Weird Fact In Physics - Can Particles Still Move At Absolute Zero?
Absolute zero is the lowest possible temperature that can theoretically be reached in the universe, corresponding to 0 Kelvin on the Kelvin scale, or approximately -273.15 degrees Celsius or -459.67 degrees Fahrenheit on the Celsius and Fahrenheit scales. At absolute zero, particles in a system possess minimal thermal energy, and their motion reaches its lowest possible state according to classical physics.
Theoretically, at absolute zero, several phenomena will occur. According to classical physics, at absolute zero, most particles including atoms or molecules would theoretically cease all motion, including vibrational, rotational, and translational motion. Also, at such a temperature, no heat energy is available to transfer from one object to another. Therefore, absolute zero represents the lowest possible temperature for any material to reach.
Does it mean all particles will stop moving at absolute zero? Well, the short answer is "No".
For particles having matter, such as electrons, atoms, or molecules, according to quantum mechanics, even at absolute zero, some particles still do not completely stop moving due to the uncertainty principle. In simpler terms, the uncertainty principle implies that the more precisely you know the position of a particle, the less precisely you can know its momentum, and vice versa. The uncertainty principle states that there is a fundamental limit to how precisely we can know both the position and momentum of a particle simultaneously. At absolute zero, particles are in their lowest possible energy state, known as the ground state. Even in this state, particles still exhibit quantum fluctuations in both position and momentum, leading to nonzero uncertainties in these properties. As a result, even at absolute zero temperature, particles possess zero-point energy, ensuring that they still have some energy even in the absence of any external energy input.
For massless particles like photons, things would be a little different. Photons do not exhibit motion in the same way as massive particles like electrons. Their momentum is not determined by their temperature. This is because the behavior of photons is governed by wave-particle duality. While they can exhibit particle-like behavior, they also exhibit wave-like characteristics. At absolute zero, the wave nature of photons still exists, allowing them to continue propagating as electromagnetic waves. As a result, at absolute zero, photons will continue to travel at the speed of light in a vacuum, maintaining their energy and momentum.