# Brainteasers for Physicists, Biologists, Chemists, Mathematicians and Other Crazy Brainiacs

You can imagine speeds of light, sound and falling objects without being a physicist, and you can envision the Earth’s vast biodensity of insects, birds and fish without being a biologist. You can grasp the infinitesimally small size of an atom and the gargantuan number of molecules you’d find in a drop of water without being a chemist; and you can fathom the immensity of large numbers and the enormity of the universe without being a mathematician. No problem, right?

And you don’t have to have any background to be interested in lightning, tsunamis, bubbles rising from ocean depths, giant worms boring through the Earth, the swing of a pendulum, the Big Bang, massive weights and startling Heights. All you need is a spark of curiosity.

Here are a few brain teasers that will assess the accuracy of your intuition about naturally occurring phenomena. Each brain teaser will provide a scenario in which a task must be completed. Your job is to estimate how long it will take to complete the task. You will answer by selecting a unit along a dimension of time that includes Nanoseconds, Seconds, Minutes, Hours, Days, Weeks, Months, Years, Decades, Centuries, Millennia, Eons, Eras or Forever? For example:

How long would it take you to walk around the block?

It would take “Minutes,” as it is unlikely that you would find a block that takes “Hours” to walk around. And certainly, it would not take “Seconds,” unless the block is the size of a ping-pong table. Similarly, if you threw a ball into the air as high as you could, and wondered how long the ball would take to return to you, you would think “Seconds.” In either of these scenarios you actually can calculate the amount of time it will take, but what we are looking for is your first impression, or intuitive response. Give them a try, and then check your answers below.

1. Imagine a perfectly smooth sphere the size of the Earth with a ribbon tied snugly around its “equator.” If you cut the ribbon and add another 12 inches of ribbon, then shake the newly elongated ribbon to distribute it evenly around the sphere, it clearly would be off the sphere’s surface; but how far off the surface? If you slid a stack of as many free pizza coupons as you could between the ribbon and the sphere’s surface (say, 100 coupons to the inch), after redeeming the free pizza coupons, how long will it take you to eat all the pizza?

2. MIT graduate Miles Stillwater is the consummate container builder. He can build a container small enough to house a flea – and large enough to hold the moon (MIT must be a very good school). Dr. Stillwater was commissioned by the Roswell Water Reclamation Authority to build an open container that is 1 mile square and 1 foot in depth in order to capture rainwater, which could then be transported to a conversion plant and made into delicious green Gatorade. If Miles were to capture a quarter inch of rainwater in his container and convert it all to Gatorade, for how long could the world champion Denver Broncos quench their thirst?

3. You’re aboard United Flight 49 from Denver to San Francisco, cruising smoothly at 32,000 feet, and you leave your comfy first-class seat to visit your spouse, who is in a middle seat in coach between two quarrelsome WWF wrestlers. Wouldn’t you know it but an unsupervised juvenile delinquent opens the emergency door right as you pass and you get sucked right out into the frigid air. You’re comforted by the notion that your entire life will flash before you as you descend to your demise. Reliving life’s key moments, envisioning friends and family, you experience the warmth of happy memories. How long will you be able to bask in the glory of nostalgia before you meet your maker?

The degree to which a correct answer seems false, or the difference between the unit of time you selected and the correct answer, is a measure of your intuition: the smaller the difference the more intuitive you are.

(Answers: 1. Months!, 2. Centuries, 3. Minutes).