Will we ever be able to shrink and grow stuff? - Luke, Brookline, Massachusetts
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.
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.
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.
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."
Hello, curious kids! Do you have a question you'd like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.
And since curiosity has no age limit - adults, let us know what you're wondering, too. We won't be able to answer every question, but we will do our best.
Salvatore Rappoccio, Associate Professor of Physics, University at Buffalo, The State University of New York