111–120 of 208 posts
In related news - pounds to kilos is "divide by 2, less 10%". Very precise too. 160lbs = 80 - 8 = 72kg
Any similar shortcut for feet inches to cm? I find this conversion to be slower to compute than miles to km or lbs to kg.
2 inch ≈ 5 cmEarlier quoted context omitted.
Kelvin IS Celsius, only starts at absolute zero. 0 C is 273 Kelvin, and 0 Kelvin is -273 Celsius. You add 273 to any Celsius measurement, and voila, it's Kelvin.
No. That's actually not quite correct. You add 273.15... The size of the degree is the same of course. My point is that if you want to use a "correct" scientific measurement on a day to day basis you'd use Kelvin. As soon as you're converting, you're converting whether from Celsius or Fahrenheit. ADDED: There's an argument for Celsius vs. Fahrenheit of course in so far as the size of the degree is baked into some oth…
Can anyone provide any reason to use Fahrenheit scale, apart from historical ones? Legit question.
In related news - pounds to kilos is "divide by 2, less 10%". Very precise too. 160lbs = 80 - 8 = 72kg
Does not seem to be very convenient for figures which are not the product of one of the first few members of the Fibonacci sequence and a power of 10, at least compared to multiplying by 1.6.
Earlier quoted context omitted.
Not if you just remember 3,5,8,13 . You do not need to remember all fibonacci numbers, just the above and rest you can multiple by 2,5,10 and get them
How many km is 4 miles? That's not on the list of numbers.
Because knowing a km is 3/5 of a mile is more useful. It follows that a mile is 5/3 of a km. From there it's basic math. 4 * 5 is 20. 20 / 3 is 6.666...
Earlier quoted context omitted.
No. That's actually not quite correct. You add 273.15... The size of the degree is the same of course. My point is that if you want to use a "correct" scientific measurement on a day to day basis you'd use Kelvin. As soon as you're converting, you're converting whether from Celsius or Fahrenheit. ADDED: There's an argument for Celsius vs. Fahrenheit of course in so far as the size of the degree is baked into some oth…
The fact that degree is the same means that energetically 1 degree C is equal to 1K. So when doing scientific calculations, for example to calculate energy needed to change the temp by X, they are the same. The fact that the scale is based on water properties seem to be just so values are easier to relate to. We are water based, after all. Can anyone provide any reason to use Fahrenheit scale, apart from historical o…
1. Fahrenheit is far more likely to cover the range of temperatures I encounter without having to use negative numbers. 0 is really cold. Anything below zero is really freaking cold. The temperature of the boiling point of water is mostly an academic point in my day to day life.
2. Fahrenheit provides about 2x the granularity of Celsius without having to use decimals
I'm not going to argue that if Fahrenheit didn't exist, we'd invent it. But it does have some advantages as an existing system.
ADDED: For engineering using SI units, of course Celsius and Kelvin make a lot more sense.
Wait, doesn’t everyone know there 1.6 times tables ?
I only had to learn tables up to 10, 11 and 12 were useful to know, but not mandatory.
16 would have also been useful for mi/km conversion and hex/dec conversion.
Isn't that rather the physicists way? Works well enough, used in a way not quite as intended by mathematicians, ... Disclaimer: I am physicist myself.
I'm fine with that - on the condition that you never, ever treat a differential operator like a fraction again ;)
In related news - pounds to kilos is "divide by 2, less 10%". Very precise too. 160lbs = 80 - 8 = 72kg
Any similar shortcut for feet inches to cm? I find this conversion to be slower to compute than miles to km or lbs to kg.
5' 7" -> 5 * 12 + 7 inches -> 67 inches -> 1 metre 27 inches -> 1 metre 67 centimetres
Which isn't quite right, but is close-ish! And not really easy enough to call a shortcut either!