Pixabay image credit
How lasers cool objects
https://www.science.org/content/article/reflections-absolute-zero
MIT using lasers to cool objects
https://news.mit.edu/2007/super-cool
One concept that fascinated me in college was “absolute zero”. Absolute zero is a temperature at which molecules stop moving, and is -459.67 Fahrenheit, and is colder than the vacuum of outer space. At this temperature, which has never been attained on Earth, the volume of a gas can be zero, and there are many theoretically interesting phenomenon that occur. A major reason to seek absolute zero is that when particles cease to move, we can see the basal quantum principles that may be masked when molecules are in motion.
When cooling objects, the traditional route has been refrigeration. Refrigeration is when a gas or liquid is cooled, and there are many methods this is achieved. Cooling towers, chillers, industrial refrigeration using a multitude of refrigerants and the like are that scientists and engineers use to lower the temperature of an object. When an object is thermally “hot”, heat exchangers may be utilized as well. When the goal is achieving absolute zero, we need to take a different approach. Enter cooling lasers.
When we picture lasers, we make an association with heat. Lasers can add or remove energy, and the field of cold lasers is booming. Scientists at MIT have approached absolute zero. Scientists have achieved a temperature of -458.23 degrees Fahrenheit, but have a long way to go to hit absolute zero. The lasers in this experiment were used to hold molecules in place. Temperature is a measure of the speed of movement of molecules, and the addition of energy causes gas molecules to speed up and increase in temperature. The volume of a gas also increases as the molecules speed up, and an interesting aspect of absolute zero is a gas with zero volume in theory.
What can we gain from absolute zero? Aside from a major case of brain freeze, quantum effects can be used to store information, and we can observe phenomenon that is theoretical in real time. Quantum entanglement is a big area of interest, because it is used in quantum computers to push qubits around and store information. The amount of energy that is required to move the needle to absolute zero will one day be achieved, but for now many questions remain.
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