Archive for February 2010

Want some salt with your Fission Chips?

February 28, 2010

Nuclear Fission is an amazing process. With a fuel that is inert (even enriched uranium won’t burn in a flame), the input of a single neutron can cause the release of more energy than tonnes of explosive.

How does a single neutron do this? A single neutron initiates a reaction which causes the release of more neutrons, each of which can initiate further reactions. This process is called  a chain reaction, as the individual events in the reaction are caused by previous events.

You can envision a chain reaction as a snowball rolling down a mountain, picking up more and more snow until an avalanche is unleashed.  You can model how a single change can cause a cascading sequence of events by playing this game (Can you beat my top score of 1170? Provide a screen shot if you expect me to believe you!).

So what does a chain reaction look like? Well, because of the size of the particles involved, the speed and energy of the reactions, we can’t actually see the individual events (fissions). If you want to see what it looks like, check the Tsar Bomba update on the Boomology post. We can theorise what they look like from what we know how they work, and we have various simulations:

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Troubles with Tri…angles

February 28, 2010

Warning: Geek Alert!!!

You have been warned – any damage to your social status is your past this point is your own responsibility.

You have been warned!

In an original series episode of Star Trek, the crew of the Enterprise encountered cute little balls of fluff – called Tribbles. Listen to them:

These “Tribbles” had one downside – they were T.R.O.U.B.L.E – the episode was called “The Trouble with Tribbles” and that trouble was that they never stopped breeding – until all the available space was occupied by tribbles.

This is similar to Pascal’s Triangle – it goes on forever and takes up every last little bit of space. Each line is longer than the last and ocntains bigger numbers:

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Boomology – The science behind nuclear explosions (updated with Tsar Bomba!) (updated again!)

February 16, 2010

The world was changed forever in 1945. The Manhattan project tested the first ever “atomic bombs” and the power that was contained in the nucleus was unleashed. The first ever atomic bomb blast was a test called Trinity, detonated on July 16th in New Mexico, USA.

It was called “The Bomb” and its effects still change the world today. The “nuclear powers” of the world are those nations that have (or are suspected to have) nuclear weapons. Ever since the first military detonation (Hiroshima), the nations of the world have sought to prevent the further spread of this deadly technology. Depending on who you consult, you will get explanations ranging from desire to maintain the nuclear nations’ political power through to altruism to remove the risk by destroying all nuclear weapons. The total nuclear arsenal of all nations is more than enough to destroy all life on earth many times over. Despite this danger, some argue that the nuclear bomb technology has been the greatest force for peace in modern history; that without it many more conventional (non-nuclear) wars would have been fought, or that World War two may have continued for many more years, resulting in even more loss of life.

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How big is big?

February 15, 2010

The metric system is a very useful way of having a common system of relation between units of different sizes. The metric system was originally proposed by an Englishman, but didn’t catch on. It was later introduced in France and has since spread across almost the entire world (see the history of the metric system), except for the U.S.A and Myanmar (but scientists across the world all use metric). The advantage of the metric system is common conversion rates – every unit is related in multiples of 10, which makes it easy to convert between different sizes. It wasn’t always so easy:

LENGTH

12 lines = 1 inch (in.)
12 inches = 1 foot (ft.)
3 feet (ft.) = 1 yard (yd.)
7.92 inches = 1 link
25 links = 1 rod, pole or perch
16½ feet = 1 rod, pole or perch
yards = 1 rod, pole or perch
4 poles .. = 1 chain
100 links = 1 chain
22 yards = 1 chain
40 poles .. = 1 furlong
220 yards = 1 furlong
8 furlongs = 1 statute mile
5280 feet = 1 mile
1760 yards = 1 mile
2240 yards = 1 Irish mile
3 miles = 1 league

Now that’s confusing! All the different conversion factors makes for such a mess – trying to remember what you multiply by to convert one unit to another is just messy! It makes it much more easy if you can just move the decimal point in order to change between relative sizes by multiplying or dividing by ten.

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You can’t dodge this…

February 13, 2010

Matrices are a core part of Mathematical Methods – there is no way to avoid (dodge) this! You must learn the basics of matrix arithmetic (adding, multiplying by a constant, multiplying by another matrix, finding the determinant and inverse) and matrix algebra (solving for an unknown using inverses, managing transformations through matrices)

So what do you have to do to “Enter the Matrix” and make it your plaything? Well, the basic arithmetic and algebra are fairly simple – but you do need to practice – you familiarity with matrices should be the same as your skill with basic timetables – they are the same. Just like junior mathematics was based of simple timestable and basic algebra, Mathematical methods is based on the skills you develop through familiarity with matrices.  So get cracking!

Here are two powerpoints that will help you get a handle on working with matrices. Watch all of the first one, but the second one goes further than you need to understand (don’t worry about shear transformations, rotations or the applications at the end) (unless you want to…) (in which case, please consider arranging for an appointment with the school nurse).

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Don’t get active, GET RADIOACTIVE

February 11, 2010

When “people” talk about radiation, it is almost always with concern. Whether it is “radiation from mobile phones/towers”  to “a bite from a radioactive spider” to “radiation from microwaves” the concern is always there. But what is radiation exactly?

Well if you use google and type in “define: radiation” the first response is:

Energy that is radiated or transmitted in the form of rays or waves or particles

So, for example, any object that gives off heat (a form of energy) is radiating! This means that you are a source of radiation!

But that’s not what we are talking about in this unit – we are specifically talking about nuclear radiation, which according to movies apparently causes things to glow green and possibly develop superpowers (exposing yourself to radiation to try and become Wolverine is not recommended!)

But this is not the way nuclear radiation actually works (suprise suprise, movies have gotten it wrong again. And again. And again! Maybe they should just give up…). Amazingly enough, after just two weeks of Physics, you know more about radiation than 90% of the Earth’s population!

Here is a slideshow that covers more than what you need to know (up to slide 34 is the end of the current topic)

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Outclassing your ClassPad

February 10, 2010

 

So you’ve got this new calculator. It’s not like the one you were used to…

It’s bigger. It’s got *less* buttons. It’s got a touchscreen. It’s weirder than an Iphone with every single app installed.

And you have to use it…

Well, around about now, you may be considering one of the following options:

  1. losing it
  2. breaking it
  3. leaving it in your locker
  4. Quitting mathematics and running away to join the circus

Well, there are other options – namely beating it at it’s own game, and making it do maths until it squeals. Making it do the maths you don’t want to…

That sounds more like it. How many times have you had to do things like solving equations (or even… shudder… simultaneous equations)? Fractions? Surds? Finding the equations of lines? Force your calculator to do it so that you don’t have to!

Get your game face on, and check out the following links to learn how to use you ClassPad:

  1. ClassPad Videos : This is the *best* – do these and you’ll have that calculator begging for mercy
  2. ClassPad Downloads: Lots of useful stuff here – including “Canyon’s Corner” a helpful question and answer section
  3. ClassPad Lesson: Lots of stepped through instructions to show you how to do things. Worth printing off and storing for future refernce
  4. ClassPad Software: Additional programs to make your calculator do even more than it already does
  5. ClassPad Solution: Links and information for even more
  6. ClassPad Instructions: Even more worked ways to learn how to torture your classpad into submission
  7. ClassPad E-activities: You can make you classpad helpful in other subjects too…

Have lots of fun, and I expect to see those ClassPads in every class