If energy is conserved why are we worried aout energy crisis?
1 Answer
Conservation of energy is the first law of Thermodynamics. The second law states that entropy doesn't decrease, which is the real problem. It basically means not all energy is equally useful.
We can make a battery, which is a nice organized form of potential energy. We can draw the energy out slowly over time, powering our phone say. Some of that energy is radiated as light or radio waves, but most of it is just radiated as heat. By powering the phone, the energy in the battery has made zillions of glass and metal and air molecules around the phone move a bit faster.
Energy is conserved. Theoretically the sequence is reversible; some energy from the molecules in the air could jump into the phone and charge up the battery. But the second law of Thermodynamics, as well as bitter experience, tells us that kind of stuff doesn't usually happen.
So that heat isn't really lost energy, but it's distributed throughout the air in a way that's not recoverable. We need the energy concentrated to use it; diffused as heat it's not as useful.
