Browsing All Posts filed under »Biology«

A simple model could explain how the first cell came into being

January 11, 2011 by

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It’s just a thought experiment, and there’s no real way to test it just yet. But it’s the first time we even have a possible working explanation for how Earth’s first tentative steps toward life might have happened. From these humble origins, protocells could eventually turn into more complicated structures, and life could begin. It’s […]

A Plethora of Hobbit Papers – Origins

September 26, 2010 by

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Fans of Homo floresiensis will be happy this month, as the Journal of Human Evolution (JHE) has a special issue devoted to these diminutive hominins whose fossils were found on the Indonesian island of Flores. There‚Äôs also a new paper out in Significance, the Royal Statistical Society journal, in which William Jungers and Karen Baab […]

Interactive tool: Practice estimating relative sizes

August 26, 2010 by

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Interactive tool for practicing comparing two lengths, areas, and volumes. It is VERY TRICKY to judge how area and volume change with size. This tool gives you good practice. Good for physics problems to do with pressure, gravity, and other places where area or volume are important. Explore size estimation in one, two and three dimensions! Multiple levels of difficulty allow for progressive skill improvement.

Interactive tool: Curve fitting functions to data points (PhET / UCBoulder)

August 26, 2010 by

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Interactive tool for fitting a straight line or other curves to data points. Great supplement to any science lab course. Let's you see how data and mathematical models relate to each other. With your mouse, drag data points and their error bars, and watch the best-fit polynomial curve update instantly. You choose the type of fit: linear, quadratic, cubic, or quartic. The reduced chi-square statistic shows you when the fit is good. Or you can try to find the best fit by manually adjusting fit parameters.

How to: Conversions using the factor-label method (Wikipedia)

August 26, 2010 by

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Brief instructions and example showing how to convert between units (say, from mi to m) using conversion ratios. Converting from one dimensional unit to another is often somewhat complex and being able to perform such conversions is an important skill to acquire. The factor-label method, also known as the unit-factor method or dimensional analysis, is a widely used approach for performing such conversions

How to: Entering scientific notation on a calculator (TI)

August 26, 2010 by

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Short 'how to' showing how to enter scientific notation on a TI (Texas Instruments) calculator. Use the Enter Exponent or [EE] key to enter numbers in scientific notation. The [EE] key is used to denote x10 for numbers written in scientific notation. Note: TI calculators use the EE button. Some calculators use the Exp button. If you don't know how to use these, you will waste your time and on some problems you'll get the wrong answer.

Online tutorial: Scientific notation (UCel)

August 26, 2010 by

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Online tutorial on using scientific notation to describe and compute with really large and really small numbers. Great review! 17 short Flash tutorials delivered in a charming British female voice. Good graphics and examples moving step-by-step through the use of scientific notation.