Mad About Science: Fusion

By Brenden Bobby
Reader Columnist

You know that guy (Brenden) who refers to nuclear fusion as an energy source at parties to try and sound smart (Brenden), but no one really knows what he’s talking about and figures he’s just full of himself (Brenden). Nuclear fusion is a real thing scientists are experimenting with now, and it could forever change the way human beings deal with energy.

Humanity currently has a few major sources of energy: fossil fuels, geothermal, hydroelectric, wind and nuclear fission, all of which behave very differently but utilize the same mechanics to create electrical energy: turning a turbine. Take a hydroelectric dam for example, it utilizes gravity pulling water downward over turbine blades attached to a generator. The action of the water turning the blades and cranking the generator converts this mechanical energy into electrical energy that we can then utilize in power grids that are fed directly into our homes and offices.

As complicated as nuclear fission is, at its core, it utilizes extremely hot temperatures created by volatile elements breaking apart (decaying) and releasing energy as heat, which converts contained water into steam that is pushed through a vent to spin a turbine. Basically, a fission reactor is a Rube Goldberg machine using extremely advanced science to spin a wheel, and nuclear fission is more or less fission in reverse.

Fission uses heavy, volatile elements like uranium and plutonium that rapidly decay, breaking down into lighter elements very rapidly and producing heat. Fusion results when lighter elements such as hydrogen smash together to become heavier elements, creating heat energy in the process. This is the same process that takes place inside of every star in the universe — in fact, stars could be described as giant fusion factories spraying light and heat into the cosmos.

Fusion is so vital as a form of energy transference that it is responsible for every other form of energy currently available on Earth. Fossil fuels, primarily petroleum, are harvested from oil reservoirs deep beneath the Earth’s surface. This oil is the carbonized, fossilized remains of ancient algal mats that once existed throughout all of the planet’s oceans. This algae likely utilized photosynthesis, like all modern plants, by which it would absorb light from the sun to trigger a reaction that would split carbon dioxide (CO2), utilizing the carbon to further grow and reproduce while spitting out the oxygen as waste. Some of the energy of this reaction was stored in the carbon, which is then released as it is subjected to heat and converted back into carbon dioxide, which generates a heat reaction and release of energy in the form of a tiny explosion.

The short version is light from the sun ejected hundreds of millions of years ago is being released to make your car move, and if that doesn’t blow your mind, I can’t help you.

You wouldn’t guess it just by glancing at it, but the Sun is huge — about 109 times the diameter of Earth. Due to this monstrous size and indescribable heat, it makes a natural fusion reactor wildly impractical to build on Earth. An object that large would be extremely dense and create a tremendously huge magnetic field, which would rip Earth into a smattering of atoms in a matter of nanoseconds. Instead, we attempt to build a much smaller version of the sun, one that we can control.

So how do you control the sun? Magnets.

Scientists effectively create a vacuum chamber filled only with the gases they want to fuse, then utilize magnets to push the contents of the chamber together to create intense pressure and heat. Once a reaction takes place, it creates heat and energy, which causes a cascading effect that triggers more reactions, which in turn triggers even more reactions — very similar to how fission works when triggering a nuclear weapon. The vacuum chamber also prevents this reaction from running wild and escaping into the rest of the world.

It’s likely that we would use the heat generated by fusion energy to heat water and spin turbines like we already do with other forms of energy production, but this heat has the potential for all sorts of other cool interactions that could completely change the future of humankind.

Strangely enough, one of the biggest benefits of fusion energy may be how we could begin to recycle plastics. Plastic polymers are essentially a collection of carbon, hydrogen and oxygen molecules — on their own, this is fairly harmless, but in their very precise construction, they become virtually indestructible and poisonous compounds, especially once they are broken down or incinerated.

However, when these products are subject to intense heat, such as the heat at the surface of the sun — somewhere around 5,500 degrees Celsius, they can be broken down into their basest forms: individual atoms of oxygen, hydrogen and carbon, which can then be separated by weight and vented into containment vats and utilized for commercial industries.

Who doesn’t want a 3-D printer that can make pure charcoal briquettes?

The future is bright! Stay curious, 7B.