On a nice, hot summer day, the first thing most people think about is going to the beach. Once there, the sand gets in your shoes and makes an extremely uncomfortable situation. So why not take off your shoes? well, because that soft, relaxing looking sand is probably HOT, so be careful.
The sun is a very strong thing. Because the sand, like on the beach of lake Ontario, is made up of mostly quartz, the heat capacity of the sand is very high, meaning that it can absorb a LOT of heat and get really warm. After only a few hours of sunlight, the heat of the sand can rise to well above the temperature outside.
Unlike things that are black in color and absorb a lot of light, the sand is actually absorbing the energy of the sun, (and maybe some light waves too.) Energy in the sun is created when there is a nuclear fusion of Hydrogen into Helium in the core of the sun. The helium atoms are radiated off of the sun through the solar system, eventually entering the Earth's atmosphere, hitting the ground and being obsorbed.
If the sand were made up of different minerals, it may not get as hot because the heat capacity might be much much lower, making it harder for the substance to heat up. The heat capacity for quartz is 830 J/Kg C, meaning it takes 830 jules of heat energy to raise the temperature of the quartz in the sand. This can be achieved very quickly. In one hour the sun produces 1.4*10^14 Joules of solar energy. Of course this energy dissipates by the time it hits the earth's surface, but that is still a substantial amount of energy.
So next time you decide to spend a day on the beach, wear sandals or things that sand can move through easily, otherwise, be prepared to feel like youre stepping on some hot coals.
*Did you know: the sun produces more solar energy every hour than the entire energy needs of human civilization? thats ALOT of energy able to be absorbed. *