Greg's Science Trivia Quiz

1.

Which time-keeping device is the most similar to a musician's tuning fork?

An atomic clock

A pendulum clock

A wind-up mechanical clock or watch

A quartz crystal clock or watch

A sundial

Not only does a quartz crystal vibrate like a tuning fork, in a watch it often has the shape of a tuning fork. Quartz is also piezoelectric, which means that its vibrations can be both driven and measured by electronics.

Explanation

Not only does a quartz crystal vibrate like a tuning fork, in a watch it often has the shape of a tuning fork. Quartz is also piezoelectric, which means that its vibrations can be both driven and measured by electronics.

2. What is the central mathematical result about democracy in the theory of voting?

Voters must be fully informed in order for democracy to work.

Ranked voting is fairer than just voting for one candidate.

Gerrymandering distorts democracy.

Party politics makes democracy less fair.

Democracy is a mathematically inconsistent concept.

Arrow's theorem says that every voting system other than a dictatorship can exhibit logical inconsistencies, unless there are only two choices. This feature of all voting system was illustrated when Olympic figure skating was scored with a voting system. The system could not always decide whether skater A or B was the winner, until after the performance of a third skater C who had no chance of winning.

Explanation

Arrow's theorem says that every voting system other than a dictatorship can exhibit logical inconsistencies, unless there are only two choices. This feature of all voting system was illustrated when Olympic figure skating was scored with a voting system. The system could not always decide whether skater A or B was the winner, until after the performance of a third skater C who had no chance of winning.

3. Even-toed ungulates are hoofed animals with even number of toes such as pigs, deer, cattle, etc. Which of the following animals are even-toed ungulates in the evolutionary tree, but are not called that?

Elephants

Giraffes

Hippos

Humans

Whales

Giraffes, elephants, humans aren't even-toed ungulates. Hippos are even-toed ungulates, but they already classified that way. Various evidence from the past several decades shows that whales are even-toed ungulates, and that they are more closely related to hippos than hippos are to other even-toed ungulates.

Explanation

Giraffes, elephants, humans aren't even-toed ungulates. Hippos are even-toed ungulates, but they already classified that way. Various evidence from the past several decades shows that whales are even-toed ungulates, and that they are more closely related to hippos than hippos are to other even-toed ungulates.

4. Suppose that you have a hot mound of mashed potatoes in the shape of a large circle about two inches thick. How much faster will it cool if you flatten the mound to double its area and make it once inch thick? (You can ignore effects at the edge of the mound.)

About the same.

About 50% faster.

About twice as fast.

About 4 times as fast.

Completely unpredictable, based on other factors.

Theoretically it's 4 times as fast, because the heat can both escape through twice the surface area and has half as far to travel through the mound. In more technical terms, in the heat equation for a stationary material says, time scales as the square of distance.

Explanation

Theoretically it's 4 times as fast, because the heat can both escape through twice the surface area and has half as far to travel through the mound. In more technical terms, in the heat equation for a stationary material says, time scales as the square of distance.

5. Suppose that you have $100,000 in savings, and otherwise your expenses equal your salary. Every month, you discover a business opportunity that has a 1 in 200 chance of quickly multiplying your investment by 500; but otherwise the investment will come to nothing. You decide to invest 2% of your total cash savings in each new venture each month. What will probably happen in the long run?

Your savings will dwindle to nothing, because the expected return is negative.

You will eventually make a big profit, because the expected return is positive.

Your savings will dwindle to nothing, even though the expected return is positive.

You will eventually make a big profit, even though the expected return is negative.

It's impossible to say; it depends on how lucky you are.

The expected return is clearly positive, but a rough calculation shows that your savings will probably dwindle to nothing. If you gamble away 2% of your savings 200 times, then your savings dwindle by more than a factor of 50. Multiplying what you have by a factor of 11 (because a 1/50 investment hits the jackpot and becomes 10 times the rest of your savings) does not make up for it. What is true is that you are left with a tiny chance of becoming extremely rich. This phenomenon of gambler's ruin in the face of positive returns is an argument against wild investments. (Not to mention an argument against playing the lottery, which doesn't even have a positive return.)

Explanation

The expected return is clearly positive, but a rough calculation shows that your savings will probably dwindle to nothing. If you gamble away 2% of your savings 200 times, then your savings dwindle by more than a factor of 50. Multiplying what you have by a factor of 11 (because a 1/50 investment hits the jackpot and becomes 10 times the rest of your savings) does not make up for it. What is true is that you are left with a tiny chance of becoming extremely rich. This phenomenon of gambler's ruin in the face of positive returns is an argument against wild investments. (Not to mention an argument against playing the lottery, which doesn't even have a positive return.)

6. What is the typical color of modern circuitry drawn on silicon chips?

Metallic gray

Sandy yellow

Multicolored

It is too small to have any color.

You can choose the color.

Visible light has a wavelength range between 400 and 700 nanometers, while the feature size of a modern computer chip (since 2012) is 22 nanometers. Although computer chips are made with a photographic process, it is made with shorter-wavelength ultraviolet light, plus other tricks to further reduce its length scale.

Explanation

Visible light has a wavelength range between 400 and 700 nanometers, while the feature size of a modern computer chip (since 2012) is 22 nanometers. Although computer chips are made with a photographic process, it is made with shorter-wavelength ultraviolet light, plus other tricks to further reduce its length scale.

7. Artistic depictions of the sun usually have rays emanating from a round disk. Why is the sun often drawn this way?

It's only an abstract symbol for the sun.

You think that you see rays from the sun because your eye is not a perfect camera.

You can see light rays that travel sideways if they are very bright.

It's the solar corona: Jets of hot gas that shoot out from the sun.

The earth's atmosphere bends sunlight and makes radial streaks.

Effects from lens and geometry imperfections in a camera are called "lens flare". Photographers sometimes add lens flare deliberately to make photographs look like what you see directly. In addition to the main effect of lens flare, you can also see rays from the sun from diffraction through your eyelashes.

Explanation

Effects from lens and geometry imperfections in a camera are called "lens flare". Photographers sometimes add lens flare deliberately to make photographs look like what you see directly. In addition to the main effect of lens flare, you can also see rays from the sun from diffraction through your eyelashes.

8. Carbon 14 is a radioactive isotope that is used to estimate the age of objects such as ancient books, ancient graves, etc. Where does it come from? Why would the Earth still have any?

It is generated by the cells of living organisms.

It is generated in the Earth's core from other radioactive processes.

It is generated in the atmosphere by cosmic rays.

Its half life is long enough that the Earth still has some of the original supply.

It doesn't start to decay until objects are buried.

Carbon 14 is created when cosmic rays hit nitrogen atoms in the high atmosphere. Carbon 14 dating works because plants absorb carbon from the atmosphere, including carbon 14. The carbon 14 clock begins when the plant is harvested (as food, to make a book, etc.) rather than when the object is buried.

Explanation

Carbon 14 is created when cosmic rays hit nitrogen atoms in the high atmosphere. Carbon 14 dating works because plants absorb carbon from the atmosphere, including carbon 14. The carbon 14 clock begins when the plant is harvested (as food, to make a book, etc.) rather than when the object is buried.

9. When you lose weight in a year-long diet, what is the essential way that it leaves?

When you go to the bathroom.

By sweating and evaporation.

You exhale it.

All of the above.

It just shrinks.

The key to your long-term weight balance is that life is carbon-based. The main way for the carbon of your cells (as opposed to water or undigested food) to leave your body is through exhalation.

Explanation

The key to your long-term weight balance is that life is carbon-based. The main way for the carbon of your cells (as opposed to water or undigested food) to leave your body is through exhalation.

10. "Medical marijuana" is a new legal concept in some states in the US. Which of the following is a difference between marijuana and all FDA-approved prescription and over-the-counter medicines?

Marijuana has cannabinoids as its active ingredients.

Marijuana is smoked.

Marijuana is a natural remedy.

Marijuana can also be used recreationally.

All of the above.

If any medicine were burned, it would create unpredictable set of chemicals, most of them harmful. On the other hand, there already is at least one prescription cannabinoid available in pill form, called Marinol or dronabinol.

Explanation

If any medicine were burned, it would create unpredictable set of chemicals, most of them harmful. On the other hand, there already is at least one prescription cannabinoid available in pill form, called Marinol or dronabinol.