# 20.28 Polarised light

Before you read this, I suggest you read post 19.9. In post 19.9, we saw that light can be considered as an electromagnetic wave. This wave consists of an electric field and a magnetic field that oscillate perpendicular to the direction of propagation of the wave, as shown in the picture above. The electric field… Continue reading 20.28 Polarised light

# 20.27 Chirality

Have you ever tried to put your right shoe on your left foot? Or your left shoe on your right foot? If you can do either, the result will be very uncomfortable! But the width, length and height of both shoes are identical. And the outer, inner and upper curvatures are all the same. So… Continue reading 20.27 Chirality

# 20.26 Boltzmann and other distribution laws

Before you read this, I suggest you read post 20.25 Normally, we think that objects spontaneously minimise their potential energy so that, for example, an object falls to the ground when it is released (post 16.21) and a stretched spring recoils when released (post 16.49). But this can’t be true for the molecules in a… Continue reading 20.26 Boltzmann and other distribution laws

# 20.25 Pressure distribution in fluids

Before you read this, I suggest you read post 17.5 Liquids and gases are both examples of fluids – things that flow into the space available to them (post 16.37). In post 17.5, we saw how the pressure in a liquid increased with depth. Normally, we think of the pressure in a gas as being… Continue reading 20.25 Pressure distribution in fluids

# 20.24 Adiabatic compression of a gas

Before you read this, I suggest you read post 20.23. In post 20.23 we saw that, when a gas is compressed, it is subjected to the same pressure in all directions, so that its resistance to compression is given by its bulk modulus, B, defined by B = –Vdp/dV                     (1) (post 20.20) where V is… Continue reading 20.24 Adiabatic compression of a gas