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Will we ever be able to shrink and grow stuff? – Luke, Brookline, Massachusetts
Maybe you’ve seen “Ant Man” or “Avengers: Endgame,” where people can grow to the size of buildings or shrink down to the “Quantum Realm” and travel through time.
This sounds fun, but unfortunately it can’t happen in real life. To see why, let’s look at how things are put together.
Everything we know of in the universe is made of the same things: atoms. They work similarly to Tinkertoys, where blocks are connected by rods to make things.
A cartoon of atoms arranged in a cube, zoomed in 20 million times.
Cadmium/Wikimedia
The simplest forms objects take are crystals. You see crystals in your life all the time, from table salt to metals. These crystals are bunches of atoms connected in repeating shapes, like cubes or hexagons.
An actual image of a crystal in a hexagonal pattern, taken with a very powerful microscope called a scanning tunneling microscope.
Guillaume Baffou/Wikimedia, CC BY-SA
If you wanted to grow or shrink something like a crystal, an ant or a person, you’d need to change the distance between the atoms. To shrink something, the distance must get smaller. To grow something, the distance must get larger.
The problem is that the rods connecting the atoms really act like tiny springs: they don’t want to be pushed together, or pulled apart. They want to stay at the same length. This length is so tiny that you could fit a thousand of them inside the width of a single human hair.
Atoms don’t like to be too close or too far apart.
Viviana Rappoccio, CC BY-ND
How much these tiny springs resist pushing or pulling is determined by the electric force, which is a constant of nature. As far as scientists know, the electric force has the same strength everywhere in the universe, for all time. To grow or shrink something, we would have to change the strength of the electric force, which is not possible to the best of our knowledge.
There are a few things in the world that do shrink or grow, but the way they do so is not by shrinking or growing at the atomic level. Usually it involves adding or removing water or something else. Grapes shrink into raisins when they lose water, and sponges expand when they soak up water.
Many cultures throughout history have removed water from the bodies of people who have died, which is how mummies are made. However, they don’t really shrink all that much. There are also ways to grow or shrink microscopic things like nano-structures by pushing or pulling their atoms together a little bit, but we can’t do the same thing to people, or ants. Sorry, “Ant-thony.”
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Authors: Salvatore Rappoccio, Associate Professor of Physics, University at Buffalo, The State University of New York
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