Why is -273 C is called absolute zero?

Answer 1

Absolute zero is the theoretical temperature at which all substances have zero thermal energy. Originally conceived as the temperature at which an ideal gas at constant pressure would contract to zero volume, absolute zero is of great significance in thermodynamics and is used as the fixed point for absolute temperature scales. Absolute zero is equivalent to 0 degrees Kelvin, -459.67 degrees F, or -273.15 C.
The velocity of a substance's molecules determines its temperature; the faster the molecules move, the more volume they require, and the higher the temperature becomes. The lowest actual temperature ever reached was two-billionth of a degree above absolute zero. It was achieved by a team at the Low Temperature Laboratory in the Helsinki University of Technology, Finland, in October, 1989.
Having a limiting temperature has several thermodynamic consequences for example at 0 kelvin all molecular motion does not cease there is just no energy available for transference to other systems it is therefore more accurate to say that at absolute zero molecular energy is minimal if we say that all substances have zero energy this is a violation of the Heisenberg Uncertainty Principal so it is impossible to have zero energy.

The opposite of absolute zero is called Planck Temperature.

As of now it is the highest possible temperature that matter can exist at.
It is approximately 1.41679 x 10^32 Kelvin.
Beyond this temperature everything turns to energy, all subatomic particles break down and become individual black holes destroying space and time.
The universe has already reached this temperature once during the first instant of the Big Bang.

Answer 2

Scientists figure that -273C is the coldest any element could get. If it became any colder it would halt atomic rotation any become something else.

This may be a means for time travel. CIV.

Absolute zero is a theoretical minimum temperature. It's impossible to get that low, but we can get very close to it. At such low temperatures superconductivity and super-fluidity are evident.

Although there is still molecular movement at absolute zero, there is no possibility of transferring any energy. If you cannot get any more energy out of it, the temperature cannot get any lower, thus it is the absolute minimum temperature.

Absolute zero is -273.15ºC on the Celsius scale, 0K (zero K) on the Kelvin scale and −459.67°F on the Fahrenheit scale.

Answer 3

Absolute coldest temperature is the temperature beyond which any object cannot go colder. This is the temperature after which there is no heat energy left in the substance. The molecular movement comes to an absolute standstill with relative to the rest of the body and hence no heat gets generated. This is also called zero-point energy. In 1848, Lord Kelvin published a paper in which he stressed the importance of inventing a scale that would start at the point of absolute coldest temperature. The zero degree on the Celsius scale started at the point where water froze and the hundred degree mark came up where liquid water became water vapor. So this scale was more with relative to water's properties rather than an absolute scale which is independent of any substance. Lord Kelvin's paper on the Absolute Thermometric Scale stated that the absolute coldest temperature which is -273 on a Celsius scale.

Answer 4

-273oC is called absolute zero as it is the coldest temperature to which anything can be made.

From my memory of school, I think:

The temperature of something is roughly a measure of the vibration of the atoms of the substance. Any moving thing has Kinetic energy and so temperature is a rough measure of the kinetic energy of the atoms.

When temperature is decreased the vibrating atoms vibrate less and so lose kinetic energy. Alternatively this can be thought of when the atoms vibrate less, they lose kinetic energy and so the temperature drops.

When they stop vibrating, they have no more kinetic energy to lose and so the temperature cannot fall any further. This happens at about -273oC

Answer 5

Because it is defined that way. Absolute zero is the lowest possible temperature - the temperature when atomic movement stops, and atoms don't have other kinds of energy which contribute to what is called "temperature" either.