How gravity works, a mysterious force.

Isaac Newton was the first person to grasp the significance of gravity as a universal force. He realised that the same force that caused an apple to fall from a tree caused the planets to orbit the sun. He understood its nature and how it could predict the shapes of the orbits of the planets and how they moved – Kepler’s Laws of planetary motion.

Gravity is a mystery. It obeys the inverse square law just like the electrostatic force does however it cannot be shielded unlike the electrostatic force. Imagine a charged particle. It is attracted to (or repelled by) another charged particle placed in its vicinity. However if a conducting plate is placed in between the two, there will be no influence of one charge on the other extended beyond the conducting plate. However it is impossible to shield gravity in the same way.

A great explanation of how gravity works

The science of camouflage.

In this video, an artist paints people to make them appear two dimensional. Art is being used as camouflage. Animals in the wild do this too of course. Zebras have their stripes, leopards have spots and some animals like the chameleon can even change the patterning on their body to fit the environment. The argument for how zebras’ stripes benefit them is that the hunter finds it difficult to distinguish an individual animal from the herd. In some cases, camouflage works differently, helping animals to blend into their surroundings when viewed from a distance.

Single use plastics are a scourge

At current estimates, only 9% of the world’s plastic production is recycled.

Just imagine – sixty years ago, there was hardly any plastic production and of the estimated 40 million tonnes produced annually, a tiny proportion is recycled. The only true solution to the plastics problem is to stop using non-biodegradable plastic altogether. There are many interesting and novel approaches to cleaning up our planet from plastic waste but the most obvious way is to avoid putting plastic waste out there in the first place.

This Yorkshire scientist is looking at ways to help dentists cut down on single use plastics.

https://www.bbc.co.uk/news/av/uk-england-south-yorkshire-49528007

Bitcoin is unpredictable

There are so many articles on Bitcoin these days. It’s going up, no down, hang on I meant up. The problem is that no-one really understands it. Maybe an investor got lucky and made a lot of money but that does not make them an expert on the matter.

Save My exams – recommended resource

Save My Exams

https://www.savemyexams.co.uk/

I highly recommend this resource for mathematics revision. This is the site I use the most. There is much material available for free, including much syllabus-specific material on the new A-level. Many of the mark schemes are available for the subscription of ยฃ60 per year. It is regularly updated.

I am always impressed at the people who spend so much time creating such sites. They really do dedicate a lot of time to them.

Another great site is Physicsandmathstutor.com. It is free to use and has a host of GCSE and A-Levรฉl material. Many students use this. You may also view my page where I list various resources here.

GCSE results: girls fare better than boys under more rigorous courses

Examination results

I think it is because boys tend to be more laid-back and don’t like to show their working. In recent years, with the introduction of the grades 1 – 9 to replace the letter grades, exams have become more rigorous to combat grade inflation.

More than one in four exam entries by girls aged 16ย received top gradesย of A or 7 and above in this summerโ€™s exams in England, Wales and Northern Ireland, an improvement of half a percentage point to 25.3% compared with last year, while just 18.6% of entries by boys in Year 11 achieved the same grades.

Guardian Education 22nd August 2019

Read more

Bad A-level maths results?

If you failed to achieve the mathematics results you were hoping for, getting bad exam results, all is not lost. Taking a year out can be a good move. There are a number of reasons why students fail to achieve the exam grades they were hoping for. Make time to reflect on where things went wrong. There will be many things that you did right of course, but somehow it didn’t come together. Many people do not perform well under stress and focussing on one subject instead of three for an extended period of time will allow you to assess your strengths and weaknesses and recoup.

When we are young, a year seems like a long time but patience is a virtue and needs to be cultivated these days when everyone expects to be able to get immediate satisfaction. Self-reflection and circumspection are all qualities which are sought by employers.

Download a copy of the syllabus and highlight topics that you are less sure about. Be honest. Then highlight those topics you have some idea about and those you are confident at. Now print out a copy of the formula booklet for your syllabus and have this to hand when you practise.

Do you learn better by watching videos of questions being worked through? If that is the case, then there are some websites with videos of questions by topic for you to browse through and watch. www.examsolutions.net is one such website.

When you are ready to try your hand at some exam questions, you can find many places online where they are sorted by topic or where you can download entire past papers. Of course, with the new maths syllabus, you do have to resort to ‘legacy’ questions once you have exhausted the available ‘new’ material. But as you become familiar with the syllabus, you will be come expert at picking through ‘legacy’ papers and identifying which questions are relevant and which are not.