Xuejian Wu for The Conversation: “ How much energy can people create at one time without losing control?”

Above our heads there is a powerful energy source created by nature, the Sun. Because the Sun is 93 million miles from us, only one-billionth of the Sun’s total energy outputreaches the Earth, creating a world blooming with life. The energy that the Sun gives the Earth’s surface every second is more than the total electricity generated from all power plants in the world in the entire year of 2018.

Here on Earth, humans power machines mostly by harvesting energy: for example, harvesting the energy of falling water and converting it to electricity in hydroelectric power plants. To create energy, you have to convert matter to energy

Chain reactions

One way to do that is to split atoms, the basic building blocks of all matter in the universe. Do so controllably and you can produce a steady flow of energy. Lose control and you release a lot of energy all at once in a nuclear explosion.

The core of every atom, the nucleus, is made up of even smaller particles, protons and neutrons. The force holding the nucleus together stores a huge amount of energy. To obtain energy from the nucleus, scientists came up with a process of splitting a heavy atom into lighter atoms. Because the lighter atoms don’t need as much energy to hold the nucleus together as the heavy atoms, energy is released as heat or light. This process is called nuclear fission.

When one atom is split, a chain reaction starts: The split atom will trigger another atom to be split, and so on. To make the chain reaction controllable, scientists developed ways to slow down the splitting, such as absorbing some of the split particles.

Read the entire story at The Conversation.