So recently, especially while enriching my cooking skills, I have been thinking about what temperature really means. Ever since I learned the concept of temperature and the degrees to measure it with, I have never really grasped what temperature means, in "absolute" terms. Is 20C twice as hot as 10C? Not really. Is 0C as cold as it can get? Also untrue. Why are there different scales of temperature measurement, even with different origins? How is this related to actual thermal energy, which as I learned later on in chemistry classes, is directly connected to temperature? Why aren't there easily understandable "conversions" between thermal energy and temperature? Not even Kelvin degrees allows this.
But recently I think I found a suitable explanation, which I now also hold as true. The temperature of an object can be defined as the OUTPUT RATE OF THE OBJECT'S THERMAL ENERGY UNTO A CONSTANT ENVIRONMENT PER UNIT OF AREA (assuming objects are three-dimensional). It's not the amount of thermal energy the object HAS. It is the rate at which it is letting it out. I would like to use 0K as the constant environment used in the definition, but I don't know enough about such extreme cases to be certain, especially with Bose-Einstein condensates and whatnot. So for the sake of explanation, let's assume the constant environment to be regular air at 25C.
So how hot does water at 50C feel when touched? 50C. Why is that? Well, because. How do we feel? How do we feel the temperature of an object? We perceive temperature only through the thermal energy being output by the object. This transmission is what allows us to perceive the object's temperature. It doesn't tell us how much thermal energy this object still has inside it, but only at what rate it is being transmitted to us.
Part of my previous puzzlement was caused by the fact that a pot on the stove is very easy to heat up to a high temperature, say 100C, but water takes a muuuch longer time. But seemingly, the water receives thermal energy at a very similar rate as the pot in which it is contained. Why, then, does water take so much longer to get to 100C?
Because water can hold a LOT more thermal energy than the metal the pot is made of. If something has more thermal energy inside it, it makes sense that it would "leak it out", "radiate it" at a faster rate, just like a leaking gas chamber with a higher pressure lets out the gas at a higher rate. But even if the water is holding more thermal energy as the metal, it doesn't mean it will radiate thermal energy faster (feel hotter) than the metal! Why? Because they're different materials, that's why. Complicated molecular chemistry stuff should provide further details, but I'm satisfied with this simple explanation.
Also from chemistry, I learned that there is this thing called specific heat. And I think its dimensionality is Joules/C. And I remember that water's was much higher than most metals'.
Hmmm... I wonder. I don't think specific heat can determine how LONG will an object take to heat up, only how much thermal energy is required to get it up a certain amount of temperature. I guess "heat transmission coefficient" can be another measurement for materials. There's this thing called aerogel, have you heard of it? I have no idea how much its specific heat could be, but they show pictures of a flower resting on a slide of aerogel with a blowtorch flaming at the slide from below, and the flower completely unharmed. So it must have suuuuuuch a low heat tranmission coefficient. Hmmm.
And so the reason why the temperatures of objects in a room tend to converge onto a single temperature is because the heat transmissions are balancing themselves out. Like a two-way chemical reaction. Dynamic equilibrium. Everyone gives the same amount of energy to each other, so everyone ends up with the same amount of energy, at all times.
Oh yeah, another thing that helps explain it. You know how metal always feels cold? That's cause it's such a good heat conductor, so what we feel is the fast transmission of heat from our skin to the metal object. Not that the metal is actually colder than, say, the shoe beside it, but the metal will absorb our heat more eagerly. Thus, it feels colder.
I wonder if I'm right about all this stuff...? I haven't done much chemistry since... long time ago. I'll go and check wikipedia out. But I like the definition I made up. Makes sense to me.
But recently I think I found a suitable explanation, which I now also hold as true. The temperature of an object can be defined as the OUTPUT RATE OF THE OBJECT'S THERMAL ENERGY UNTO A CONSTANT ENVIRONMENT PER UNIT OF AREA (assuming objects are three-dimensional). It's not the amount of thermal energy the object HAS. It is the rate at which it is letting it out. I would like to use 0K as the constant environment used in the definition, but I don't know enough about such extreme cases to be certain, especially with Bose-Einstein condensates and whatnot. So for the sake of explanation, let's assume the constant environment to be regular air at 25C.
So how hot does water at 50C feel when touched? 50C. Why is that? Well, because. How do we feel? How do we feel the temperature of an object? We perceive temperature only through the thermal energy being output by the object. This transmission is what allows us to perceive the object's temperature. It doesn't tell us how much thermal energy this object still has inside it, but only at what rate it is being transmitted to us.
Part of my previous puzzlement was caused by the fact that a pot on the stove is very easy to heat up to a high temperature, say 100C, but water takes a muuuch longer time. But seemingly, the water receives thermal energy at a very similar rate as the pot in which it is contained. Why, then, does water take so much longer to get to 100C?
Because water can hold a LOT more thermal energy than the metal the pot is made of. If something has more thermal energy inside it, it makes sense that it would "leak it out", "radiate it" at a faster rate, just like a leaking gas chamber with a higher pressure lets out the gas at a higher rate. But even if the water is holding more thermal energy as the metal, it doesn't mean it will radiate thermal energy faster (feel hotter) than the metal! Why? Because they're different materials, that's why. Complicated molecular chemistry stuff should provide further details, but I'm satisfied with this simple explanation.
Also from chemistry, I learned that there is this thing called specific heat. And I think its dimensionality is Joules/C. And I remember that water's was much higher than most metals'.
Hmmm... I wonder. I don't think specific heat can determine how LONG will an object take to heat up, only how much thermal energy is required to get it up a certain amount of temperature. I guess "heat transmission coefficient" can be another measurement for materials. There's this thing called aerogel, have you heard of it? I have no idea how much its specific heat could be, but they show pictures of a flower resting on a slide of aerogel with a blowtorch flaming at the slide from below, and the flower completely unharmed. So it must have suuuuuuch a low heat tranmission coefficient. Hmmm.
And so the reason why the temperatures of objects in a room tend to converge onto a single temperature is because the heat transmissions are balancing themselves out. Like a two-way chemical reaction. Dynamic equilibrium. Everyone gives the same amount of energy to each other, so everyone ends up with the same amount of energy, at all times.
Oh yeah, another thing that helps explain it. You know how metal always feels cold? That's cause it's such a good heat conductor, so what we feel is the fast transmission of heat from our skin to the metal object. Not that the metal is actually colder than, say, the shoe beside it, but the metal will absorb our heat more eagerly. Thus, it feels colder.
I wonder if I'm right about all this stuff...? I haven't done much chemistry since... long time ago. I'll go and check wikipedia out. But I like the definition I made up. Makes sense to me.
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