A bit about space physics

Next post, I want to tell you a bit about space physics, what it involves, and why it's important. Firstly, you need understand a bit about the Earth, and the sun, and how they interact. The sun provides us with the light which we need to survive. It makes it warm so we can enjoy ourselves at the beach, and there is nothing better than the suns warming rays after you have been really cold. The sun gets its energy by fusing hydrogen atoms in its core. That is what happens in a hydrogen bomb. A whole lot of radioactive particles are created in this process (stuff that are really bad for us). The sun hurls these radioactive particles out in all directions, at 400km per second (up to 800 km per second when the sun gets angry). This is called the solar wind, and the Earth is constantly bombarded by it.

The earth would be cooked, if we wernen't protected by the Earth's magnetic field. The Earth's core produces a magnetic field, similar to that created by a bar magnet. It's what makes a compass point towards (magnetic) north. The picture below shows what this magnetic field looks like.

Well, thats what the field produced by the Earth would like, if it wasn't hit by the solar wind. In reality, it looks more like this:

Notice how the field on the side of the Sun is all squashed up, and that away from the Sun it is all stretched out? This is a pretty drastic change to the magnetic field. Also, as the solar wind speed changes, such as after a solar flare where particles are shot out in much higher quantities at a much higher speed, it causes a drastic compression or expansion of the magnetic field. Faradays Law says that a changing magnetic field will induce a current in a conductor. So one consequence is that electrical currents are created in our power lines. If the current in these power lines become too great, they can cause the lines to melt. One thing which space physicists do is to monitor the Sun, trying to predict such solar flares, to warn power suppliers. One thing to look out for is the occurrence of sun spots. More sun spots means there is a higher chance of a solar flare. The power suppliers will then reduce the current in power lines, to minimise the risk of them burning out.

In 1859, the largest solar flare ever recorded hit the Earth (http://en.wikipedia.org/wiki/Solar_storm_of_1859). This caused ALL the telegraph wires in the US to melt. If this kind of thing had to hit us today, global power supply would likely be destroyed.

Not all of the solar wind is diverted by the magnetic field. Some of it penetrates past the barrier, and becomes trapped in the field. These particles then travel along the magnetic field and interact with our ionosphere and atmosphere. This is what causes Aurora (the northern and southern lights). Another effect of this is modifying radio propagation conditions (radio signals reflect off the ionosphere). Ham radio operators often keep track of solar conditions for this reason. These particles have all kinds of other effects as well (there is evidence that they even trigger lightning strokes).

As you can see, our magnetic field is incredibly important. Scientists believe that Mars was once a planet like ours, with water, and a breathable atmosphere, but when its magnetic field died, the solar wind began to erode away its atmosphere. This may sound familiar if you have seen the movie, "The Core".

This post was just a heads up, hopefully alerting you to the hazards of our closest star!

My first blog (and its first post)

Well, I have had very limited experience in blogging, having blogged twice only because I had to, and even then it was on some obscure server which 20 people have access to (and only a fraction of them even try to access it). So, having seen some peoples blogs, I decided that for me who has alot of stuff on my mind, this would be a great place to get it out.

Seeing as how its my first blog, lets do an introduction. I am a Phd student, studying space physics in Durban, South Africa. Since most of my (work) day is consumed by space physics, a lot of my blog will be flavoured with space, and general physics. Also, because I consider myself a nerd anyway (or geek, depending on your interpretation) , there will be a generous helping of nerdiness in this too.

I am a 20-something year old male (for the next five years anyway :P), and I enjoy reading, watching cricket and rugby, computer games (Starcraft 2!!!), geo-caching (I'll explain what that is later) technology, music (and playing it) and of course, science!

Something I get asked a lot is, "Are you going to be a rocket scientist one day?". This question can be rather annoying, because space physics (believe it or not) doesn't actually involve much of space. Astronomy is the study of stars, galaxies, black holes, the big bang and stellar evolution. Space physics, is quite plainly, the study of the Sun, and how it affects the Earth, and the space nearest us.

That will do for now. Looking forward to getting more stuff out there soon, and for now, I think a more in depth look at space physics will be required... later.