Science Myths You Probably Still Believe…

Days Get Shorter In The Winter

Surely this one is true? It certainly feels dark and horrible in the winter.

This, however, gets a thumbs-down on a technicality, as the first day of winter, December 21st/22nd, is also the shortest day of the year, meaning that the subsequent days of winter after that are actually getting progressively longer.

Similarly, the first day of summer is also the longest day of the year, meaning that the subsequent days get progressively shorter. 

In fact, if you were to split the year up into two halves between the two solstices, winter and summer, at a single location they each contain exactly the same amount of daylight.

Tongue Rolling Ability Is Genetic

Between 65 and 81 percent of people on the planet can roll thier tongue and most people will learn that this is down to their genes. Seeing as we knew by the 1950s that pairs of twins could have different tongue rolling abilities, this seems highly unlikely.

In reality, it’s likely to be a developmental difference. Perhaps a trick that is learnt by some in early infancy by discovering a certain group of muscles, but others never master it, a bit like ear-wiggling. In fact, an experiment in the 1940s found that the skill could be taught, increasing the number of tongue rollers in a group of of 6–12 year olds by 20%. For the same reason you can learn how to walk, but not how to have blue eyes, this implies that it is not genetic but learnt behaviour.

If this were true, then two non-rolling parents could never produce a tongue roller, providing a simple alternative to paternity testing.

The Earth Is Closer To The Sun During Summer*

*In the northern hemisphere.

Apologies to the southerners out there, this is a very northern-centric misconception.

It seems to make logical sense to us that the hottest days of the year would coincide with the closest point in the Earth’s elliptical orbit (or the perihelion if you want to get fancy), but in reality, we are at our cosiest with our solar neighbour in January.

In actual fact, the reason why it is hotter during the northern summer months is to do with the Earth’s tilt on its axis. During this time, the Earth is tilted towards the sun, causing its rays to hit us more directly, whereas during the winter months, the rays hit us at a more oblique angle, making it cooler.

This is, of course, all reversed in the southern hemisphere when the hottest months do indeed coincide with the perihelion.

Water Conducts Electricity

Whilst it’s probably not a great idea to take your toaster into the shower with you, water is actually not a great conductor of electricity.

In fact, the conductivity of water is based on how many impurities it has in it, as it is actually there that are conducting the electricity. Seawater, for example, is an excellent conductor of electricity due to its high salt content, but distilled water that has had all of its impurities removed will act as an insulator at normal voltages.

Tap water, although it tastes fresh, also has impurities in it and will conduct electricity, which is why it is still a bad idea to use electrical items in your bathroom.

Water Is Blue Because It Reflects The Sky

Most of us learn this as a kid, when our beleaguered parents have spent all day answering our persistent questions about the world. By the time the “Why is the sea blue?” question rolls around, they’re too tired to even google it and will probably have told us that it’s because it reflects the sky (unfortunately, this usually leads to the “Why is the sky blue?” conversation).

In fact, water is blue because it’s blue.

In small quantities, it appears to be clear, water’s blue hue becomes more and more apparent as the volume increases. Large quantities of water are actually blue, regardless of the colour of the sky, because it absorbs longer light wavelengths (the “red” end of the spectrum) and scatters the shorter blue wavelengths. Basically, the ocean is blue for the same reason the sky is blue.

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