How Much Does a Cloud Weigh?

iStock / B&M Noskowski
iStock / B&M Noskowski

Reader Jane wrote in to note that clouds look so nice and fluffy and lighter-than-air, so they certainly can’t weigh much. Right? 

When Peggy LeMone was in junior high, a friend’s dad pondered that same question, and she kept it in the back of her mind for years. Now all grown up, LeMone is a researcher at the National Center for Atmospheric Research, and she’s figured out an answer. Today, she shares her cloud-weighing technique with us. 

First, figure out how dense the cloud is. Scientists have measured the water density of a typical cumulus cloud (the white, fluffy ones you see on a nice day) as 1/2 gram per cubic meter—about a small marble’s worth of water in a space you and a friend could comfortably sit in. The density will be greater for different types of clouds. 

Next, figure out how big the cloud is. By measuring a cloud’s shadow when the sun is directly above it, you can get an idea of its width. LeMone does this by watching her odometer as she drives under a cloud. A typical cumulus, she says, is about a kilometer across, and usually roughly cubical—so a kilometer long and a kilometer tall, too. This gives you a cloud that’s one billion cubic meters in volume. 

Do the math with the density and volume to determine the total water content of the cloud. In this case, it's 500,000,000 grams of water, or 1.1 million pounds. That’s a lot of weight to wrap your head around, so LeMone suggests putting it in more familiar terms, like elephants. That cloud weighs about as much as 100 elephants. If you’re a Democrat and you’re feeling partisan, she says, you could substitute 2500 donkeys. If you care more for dinosaurs than politics, you could also say the cloud weighs about as much as 33 apatosauruses.

If all those elephants or donkeys or dinosaurs were hanging out in the sky, they’d fall. So how does a several-hundred-ton cloud stay afloat? For one thing, the weight isn’t concentrated in a hundred elephant-sized particles or even a billion marble-sized ones. It’s distributed among trillions of really tiny water droplets spread out over a really big space. Some of these droplets are so small that you would need a million of them to make one raindrop, and gravity’s effect on them is pretty negligible. 

What’s more, the cloud is less dense than dry air, so it's buoyant. It also helps that all those little droplets get some lift from updrafts of warm air. Those droplets don’t float forever, though. When the cloud’s water density increases and the droplets get bigger and heavier, the cloud eventually does fall, bit by little bit, in the form of rain. 

Mystery Solved: Scientists Have Figured Out Why Some Squirrels Are Black

Rena-Marie/iStock via Getty Images
Rena-Marie/iStock via Getty Images

It can be something of a surprise to see an animal sporting a fresh coat of paint. Blue lobsters occasionally surface after being caught in traps. A pink dolphin was spotted in Louisiana in 2007 (and several times since). In the Chinese province of Shaanxi, a cute brown and white panda greets zoo visitors.

Another anomalous animal has joined their ranks. Black squirrels have been spotted in both the United States and the UK, and now scientists believe they know why.

Like many animals with unusual color schemes, black squirrels are the result of a genetic detour. Researchers at Anglia Ruskin University, Cambridge University, and the Virginia Museum of Natural History collaborated on a project that tested squirrel DNA. Their findings, which were published in BMC Evolutionary Biology, demonstrated that the black squirrel is the product of interspecies breeding between the common gray squirrel and the fox squirrel. The black squirrel is actually a gray squirrel with a faulty pigment gene carried over from the fox squirrel that turns their fur a darker shade. (Some fox squirrels, which are usually reddish-brown, are also black.)

A black squirrel is pictured
sanches12/iStock via Getty Images

Scientists theorize a black fox squirrel may have joined in on a mating chase involving gray squirrels and got busy with a female. The black fur may offer benefits in colder regions, with squirrels able to absorb and retain more heat, giving them a slight evolutionary edge.

In North America, black squirrels are uncommon, with one estimate putting them at a rate of one in every 10,000 squirrels. In 1961, students at Kent State University in Ohio released 10 black squirrels that had been captured by Canadian wildlife authorities. The squirrels now populate the campus and have become the school’s unofficial mascot. Their coloring might help them hide from predators, which might come in handy at Kent State: The campus is also home to hawks.

[h/t The Guardian]

15 Scientific Ways to Relax for National Relaxation Day

iStock/anyaberkut via Getty Images
iStock/anyaberkut via Getty Images

Today is National Relaxation Day, so you have a great excuse to take it easy. Here’s how science can help you have the most laid-back day of the year.

1. Get a house or office plant.

Spending time in nature improves your overall wellbeing, but it turns out even just a little greenery is great for your health. Studies have shown patients in hospital rooms with plants report lower stress. Even just stepping into a lush space can reduce your heart rate. Plus, plants are effective at increasing oxygen and clearing out toxins, which should help you breathe easier—literally.

2. Avoid screens before bedtime.

Artificial light from TV and computer screens affects melatonin production and throws off circadian rhythms, which messes with your sleep. Studies have found that young adults were more likely to suffer from sleep disorders, high stress and even depression if they reported intensive use of cell phones and computers at night.

3. Eat a banana.

Potassium helps your body regulate blood pressure. Keeping that under control should help you bounce back more quickly from what’s got you stressed.

4. Indulge in some citrus.

Still hungry after that chocolate and banana? Try citrus. Recent studies show that vitamin C helps to alleviate the physical and psychological effects of stress.

5. Listen to classical music.

Portrait of a beautiful young woman lying on sofa with headphones on and closed eyes, relaxing
BartekSzewczyk/iStock via Getty Images

Any music you enjoy is bound to make you feel better, but classical music, in particular, has been shown to slow heart rate, lower blood pressure and even decrease levels of stress hormones.

6. Drink green tea sweetened with honey.

Green tea contains L-theanine, which reduces stress, and honey—unlike cane sugar—has been shown to counteract free radicals and reduce inflammation, which is sometimes linked to depression.

7. Give yourself a hand massage.

Especially if you spend all day typing, hands can get really tense. A quick massage should be doable at your desk and if you incorporate some lavender-scented lotion, you’ll get extra relaxation benefits.

8. Lock lips with someone.

Romance is relaxing! Kissing releases oxytocin, a chemical that is shown to reduce levels of the stress hormone cortisol.

9. Chew some gum.

No matter what flavor it is, the act of chewing gum has been proven to lower cortisol and improve reported mood.

10. Blow up a balloon.

Young woman blowing up a blue balloon against a yellow background
Deagreez/iStock via Getty Images

Reacting to stress with short, shallow breaths will only exacerbate the problem—your body needs more oxygen, not less, to relax. Blowing up a balloon will help you refocus on your breathing. No balloons around? Just concentrate on taking a few deep breaths.

11. Mow the lawn.

Research shows that a chemical released by a mowed lawn—that fresh-cut grass smell—makes people feel happy and relaxed. Plus, knocking it off your to-do list will give you one less thing to stress about.

12. Find something to make you laugh.

Watching a funny video online does more than just brighten your afternoon, it physically helps to relax you by increasing the endorphins released by your brain.

13. Grab some chocolate.

What’s also good at releasing endorphins? Chocolate. Studies show that even just 40 grams of dark chocolate a day can help you de-stress.

14. Focus on relaxing all of your muscles.

Take a break from whatever you’re doing and, starting at your toes and working upwards, spend a few moments slowly tensing, and then releasing, the muscles of each part of your body.

15. Take a mental vacation.

Man takes a break from work to meditate at his laptop
AaronAmat/iStock via Getty Images

If you’re feeling overwhelmed at work, take a moment to close your eyes and picture a particularly relaxing scene. It may sound cheesy, but numerous studies show that just a few minutes of disengaging from your stressors rejuvenates your ability to tackle the work.

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