Many of you who are doing exams this year will be revising or starting to think about revising. As a tutor, I am often asked, “What should I revise?” The answer is, unfortunately, everything that you have covered in the course. No one except the exam writers know what is going to be in the exams in any single year, so always make sure that you cover everything.
Barnaby Lenon, an ex-headmaster at Harrow, has recently written in a blog that GCSE students should revise their course at least three times. The same applies for A level students, but officially there is no magic number given as to how many times you should do so. Usually, however, it will be more than once. Some lucky people, the exceptions, can read something once and it will “go in”, but more will have to go through the course over and over again for it to sink it. We are all different, and this is the main point with revising – what works for one person will not work for another.
With all this in mind, there are some tips below. Remember, some will work for you, some won’t.
• Find a good place to work. Some of you will like quiet, others will like some noise. We all work best in certain places. Some students may like to work in a library, others in their room, others in a coffee shop. Find a place that works well for you and stick to it.
• What time works best for you? Some people work better early in the morning, others in the afternoon, others late at night. Again, stick to what works for you. If you are a night owl, it’s pointless to try and force yourself to get up early and study – it just won’t work as well. Use your strengths and find the best time to suit you.
• Avoid distractions. There are so many distractions today: mobile phones, television, emails and so on. It can make it hard to study. If you are reading this now but also looking at your social media feed on your phone, for example, it’s doubtful all you are reading will go in. So avoid such distractions if you can. Turn off your phone. Turn off your emails. If you find it hard to do this, give yourself a time limit, “I will revise for one hour, then spend five minutes looking at my phone.”
• With the above point also in mind, some students find it hard to sit down and study for long periods. Others prefer it. Again, you should do what suits you best. If you do find it hard to sit for long periods, give yourself a reward. One student I worked with played volleyball at national level. He found it very hard to sit down for long periods and study. Consequently he was doing hardly any revision. We came up with a plan. He would revise for 50 minutes, then go outside and play with a ball or go for a jog for ten minutes. Then he would revise for 50 minutes again and so on. This worked well for him. You may find a similar reward works for you, looking at your phone, going for a walk, making a cup of tea, watching TV, phoning a friend and so on. Decide on your time limit and give yourself a reward.
• Aim to study for no more than two and a half hours without taking a break. You are probably not revising as well as you would if you carry on revising after that time.
• Making and reading notes and using flashcards can all work well for some students. Others can make recordings of their notes and listen back to them when they are going for a walk or even when they are sleeping at night – Mind maps and memory palaces can also be useful when revising. Again, find a method that works well for you and stick to it.
• If you are reading something and it isn’t sinking in or you don’t understand it. Try a few of the following techniques…
o Read it out loud. When you do this, sometimes it seems to make more sense.
o Try and explain it to someone else – You may find that you know far more than you think you do when you explain it to another person.
o Read it in another way. There are a lot of resources online today, so if you don’t understand your notes or textbook, look online and find another explanation.
• Making a revision timetable for when you intend to revise your subject is also useful. You may be revising for more than one subject, so work out when you are going to study and make a plan for each subject.
• Practice exam papers and old TMAs under “exam conditions.”
• Try to take off a day a week. You decide which day. Take some time off from all that studying.
• Try to start revising as soon as you can. The earlier you start to revise, the more revision you will do.
Remember, you have revised before. You know what has worked well for you and what didn’t. So if you have a good way of revising, stick to it. But if your way hasn’t worked so well, why not try another option from those listed above? There is also of course a lot of advice out there online and in books. The best way to revise is the way that works for YOU! So find your best method and stick to it.
Finally, though success in them is all about your hard work and revision, I am still going to wish you this – Good luck with your exams!
On the 15th September 2017, a twenty year long mission by the NASA Cassini space probe came to an end when it plunged into Saturn’s upper atmosphere.
Launching in 1997, and planned for years beforehand, Cassini was intended to study as many moons as possible, in particular, those surrounding Jupiter and Saturn. One of the objects of the mission was also to learn more about the possible existence and availability of water in on the astral bodies it passed. In this regard alone, the many pictures taken by Cassini produced much revealing and exciting information.
Thanks to Cassini’s observations of Saturn’s largest moon, Titan, scientists have discovered that it possesses lakes, rivers, channels, dunes, rain, clouds, mountains and possibly volcanoes, just like Earth. Another of Saturn’s moons, Enceladus, revealed sprays of icy particles erupting from its surface; jets of ice-water three times taller than the width of Enceladus itself. Further, Cassini was able to get as close as 15 miles from this moon’s surface and determine that there was a global subsurface ocean, which might have the conditions suitable for sustaining life.
One of Jupiter’s moons, Europa, also shows extensive evidence of water. Its surface is covered with a layer of frozen ice, which scientists again believe hides an ocean beneath. As a consequence, Europa is often touted as a possible abode for life. Cynthia Phillips, a Europa project scientist at the Jet Propulsion Laboratory, believes there is a lot of indirect evidence for a liquid ocean, “We’re almost certain one is there…” she told Space.com “… the mass of Europa, combined with its density… gives a figure close to one [gram per cubic centimetre] …water is the only material like that.”
The question of the amount (or existence) of water in space has long been debated, often with a view to it sustaining mankind in the future. Mars in particular has attracted a lot of speculation of this nature. Images from the so-called Red Planet have shown dried up riverbeds, lakes, and coastlines across its surface. Recent satellite images from the Aeolis Dorsa region of Mars have uncovered new evidence of the densest river deposits recorded to date. These deposits are believed to date from water that flowed on the surface over 3.5 billion years ago. The channels and ridges formed by these ancient rivers are being studied in the hope that we can better understand the two evolutionary cycles of Mars and Earth, to see if links can be made.
With Cassini’s mission generating a colossal amount of data, scientists now have the opportunity to learn more about the environment of space, the evolution of numerous planetary moons, and the amount of water those moons and their commanding planets could hold now, or may have done in the past.
Will this information lead to mankind ultimately growing food- or even living- in Space? Only time will tell.
Albert Einstein was born on March 14th, 1879 in Ulm, Württemberg, Germany. He was to go on to become the most celebrated physicists of all time.
Of a secular Jewish family, Einstein attended elementary school at the Luitpold Gymnasium in Munich. Einstein never settled at school and towards the end of the 1880s, Max Talmud, a Polish medical student became Albert’s informal tutor. It was Talmud who introduced Einstein to science.
Before he could finish his schooling, Einstein’s parents moved to Italy for better jobs. However, he chose to remain in Germany to finish his studies. This despite the fact that whilst he was good at maths and science, his teachers didn’t agree he was a worthy pupil. His Munich schoolmaster said “he will never amount to anything”. Hope for us all, perhaps.
Einstein went on to Zurich technical college. He graduated with only average marks, and two years later he was employed at a patent office in Bern. He found the work easy here, and was able to spend a good deal of his time thinking more about physics!
It was during this time that he wrote a paper entitled “On the electrodynamics of moving bodies”, which would later become known as Einstein’s Special Theory of Relativity. This showed that measurements of space and time were relative to motion, and this subsequently forced physicists to re-evaluate some of their most basic concepts.
As time passed, so Einstein’s fame and influence continued to grow. In 1915, he announced his most famous work, the General Theory of Relativity, which was the final culmination of an eight-year obsession with gravity. With its astonishing implications about the nature of time and space, it displaced Newtonian mechanics and shook the physics world. It suggested that space and time were one and the same and that gravity was not a force as Newton described, but rather the effect of objects bending space-time. His theory was given the weight of observational evidence when it was used to correctly predict anomalies in the orbit of Mercury; a problem that Newton’s theory of gravitation had been unable to resolve.
In 1919 the British physicist Arthur Eddington went to a small African island to observe the total eclipse of the Sun so that he could test Einstein’s theory; Einstein had predicted that gravity should bend light. The eclipse proved he was right, and our view of the Universe was changed forever. As a result of this and all his other work, Einstein was subsequently awarded the 1921 Nobel Prize.
Einstein continued to make substantial contributions to physics, including his desire to find a more complete and less complex theory for Quantum Physics. He sought to make sense of sub-atomic behaviour in a way that his general relativity theory could not.
Einstein died at the age of 76 on 18th April 1955, after suffering an abdominal internal bleed, which he refused to have treated. For all his successes, Einstein never was able to find a theory for Quantum Physics, though. He made a huge contribution to the way in which we understand the Universe, but with this failing, Perhaps some things are meant to evade the greatest of minds, though – it is a theory which still eludes physicists’ today.
Scientist and mathematician Galileo Galilei was born on February 15th, 1564, in Pisa, Italy. A pioneer of maths, physics and astronomy, Galileo’s career had long-lasting implications for the study of science.
In 1583, Galileo was first introduced to the Aristotelian view of the universe, which was a religion-based view of how the world worked. A strong Catholic, Galileo supported this view until 1604, when he developed theories on motion, falling objects, and the universal law of acceleration. He began to openly express his support of the controversial Copernican theory, which stated that the Earth and planets revolved around the sun, in direct contrast to the doctrine of Aristotle and the Church.
In July 1609, Galileo learned about a telescope which had been built by Dutch eyeglass makers. Soon he developed a telescope of his own, which he sold to Venetian merchants for spotting ships when at sea. Later that year, Galileo turned his telescope toward the heavens. In 1610 he wrote The Starry Messenger, where he revealed that the moon was not flat and smooth, but a sphere with mountains and craters. He discovered that Venus had phases like the moon, and that Jupiter had revolving moons, which didn’t go around the Earth at all.
With a mounting body of evidence that supported the Copernican theory, Galileo pushed his arguments against church beliefs further in 1613, when he published his observations of sunspots, which refuted the Aristotelian doctrine that the sun was perfect. That same year, Galileo wrote a letter to a student to explain how Copernican theory did not contradict Biblical passages, but that scripture was written from an earthly perspective, and that this implied that science provided a different, more accurate perspective.
In February 1616, a Church inquisition pronounced Galileo as heretical. He was ordered not to “hold, teach, or defend in any manner” the Copernican theory regarding the motion of the Earth. Galileo obeyed the order until 1623, when a friend, Cardinal Maffeo Barberini, was selected as Pope Urban VIII. He allowed Galileo to pursue his work on astronomy on condition it did not advocate Copernican theory.
In 1632, Galileo published the Dialogue Concerning the Two Chief World Systems, a discussion among three people: one supporting Copernicus’ heliocentric theory of the universe, one arguing against it, and one who was impartial. Though Galileo claimed Dialogues was neutral, the Church disagreed. Galileo was summoned to Rome to face another inquisition, which lasted from September 1632 to July 1633. During most of this time, Galileo wasn’t imprisoned, but, in a final attempt to break him, he was threatened with torture, and he finally admitted he had supported Copernican theory. Privately, though, he continued to say he was correct. This ultimately led to his conviction for heresy and as a result he spent his remaining years under house arrest.
Despite the fact he was forbidden to do so, Galileo still went on to write Two New Sciences, a summary of his life’s work on the science of motion and strength of materials. It was another work that has helped cement his place in history as the world’s most pioneering scientist, even if he was not fully appreciated in his own time. Galileo Galilei died on January 8th, 1642.
With Wimbledon coming up, we thought it would be fitting to think about spinning tennis balls.
The basic spin shots in tennis are topspin, backspin, and slice or side-spin on the serve.
The spinning of tennis balls is defined by Bernoulli’s principle which states that when the velocity of a fluid increases the pressure decreases. Air behaves as a fluid and so when a tennis ball is spinning the air flows faster on one side of the ball and slower on the other. This creates a pressure difference on the two sides of the ball which in turn creates a force on the ball towards the area of low pressure causing the ball to move through a curve.
When a ball rotates, the air in contact with the ball’s surface rotates with the ball. The hairy, fuzzy nature of a tennis ball means it has the ability to drag a lot of air relative to a smooth ball, and therefore spin is enhanced.
A topspin shot is made by sliding the racquet strings up and over the ball. The friction between the racquet strings and the ball makes the ball spin forward, towards the opponent. The shot dips down after impact and also bounces at a lower angle to the ground than a shot hit with no topspin. This is the normal direction of spin when a ball bounces due to friction from contact with the ground, but additional spin is applied by the strings. This additional forward spin makes the ball come off the ground at speed.
A backspin shot is hit by sliding the racquet strings underneath the ball as it is struck. This causes the ball to spin towards the player who just hit it. This stroke requires about half the racket head speed of a topspin shot because the player is not required to change the direction of spin. When the ball bounces it comes off the ground at a slower speed to a topspin shot.
In the case of topspin, the top of the ball spins into the oncoming air and the front of the ball moves downwards dragging air down with it. More air gets pulled under the ball than goes above it. Since more air has to pass under the ball it has to move faster. This means there needs to be a higher velocity on the lower side of the ball, and subsequently a lower velocity on the top of the ball.
On the top side of the ball this lower velocity creates a higher pressure, and at the bottom the higher velocity creates a lower pressure as in Bernoulli’s Law. With high pressure on top and low pressure on the bottom, there is an imbalance in the forces on the ball which curves it downward from its straight line path. In backspin, the same principles are in action, except in this case the bottom of the ball has the lower velocity so the pressure is higher. The same principle also applies to side-spin.
To see all these types of spin being put to good use, simply turn tune in to the Championships in the next few days.