like a physicist

quantumaniac:

Unsolved Physics Questions : The Lifetime of a Proton

Until only a few decades ago, the lifetime of protons was considered infinite. Unlike the unstable neutron, protons were assumed to never breakdown into smaller particles. During the 1970s this view radically changed. The 1970s was an exciting decade for Physicists, with new breakthroughs like the Standard Model circulating the Physics world. Physicists soon realized that in order for this new unified theory (the Standard Model) to work mathematically, protons would have to be unstable. Although it may seem counterintuitive, mathematically speaking if you wait long enough a proton should breakdown into lighter subatomic particles - such as a positron and a neutral pion. 

Since then, many Physicists have been studying proton decay - but with no results so far. A proton has never actually been seen breaking down, which proves that either protons never actually decay or their lifetimes are extremely long, perhaps billions or even trillions of years! Sitting in underground laboratories such as the Super-Kamiokande Experiment pictured above, these Physicists have been staring at these large tanks of water waiting for a proton to decay. Although they cannot be sure of the incredibly long lifetime quite yet, the current estimate of the half-life of a proton is about 1.1 * 10³⁴ !

quantumaniac:

Antimatter 

All objects that we can see on and from Earth are composed of regular, everyday matter. This matter is composed of atoms, which are composed of particles; protons, neutrons, electrons and the like. Similarly, antimatter is composed of antiparticles; such as positrons, antiprotons and antineutrons. These antiparticles are, of course, composed of antiquarks. Antiparticles can even collect together to form antiatoms! Thus, all of our matter-composed elements are possible with antimatter - antihydrogen for example. 

In an antiparticle, charge must be opposite, and mass must be basically exactly the same. Electrically neutral particles aren’t identical to their anti-counterparts, since they are still composed of antiquarks and antiparticles. 

In 1928, Paul Dirac paved the first path to antimatter when he predicted positrons. Antimatter is not just a theoretical mathematical anomaly - it exists in nature. Antiparticles are created during beta decay, and in the interaction of cosmic rays (most notably gamma rays) and Earth’s atmosphere. Due to our universe’s conservation of charge, it is not possible to create an antiparticle without creating a particle of opposite charge or destroying a particle of the same charge. However, some (typically near or exactly massless) particles are their own antiparticles, such as photons, the theorized gravitons and some WIMPs.

Interestingly, when matter and antimatter collide - annihilation occurs. The collision can produce such emissions as high-energy photons (gamma rays,) or even other particle-antiparticle pairs. The particles that are their own antiparticles, such as gravitons and photons, can even annihilate with themselves! One of the greatest mysteries in Physics today is that, since this collision occurs, why the universe seems to be composed of mostly matter. In a process called baryogenesis, an asymmetry has occurred in the universe between matter and antimatter - and scientists are working hard as we speak to figure out why that is.  

quantumaniac:

Super-Heavy Hydrogen Atoms 

Who ever said that alchemy wasn’t possible? Well, on the atomic scale - it’s been done.

A Helium atom consists of a nucleus and two electrons orbiting said nucleus. The nucleus is composed of two protons and two neutrons. On the other hand, a Hydrogen atom has only one proton and one electron. Typically, it is pretty simple to distinguish the two from each other! 

Meet the muon. The Greek letter mu, where the particle derives its name, also serves as it’s symbol - μ. Muons are very similar to electrons since they also have a negative charge - but muons are far more massive than electrons. If a muon is replaced with one of the electrons in a helium nucleus, the muon sits about 200 times closer to the helium nucleus than an electron would (due to all of its mass.) Since it is so close to the center, the negative charge of the Muon effectively cancels out the positive charge of one of the protons in the nucleus. Thus, the remaining electron continues orbiting the nucleus and since the positive charge in the nucleus is now only one, the atom behaves just like a regular hydrogen atom - even though it is 4.1 times heavier than normal! 

For a video description of this, check this out!