Recent content by Andrew Mason

Thanks for posting this. This article suggests the oldest formations that show no signs of having been affected by a seismic shift are about 12,000 years old. "Based on the data, we think that the fault may be at a relatively late stage of a seismic cycle, having accrued a slip deficit, or...

Ok. Suppose the top vertical scale was directly connected to the rigid (but massless) pulleys and frame like this:

The anomaly is that 25 appears to cost less than 20. AM

It is not clear what you are trying to equate. I will answer this on the assumption that you are trying to equate internal energy for the same mass of water at different external pressures. The air pressure at 10 m above sea level would be about 101.2 kPa and at 1800 m it would be about 83.6...

This might help. Gravitation, Misner, Thorne & Wheeler, 2017, page 4: AM

In a reversible Carnot cycle beginning with the forward heat engine direction, if one stores the output work and then applies that work to the reverse cycle, one would return to the initial states of system+surroundings - in which case |Qh| is the same in both as is |Qc|, with the heat flow Qh<0...

For any heat engine or heat pump ##W=|Q_h|-|Q_c|##. Since W is not 0 in either a heat engine or heat pump, ##|Q_h| \ne |Q_c|##

Rutherford would have known how many atoms were in a mole of gold using Avogadro's number. That number had been accurately determined from Milliken's oil drop experiment to determine the charge of an electron compared to a Faraday, which is the charge of a mole of electrons. So he would have...

The mass of a basic unit would be one kilogram divided by the number of such units in a kilogram. The problem Newton had was that he did not know that that basic unit was. At the time, it was by no means obvious that all matter consisted of the same basic units. Gold was dense and had other...

It’s not particularly insightful to define mass as inertia. Newton understood that there was a relationship between gravity and inertia. If he had defined mass as inertia he would need a different definition for mass as the source of gravity. So he defined mass to be something that was common...

Newton could have defined "mass" of a free body as the applied force divided by its resulting acceleration. But defining "mass" as "inertia" in that sense would be circular, as force is defined by change in quantity of motion per unit time and quantity of motion is mass multiplied by change in...

The NY Times is reporting the discovery of a new ultra-high energy (UHE) neutrino. This is reporting on a paper published in Nature today: https://www.nature.com/articles/d41586-025-00444-1 According to the article, the muon produced by the collision of a cosmic neutrino with a molecule in the...

A very good person. He was instrumental in brokering peace between Israel and Egypt. But he had the misfortune of being President during the Iran hostage crisis and an period of unparalleled high inflation. A humanitarian whose life was all about serving others. AM

The 1950's were a bit wild. I would have thought that the metre thick lead shielding in the large blast shield needed to protect the crew from the intense radiation of the nuclear explosion would make it a non-starter for a space craft. Nuclear rocket propulsion using thermal nuclear power...