After the many ramblings I made regarding Dark Matter previously, I want to turn around and think about Baryonic Matter again. Ordinary Matter is something that physicists know much more about than the mysterious Dark Matter and Dark Energy, even though in reality they do make up more than 95% of our known Universe. We are more knowledgeable about Baryonic Matter because of its presence all around us, after all, it is everything we can see and detect: from forms of life, elements in the Earth’s crust and mantle, buildings, cars, the Earth, the Sun, all of the stars… you get the idea.
Now, the stuff that makes up the matter. Firstly what comes to our mind may be elements, which are a table of 100 odd substances that are often called the “primary constituents of matter”. These elements can be identified through their chemical properties and are placed in the Periodic table in order of increasing atomic number (the number of protons in its atom’s nucleus).
Atoms are another level down from the elements of the periodic table, which distinguishes different types of atoms. Atoms themselves is another study on its own. In the early 20th Century, Rutherford and a couple other physicists discovered an awful lot that directly correlates to our modern understanding of the atom through an experiment – firing alpha particles at a piece of gold leaf.
A couple of months ago I talked about a piece of evidence supporting the existence of Dark Matter which is the fact that the stars in the outskirts of galaxies were seen to move at a similar pace as galaxies near the galactic core, defying the norm of the Keplerian Decline.
Recap: Dark Matter makes up roughly 25% of the Universe, so it is five times more prevalent than ordinary Baryonic Matter. Physicists gave it the name Dark Matter not because of it having some mysterious evil property or anything of that sort, but because it simply does not interact with Electromagnetic Radiation. I agree Physicists are a creative bunch.
Last post I did a short guide on Special Relativity and I briefly mentioned time dilation which touches on the concept of Time Travel. Time Travel, like Parallel Universes or Teleportation is something that at a glance seems improbable, “beyond the boundary of physics” and just a complete work of science fiction, but interestingly enough all three of these areas are studied in-depth within the field of physics.
Einstein thought about space as a piece of fabric and essentially called it the fabric of space-time. We can think about time as a dimension, like length and width and height, there is a temporal dimension. Time travel is simply our progression through this dimension and we are all time travelling at this very moment because we are experiencing the passing of time. Time travelling to the future is a crucial everyday task, and it happens more naturally than people may acknowledge.
Einstein’s famous “Warping of Space and Time”
Albert Einstein is probably the most popular scientific figurehead in modern culture with his iconic messy hair and white lab coat. His image has been deemed by many people to be the stereotypical scientist. He is one of the favourite picks by young children to dress up for Halloween and his name is also a synonym of words such as “genius”. Additionally the very recent announcement of the detection of gravitational waves once again awakened people’s admiration for , however despite his immense popularity, most of the public have no idea what pioneering contributions he had made in the field of physics. Einstein’s breakthrough came from his work on Gravitation through his developments of two successful theories: Special and General theory of Relativity, with General Relativity becoming one of the two great pillars of modern physics, the other being Quantum Theory. In this post I will attempt to cover the basic concepts of Special Relativity.
On Wednesday I – with some other students who expressed an interest in pursuing engineering – attended a talk by a civil engineer. Essentially it was just a talk about his life and some big projects he was involved in, e.g the London 2012 velodrome. I found it rather dull since it focused on civil more than anything else. Was never extremely interested in the engineering discipline so not being fully engaged with the talk isn’t a surprise. Well he’s a civil engineer after all – though he is an Imperial College London graduate which was cool.
Though in contrast I also attended one of the Gifford Lectures held in Glasgow University recently in which the speaker was Caltech Professor Sean Carroll and it was a pretty interesting experience. Carroll spoke about ideas that were mainly based around entropy and his book “The Big Picture”. I was gutted that I could not make any of the other lectures in the series – because of overwhelming amounts of school work of course – but Sean Carroll’s lectures are definitely worth checking out and the inside of Glasgow University was stunning.
Obviously I need to go back to talking about Physics class today. We started Special Theory of Relativity yesterday and I could not enjoy it more. It was incredibly amusing to see all the astonished faces while my teacher was explaining time dilation. And how approaching the speed of light you could theoretically travel into the future but sadly not the past. My classmates’ reactions and sense of denial were absolutely remarkable. You don’t know how much I love watching bewildered reception to physics phenomena!
Till next time,