Because ignorance is not cool

I feel that I could endlessly apologise for my absence, but what good would that do? That said, I am sorry about the aforementioned absence – it is a particularly busy time at the moment. (Yes, even busier than what sadly seems to be the norm for most people these days.) Sometimes, life also happens, and I opt to go with it.

If for some unfathomable reason, one or more of you have missed my ramblings and postings of video clips, I would like to offer up the following super slow-motion clip, and ensuing discussion, of the physics of slinkies, and how they “hover” above the ground before falling when dropped. The gist is that both ends of the slinky are “attracted” to its centre of gravity, and external forces (gravity, in this case) will pull both ends of the slinky towards the centre of mass of the Earth. There are resultant momentary not-quite-cancellations of forces, which are enough for the slinky to “hover”… Oh never mind me, go watch the super slo-mo, you know you want to!

Finally, we celebrated 100 years since the birth of Alan Turing on June 23rd! Most of us have more to thank him for than that of which we are presently aware. I randomly – seems to a key adverb in my life – came across a letter to the Guardian newspaper sent by a former professor of mine from Imperial, which seems to be a much more coherent description of some of Turing’s achievements than many a big celebratory feature. Worth a read!

On that note: what would you like to read about? Perhaps I should have asked earlier. Hm.

Not this again (anti-sexism rant coming up)

“What a strange decision for a young woman – to study physics.”

When one (female) is told this by one of one’s parents’ acquaintances (male – whose spouse is observing the conversation and, to her credit, looking slightly embarrassed), and the customs advise to not violently speak up for oneself, the remainder of the conversation becomes a bit stilted.

Especially when more comments were to follow. From which I can summarise that the speaker feels that women (“girls”) ought not to study physical sciences or engineering as the pace of these subjects in future working environments (at least he permitted the thought that a female might work in such an environment) would be difficult, what with having to take breaks to have children, and care for both the young and the elderly of the family.

I decided not to doggedly argue the reverse case, because I did not feel like insulting my male friends in similar fields, by implying that they are less capable of taking care of family members, or showing the responsibility and maturity required to raise children. Which is effectively what would have become of it if I have indulged my argumentative vigour.

Or, I am a massive wimp, for not dismissing customs and going with gut-feeling.

Science in the Alternative Media

Would it be possible to teach children science and engineering, and the joys of it all, by letting them watch television? In fact, I am willing to put a wager on the fact that a good number of pupils would rather listen to a stereotypically attired professor on the screen, showing them exactly the same equations and going through the same nomenclature as their teacher, than be an audience for the real thing. Most of the time, at least.

Having stepped into the shoes of a science teacher, I now have even more respect for them than I did as a gawky student; and I realise why teachers are vital – a real person can answer back, stimulate conversation and actually be spontaneous. However, television does bring great opportunities to sneak more science into the “background” of life, and in creative ways. Naturally, such a television viewing experience caused this post. I watched “James May’s Toy Stories” when it first came out, greatly enjoyed it, and was delighted to find a special episode featuring a retrial of the one mission that had failed. (I should explain for the uninitiated amongst you that in each episode, a classic toy (think Lego) was revived, and used on a very large scale (think building a real house).)

On the surface, there are model railway enthusiasts, Brits, Germans, engineering on a 1:87 scale, whisky, beer, healthy competition and ice cream. What more could you want? Though if you think about it, a whole host of scientific or engineering topics had been explored. From the engineering point of view, the viewer was treated to explanations of steam trains and the workings of “coal power”; electric trains and why you should be cautious of how many volts you feed into the vehicle (to not burn the engine out); and the the newly invented contraption – the “track-o-matic”, where we were shown a nearly Goldbergian (cause and effect) process of how the model rail-tracks were laid at the same speed as the machine was pulled forwards. From a scientific point of view, each team were to create a brand new way, with yet another backup, to propel a model train along the railway. Things explained were: hydrogen cells and their storing abilities; alkaline cells and why they are better than regular batteries; how to distil fuel from sauerkraut, etc….

I may still be a gawky student inside who enjoys these things, but surely this could be used as a format in which to being more science to the public?

Why magnesium does not make the Earth orbit the Sun

Well, magnesium probably does play a part in keeping Earth in its orbit, but the chemical compositions of both the Earth and the Sun do not contain enough quantities of magnesium for it to be of significance. [1]

No, what I am getting at here is the force that keeps Earth in its orbit, GRAVITY.

GRAVITY

• If you are five years old and, more likely than not, reading this with mummy and/or daddy, all you need to know about gravity for now is that it makes things stick to the ground. Gravity is something that, unfortunately, makes a dropped ice cream fall to the floor; but it also keeps you from floating away uncontrollably if you jump up.
• If you are ten, you may know that gravity is a force, that does not only exist on Earth, but also on other planets and stars. The gravitational pull of the Moon is what gives us tides on Earth.
• If you are fifteen, and doing GCSEs if you live in England, it is time to get to grips with some equations and numbers*; but first…

The gravitational force attracts things with a mass to each other; whilst standing, the Earth pulls you   towards its centre (down), although the surface (ground) prevents you from sinking in. At the same time, because you have a mass too, you are pulling the Earth towards your centre of mass as well. However, due to the fact that Earth is so much larger, you can barely notice the Earth move.

Gravitational force increases when: [2]

1. the masses of the objects involved increases
2. the distance between the objects decreases

This centre of mass I am talking about is, for any spherical (round) object, is essentially its centre. On an object that is not spherical, this becomes a little bit tricker, so we shall not look at it right this moment.

"Down" is the same direction everywhere on Earth.

• If you are twenty, you will either already know all you need about the gravitational force for your field, or you will have associated yourself enough with the quantum world to completely lose interest in gravity.

As gravity increases with the object’s mass, it is the reason why you and I stick to our planet Earth, and (partially*) why the Earth stays nicely in its orbit around the massive Sun.

*The equation and numbers, as well as the explanation of “partially” be our next focus.

[1] Chemical composition of Earth, Venus, and Mercury; John W. Morgan and Edward Anders; Proc Natl Acad Sci U S A. 1980 December; 77(12): 6973–6977

[2] BBC Bitesize, KS3 Science, Forces and Motion (accessed on publishing date)