In this blog we'll be giving a short intro to the understanding od entropy.

So why is our title blurry?

That would be because entropy is basically the measurement of disorder and randomness in a system. To better understand its meaning we need to review the four laws of thermodynamics, as entropy is the core idea behind these laws.

·         Zeroth law of thermodynamics – If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.

·         First law of thermodynamics – Energy can neither be created nor destroyed. It can only change forms. In any process, the total energy of the universe remains the same. For a thermodynamic cycle the net heat supplied to the system equals the net work done by the system.

·         Second law of thermodynamics – The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.

·         Third law of thermodynamics – As temperature approaches absolute zero, the entropy of a system approaches a constant minimum.

The main idea of the third and second law is that the more we approach absolute zero the less entropy we have. The colder the system is the less energy there is, and the less energy there is, the more organization among the particles can be observed. It also works the opposite way, the more heat or energy contained in a system the more entropy we can observe.

So now that we have basic knowledge of the laws of thermodynamics and entropy we can answer the following question.

It may look like the glass with the chips of ice has more entropy because it looks all disorganized in the inside, but because the water are frozen its molecules are moving at a slower rate than the ones in the glass with the warm water. Just as the laws say, the closer we're are to absolute zero the less entropy we'll have.

Here is another example:

The graph shows the relationship between entropy and temperature, and how it differs between the different states of matter.

The last topic in today's blog will be the definition of absolute zero.

Absolute zero can define as the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reaches its minimum value, taken as 0. The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement, absolute zero is taken as −273.15° on the Celsius scale which equates to −459.67° on the Fahrenheit scale.