Scientist reveals why we can’t tell whether washing on the line is cold or wet in winter

As the winter chill sets in Down Under an Australian scientist has set the record straight on why we can never tell if our washing is still wet or cold – and what it’s most likely to be.

Dr Karl Kruszelnicki, a famous science commentator, spoke to Junkee about the common cold weather conundrum and the mechanism by which clothes dry when you hang them out on the clothesline.

When we hang up an item outside what we’re actually doing is relying on the water on it to evaporate into the air, leaving it bone dry.  

As those water molecules evaporate they also lower the temperature around the clothesline, something that you wouldn’t normally notice when the weather is balmy.

But in winter this surrounding temperature is chillier and that’s why we have such difficulty telling wet and cold apart – because our touch receptors are actually not programmed to tell us. 

‘If you’re touching something that is cold, you have temperature sensors in your hand. You have sensors in your fingers for hot, cold, dull touch and sharp touch as well as vibrations,’ Dr Karl told the publication.

Scientist Dr Karl Kruszelnicki (pictured)

 ‘You don’t have a direct sensor for wet, what you have is a sensor for heat. If something is wet, it’s more likely to evaporate and then remove some heat from the local area. So if you touch something that’s cold, you think “that’s cold.”‘

‘But if you touch something that’s wet, there’s that link in your mind where you get a little bit confused. Like you’re taking off the sheets at the end of the day and they’re cold, but are they dry? It’s because you don’t have a sensor for wet.

So while you’re thinking to yourself ‘I hung these out hours ago in direct winter sunshine so they must be dry’ your body is undecided because of how cold they feel to the touch.  

Even if the day itself features little to no sun, but there is wind, those water molecules can be ‘blown’ off the clothes while they’re hanging out – something nations in colder climates rely on. 

Plenty of Aussies were surprised by this information and had there own tactics for working out of an item of clothing is cold or wet.

‘My mum taught me to press washing to your cheek if you’re not sure if it’s damp or just cold. It works,’ one woman wrote on Facebook.

‘My mum always said get the washing off the line before 3pm during winter or it will get damp… as in wet! Mum’s know…,’ said another.

A third added: ‘This is the eternal winter question’.