# Happy 450th Birthday Galileo!

Today (February 15, 2014) is the 450th anniversary of the birth of Galileo Galilei. Galileo made many contributions to science including describing the motion of pendulums and falling objects, his improvements to the telescope, his astronomical discoveries (including 4 of Jupiter’s moons), and his support of heliocentrism (the astronomical model wherein the planets move around the sun, described by Copernicus).

Until Galileo, scientists typically conducted qualitative studies, meaning they relied on descriptions of characteristics rather than on measured quantities or values. One of Galileo’s most important contributions to science was that he used mathematics to describe his scientific observations. He was one of the first thinkers to state that the laws of nature are mathematical. He also understood the relationship between mathematics and physics. He understood that the parabola is a conic section , a mathematical function where the y-value is a function of the square of the x-value (for example, y=x2), and the trajectory of a falling object. If you throw ball, it follows a parabolic path.

Galileo mostly applied the standard mathematics of the day to his scientific pursuits, but he did produce the Galileo’s paradox, which shows that there are as many perfect squares as there are whole numbers, even though most numbers are not perfect squares.

Galileo also proved that objects fall at the same rate, regardless of weight. Before that, people believed that heavier objects fell faster than lighter objects. Of course, we know that sometimes lighter objects fall more slowly, but this is due to air resistance. On the Apollo 15 mission, Commander David Scott showed that in the absence of air, a feather falls at the same rate as a hammer.

Legend has it, Galileo performed the falling object experiment by dropping objects off the Tower of Pisa. In the video below, Galen Weitkamp, professor of mathematics at Western Illinois University, explains some of the math describing falling objects.

# Happy Tau Day

As a math lover, I love that I share my birthday with τ (tau) Day. What is τ you ask? It’s 2π of course (τ = 2 x 3.14 = 6.28). Why give 2π a name and a day? Well, watch these 2 videos, one from Vi Hart and the other from Numberphile, to see what the fuss is all about.

# Maker Faire Bay Area 2013

My family and I spent this past weekend exploring all the wonderful sights and activities at Maker Faire Bay Area. Maker Faire is billed as a family-friendly festival of invention, creativity and resourcefulness, and a celebration of the Maker movement. We saw flaming sculptures, robots, giant musical tesla coils, people on stilts, Tapigami, the EepyBird Coke & Mentos show, and much more. The kids polished rocks; did lots of art projects, including a claymation video and an octopus made from gloves; helped build a beehive; made soap and silly putty; and climbed into a life-sized bejeweled flying saucer. If there is a Maker Fair event near you, GO!

Here a few math-themed photos I took at the event.

Koch snowflake ornament

Nerdy t-shirt designs by Lovebian

Geometric sculptures

Geometric building pieces at the Story Lamps booth

Math Sculptures booth

Math Sculptures booth

Hanging geometric sculptures

Some math-y patches

Geometric puzzles

T-shirt seen at Maker Faire

# February 21st is Introduce a Girl to Engineering Day

Introduce a Girl to Engineering Day is devoted to teaching girls about the field of engineering, a field traditionally dominated by men. This event aims to address one of the causes of this gender disparity, a lack of familiarity with the field.

For more information, resources, and hands-on activities for K-12 kids, go the Introduce a Girl to Engineering Day webpage.

Introduce a Girl to Engineering Day, 2013, is dedicated to the memory of Dr. Sally Ride.  Dr. Ride was America‘s first woman in space and founder of Sally Ride Science, a company devoted to promoting K-12 science education.