Earth’s rotational speed

The page here which allows you to create a scale model solar system based on a class room Earth globe has been updated. It also displays the speed of the Earth’s rotation at the point you’ve centered the model on (e.g. your school, a local park, etc.). This is based on a simple formula:
v = cos(lat) * (circ / hs)

lat = your latitude (computed by the page from an address)
circ = circumference of the Earth at the equator: 24,901 miles
hs = hours in sidereal day: 23.9344696

At the equator, that’s a little over 1040 mph, 915 mph at the Kennedy Space Center, 810 mph at the White House, 730 mph in Ottawa, Ontario.

And we are all traveling at over 66,000 mph on our yearly trip around the sun.

try it yourself

Ready to teach lesson plans

North Carolina educators (or those elsewhere too I suppose) will find at, a resource maintained by the UNC School of Education, very useful. It’s geared to the North Carolina Standard Course of Study (which will soon be a based on a national curriculum). This isn’t just a collection of suggestions (like this blog), it’s fully developed lesson plans with activities.

Some are more ambitious than others (“you’ll need a Panoramic photo of the southern horizon, enlarged to 7-foot × 3-foot” vs. “each students needs a 8-inch plate with a 2-inch length of drinking straw”)

read more

for science educators, outreach volunteers, amateur astronomers, or maybe just me