Category Archives: Engineering

Q: Could we get rid of CO2 if we pumped it through a pipe into space?

Posted on May 31, 2019 by The Physicist

Physicist: Like any plumbing fix: it depends on the pipe. Evangelista Torricelli, the first to measure the weight of the air above us, once famously wrote that “Noi viviamo sommersi nel fondo d’un pelago d’aria.” (“We live submerged at the … Continue reading →

Posted in -- By the Physicist, Engineering, Physics | 37 Comments

Q: How was the number π first discovered? How did we first figure out it was 3.14…?

Posted on August 24, 2018 by The Physicist

Physicist: Unfortunately, the use of the number π is older than recorded history so… who knows?  But the use of π at the beginning of recorded history wasn’t too sophisticated, so we can make guesses. π is the ratio of … Continue reading →

Posted in -- By the Physicist, Engineering, Geometry, Math | 10 Comments

Q: How hard would it be to keep the Moon from drifting away?

Posted on February 12, 2018 by The Physicist

Physicist: Almost prohibitively! Ever since the Moon entered the scene 4.5 billion years ago, it’s been slowly drifting away.  Initially it was around 15 times closer and bigger across in the sky.  The effects that push it away decrease rapidly … Continue reading →

Posted in -- By the Physicist, Astronomy, Engineering, Physics | 13 Comments

Q: Is it more efficient to keep keep a swimming pool warm or let it get cold and heat it up again?

Posted on November 8, 2017 by The Physicist

The original question: I’m having a debate with my wife that I think you can help us resolve.  We have a swimming pool in our back yard.  It has an electric heater, which we set to keep the pool water … Continue reading →

Posted in -- By the Physicist, Engineering, Physics | 22 Comments

Q: If the world is a giant magnet, how come we can’t build a repelling magnet that can float?

Posted on July 8, 2017 by The Physicist

Physicist: Three big reasons: 1) The Earth’s magnetic field is hella weak 2) it’s so big and roughly uniform that there’s no reason for a magnet to go one direction or the other 3) floating a magnet in a magnetic … Continue reading →

Posted in -- By the Physicist, Engineering, Physics | 3 Comments

Q: Is it possible to parachute to Earth from orbit?

Posted on January 30, 2016 by The Physicist

Physicist: Yes and no, but mostly no. It’s certainly possible to parachute safely to Earth from the top (or nearly the top) of the atmosphere, but this question isn’t about parachuting from space it’s about parachuting from orbit.  An orbit … Continue reading →

Posted in -- By the Physicist, Engineering, Physics | 12 Comments