Monthly Archives: February 2013

Q: If a man hangs on an un-insulated wire using both his hands what will happen and why?

Physicist: Just a quick note before answering this; hanging off of power lines holds a special place simultaneously in both in the Very Long List of Stupid Things to Do and the Somewhat Shorter List of Last Things to Ever … Continue reading

Posted in -- By the Physicist, Physics | 28 Comments

Learning intro number theory

Physicist: We occasionally get questions about free learning resources.  Khan academy is excellent, and if you poke around you can find a smattering of free class notes and text books, but generally speaking the more more detailed/advanced the material, the … Continue reading

Posted in -- By the Physicist, Brain Teaser, Math, Number Theory | 5 Comments

Q: Is the Alcubierre warp drive really possible? How close are we to actually building one and going faster than light?

The original question was: Is this f’real? Astronomer: The Alcubierre spacetime metric is named after a Miguel Alcubierre, a physicist who was also a Star Trek fan. It describes a type of bubble in space, where you could put, for … Continue reading

Posted in -- By the Physicist, -- Guest Author, Physics, Relativity | 52 Comments

Q: Is darkness a wave the way light is a wave? What is the speed of dark?

Physicist: The very short answer is no: darkness is not a wave.  There are no waves in the dark for very much the same reason that there’s no surfing (or ocean waves) in Death Valley.  Darkness, being an absence of … Continue reading

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

Q: Is it a coincidence that a circles circumference is the derivative of its area, as well as the volume of a sphere being the antiderivative of its surface area? What is the explanation for this?

Physicist: For those of you not hip to the calculus groove, here’s what’s going down:  The derivative of Y with respect to X, written , is just a description of how fast Y changes when X changes.  It so happens … Continue reading

Posted in -- By the Physicist, Math | 13 Comments

Q: If hot air rises, why is it generally colder at higher elevations?

Physicist: Beautiful question! The short answer is that if you have a warm bubble of air it will rise, but as it does it’ll expand in the lower pressure environment, which causes it to cool. If you’re not familiar with … Continue reading

Posted in -- By the Physicist, Physics | 9 Comments