The First Law of Thermodynamics: Why Energy Never Disappears

The First Law states that energy cannot be created or destroyed—only transformed.
This principle is also known as the law of conservation of energy.
When you eat food, your body converts chemical energy into movement, heat, and work.
A light bulb transforms electrical energy into light and heat, but the total energy stays constant.
In engines, fuel’s chemical energy becomes motion and exhaust heat—nothing vanishes.
Even when energy seems “lost,” it’s just spread out, often as low-grade heat.
The First Law underpins every power plant, battery, and motor on Earth.
It explains why perpetual motion machines of the first kind are impossible.
The law links physics, chemistry, and biology—energy changes unite all sciences.
Remember: the universe is an energy accountant, and every “deposit” must balance.