My friend Lindsey du Toit knows the feeling. She’s a scientist at Washington State University and works with lots of onions. Her research helps farmers grow good vegetables for us to eat.
“It’s not the onion itself that makes us cry,” she explained, “but a chemical reaction that starts when you cut into it.”
I wondered how exactly this chemical reaction worked. To find out, we set up a microscope in her lab and chopped up a Walla Walla sweet onion. I wiped a few tears from my cheek and slid a tiny piece of onion under the lens.
Read all of this answer from Dr. Universe at https://askdruniverse.wsu.edu/2016/08/22/onions-make-us-cry/.
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