It is quite incredible to think about how much physics has developed in the last 300 years. Although we think of the ancient Greeks as being pretty competent the truth is they weren’t really that good on the science front. It was the work of Issac Newton and his contemporaries that brought us the idea of forces and momentum. Of course now a days these are very basic concepts but were revolutionary when Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) was published. The very idea of using such rigorous mathematics to describe mechanical systems such as the motion of the planets was unheard of but by the end of the 1700s there was no doubt that force and momentum were inherent aspects of motion. Now Isaac Newton loved to make things difficult for everyone around him (anyone who has tried to use his calculus notation over Leibniz’s will know that) and so his seminal work was published in Latin. This meant that someone had to translate it. In France, this task fell to an Émilie du Châtelet (whose birthday is coincidentally today in 1706) , a woman who, thanks to her family being a member of the lower nobility, had managed to achieve a great standard of education to supplement her brilliance. Historically she is more remembered for being the partner of Voltaire, but her translation was truly her most brilliant work (from my possibly biased perspective). Not only did it perform the necessary task of opening the literature to the French scientific community, her commentary that accompanied the translated Principa was exemplary. In it Émilie derives the concept of the conservation of energy, an idea that had not been considered before. It was only a few years prior that she herself had proved that kinetic energy was proportional to objects velocity squared. Before her work, energy was thought to be synonymous with momentum and as such no new conservation for it had been considered. Unfortunately (or perhaps luckily) she had only just finished her translation before she died 1749.
Just an interesting tale to tell considering it is her birthday. Whenever you feel the need to say that “energy cannot be created of destroyed” perhaps you’ll remember this. Until tomorrow, goodnight.
Acetylcysteine (C5H9NO3S) is a drug with the notable property of being used to treat a variety of ailments. Paracetamol overdose is a particularly important use, but it also is used to treat bronchitis, chemotherapy side effects, HIV and also has found a use as a psychiatric treatment. It is known for being quite safe with side affects such as vomiting and redness of the skin being quite manageable. The most serious side effect is that 5% percent of people experience an anaphylactic shock that may require immediate treatment when they take acetylcysteine. However it is none of these purely medical concerns that are relevant for today’s paper. Instead the focus is on another property this drug possesses. A physical antimicrobial mechanism which has been reported as being effective at disrupting bacterial adhesion, hampering of their polysaccharide production and ultimately breaks up biofilms.
The most famous equation of perhaps the entirety of physics history: E = mc2. The simple statement that energy is inherently connected to mass. There are many caveats and extensions that can be understood but the basics is just that. A particle will have an energy that is stored partly as mass and partly as kinetic energy. In nuclear reactions we have discovered processes which ultimately lose some amount of mass, this is converted into energy with explosive potential (as the equation tells us that every kilogram of mass will provide c2 Joule worth of energy). The process can also work in reverse. Provide a photon with enough energy and it could very well produce mass in the form of an electron and a positron most commonly.
The main problem with radiation therapy is known is almost everybody. The there is an undeniable danger associated with high energy anything, whether it be waves or particles, entering out bodies. But, as tumours grow bigger and more aggressive it becomes more necessary to use more powerful beams. So this is the main concern of traditional radiotherapy: “how do we target these protons so that they don’t do more damage to the person then the cancer would?” This is where the concept of minibeam radiation therapy came from.
Sandstone can create some of the most impressive geological formations on earth. The image on the right demonstrates a bridge that seems so mechanically perfect that looks to almost have been carved. Other formations include standing pillars of sandstone and piles of balancing rocks which have left geologists in amazement since antiquity. Their constant sculpting by wind and water has taken millions of years of reach the current point, but it’s quite unclear why the current point was the one to be reached. The shapes of these sandstone structures are not obvious results of the erosion process and the mechanics of why such bizarre formations come into existence is what today’s paper is looking into.