Forces

One of the most amazing implications of Einstein’s relativity is the fact that the inertial mass of an object depends on its velocity. That sounds like a difficult thing to test, but that’s exactly what happened through a series of experiments performed by Kaufmann, Bucherer, Neumann and others.

An object at rest stays at rest, and object in motion tends to stay in motion. This is inertia, defined famously by Isaac Newton in his First Law of Motion.

Put that pedal to the metal and accelerate! It’s not just velocity, but a change in velocity. Let’s take a look at acceleration, how you measure it, and how Einstein changed our understanding of this exciting activity.

Why don’t we have insects the size of horses? Why do bubbles form spheres? Why does it take so much energy to broadcast to every star? Let’s take a look at some non-linear mathematical relationships and see how they impact your day-to-day life.

An object at rest tends to stay at rest. An object in motion tends to stay in motion. Isaac Newton dismantled the traditional idea that objects would tend to slow down over time, and described the concept of inertia: the amount an object will resist changes in its motion.

Our entire civilization depends on energy: getting it, converting it, burning it, and conserving it. But how do physicists think about energy? How do they measure and quantify it. And what is energy’s special relationship with mass?