What If - by Randall Munroe

Published:

What If - by Randall Munroe

Read: 2024-10-13

Recommend: 8/10

The cartoons in this book are hilarious, and many of the questions and answers could serve as great material for science fiction. One question that really made me laugh was, ‘Is it possible to cry so much that you dehydrate yourself?’

Notes

Here are some text that I highlighted in the book:

  1. it turns out that trying to thoroughly answer a stupid question can take you to some pretty interesting places.

  2. Blue-green algae, or cyanobacteria, were the first photosynthesizers. They breathed in carbon dioxide and breathed out oxygen. Oxygen is a volatile gas; it causes iron to rust (oxidation) and wood to burn (vigorous oxidation). When cyanobacteria first appeared, the oxygen they breathed out was toxic to nearly all other forms of life. The resulting extinction is called the oxygen catastrophe. After the cyanobacteria pumped Earth’s atmosphere and water full of toxic oxygen, creatures evolved that took advantage of the gas’s volatile nature to enable new biological processes. We are the descendants of those first oxygen-breathers.

  3. All 1875 watts have to go somewhere. No matter what happens inside the box, if it’s using 1875 watts of power, eventually there will be 1875 watts of heat flowing out. This is true of any device that uses power, which is a handy thing to know. For example, people worry about leaving disconnected chargers plugged into the wall for fear that they’re draining power. Are they right? Heat flow analysis provides a simple rule of thumb: If an unused charger isn’t warm to the touch, it’s using less than a penny of electricity a day. For a small smartphone charger, if it’s not warm to the touch, it’s using less than a penny a year. This is true of almost any powered device.

  4. Is it possible to cry so much you dehydrate yourself?

  5. in an airliner cabin, which are typically kept pressurized at about 70 percent to 80 percent of sea level pressure, judging from the barometer in my phone.

  6. REENTERING SPACECRAFT HEAT UP because they’re compressing the air in front of them (not, as is commonly believed, because of air friction).

  7. They say lightning strikes the tallest thing around. That’s the kind of maddeningly inexact statement that immediately sparks all kinds of questions. How far is “around”? I mean, not all lightning hits Mount Everest. But does it find the tallest person in a crowd?

  8. After the current hits the tall object, it flows out into the ground. If you’re touching the ground nearby, it can travel through your body. Of the 28 people killed by lightning in the US in 2012, 13 were standing under or near trees.

  9. While colds are no fun, their absence might be worse. In his book A Planet of Viruses, author Carl Zimmer says that children who aren’t exposed to rhinoviruses have more immune disorders as adults. It’s possible that these mild infections serve to train and calibrate our immune systems. On the other hand, colds suck. And in addition to being unpleasant, some research says infections by these viruses also weaken our immune systems directly and can open us up to further infections.

  10. The immune response is actually the cause of your symptoms, not the virus itself.

  11. If you stand on the North Pole, you’re 20 kilometers closer to the center of the Earth than if you stand on the equator, and you feel a stronger pull from gravity. Furthermore, if you’re on the equator, you’re being flung outward by centrifugal force.

  12. Chemotherapy drugs are blunt instruments. Some are more precisely targeted than others, but many simply interrupt cell division in general. The reason that this selectively kills cancer cells, instead of harming the patient and the cancer equally, is that cancer cells are dividing all the time, whereas most normal cells divide only occasionally.

  13. Gravity in low Earth orbit is almost as strong as gravity on the surface. The Space Station hasn’t escaped Earth’s gravity at all; it’s experiencing about 90 percent the pull that we feel on the surface. To avoid falling back into the atmosphere, you have to go sideways really, really fast. The speed you need to stay in orbit is about 8 kilometers per second. Only a fraction of a rocket’s energy is used to lift up out of the atmosphere; the vast majority of it is used to gain orbital (sideways) speed.

  14. A human falling with arms and legs outstretched has a terminal velocity in the neighborhood of 55 meters per second. It takes a few hundred meters to get up to speed, so it would take you a little over 26 seconds to fall the full distance.

  15. Wingsuits let you fall much more slowly. One wingsuit operator posted tracking data from a series of jumps. It shows that in a glide, a wingsuit can lose altitude as slowly as 18 meters per second—a huge improvement over 55.

  16. information is fundamentally tied to the recipient’s uncertainty about the message’s content and his or her ability to predict it in advance.

  17. When, if ever, will Facebook contain more profiles of dead people than of living ones?