In liquids and solids, the heat conduction occurs through the valance electrons of the material. When you have a gas, most of the heat is conducted through radiation. When you conduct heat through a vacuum, it's all by radiation.
Thermal energy is is very general - heat simply passes through like any other solid with the molecules vibrating next to each other creating friction and effectivly passing the heat though them.
However if your on about a greenhouse then this is different, short wave radiation from the sun has enough energy to penetrate the glass and reach the earth but long wave radiation emitted from the earth does not have enough energy to penetrate the glass to remains inside heating the inside of the greenhouse.
There are two mechanisms by which a vacuum flask retains the temperature of the contents. [Both hot or cold.]
Construction The vacuum flask is made as a double-walled flask, with the two walls joined only towards the neck, the space between the walls evacuated, and the vacuum-facing surfaces silver-coated.
1 By having a vacuum between the walls of the flask, this reduces heat transfer by conduction or convection.
2 By having the walls of the flask (where they face the vacuum) silver coated, this reduces the heat transfer by radiation.
Vacuum flasks are made of glass or stainless steel. The steel versions are much more robust, but at the expense of being a poorer heat retainer. This is because the heat may still be transferred between the two flasks at the neck where they are joined. The mirrors facing the vacuum may be inferior to the sliver coated glass.
It isn't reduced because of conduction, conduction is a way to transfer heat
btw a vaccum flask works like this:
In order for heat to transfer by convection, there has to be air or water in order for the molecules to move from place to place. So both these heat transfer techniques require a medium of some sort. In a vacuum, there's no particles at all, so there is no medium present in order for these heat transfers to apply.
Will glass transfer thermal energy? Would wood or metal be a better conductor? Why?
Quantum Tunneling transfers vibrational energies from one molecule to the next. Second law of thermodynamics dictates this will occur until both have the same amount of vibrational energy.
Conduction can only occur in solids so there is a vacuum between the inner layer of the flask and the outer surface of the flask which almost eliminates heat losses through conduction.
by conduction and radiation ;)
this fails
Heat is transferred by energy waves moving through space.
heat is transferred only from high energetic concentration to low energetic concentration. therefore heat cant be transferred in any usual way.
convection (from the movement of fluids), conduction (through solids), and radiation (through air and space).
Since that's what heat is (the motion of atoms), how better to transfer than by random collisions? yes.
Heat can be transferred through liquids and gases by means of conduction as well as conduction.The difference is that convection is not possible in solids.ConductionDuring conduction, heat is transferred due to the vibration of the molecules. A molecule at a higher temperature has more energy, and hence vibrates faster. It collides with other atoms and passes energy onto it. The chain continues and heat is transferred without any appreciable movement of molecules.ConvectionIn convection, the hotter particles move around in the fluid, transferring energy to the colder molecules. For example, when heating water in a vessel on a stove, the water at the bottom is heated first. It rises to the top and the cooler water flows down to be heated. This continues and heat is transferred throughout the fluid. Heat is transferred with the movement of molecules.
this fails
radiation
Convection occurs when heat is transferred into an object through motion or movement; an example would be boiling water.
Convection occurs when heat is transferred into an object through motion or movement; an example would be boiling water.
it can be transferred through metal...and glass...
conduction
Heat is transferred through contact between molecules.
Heat is transferred through contact between molecules.
Heat is transferred through contact between molecules.
Heat transferred in convection occurs through movements of fluids.
Heat is transferred through particles by radiation through space or conduction by touch or convection when the heat flows in a circular pattern
Conductive heat.