July 2009 Archives

Understanding Weightlessness

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The astronauts of Space Shuttle Endeavour are coming to the end of their 16-day mission to work on the International Space Station, and our minds wander to thoughts of physics, especially the physics of objects in space. 

We often think that astronauts are weightless while they're in space, but the fact is gravity is still acting on their bodies. When the space shuttle is at an orbit of 250 km, the force of gravity on an astronaut is 92% of what it is when they stand on the surface of the earth. 

So, although astronauts are not actually weightless in space, they feel and look as though they are weightless. This is called apparent weightlessness.

Watch and listen as Professor Stephen Pollock explains apparent weightlessness in this video from Thinkwell's online Physics series.


Nuclear Function: Who's in Charge?

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What controls a cell? You may have heard that the nucleus is the "brain" of the cell, implying that it's the structure that's in charge. 

However, if you take a look at a cell from a functional rather than structural point of view, it becomes very interesting. Structure follows function--if something has a role to do, then it better be built to perform that role--even at the molecular level. 

Watch and listen as Professor George Wolfe discusses the magnificent array of the different structures in cells, why their functions are so important, and how these functions act in a collective process in this video from Thinkwell's online Biology series. Who knows, the idea of the nucleus being the brain of a cell just might become an outdated concept.


The Nature of Energy

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Energy is the capacity to do work or transfer heat. When applied to our individual lives, this could mean having whatever it takes to go out and get the shopping done, get your car washed, or whatever. If you have a lot of energy, you have the ability to do a lot of work.

When applied to science, energy can mean the ability to transfer from one system to another via heat.

Watch and listen as Professor Gordon Yee describes different types of energy and demonstrates that there's a lot more to chemical reactions than the rearrangement of atoms to form new molecules in this video from Thinkwell's online Chemistry series. 


Naming Chemical Compounds

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If you want to talk about, say, German literature, you're probably going to need to know a good deal about the German language. In much the same way, if you want to talk about Chemistry, you're going to need to learn something about chemical language, or nomenclature, and the systems and rules used to form the names of chemical compounds.

There are definite trends in how chemical compounds are named. For example, did you know that most molecular compounds use Greek prefixes?

Watch and listen as Professor Dean Harman discusses some of the most common names of ions, molecules, and acids and identifies the trends used when naming these compounds in Thinkwell's "Naming Chemical Compounds."


Lab Coats and Lab Safety

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Have you ever thought of a piece of clothing as a status symbol? I recently read an article in Slate that answers the age-old question, "Why do doctors wear white lab coats?"

I thought it was particularly interesting to learn that doctors have adopted these wears from laboratory workers because they believe white lab coats reflect a level of high status and important regard. You can find the full article and dive even further into the history of these white coats here.

As we were putting together our Biology and Chemistry videos at Thinkwell, we learned that these white coats serve a great purpose in the laboratory: safety! Check out Professor Gordon Yee as he demonstrates important lab safety techniques and why it's so important to wear one of these special coats during experimentation.


The Articles of Confederation

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On July 4, 1776, the Continental Congress formally adopted a Declaration of Independence announcing that the thirteen American colonies were independent of the British Empire.

As we were celebrating our country's independence this past weekend, we were thinking about how it all started and what followed during the days of the American Revolution.

Watch and listen as Professor Gerald Rosenberg takes us back to the planning and implementing of our government and constitution and describes the unique circumstances under which they came to be in Thinkwell's "The Articles of Confederation."

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About this Archive

This page is an archive of entries from July 2009 listed from newest to oldest.

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