## Is the Wii Fit Actually Good For You?

So Wii Fit is pretty fun, and I do quite enjoy using it. However, does it actually make you any fitter? Is it any good for weight loss? Do all the new balance games actually make you better at balancing?

A study from the University of Queensland by Nitz, Kuys, Isles and Fu starts to look at the question. It clearly labels itself as just a starting point, and not anything to draw conclusions from, but it is the best we seem have for now.

I'm awesome at this game.

So, in fact the study used staff their friends from the physiotherapy department of Queensland university. They choose ten of them, all female and between 30 and 60 years old. (The journal it is published in is interested in the menopause.) They then got them to play Wii Fit for two 3-minute sessions per week, for ten weeks.  They were required to use activities in all four areas (Balance, Yoga, Aerobic and Strength), although the difficult level and intensity was up to them to choose and improve as they progressed.

They reported the balance improved, but remarked upon the similarity of the tests that the Wii made you do, and that they used. I suppose you could take this further and ask “Are they just getting good at a single test, or are they really getting better?”. I found whilst using Wii Fit that I got very, very good at particular balance games, but this didn’t seem to transfer well.

Strength was improved, although I must remark that Wii Fit doesn’t do anything too interesting for strength tests. A book would do just as well. It’s not even fun!

Flexibility and reaction time did not improve. The women in the study did lose weight (although looking at the results, I don’t think very significantly although they do not explicitly say this), although they all also ended up exercising more in other ways. Perhaps this means that it is good at motivating you? It’s not really possible to say things like that, I suppose. However, none of the subjects reported actually feeling more healthy.

So it seems like the Wii Fit can be good for your balance, but is less likely to be helpful in actual weight loss. It might help motivate people, too.

It is probably worth noting that another experiment looked at Wii Sport games (as oppose to those that actually use the balance board and are made for fitness purposes). Graves, Stratton and Ridgers et al. looked at if young people can claim that using the Wii is part of their exercise routine. The answer is: No. Especially if you are a girl.

And if it is interests you, it looks like Wii Tennis is about 2 MET units.

## Quantum Computing and Shor’s Algorithm

Quantum Computers allow new types of probabilistic algorithms to be developed that can solve complicated problems much more quickly, on average, than the classical techniques.

About 4 years ago I wrote about Shor’s Algorithm, which can be used to factorise numbers, for my A-Level coursework. I’m posting an adaptation of it here for anybody interested. It is definitely a much better introduction to the algorithm than any of the sources I used to research it!

There is also a little bit about Quantum Mechanics and possible ways of actually making a Quantum Computer, although the descriptions are neither very accurate nor in depth. It isn’t really the point of it though, it is just there to make it stand-alone.

The Daily Mail, an appallingly bad British newspaper, published a list of questions that parents struggle to answer from their children. The survey it was from is unnamed, but it claimed to have asked 2,500 parents. This image from the article summarises them:

I’ve had a go at giving some answers, but they aren’t detailed answers. Unanswerable questions and ‘Where do babies come from?’ are ignored. The latter merely because it isn’t hard to answer, just awkward.

A common way is as follows: Get some sort of wheel to move. This could be a water wheel, or it could be from evaporated water from burning coal or from a nuclear reaction. The wheel then rotates a wire around the magnet (or rotates the magnet instead). When an electrical conductor cuts a magnet (when it is moving perpendicular to it) an electrical current is generated.

What are black holes?

Black holes are things in space that has such a strong gravitational pull that not even light can escape from its gravitational field.

What is infinity?

Maths is free, infinity is whatever you want it to be 🙂

Why is the sky blue?

Some light is absorbed by particles in the sky before it reaches our eyes. Light of all wave lengths is emitted from the Sun, but those with a smaller wavelength are absorbed more. Blue has the least wavelength of all, and so it gets absorbed the most. It then gets re-emitted in any direction. As you can see blue light from any angle, the sky looks blue.

So the sun itself looks like the colours that are left: Red and Green. Red and green light together looks yellow.

Why do we have a leap year?

A day is 24 hours and there are 365 days in a calendar year. The problem is that in a solar year there are actually about 365.25 days. Thus every four years an extra day is added in order to sync the calendar and the solar position together, so that seasons fall at the same time every year.

In fact, it is a bit less than 365.25 days for a solar year, and so some leap years are ‘missed out’.

How do birds/planes fly?

By the upward force caused by air moving under their wings, and the forward force eventually caused by the air flowing over its wings.

Why do onions make you cry?

When you cut up an onion, you let various chemicals in it mix together. They react to form a particular chemical that can react with the water in your eyes to create sulphuric acid, which burns your eyes! So when the chemical gets in the air and gets to your eyes, it stings, and so your body releases more tears in order to protect your eyes.

Where does the wind come from?

Air on the earth keeps getting heated up, or cools down, for various reasons. When air cold air and hot air are next to each other one moves above the other and winds are formed.

Why is the sea salty?

It comes from eroded rocks in the sea and in rivers that feed the sea.

How big is the world?

One way of finding this out is assuming it is a sphere and measuring the curvature. You find out the diameter is about 8,000 miles. You can work out from that it is about 25,000 miles to go around. You can also work out that it is about 200 million square miles.

Britain is about 95,000 square miles, and so the earth is 2,000 times the area of Britain.

What is a prime number?

It is a positive whole number such that only itself and 1 are divisors. 1 is not counted as a prime number.

They are important as every number is the product of prime numbers in a unique way.

What makes thunder?

The lightening heats up the air around it very quickly. As it moves away, it makes the thunder noise.

To keep them from becoming dry and also to try and prevent bits of grit getting in them.

Where does water come from?

Water is not really used up (in general), and so we just keep reusing the water that has always been on earth.

## Book: The Science and Politics of Global Climate Change

The Science and Politics of Global Climate Change: A Guide to The Debate‘ (C.U.P) by Dessler, a professor in the Department of Atmospheric Sciences at Texas A&M University, and Parson, a professor of Natural Resources & Environment at University of Michigan.

This is a simply written book explaining Climate Change in a scientific manor, which is beyond the quality you will find in books on the ‘Popular Science’ shelf, and of course it is written by scientists and not journalists. I found the second half of the last chapter, on the politics of it, slow and boring reading, but apart from that it was all very interesting, particularly the earlier chapters.

The second edition is out in March which will have a longer introduction to the science. No science knowledge at all is needed really. All technical language is explained.

There is no doubt at all that the earth is warming up, and it certainly seems as though it is caused by humans. Once this is established by reference to various data sources and other explanations (with strengths and weaknesses explained) it moves on to what should be done about it.

It won’t help some people though. To quote from a recent Telegraph blog written by an idiot:

[F]raudulent scientists have gained millions of pounds by taking selective samples of natural climate change, whipping up a Grande Peur and using it to advance the cause of world government, state control and fiscal despoliation of citizens.

2010 should be the year when all that ends. It is time for Zero Tolerance of [Anthropogenic Global Warming] fraudsters and their political masters.

Probably for people reading such conspiracy theories this book is more relevant.

## XKCD: Dimension Analysis

Just a verification that the units work and also evaluating the value:

Energy: This is measured in Joules, which are:

$\rm kg \cdot m^2 \cdot s^{-2}$

Pressure at the Earth’s core: This is a pressure, and so measured in Pascals. Pascals are in fact Newtons per Metre squared, or:

$\rm kg \cdot m^{-1} \cdot s^{-2}$

Gas Mileage: This is the amount of distance it goes per amount of petrol in the car. Therefore it is metres per cubic metres, or:

$\rm m^{-2}$

Distance: Distance is just metres.

Therefore the units of the equation are:

$\frac{\rm kg \cdot m^{2} \cdot s^{-2}} {\rm kg \cdot m^{-1} \cdot s^{-2}} \times \frac{\rm m^{-2}}{\rm m} = \frac{\rm m^{2}} {\rm m^{-1}} \times \frac{\rm m^{-2}}{\rm m} = \rm m^3 \times \rm m^{-3}$

Which is of course dimensionless. Now what about the actual values?

Planck Energy: Wikipedia puts it at 1.956×109 J

Earth Core Pressure: Wikipedia puts it at between 330×109 Pa and 360×109 Pa

Prius Mileage: The American Fuel Economy website puts it at about 50 miles per gallon. Google can covert this to 21×106 m-2

Minimum Width of The English Channel: Answers.com says, via it’s Columbia Encyclopedia source, that 34×103 m is the minimum width.

Putting all this into the equation gets a value of around 3.6. Which is certainly near enough!