Scientists Say: Cryogenic

Cryogenic (adjective, “Cry-oh-JEN-ick”)

Cryogenic refers to technology that works in or relies on very low temperatures. Typically, cryogenic tech involves temperatures lower than –150° Celsius (–238° Fahrenheit). The word cryogenic also refers to fields that build systems for achieving and using these cold temps.

Cryogenic tech is often useful because it alters a substance’s state. For instance, cooling can change something from a liquid into a solid. Or a gas into a liquid.

Here’s an example. Cryogenics can cool rocket fuels, such as hydrogen and methane. This turns the fuels — which would be gases at room temperature — into liquids. Those liquids can then be stored in tanks and burned, granting rockets the thrust needed to lift off into space.

Cryogenic tools might also be used during surgery. This is called cryosurgery. It allows doctors to freeze off diseased tissue, such as cancerous cells.

In other cases, cryogenic tech is used to preserve cells, such as egg cells. Say someone wants to have a child in the future. But they aren’t sure if the egg cells in their body will still be viable at that time. (Viable means the cell can still be fertilized.) That person could have some of their egg cells frozen in their current state. Think of this as pressing the “pause” button on life. The eggs can be reawakened and fertilized later.

Biologists might also freeze lab samples to keep them from decaying. In conservation biology, scientists might preserve the DNA of an endangered species. That way, scientists might be able to clone new members of that species in the future. (To clone means to grow a genetic copy of another individual.)

This field is even useful for preserving food. Quick-freezing can often better retain food’s qualities than just putting it in a freezer. In the freezer, teeny-tiny ice shards form in food, which can change its taste. Cryogenics allows for “flash-freezing.” This process quickly freezes food before these shards can form. 

In a sentence

By turning fuels from gas into liquid, cryogenics can create high-density rocket propellant.

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