Hi, Dr. Universe, Can you hear in space? -a curious reader
Dear curious reader,
Your question reminds me of an experiment: You put a ringing alarm clock in a jar and use a hose to slowly suck out all the air. As the air escapes, the ringing gets quieter until there’s no sound at all.
The inside of the jar becomes what scientists call a vacuum. It’s empty. Just like space. » More …
What are fingernails made of? -Amy, 8, Seattle, WA
My claws can come in quite handy when I need to scratch my ears or climb trees. I bet you’ve found that your own fingernails can be useful tools, too. Perhaps you’ve used them to pick up a penny or peel an orange. » More …