If heat is energy, then what is cold?
153029
The cold is less heat\n& since the heat is energy so cold is also an Energy
159463
Thermal energy is heat that comes in 3 forms: conduction, convection, and radiation.  Conduction is when you are cooking on a stove and the heat passes through the metal in the burner and into the pan.  Convection is when air passes over a warm surface and rises or moves because of the increase in energy and takes the thermal energy with it.  Radiation is how the Sun brings energy to the Earth and other planets.  Thermal energy is measured in Joules (J for short) or British Thermal Units (BTUs).  The transfer of heat is measured in Joules per second, or watts, and BTU/hour.\n\nIts use is almost every aspect of our lives, from your body keeping itself warm to cooking to keeping your house warm to chemical reactions that generate heat.  If you want to study thermal energy, you might major in Mechanical Engineering or Physics in college.  I have a degree in Mechanical Engineering.
605145
no...it cant get colder than absolute zero....thats why its called absolute....molecules dont move forward or backward ....you should think of them as energy particles....electrons dont really move around a nucleus either....dont think of them as planets around the sun they are more like energy fields.  the more negative the charge the more "electrons"....if there is any movement....even if it were possible to move backwards it would be warmer....movement causes friction and, therefore, heat.  it you cant get less than nothing.
72195
No.  That would actually cause you to burn less calories.  When you're cold, your body burns energy to heat you up to 37C.  When you're hot, your body has to work less to heat you to that level so you burn less calories.
804973
A fundamental axiom: cold air is heavier than warm air.\n\nThus, cold air sinks (like into a valley) and hot air rises.\n\nHowever, the temperature gradient (how temperature changes with increasing altitude) is negative.  This means air gets colder as altitude increases.  So what we have is cold air at altitude pushing down on warm air near ground level.\n\nThe warm air heat comes from the ground, which is heated by our Sun.  In summer, there is a lot more of that solar energy to heat the ground and lower air in the valley than in winter.  Thus, the valley air is warm.  In fact, the weight of the colder upper air contributes a little bit to the heat below because a gas under pressure does heat up.  But in winter, when there is far less solar energy and resulting heat, the naturally colder air above settles into the valley.  \n\nBoth the cold and warm air are more or less trapped in the valley because of the hills or mountains surrounding it.  Thus, the cold air stays colder because no warm air is blown from the surroundings into the valley.  And the warm air stays warmer because no cold air is blown into it.
342274
As my college chemistry professor said:\n\nOn a warm day, ther-mo-dy-nam-ics tells you that your cold beer is not going to get colder, it's going to get warmer so you better drink it sooner rather than later.\n\nThus, heat flows from hot to cold, not cold to hot.\n\nAnother way to look at it this.  Cold is not the presense of something, it is the absense of something.  It is the absense of thermal energy.  At absolute 0, there is now thermal energy in the system.  While placing something hot in the system will make the hot thing colder, it is because the thermal energy is migrating from the hot thing to warm up the cold surroundings.
82857
Zero degrees Kelvin (but not F or C) is as you suggest no temperature at all. Atoms don't move and there is no thermal energy.\n\nOf course, you can't get all the way to 0K in real life, that I know of. Liquid Helium is about 4K which is the lowest most people ever see.\n\n\n---- \n\nOK so a lot of differences in opinion here. First off, cold is not a temperature. Cold is lack of heat. The scientific definition of temperature (from American Heritage) is: \n\nA measure of the average kinetic energy of the particles in a sample of matter, expressed in terms of units or degrees designated on a standard scale.\n\nSo at the risk of sounding like a lawyer or politician, it depends on your definition of temperature and your definition of "no". But in scientific terms, 0K is no thermal activity.
1142068
In physics, heat is defined as energy in transit.Generally, heat is a form of energy associated with the motion of atoms, molecules and other particles which comprise matter. Heat can be created by chemical reactions (such as burning), nuclear reactions (such as fusion taking place inside the Sun), electromagnetic dissipation (as in electric stoves), or mechanical dissipation (such as friction). Heat can be transferred between objects by radiation, conduction and convection. Temperature, defined as the measure of an object to spontaneously give up energy, is used to indicate the level of elementary motion associated with heat. Heat can only be transferred between objects, or areas within an object, with different temperatures, and then only in the direction of the colder body.\n\n\nfor elaborate details refer to the link below:\n\nhttp://en.wikipedia.org/wiki/Heat
29543
Thermal energy is kinetic energy due to disordered motions and vibrations of microscopic particles such as molecules and atoms.
35621
The phrase "twice as cold", has no meaning.\nYou could argue that one temperature is twice as warm as another, if they were measured from absolute zero.
621743
We cannot make a substance cold. \n\nWe can remove the heat from one place to another.\n\n  What is the difference between ice and water?\n\nFrom ice we have removed heat. The water is water because we have not removed heat from it. \n\nWe should not say ice is cold when compared to water, because we have not made it cold but we have removed heat from it.\n\nSimilarly when we want some hot coffee, we should ask, I want a coffee in which heat is added because we cannot make coffee hot.\n\nThank you.
662425
Heat packs work by utilising exothermic reactions & cold packs work by using endothermic reactions. Meaning that once you start off the reaction, exothermic reactions lose energy & give it off as heat & endothermic reactions require energy & use heat from the surroundings.
39424
heat is the measurement of thermal energy
124587
I am going to take a guess and say the moon.\n\nNo, I am kidding, it's the Sun\n\nSolar energy can be converted in to electricity and heat.
819186
In very simple terms, nature does not like imbalance.  Heat is a quantity of energy.  So the hot thing has more energy than the cold thing.  The imbalance is got rid of by the hot thing giving up energy, and the cold thing absorbing it.
129713
MeghnarMajhi is right.\n\nTemperature <==> Heat
336735
Heat can be compared to magnetism or gravity.  You need the movement or change of heat energy to generate electricity, just like you need movement or change of a magnetic field to generate electricity.\n\nYou can generate electricity from DIFFERENCES in heat energy levels (Seebeck effect)\n\n\nIf you're looking for a non-mechanical device, check out a Peltier junction.   This is an array of dissimilar metals (thermocouples) that will generate electricity as heat energy moves through it.   It is also a reciprocating device, meaning that if you put an electrical current through it, one side will get hot, and the other cool.  It is the technology used in portable electric travel coolers that you see these days.