absolute zero is a temperature.
at with all energy inside a physical mass would cease to move, (vibration of molecules).
it does not follow that if there are not molecules moving because there are no molecules inside a space that the temperature would be absolute zero.
Yes, temperature of an item is caused by molecular vibration in a physical substance, but temperature is not in its a singular property or transverse vibrations from one element to another.
if this were the case, then we wouldn't feel any heat from the sun because there would not be enough solid matter for the heat energy as molecular vibration to move along.
indeed, it is the case that with a fresh brazing rod, I can braze two sheets of steel together (temperature at the blow torch ~800 degrees centigrade, yes hold the bare metal brass rod with my hand and no gloves. (at a distance of 12" from the heat source).
transference of heat as a physical energy through vibration of molecules can, and does occur, but this is an inefficient way for this heat to radiate.
In the same example as above I can feel the heat radiated from the blow torch, not because air is a better conductor of temperature than a metal brass rod (indeed it is not). but because a much more efficient way that heat does actually radiate is through longitudinal electromagnetic waves. Infra-red radiation...
infra-red radiation does not require mass, and indeed can (and does) travel through the vacuum that we like to call space.
so, back to the original question.
assume that you have a perfect vacuum, and by perfect vacuum you mean not just a differential of pressure between that and your surroundings.
temperature could not reach the vacuum through vibration of molecules to transfer energy, but infra-red radiation, (as in heat), could and would still go right through the vacuum.
so... at the centre of the vacuum, there is no temperature, at least no temperature that can be measured, the only heat source is infra-red radiation, and that goes through the vacuum without being disturbed and no energy is lost.
however, if you put a thermometer in there you would record a temperature, this would be the temperature of the thermometer, not the temperature of the vacuum. (you've also lost your perfect massless vacuum as there is now stuff inside it).
the thermometer would have temperature because the infra-red radiation would heat up the molecules in the thermometer/temperature probe.
Whenever we measure temperature we don't actually measure the temperature, we see the physical properties that the ambient heat that is radiated to the temperature recording device has altered.
example, mercury thermometer, in a pan of boiling water, it doesn't tell you that the temperature is 100degC, it tells you that an amount of heat energy has transferred into a pool of liquid that expands under heat has occurred, by measure that expansion through a capilliary tube with graduations on it we can see roughly what the temperature is...
but, if we put one end of the thermometer in boiling water, and the other end at 200degC below freezing, the glass bulb containing the mercury would be chilled, and the heat energy from the water would go into heating up the tube rather that the mercury...
in this case we'd see a temperature of say 0deg C in a pot of boiling water. (being measured on the thermometer, even though we truly know that the boiling water (at sea level) is actually 100degC).
at with all energy inside a physical mass would cease to move, (vibration of molecules).
it does not follow that if there are not molecules moving because there are no molecules inside a space that the temperature would be absolute zero.
Yes, temperature of an item is caused by molecular vibration in a physical substance, but temperature is not in its a singular property or transverse vibrations from one element to another.
if this were the case, then we wouldn't feel any heat from the sun because there would not be enough solid matter for the heat energy as molecular vibration to move along.
indeed, it is the case that with a fresh brazing rod, I can braze two sheets of steel together (temperature at the blow torch ~800 degrees centigrade, yes hold the bare metal brass rod with my hand and no gloves. (at a distance of 12" from the heat source).
transference of heat as a physical energy through vibration of molecules can, and does occur, but this is an inefficient way for this heat to radiate.
In the same example as above I can feel the heat radiated from the blow torch, not because air is a better conductor of temperature than a metal brass rod (indeed it is not). but because a much more efficient way that heat does actually radiate is through longitudinal electromagnetic waves. Infra-red radiation...
infra-red radiation does not require mass, and indeed can (and does) travel through the vacuum that we like to call space.
so, back to the original question.
assume that you have a perfect vacuum, and by perfect vacuum you mean not just a differential of pressure between that and your surroundings.
temperature could not reach the vacuum through vibration of molecules to transfer energy, but infra-red radiation, (as in heat), could and would still go right through the vacuum.
so... at the centre of the vacuum, there is no temperature, at least no temperature that can be measured, the only heat source is infra-red radiation, and that goes through the vacuum without being disturbed and no energy is lost.
however, if you put a thermometer in there you would record a temperature, this would be the temperature of the thermometer, not the temperature of the vacuum. (you've also lost your perfect massless vacuum as there is now stuff inside it).
the thermometer would have temperature because the infra-red radiation would heat up the molecules in the thermometer/temperature probe.
Whenever we measure temperature we don't actually measure the temperature, we see the physical properties that the ambient heat that is radiated to the temperature recording device has altered.
example, mercury thermometer, in a pan of boiling water, it doesn't tell you that the temperature is 100degC, it tells you that an amount of heat energy has transferred into a pool of liquid that expands under heat has occurred, by measure that expansion through a capilliary tube with graduations on it we can see roughly what the temperature is...
but, if we put one end of the thermometer in boiling water, and the other end at 200degC below freezing, the glass bulb containing the mercury would be chilled, and the heat energy from the water would go into heating up the tube rather that the mercury...
in this case we'd see a temperature of say 0deg C in a pot of boiling water. (being measured on the thermometer, even though we truly know that the boiling water (at sea level) is actually 100degC).
