Specific Heat Capacity

Every material has a unique 'thermal personality.' Some materials, like metals, are eager to change temperature with just a little bit of energy. Others, like water, are 'stubborn' and require a lot of energy to heat up. This property is called Specific Heat Capacity ($c$). It is defined as the amount of heat energy required to raise the temperature of 1 kilogram of a substance by 1 degree Celsius (or 1 Kelvin). The standard unit for specific heat capacity is $J/(kg \cdot ^\circ C)$ or $J \cdot kg^{-1} \cdot ^\circ C^{-1}$.

To calculate exactly how much energy is moving in or out of an object, we use the heat equation. In this formula, $Q$ represents the heat energy (measured in Joules, $J$). The variable $m$ is the mass of the object in kilograms ($kg$), and $c$ is the specific heat capacity. The symbol $\Delta T$ (delta T) represents the change in temperature, calculated as $T_{final} - T_{initial}$. If $Q$ is positive, the object gained energy; if $Q$ is negative, the object lost energy to its surroundings.

Water has an unusually high specific heat capacity ($4186 J/kg \cdot ^\circ C$) compared to land ($800 J/kg \cdot ^\circ C$) or air. This means the oceans can absorb massive amounts of solar energy during the day without getting much hotter. At night, they slowly release that heat. This is why coastal cities have milder climates than inland deserts. Without water's high specific heat, Earth's temperatures would swing wildly between boiling hot days and freezing nights.