Pennies aren’t of much use, but they can be part of a bet you’re likely to win

Q. If every penny counts, how many of them could you drop into a wine glass filled to the brim with water before spillage occurs?

A. Most people will say a coin or two, but amazingly you can drop in at least 10 pennies without spilling a drop, points out Richard Wiseman in his book “101 Bets You Will Always Win.” The secret here is that the water molecules cling firmly together–known as surface tension. The dropped in pennies merely stretch out the surface of the water as it rises and forms a dome along the rim. But add too many pennies and the surface tension won’t be strong enough to hold, so the water overflows.

But notice that if you add detergent to the water, the surface tension will be much lower and far fewer pennies can be put in the glass before spillage takes place.

Q. It took 2,600 workers toiling in round-theclock shifts for 17 years to complete the project—at a cost of $12 billion dollars. What is this engineering wonder?

A. It’s the 35.4-mile Gotthard Base Tunnel, the longest tunnel on earth, carved a mile and a half under the Swiss Alps to speed travel between the North Sea and the Mediterranean, says Rachel Nuwer in “Smithsonian” magazine. Four boring machines, each the length of four football fields and fitted with rock-chomping steel roller-cutters, advanced about 130 feet per day. When the final 18 miles were bored, the north and south tunnels met in the middle and “were off by only a few centimeters”! Reportedly, the 28 million tons of excavated rock were reused, much to form the concrete lining.

With the tunnel, some 15,000 passengers per day will have their trip from Zurich to Milan cut from four hours to three. Even more important, the tunnel will accommodate four times as many cargo trains per day as the nearest working tunnel — resulting in cleaner air as 40 million tons of freight annually shift away from trucks and onto rails. Q. You’ve got 10 coins on the table and 3 empty wide-rimmed tapered glasses A, B and C. You bet your friend you can place the 10 coins into the 3 glasses and wind up with an odd number of coins in each of them. Can you decipher such odd thinking? A. With your one powerful brain, you can do it — and here’s how: Put 3 coins into glass A and 3 into B and the remaining 4 into glass C, suggests Richard Wiseman in his book “101 Bets You Will Always Win.” Then insert glass B down into glass C as far as possible. Now glass A has 3 coins and glass B with 3 + glass C with 4 = 7 coins! “Technically, each glass now holds an odd number of coins.”

Q. Picture the scene: A quiet city street suddenly erupts in gunfire, two armed men facing off— one aiming north, the other south. Then a big bang followed by another bang. But who fired first? A. Enter Robert Maher, music lover and skilled in math and science, who studies humans’ contribution to noise, including the relatively new forensic field of gunshot acoustics, says Meghan Rosen in “Science News” magazine. Regarding the scene in question, surveillance cameras missed the action but did record a distinctive echo following the first gunshot but not the second. Maher concluded that “the first gunshot’s sound probably bounced off a big building to the north,” meaning the person facing north was the first to shoot.

Now Maher and colleagues at Montana State University in Bozeman are working to build a database of sounds made by 20 different guns, seemingly alike to the untrained ear but with distinct sound waves. Eventually, it’s hoped, “investigators might be able to use the information to figure out what kinds of guns were fired at a crime scene.”