Pressure explains why an applied force makes a drawing pin goes into the noticeboard and not your thumb: it also explains why a sharp knife is safer than a blunt one when practising culinary skills. There is also another aspect of pressure that relates to forces within a fluid (liquid or gas) and that is … Continue reading Under(water) Pressure
Thermal Equilibrium
Any object that has a constant temperature is in a state of thermal equilibrium. This means the rate at which energy is transferred to the object is exactly equal to the rate at which energy is transferred from the object. In the context of electromagnetic radiation, we can state that the rate at which the … Continue reading Thermal Equilibrium
Telescopes in Space
Why do we put telescopes in space? The reason is not to get "closer" to the things we are trying to observe! Although the Earth's atmosphere extends much further, we generally think of space as starting about 100 km above the Earth's surface (see here for more details) and that's a tiny distance compared even … Continue reading Telescopes in Space
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