Coding classes in Neath Port Talbot

Picture the two shafts as tall columns of air joined at the bottom. Warm air is lighter than cool air, so the cool column presses down harder and shoves air round and up the warm one. This is the stack effect, the same thing that makes a chimney draw. The learner codes the ideal gas law to find air density at each temperature, subtracts, and multiplies by gravity and the 732 metre depth. The temperatures below are our own guesses, not colliery readings, and the model skips the fact that air gets denser deeper down.

A difference of 15 degrees gives about 450 pascals, the weight of a 46 millimetre column of water. That is real, useful suction, and the deeper the shaft, the stronger it gets: the same temperatures give about 62 pascals at 100 metres and 185 at 300. But the last row shows the catch. On a hot day the surface air can be warmer than the air coming up, the push drops to nothing or runs backwards, and the mine would stop breathing. That is why the record mentions a fan house: a fan keeps the flow steady whatever the weather.

The code also has a trap. The gas law needs temperature in kelvin, that is Celsius plus 273.15. Feed it Celsius instead and the program says air at 10 degrees is about 35 kilograms per cubic metre, nearly thirty times its real weight, and the draught comes out above 150,000 pascals. Learners write a check that any air density must sit near 1.2, so the slip is caught the moment it happens.

Catching an impossible number before it spreads is a strong reason for a Neath Port Talbot teenager to keep coding in 2026. The longer argument is in why teenagers should still learn to code in 2026.