GREAT UNKNOWNS

BIG QUESTIONS. ANSWERS YOU CAN’T FIND ON THE INTERNET.

Is it better for fuel economy to carry my extra luggage in a roof box or in a trailer?

Downsizing is a thing and smaller cars mean less space to pack bulky items, particularly when you’re travelling long distances with a full load of passengers. Roof box manufacturer Thule says it has conducted independent testing that shows, surprise surprise, that a roof box is worth a fuel saving of between five and six per cent compared with towing a similarly laden light trailer.

According to Thule, a family sedan car making a round trip to Durban from Gauteng could save as much as seven litres in fuel, besides lowering stress and wear on the vehicle and generating fewer emissions.

Of course, there are other considerations than just fuel economy. If you think about it, a roof box will raise the car’s profile, but if designed aerodynamically it won’t significantly add to aero drag and will not add to mechanical drag, as a trailer would. You also have to weigh up the trailer’s effect on driving dynamics, from acceleration to cornering to braking, and the roof box’s impact on centre of gravity and how that translates into different vehicle handling.

Modern roof boxes are light, strong and streamlined and typically can swallow up as much as 600 litres weighing up to 75 kilograms. They are practically maintenance-free and don’t need annual licensing (or a to whitch) like a trailer does. Parking and manoeuvring are a non-issue compared with a trailer. But there’s no question that a trailer is a better bet for really bulk items and those trips to the tip or the recycling site.

Do most cocktails produce a chemical al reaction, or do the ingredients simply taste good together?

Cocktails can indeed produce chemical reactions, but those most often occur in your liver, or perhaps between you and your drinking companion (wink, wink) – not in a high-ball glass.

When most of us think of chemical reactions, we picture something like baking soda and vinegar. Something impressive, volcanic. The reactions that occur in cocktails are more subtle: so subtle, in fact, that many scientists wouldn’t even consider them true chemical reactions, but rather “material changes”. One example: the dissolution of sugar in a cocktail. “Getting down to the nitty-gritty, chemical reactions are ‘when bonds are broken and formed’, ” says Darcy Gentleman, PHD, of the American Chemical Society. “When you take something like sugar and dissolve that in water, there are new bonds created between the water and the sugar and some of the sugar-to-sugar bonds break. So by strict definition, you could say that’s a reaction. But whether dissolving is a chemical reaction is a debate.”

Similarly, combining acids and bases in a cocktail could cause a chemical reaction. Clam juice, for instance, will slightly neutralise the more acidic tomato juice in a Caesar, says Gentleman. Likewise, says Dave Arnold, owner of Booker and Dax food research lab, ingredients such as egg whites and milk can react with alcohol to improve flavour. “With egg whites, the proteins tend to bind with polyphenols and reduce astringency,” he says. “If you look at a whisky sour – which has egg whites if you’re making it right – the egg white is there to soften the whisky that would otherwise be too oaky. I’d consider that a chemical reaction.” We consider it a welcome improvement, reaction or not.