# Twice as warm

Now I now from Physics that if it is 1 degree outside and the next day it is 2 degrees it isn’t twice as warm but why not?

What temp is twice as warm as 1 degree.

It depends on the scale you are using. If you are talking Degrees Kelvin, then 2 degrees is twice as warm as 1 degree.

275 degrees Celcius could be considered twice as hot as 1 degree Celcius. That’s because 1 Celcius would be 274 Kelvin, and 275 Celcius would be twice that-- 548 Kelvin.

Along the same lines, 493 Fahrenheit would be twice the temperature as 1 Fahrenheit.

If you’re multiplying temperatures, you need to use one of the absolute scales - Kelvin (C + 273) or Rankine (F + 459.67). I’ll assume that when you say it’s 1 degree outside, you mean 1 degree Fahrenheit. So 1 F = 460.67 R (apologies for lack of degree symbols). 2 times that would be 921.34 R = 461.67 F. Too warm for my blood.

Likewise 2 F is 461.67 R which is 1.0022 times as warm as 1 F. A paltry difference.

As for the whys, well temperature is a scale designed to express energy flow. Two objects are considered equally “hot” in this sense when heat does not flow from one to the other. Expressing how hot something is in this way is a rather qualitative idea. Just because something is “twice as hot” in this sense as something else does not mean that it contains twice as much thermal energy.

In this spirit, the only natural temperature that we can consider completely unhot is absolute zero (0 Kelvin). So we can call something twice as hot as something else if its temperature is twice as far from absolute zero.

Doh! I was careless and quick with my Fahreheit calc. Stainger is most certainly correct with his numbers.

S’OK, Undead Dude. I cheated and used my Convert.exe tool!

Can someone explain this so I can understand it.

I was refering to 1 degree farenheit and 2 degrees farenheit. Obviously it has something to do with the type of measure but can someone talk to me like I’m 5.

I’m thinking if I have 1 cookie and the next day 2 cookies that means I have twice as many cookies as the day before. But tempature must be some sort of different measure.

Basically there are several different temperature scales. One of which is called the Kelvin Scale. This measures from a point called absolute zero. Basically this is as ‘cold’ as anything can ever get. Now this is approximately 300 degrees Celcius below zero. So 1 degree Celcius is really more like 300 degrees.

Does this help?

Markxxx, your problem is that you think zero degrees means it has no warmth at all. But it does, and the proof is that you would much prefer zero degree weather over fifty below, which itself is better than a hundred below zero.

You might not aware that there is a limit to how cold things can be. This is called “absolute zero”. At that point, all molecular activity is stopped, generating no heat. (To get that totally cold is not possible, but the scientist have gotten awfully cold.)

You’re probably familiar with the Fahrenheir and Celsius scales, but not with the Rankine and Kelvin scales. These have degrees spaced the same way, but a different starting point, anmely at Absolute Zero. So it is impossible to have “below zero” temperatures on the Rankine and Kelvin scales. Zero Kelvin is at 273 below 0 Celsius, and zero Rankine is at 459.67 below zero fahrenheit.

If you use one of those scales, then 2 degrees is indeed twice as warm as one degree. But if you use normal temperatures – say, 70F or 25C – you don’t realize that this is already so much warmer than absolute zero, that if you’d double it, you’d literally roast.

Sorry, what I meant to say was:

but the scientists in the lab have gotten awfully close.)

I’m going to try to explain this with cookies.

This scientist named Fahrenheit was working with a measurement system using Chips Ahoy cookies. He laid 460 cookies on the table and said, “To best suit my way of thinking, I will measure cookies from here.” 460 Chips Ahoy cookies were thus zero on his scale.

Likewise, another scientist, Celcius, was working with a measurement system using larger cookies, like Famous Amos (I think). He laid 273 cookies on the table and said, “To best suit my way of thinking. I will measure cookies from here.” 273 Famous Amos cookies thus became zero on his scale.

Then this guy named Rankine came along and said, “Fahrenheit is a moron. Zero cookies should be the complete absense of cookies, dammit. My system of measurement will still use Chips Ahoy cookies, but zero on my scale means that there aren’t any frigging cookies!”

Likewise, another guy, Lord Kelvin, said, “Celsius was an idiot. Zero cookies should mean that there are no cookies. My system of measurement will employ Famous Amos cookies, but zero on my scale means that there are no cookies to be had.”

Hope that helps.

“but the scientists have gotten awfully cold” – ROFL! A mistyping that made as much sense as what you intended to post!

This also helps to explain how electromagnetic signals can embed cookies on your hard drive.

Okay, I won’t go as far as cookies, but let me describe the temperature scales like this:

Suppose you have a wall in your house. You have a ruler, so you decide to mark how high points are on the wall. You start by marking the point where the wall meets the floor as 0 inches. You make marks up the wall – 10 inches, 20 inches, 30 inches. So now you start thinking about how high things are off of the ground. You are about to say that this 30 inch chair is twice as far off the ground as this 15 inch stool, when you remember that you are on the second floor! Yikes! Well, your chair isn’t nearly twice as high off the ground as the stool! So now you want to get your scale working again, but you don’t want to erase all of your lovely marks, so you go down to the first floor and you start marking in negative numbers down from the ceiling (let’s just pretend that the floor is really thin!). So you mark -10 inches down from the ceiling, -20 inches, and so on. When you get down to the floor, you find yourself at -120 inches. So now if you bring your stool and your chair downstairs, the stool will rise to -105 inches, and the chair will rise to -90 inches. But the absolute distance from the ground of the stool is 15 inches and the absolute distance from the ground of the chair is 30 inches. So now the chair really is twice as high above the ground as the stool.

So now it gets into your head: I have a little block that is one inch high on the second floor (so your marks say it is at “1 inch”). How high would something be on this scale, if it was twice as high off the ground as the top of the block? You realize that your block is really 121 inches off of the ground, so you know that this other object needs to be 242 inches off of the ground. So bring a ladder on to the second floor and you extend it to 242 - 120 = 122 inches. So your second floor markings say that the block is 1 inch high and the ladder is 122 inches high. But if you look from outside the window, you can see that the ladder is really twice as high off of the ground as the block.

I hope this made things clearer rather than more confusing. So the analogy, as you might have guessed is that your marks on the wall are like the fahrenheit scale, and the distance from the ground is like an absolute scale.

Any clearer I hope?

Aww, but I liked it better the first way. And it actually still kinda made sense!

Depends what the meaning of ‘is’ is. Well, rather, what the meaning of ‘warm’ is. After all, the concept ‘warm’ was around long before those “awfully cold” scientists figured out there was an absolute zero. And if we’re talking about the effect of the temperature of one thing on another thing, the heat conductivity of what’s between the two things, or else the situation with convection or radiation, as either affects the receiving thing. Not sure of the physical process that causes politicians to make my temperature go up.

And, BTW, what was Réaumur’s excuse?

And then weathermen came around with chill factors and I forget what they call it on the hot end of things.

Probably, after this thread, cookie recipes will have to be rewritten to give baking temperatures in Rankine degrees.

Hey, and what about Web pages? How does one tell when one is twice as cool as another?

Well, OK, this post ain’t so hot, but it’s not twice as cold as the others.

Ray (It’s just a warmover. . .and I’m just warming up.)

Thank you all. I am familiar with the concepts what confused me is why you had to convert to Kelvin. And now it makes sense because on that scale 0 actually represents a starting point. And on the other scales it doesn’t.

Be careful with those cookies! You’ll poke someone’s eye out.

UD, good analogy. Now to add to that your measurements use the inches scale. This is comparable to the Fahrenheit/Rankine scale. If you measured all your heights using a meter stick (not a yardstick) it would compare to the Celsius/Kelvin scale.