No, You Can’t Have a Solar-Powered Passenger Plane
The angle at which the light hits the panel, θ, is measured from a line perpendicular to the surface. This means you will get a maximum solar panel power when …
dot physics
How to Run on the Moon
When the elevator is stopped, the two forces are equal and opposite, and the net force is zero. But if you’re accelerating upward, the net force must also be upward. …
If Betelgeuse Explodes, Just How Bright Will It Get?
Theres a famous star that I’m sure you’ve seen in the sky. Its name is Betelgeuse, and you can find it in the Orion constellation, where it marks Orion’s right …
What Kind of Battery Would You Need to Power a Lightsaber?
Melting an ice cube takes 3.34 x 105 joules per kilogram. So a single ice cube with a mass of 50 grams would take 16,700 joules. You can already see …
Can You Really Run on Top of a Train, Like in the Movies?
Just because you see something done in a movie, that doesn’t mean you should try it yourself. Take, for example, a human running on top of a moving train. For …
Can You View a Round Solar Eclipse Through a Square Hole?
If you live in the US and missed the last total solar eclipse in 2017, good news! You’re about to get another chance. There will be a total solar eclipse …
How Do Heat Pumps Work?
Now stretch it really hard and quickly hold it to your upper lip, which is sensitive to temperature. You will feel that it’s warmer than it was before. That’s because …
How to Convince Your Flat-Earth Friends the Earth Is Round
Illustration: Rhett Allain You can see that we have a right triangle with the hypotenuse equal to the distance from the observer’s eyes to the center of the Earth (R …
Why the Polar Vortex Is Bad for Balloon Artists
It’s been crazy cold this week, even down where I live in Louisiana, thanks to an outbreak of a polar vortex. This frigid air is bad for all kinds of …
School of Rock: The Physics of Waves on Guitar Strings
The rubber band example does indeed have two nodes—they are at the ends of the rubber band where your fingers hold it. We only have half a wavelength in the …