particles and their properties

The hinterland of particle physics

Particle Physics is collectively an effort to study the exciting world of subatomic particles and the nature of their interaction. By subatomic we mean anything that happens within the atom or below and not above. The implications could cover as much above, as it would be entailed by the precincts of natural laws.

eg If a process corresponds to as big a size as is a micro-gram, its evidently not subatomic size in length dimension. The subatomic size by its definition of length scale would correspond to a femto-meters. But the given process is subatomic, while the result of having a size of micro-gram would not be.

Hence while the size of the subatomic entity can roughly be put by a femto meter, nonetheless a particle of the size of pico-meter might find relevance in the study of subatomic processes due to such eerie connections. For another matter a micro-gram is the unit of mass and not that of magnitude of distance.

Quantum Entanglement .. a short primer !

This fact is inherently, nothing but the concept of Quantum Entanglement. Unlike classical particles which are completely independent of each other the quantum sized objects are not. For physical intuition they are at a very small and subtle level intertwined with each other as if threads are kind of tied onto each other. We can-not toss an electron because the whole concept of one electron completely independent of all other makes sense only when all other electrons are not interacting because they are arbitrarily far away.

This year’s Nobel prize in Chemistry.

What happens when some UV falls on biological molecules? (or any kind) some of these molecules like the wooden pole absorb the energy and there still remains energy which they can emit as visible light. So the UV light kicks the molecules and the molecules in turn emit visible light. This implies that the UV wavelength that the molecules absorbed energy at are very small compared to the wavelength at which they emit visible light. This is always the case.

When we say some materials are fluorescent it means they absorbed higher energy and emitted lower energy radiations of colorful light.

But this has a great deal of application apart from its theoretical interest.

3 myths of physics, especially in textbooks.

2. Last year in a text book in Indian High School curriculum, I spotted and corrected with my students, the following:

Myth; there are only 3 quarks that have been detected or FOUND/confirmed so far, in nature.

Its based on a knowledge that was true more than 3 decades ago. All quarks, 6 of them, have been confirmed as hypothesized, the last of them was confirmed 2 decades ago. So there is really no reason why these facts should have been omitted from the text books that are updated every few years as such. Who are our experts?

3. During my freelance research, I have pointed out the following fact within last 3 or 2 years. A recurring myth in very advance texts of physics, concurrently followed in major and wide number of universities around the world, some of the finest texts in the field of particle physics and widely believed to be excellent, which they are nonetheless.

Myth; (particle life time and range of forces) A (force carrier) particle is long range if its mass is zero. Lifetime is the uncertainty that gives rise to an energy which is equivalenced through Einstein’s mass-energy relation and mass being zero, we have an infinite range as range is inversely proportional.

Fact; This is murky waters. Its a manipulation of sorts. Experimentally life times are quite arbitrary, while mass is supposedly fixed. Neutrino has a mean-life from 15 seconds to 10 billion seconds in order of magnitude .. I have hypothesized that’s possible, because it has such a high energy, and given it can’t lose this energy via any possible processes, it must live that long.

Why is the helicity for a mass-less particle Lorentz invariant?

Result; now that photons are mass-less, their energy, momentum, speed, etc are no more variables, in the sense of arbitrariness. They are constants, taking only a few values, but constant in a given situation. But other particles have these properties; arbitrary. So electrons energy and momentum are not fixed, but arbitrary.

But as long as we are considering only elementary particles (that is, we are in a Quantum Zone) eg, electrons, protons, photons, and not nutmegs, soccer balls and airplanes and satellites there is another quantity that is of important consequence that is constant. Spin; whether a mass-less particle or not, spin has the same magnitude for them. that is spin is same for photon, its always 1. Spin for an electron is always 1/2. Spin for proton is always 1/2. Its for this reason photon is called a Boson**. Any thing with spin, 0, 1, 2, etc will be a Boson. Anything with spin 1/2, 3/2 etc will be called Fermion.