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.
For anyone interested in taking a break from the books for a bit and taking a field trip to a Science Museum, or wishing to take part in an event on any part of the subject, the following may be of interest…
British Science Week 2015 will take place 13 – 22 March. This is a ten-day celebration of science, technology, and engineering and features, entertaining and engaging events across the UK for people of all ages. You can find more information, including activity packs for different age groups, through their website at http://www.britishscienceassociation.org/british-science-week . Anyone can organise an event or activity, and the British Science Association helps organisers plan by providing what are free support resources.
The Big Bang Fair UK: Young Scientists and Engineers Fair www.thebigbangfair.co.uk/
This fantastic event is coming back to the NEC this month from 11 – 14 March 2015. Visitors can meet engineers and scientists from large multinational corporations and a range of diverse and unique UK companies.
The Summer Science Exhibition at the Royal Society London
The Royal Society’s Summer Science Exhibition is their main public event of the year and showcases the most exciting cutting-edge science and technology research and provides a unique opportunity for the public to interact with scientists.
The Royal Society Summer Science Exhibition 2015 runs from 30 June – 5 July at the Royal Society, London.
There are a great many science museums in the UK. Here are some of the best.
1) Science Museum, Birmingham includes a science garden, planetarium and an interactive show which lets children explore the human body by seeing what it’s like to shrink to the size of a living cell. thinktank.ac/
2) National Space Centre, Leicester. Here you can explore the wonders of the Universe and discover the science behind the search for extra-terrestrial intelligence, plus take a tour of the 42m high rocket tower. There is also the Sir Patrick Moore Planetarium. spacecentre.co.uk
3) Museum of the History of Science, Oxford, has an unrivalled collection of early scientific instruments in the world’s oldest surviving museum building. mhs.ox.ac.uk
4) Museum of Science and Industry (MOSI), Manchester is currently showing a 3D printing exhibition. mosi.org.uk
5) The Science Museum, London contains a new nanotechnology exhibition, and the space travel exhibition is outstanding. I found the history of medical science exhibition very good. sciencemuseum.org.uk
6) Techniquest, Cardiff is currently showing an exhibition of colourful chemistry over the weekends 28 February – 22 March. techniquest.org
7) MAGNA, Rotherham has a fantastic electric arc furnace exhibition, including pyrotechnics. visitmagna.co.uk
8) Discovery Museum Newcastle www.twmuseums.org.uk/discovery.htm
This museum houses the finest collections of scientific material outside London and has important collections of maritime history.
The museum contains Charles Parsons’ ship, Turbinia, and Joseph Swan’s historic lightbulbs.
The Turbinia is my favourite museum exhibit which I saw on a school trip in 1967. She was designed by the Tyneside engineer Sir Charles Parsons in 1894 and was the world’s first ship to be powered by steam turbines. Until 1899, Turbinia was the fastest ship in the world, reaching speeds of up to 34.5 knots.
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.
What initial conclusions about the future of GCSE exams can we draw from the mountain of documents which Michael Gove and the Department for Education released last week? And who will the winners and losers be if these proposals come to pass in their current form?
There is no doubt that the new exams will be harder and more “academic”. If not a return to the degree of difficulty posed by the old O-level exams, these new outline specifications match the difficulty and depth of the current IGCSE (International GCSE) specifications set by Edexcel and the Cambridge board. The message seems to have been: take the best of the current IGCSE specs and call it a GCSE instead.
The subject advisers seem to have taken this brief quite literally in most of the core subjects. It is perhaps most clearly seen in Mathematics, a subject in which the IGCSE specifications already require a number of skills that have been beyond the scope of the GCSE Maths syllabuses for 25 years but which are fundamental to AS level Maths. These include function notation, kinematic problems, set notation, rates of change and Venn diagrams, to name but a small sample of topics. There they are in the new drafts in bold print. This is IGCSE Maths by another name.
Most topics are not in bold print, implying that the boundary between what is now the GCSE Foundation and the current GCSE Higher levels is set to shift. Vectors, formerly to be found in the GCSE Higher level requirements, appear in plain text here, including the multiplication of vectors by a scalar. Some maths teachers may need to go on a refresher course to master the required skills!
Similar principles underlie the Science draft. Not only will the individual specifications require considerably more depth of study, as they do in today’s IGCSEs, but the Combined Science qualification will be the equivalent of two GCSEs, not one, just as it is today with IGCSE Science but not GCSE Science. The simple principle behind GCSE Science is to take one-third of the Biology specification, one-third of the Chemistry and one-third of the Physics, while IGCSE takes two-thirds of each of the respective individual subject specifications. The new proposals unashamedly mimic the IGCSE formula.
If this means that all candidates will now face a choice between tackling the new Double Science GCSE or leaving school without any formal recognition of their achievements in the sciences, there will be huge numbers of schoolchildren who fall in the latter category. While the old “everybody passes” philosophy of GCSE had its disadvantages, do we really want to stigmatise a whole generation as incapable of taking and passing the “simplest” of the new science specifications?