Why are plants green? –Nadia, 8, Australia
Dear Nadia,
A lush tropical rainforest, a field of sunflowers, a garden in your neighborhood. Our Earth is home to all kinds of plant life. From trees to catnip, there are thousands of different species of plants. Most of these plants are green, but not all of them.
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Thanks for taking the 2017 Kid Survey! Dr. Universe loves answering your questions. Now she’s got some questions for YOU.
Dr. Universe: How do bugs walk on water? -Annelise W., 6, Seattle, WA
Dear Annelise,
The other day I was out ice skating when I started thinking about your question. Water strider bugs skitter across ponds almost as if they were skating on ice. » More …
Hi Doc. Universe, I was wondering how vaccines work because I would really like to make a better way to get a shot that doesn’t hurt so much. Thanks. -Jacob, 10, Cayman Islands
Dear Jacob,
The quick, little sting of a vaccine shot can provide us with some big protection from germs that cause disease. » More …
Spiders can do some amazing things with their sticky, stretchy, and super-strong silk. Us cats are pretty curious about these little silk-spinning machines, too. Besides chasing spiders around, I’ve watched them use silk to build webs, catch bugs, and protect their young spiderlings.
You are onto something. Quick, to the bat-lab! That’s where I met up with my friend Christine Portfors, a scientist at Washington State University who studies fruit bats.
Ever since I was a kitten, I’ve loved picking up big maple leaves in the fall. I’d take them home, put them under a piece of paper, and rub the side of a crayon over the top. It makes a great print of the leaf.
Most spiders have quite a few eyes, but they usually can’t see very well. Then again, seeing isn’t everything. That’s what I found out when I went to visit my friend Rich Zack, a scientist at Washington State University who knows a lot about insects and spiders.
Why are apples red?Just the other day I was biting into a crunchy, delicious red apple when I was reminded of your question. I started wondering why apples are red, too. I called up my friend and apple expert Kate Evans, a scientist here at Washington State University. Her research helps us develop new kinds of apples.
A couple months before you were born, your skeleton was soft and bendy. It was made out of cartilage, the same material that’s in your nose and ears now. But when certain cells in your body called osteoblasts and osteoclasts began to work together, new bone started to form.
Dr. Universe: How can birds fly when they flap their wings, but when we flap our arms nothing happens? – Ravin, 9, London, UK
Dear Ravin,
No matter how much you flap your arms or I flap my paws, gravity keeps us pulled to Earth. But when birds use their strong muscles to start flapping their wings, something amazing happens. » More …
Why do volcanoes “die”? -Loretta, 11, Mexico
Dear Loretta,
Each volcano’s life is a little different. Many of them are born when big chunks of the Earth’s crust, or tectonic plates, collide or move away from each other. The moving plates force hot, liquid rock, or magma, to rise up from deep within the Earth. » More …
Dr. Universe: How do lunar rovers work? -Pedro, 10
Dear Pedro,
When I got your question, I started to imagine what it would be like to drive a rover on the moon. As we bounced along craters, we could kick up moon dust and stop to gather samples of moon rock. » More …