# Twice Zero Degrees?

'If it is zero degrees today and tomorrow will be twice as cold, what temperature will it be tomorrow?

Thomas Pearce said:

Since measurement of temperature is completely arbitary, a different point of reference must be made, and the most obvious one to choose is room temperature. Room temperature can vary from 20C to 27C, so twice as cold as 0C could be said to range from -20C to -27C.

However, our perception of temperature change, as with most things, is not linear, but rather logarythmic. As such, the change would be related to the log of the natural constant, "e". However, this extends beyond my education, and so I cannot provide an accurate number for this double.

Max Pearce said:

I have 3 answers: -9 degrees Celsius, -136.5 degrees Celsius and -7.8 degrees Celsius.

For the first one, I converted 0 degrees to Fahrenheit (32F), halved that, and converted back to Celsius.

For the second, I did the same, but converted to Kelvin (0C = 273K).

For the third, I did this:

After taking the average maximum and minimum temperatures from each month (recorded by the Met Office), I found the mean of those two numbers for each month, to get a monthly average temperature. I took the inner quartile range of the year (took away the 4 coldest months and the 4 warmest months) to find the more accurate months (consisting of March, April, May, September, October and November) to find an average temperature that would not be affected by the extremities. I then found the average (mean) of these months, to get a number of 7.8 degrees. 0 degrees is 7.8 under the average temperature, so -7.8 is twice as cold.

Callum Barnard

On the way to good thinking about temperature being a matter of perception with this...

"As our bodies are used to the average of 13 degrees celcius in the uk, if it is 0 degrees celcius then we find it is 13 degrees celcius colder than we are used to, therefore i feel that if it was twice as cold then around -13 degrees celcius. "

We were VERY tempted to go with Amy Bowles answer:

"the temperature is irrelevant, if I have to wear another pair of tights then it's twice as cold" - simply because it made us laugh. Thanks for that Amy.

Thanks and Merry Christmas everyone.

Anyone stuck for an idea for a Christmas present for someone who enjoys all these mad ideas - - can I recommend the actual source as a pressy - 'The Little Book of Thunks' - Ian Gilbert.

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