Euler made contributions to:
  • infinitesimal calculus
  • graph theory
  • mathematical analysis
  • mathematical terms notation
  • mechanics
  • fluid dynamics
  • optics
  • astronomy
  • music theory

Born on this date in Switzerland, Euler showed his talent for math early. He entered a university at age 13, received his Master of Philosophy at age 16, and completed his doctoral dissertation at age 19. He was not able to get a job at his alma mater, in Switzerland, so he ended up moving to the Russian Empire to work as a physics professor. Eventually he moved to Berlin, in what was then Prussia but is now Germany, to continue as a professor of mathematics and physics.

Check out Eulerian Diagrams!

I have always called the sorts of illustrations seen here (above and right) Venn Diagrams, but John Venn himself called his diagrams Eulerian Circles. Euler had diagrammed subsets and disjoints with circles and other enclosed curves long before Venn was even born. However, Venn pointed out some problems with Euler's diagrams: apparently they are open to multiple interpretations rather than just one logical interpretation.

So Venn created a more restricted version of Eulerian diagrams, one in which all logically possible sets are represented. That means that, in a Venn Diagram, there will often be subsets that are empty. In the example below, which zone (or subset) of the Venn Diagram will be empty?
(There are no animals that
are both birds and mammals.)

Create your own Euler Diagram. Maybe you could make one that compares and contrasts insects and spiders, or that illustrates how various types of polygons, foods, or mammals are the same and different.

Not all of Euler's diagrams were circles.
Here are Euler Diagrams of triangles and
quadrilaterals.


Also on this date:






New Year Celebrations in Cambodia and Laos














Plan ahead:

Check out my Pinterest boards for:
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October 6 – Remembrance Day in Turkmenistan

Posted on October 6, 2013

What are the people of Turkmenistan remembering today? 

They are flying their flags at half-mast to remember the victims of an earthquake that happened on this date in 1948. 


The 7.3 earthquake was one of the deadliest in human history and devastated the capital city of Ashgabat.

The fire you see here has burned non-stop
for 40 years. This giant hole-full-of-fire was
formed when people drilling for natural gas
accidentally caused the cavern full of
dangerous methane gas to collapse.
A nation that was once part of the Soviet Union, that is next door to Afghanistan, and that suffers from really high unemployment...you can probably guess that life is not incredibly easy in Turkmenistan. However, the nation has enjoyed recent economic growth because of its large reserves of natural gas. It also has oil resources and grows enough cotton to export some.



Turkmenistan is a bit larger than my native state of California, but it doesn't have quite as much good agricultural land as Cali does—because 80% of the nation is covered by a black-sand desert!

I noticed an “export treemap” diagram (above) in the Wikipedia article about Turkmenistan. It shows how dependent the nation's economy is on just three things (natural gas, oil, and cotton). It would be great if the nation could diversify—which means build many different industries instead of depending on just a few industries. Compare the diagram to the U.S. export treemap below.


Is diversity always good? I was thinking about how wonderful biodiversity is (lots and lots of different creatures in a habitat, instead of just a few), how wonderful cultural and ethnic diversity is (many different types of music and food available, along with many different holidays and traditions)...and of course a nation is much stronger with economic diversity, too.

I can't think of a kind of diversity that's bad...can you?

To learn more about Turkmenistan, check out this earlier post.


Also on this date:




















National German-American Day



















Plan Ahead:

Check out my Pinterest boards for October holidaysOctober birthdays, and historical anniversaries in October.


And here are my Pinterest boards for November holidaysNovember birthdays, and historical anniversaries in November.