5 ms·

Specifying "times" in Celsius is fine... as long as you stay either positive or negative. Implying that you can only specify multiples in Kelvin is being pedan

by ethbr0 3y ago

Specifying "times" in Celsius is fine... as long as you stay either positive or negative. Implying that you can only specify multiples in Kelvin is being pedantic.

sgjohnson 3y ago
But not really. 100°C times two is not 200°C. 100°C times two is 473°C
- ethbr0 3y ago
  Howso? If the conversion to Kelvin is additive (as opposed to something more complicated), and multiplying in Kelvin is fine, then how is multiplying effectively-unsigned in Celsius not fine?
  - sgjohnson 3y ago
    Ok, another example. Is 10°C 10 times as hot as 1°C? No. Multiplying kelvin is fine because kelvin is an absolute scale.
    - _a_a_a_ 3y ago
      > No. For a given baseline, perhaps yes?. Kelvin has its baseline inherent, for C you can pick what you like if you're clear about it. Perhaps. (Edit: and using only positive or negative temps as pointed out above)
      - ethbr0 3y ago
        Yes. Parent's spaghetti examples weren't the most illustrative. What I believe they're griping about is that "10°C does not have 10x as much heat as 1°C." In actuality, "10°C has 10x the difference in heat that 1°C has relative to the freezing point of water." So it's a comparison definition quirk, not a numerical one.
  - yarg 3y ago
    c = k + 273 x * c = x * k + x * 273 This leaves multiplied celsius off by a delta of (x - 1) * 273.
    - ethbr0 3y ago
      That's showing multiplied Celsius in terms of Kelvin, no? 1 Celsius = 274.15 Kelvin 10 Celsius = 283.15 Kelvin Obviously 283.15 K != 10 * 274.15 K. But that's not what's being said, per my lower comment -- it's 10x the difference relative to the freezing point of water, compared to 1°C. The original upthread comments I were taking issue with were saying that multiplication has no meaning / is invalid in Celsius. It does have a meaning, and it's mathematically consistent. It may not mean what's being assumed, but nuance doesn't mandate "thou shalt never," IMHO.
      - yarg 3y ago
        When I say multiply by n, what I'm really doing is applying a delta of (n - 1) times my distance to the origin. The origin with celsius isn't at zero, so you're prevented from doing what you were pretending was multiplication (at least in the most natural way of doing it). Obviously you can negate your offset, multiply and reapply your delta. It's a bit damned awkward though.
petesergeant 3y ago
> Specifying "times" in Celsius is fine... as long as you stay either positive or negative 127C is twice as hot as -73C though
- hermitcrab 3y ago
  <pedant>C is a measure of temperature, not heat.</pedant>
_Microft 3y ago
The Celsius scale is an "interval scale" while the Kelvin scale is a "ratio scale". One cannot take ratios of Celsius values as ratios are not even defined for that. https://en.wikipedia.org/wiki/Level_of_measurement https://en.wikipedia.org/wiki/Level_of_measurement
jenadine 3y ago
It's a bit the same as with time, multiplication of the time of the day don't make much sense. I started the work at 1:20 pm, but my colleague started three times later, at 4pm.

by ethbr0 3y ago

Specifying "times" in Celsius is fine... as long as you stay either positive or negative. Implying that you can only specify multiples in Kelvin is being pedantic.

sgjohnson 3y ago

But not really. 100°C times two is not 200°C. 100°C times two is 473°C

ethbr0 3y ago
Howso? If the conversion to Kelvin is additive (as opposed to something more complicated), and multiplying in Kelvin is fine, then how is multiplying effectively-unsigned in Celsius not fine?
- sgjohnson 3y ago
  Ok, another example. Is 10°C 10 times as hot as 1°C? No. Multiplying kelvin is fine because kelvin is an absolute scale.
  - _a_a_a_ 3y ago
    > No. For a given baseline, perhaps yes?. Kelvin has its baseline inherent, for C you can pick what you like if you're clear about it. Perhaps. (Edit: and using only positive or negative temps as pointed out above)
    - ethbr0 3y ago
      Yes. Parent's spaghetti examples weren't the most illustrative. What I believe they're griping about is that "10°C does not have 10x as much heat as 1°C." In actuality, "10°C has 10x the difference in heat that 1°C has relative to the freezing point of water." So it's a comparison definition quirk, not a numerical one.
- yarg 3y ago
  c = k + 273 x * c = x * k + x * 273 This leaves multiplied celsius off by a delta of (x - 1) * 273.
  - ethbr0 3y ago
    That's showing multiplied Celsius in terms of Kelvin, no? 1 Celsius = 274.15 Kelvin 10 Celsius = 283.15 Kelvin Obviously 283.15 K != 10 * 274.15 K. But that's not what's being said, per my lower comment -- it's 10x the difference relative to the freezing point of water, compared to 1°C. The original upthread comments I were taking issue with were saying that multiplication has no meaning / is invalid in Celsius. It does have a meaning, and it's mathematically consistent. It may not mean what's being assumed, but nuance doesn't mandate "thou shalt never," IMHO.
    - yarg 3y ago
      When I say multiply by n, what I'm really doing is applying a delta of (n - 1) times my distance to the origin. The origin with celsius isn't at zero, so you're prevented from doing what you were pretending was multiplication (at least in the most natural way of doing it). Obviously you can negate your offset, multiply and reapply your delta. It's a bit damned awkward though.

petesergeant 3y ago

> Specifying "times" in Celsius is fine... as long as you stay either positive or negative 127C is twice as hot as -73C though

hermitcrab 3y ago
<pedant>C is a measure of temperature, not heat.</pedant>

_Microft 3y ago

The Celsius scale is an "interval scale" while the Kelvin scale is a "ratio scale". One cannot take ratios of Celsius values as ratios are not even defined for that. https://en.wikipedia.org/wiki/Level_of_measurement https://en.wikipedia.org/wiki/Level_of_measurement

jenadine 3y ago

It's a bit the same as with time, multiplication of the time of the day don't make much sense. I started the work at 1:20 pm, but my colleague started three times later, at 4pm.