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.ultimate
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If tempertaure means the movement of particles, Can tempertaure be below 0 Kelvin? I mean no movement, vacumm
.ultimate said:What will happen if we put a heated (suppose) metal in vacuum? Will it lose its heat? But how can this be possible, since there are no particles in the sorruonding vacuum?
Kanse said:I don't understand the last part. 0 Kelvin is absolute zero. Particles don't move in 0 Kelvin. http://en.wikipedia.org/wiki/Kelvin
.ultimate said:If heat means the movement for patricles, plase clarify how this movemnt subsides by loss of heat as radiation, how can IR radiation be responsible?
pixel01 said:Heat is one kind of energy which is the kinetic energy of the particles. In this case, this kind of energy is converted to radiation, the IR which is also another kind of energy.
The energy from the sun to reach Earth is transferred by this way as well.
.ultimate said:Arent Infra-red eletromagnetic waves? If that is so, can over wavelngth em waves also be considered to carry heat energY?
ZapperZ said:Say what? What is "over wavelength"?
What we call "radiant heat" is defined as the IR spectrum. This is because this is the range of the em spectrum that many of our common molecules (such as water and our skin) can receive the energy efficiently and convert to what we call "heat".
ALL em waves carry energy, but not all of this energy are converted efficiently to what we normally call heat. UV spectrum can heat up ordinary glass because it absorbs that spectrum efficiently, yet visible light has no affect on it.
This thread has become rather confusing and unfocused.
Zz.
.ultimate said:Sorry, I meant 'other' wavlenght, I apologise if it caused any misconfusion
How can you hypothesize that enrgy can be Absorbed
As Energy is indirectly proportional to Wavelngth, shorter wavelngth Electromagnetic waves SHOULD also be considered to cause Heat
By the way, Can you please clarify what you mean by Heat in the above context
ZapperZ said:That is what happens when light "disappears" when it hits objects.
Not it doesn't. You are forgetting one half of this important equation
- THE NATURE OF THE RECEIVER.
The TYPE of material can also dictate if em radiation of a certain wavelength can be absorbed. No material has an infinite bandwidth of absorption. Your skin is obviously transparent to x-ray, which has a higher energy than visible light which is absorbed by the skin and turned into heat.
Atomic or molecular KE or lattice vibrations, the SAME way it is defined in thermodynamics!
.ultimate said:If you say all the EM radiations carry energy. How can the energy 'dissapper'? Isnt that violation of Enery-Mass equivalence
All matter is supposed to be made of same material. And What do you mean by 'nature' in atomic terms.
Well, this is purely hypothetical. X-rays are not absorbed by skin neither by bones. I recently postulated the reason for reflection of light
Size of wavelength of Visible radiation = of order of [tex]10^{-7}[/tex]
and size of whole atom = [tex]10^{-10}[/tex]
Size of nucleas = [tex]10^{-15}[/tex]
Empty space = [tex]10^(-5}[/tex]
Hence the EM wave will not penetrate through the atom, and the photon will be reflected as such.
Fine that Heat is considered to be molecular Kinetic Energy, But how can it be 'lost' as radiations?
Zzzz. (sleeping)
haiha said:I think there's no concept of vacuum's temperature at least for classical physics. Because temperature measures the movement and/or oscillation of particles, so no particles mean no temperature. It is like you say of the speed of a car, but if there's no car, the speed of nothing is meaningless.
I am not sure if in modern physics when they say the vacuum is not nothing, but somethingl, the temperature concept can be applied.
.ultimate said:If tempertaure means the movement of particles, Can tempertaure be below 0 Kelvin? I mean no movement, vacumm
.ultimate said:Size of wavelength of Visible radiation = of order of [tex]10^{-7}[/tex]
and size of whole atom = [tex]10^{-10}[/tex]
Size of nucleas = [tex]10^{-15}[/tex]
Empty space = [tex]10^(-5}[/tex]
"Less than 0 kelvin" refers to temperatures below absolute zero, which is the lowest possible temperature on the Kelvin scale. It is often described as "negative" or "minus" kelvin.
At absolute zero, all molecular motion stops and there is no further decrease in temperature. However, in theoretical studies, it has been suggested that temperatures below absolute zero may be possible due to the unusual behavior of certain quantum systems.
Temperature is a measure of the average kinetic energy of the particles in a substance. It is a fundamental physical property that determines the direction of heat transfer and is commonly measured in units of degrees Celsius, Fahrenheit, or Kelvin.
The Kelvin scale is an absolute temperature scale where 0 kelvin (0 K) is equivalent to absolute zero, the lowest possible temperature. Unlike the Celsius and Fahrenheit scales, the Kelvin scale does not use negative values, making it useful for scientific calculations.
As of now, "Less than 0 kelvin" is only possible in theoretical studies and has not been achieved in real life. However, scientists continue to research and explore the behavior of matter at extremely low temperatures, which may one day lead to the discovery of temperatures below absolute zero.