Wednesday, August 11, 2010

First Birthday Celebrations

Our little man turned one last week!
Click here for some details and lots of photos.

Monday, August 9, 2010

Romans series

Blogging through Romans is proving much more difficult than anticipated. I ended up substitute teaching at church4kids on Sunday morning, so I missed another sermon, and they don't seem to be on the website. But more than that, I've having trouble finding the time (and realistically, the inclination) to get my thoughts organised enough for blog posts.

I'll try to post a few random thoughts as the series goes on, but don't expect anything regular or profound. Just pray that I would gets lots out of the series, whether I blog about it or not.

Saturday, August 7, 2010

Home Alone

I'm alone in the house.

It's very strange.

I can probably count the time I've been at home alone in the last year on one hand. Today, Dave & SP have popped to the park for some fun, while I finish off a photobook.

It's lovely, but I miss them.


Friday, August 6, 2010

National Engineering Week - Special Edition

Over the last four days I've tried to share a little bit about the different facets of engineering and how it affects people on a day to day basis. What I hope you've gotten out of it is that engineers are very useful folk to have around, even if our contribution to society is not as immediately obvious as doctors and teachers.

To wrap up the series I want to try and give a brief introduction to microwave engineering, which is my field of professional interest. Microwave engineering is all about the generation, transmission, detection, and processing of signals at microwave frequencies. What are microwave frequencies you ask? Anything from 300 MHz to 30 GHz is considered microwave. 30 GHz to 300 GHz is considered millimetre wave. The reason for this is that at 30 GHz, the wavelength of the signal (i.e. the distance between one peak and the next) is 10 millimetres. Below microwave frequencies we have radio frequency in the 30-300 MHz range. Oh, and MHz is short for megahertz, which means the signal goes up and down one million times per second. GHz is short for gigahertz - one billion times per second. In perspective, humans can hear frequencies from around 80 Hz up to 40 kHz. Concert pitch, or A-440 is 440 cycles per second.

Some situations where people use microwaves:
- FM radio (RF, around the 100 MHz region)
- cordless phones, mobile phones, bluetooth and any of your wi-fi/wireless network connections (anywhere from 900 MHz to 5.4 GHz depending on what it is)
- GPS navigation (around 1.3-1.5 GHz)
- Microwave ovens
- Point to point communication links (the dishes that look like a squat grey cylinder on the side of buildings and TV towers)
- Police radar
- Weather radar
- Vehicle anti-collision radar
- Air traffic control radar
- Military radars

My work is mostly related to the last item on the list. In the military environment there are basically two groups of microwavers. Those on the radar side, who try to generate signals to find and track other ships/aircraft/whatever, and those on the countermeasures side, who try to pick up the radar before it sees you, or send out a fake signal to make the radar think you're somewhere else.

I don't actually build the systems that do those sort of things. The company where I work builds some of the components that go into those systems. It's interesting, and it's challenging because not only do you have to deal with very small spaces (I know aeroplanes look big on the outside, but there's not much space inside for this sort of thing) you also have to deal with severe environmental conditions like very high temperatures (85 Celsius is normal), very low temperatures (it gets down to below -40 Celsius at cruising altitude), dust, salt, vibration, and high shocks (like when a missile hits a few metres away, or when an aircraft launches from a catapult).

The observant among you would also have noted that I mentioned photonics a few days ago. Photonics is a branch of fibre optics, using light waves to transmit and process these signals. The cables that make international phone calls and the internet possible are all fibre optic cables now. The infamous national broadband network (which is a great concept turned into a stinking mound of sewerage by the government and beauraucrats) also uses fibre, lots of it.

Naturally I think all of the above are some of the great things that microwave engineers are involved in. When we get things wrong they're not usually as spectacular as a bridge falling down, but still worth acknowledging. The microwave mortuary has a lot reports, scroll down to an entry from late 2006 for one that I'm quite familiar with... Warning: this page has heaps of photos so will take a while to load, even over broadband.

So there you have it. Engineers are everywhere, doing all sorts of stuff. Like doctors, we're very useful unless we make a mistake, which tends to upset people.

Thanks for reading.

Thursday, August 5, 2010

National Engineering Week - Electronics

In yesterday's post I said that electrical engineering is all about electricity - power stations, transmission grids and HVAC were my examples. Trying to sum up electronics engineering in a single word is like trying to dig the Panama canal with a forked stick - it just ain't gonna happen. Suffice to say, electronics is all the other stuff that uses electricity.

So examples that affect your daily life include: the computer or phone that you're reading this blog on, all the background stuff that makes the internet work, your TV, radio, wristwatch (unless you wind its mechanism every day by hand, it's got electronics in it), digital cameras/video cameras, portable DVD players, speed cameras, red light cameras, smoke alarms, just to name a few.

Although computers are ubiquitous, to the point that even a cheap calculator has more computing power than the Apollo program, and you can buy programmable calculators with more power than could be dreamt of 20 years ago, I think wristwatches are one of the coolest applications of electronics. That's mainly because of an article I read on a flight to Adelaide a few years ago. It was an interview with one of the senior designers at Seiko, talking about all the things they did to make their top end (think 5 figure price tag) watches work. The accuracy of the components, the efficiency of the circuit - most consumer batteries work at milli-amp current levels. This guy could tell you where every micro-amp was used! (There are 1000 micro-amps in a milli-amp if you didn't know). Like a lot of higher end watches these days, it had a small solar cell and other cool tricks to harvest energy from its environment. I wish I could remember more about it, but when you finished the article, you could understand why the watch cost so much, it's an engineering masterpiece.

But electronics engineers still make enough mistakes... like the unintended acceleration problem with Toyota vehicles earlier this year, or Dell's exploding laptop, or the famous calculation problem with early model Pentium chips from Intel.

If you've ever had trouble understanding what I do for a living, come back tomorrow and read our final post in this series. It might help. A little. Maybe.

Wednesday, August 4, 2010

Fruit & Veg

I went to the GP yesterday, with a variety of (non serious) complaints. We decided (pending further tests), that it's probably just down to depletion of my body's resources, after pregnancy and a year of breastfeeding.

So my primary treatment is to eat more and eat better. I thought I was doing pretty well, but apparently not.

I just checked out the Qld Government Nutrition Guidelines, and the standard whilst breastfeeding is 5 serves of fruit and 7 serves of veggies per day! I'm pretty sure I haven't been hitting that target very often...

Just as well we get on well with our local fruiterer.

National Engineering Week - Electrical

We're half way through National Engineering Week and now we're starting to get to the stuff that I actually know something about. Only starting to mind you, the chasm between electrical and microwave/photonics engineering is just as big as between electrical and civil engineering.

There's also a distinction that I'd like to make between electrical and electronics. Electrical is all about electricity - power generation and transmission from power stations to users are the big ones, I'll also lump HVAC (which stands for Heating, Ventilation and Air Conditioning) in here too, since they usually use 240V AC (i.e. mains power, the stuff running around in the walls of your house).

Power generation is obviously pretty important, especially in western society. You wouldn't be reading this blog, or catching an electric train without it.

The transmission side of things is just as important though. The big thing with transmission is the concept of loss. Crudely simplified, the power station puts a signal onto the line at their end, but it's smaller when it finally gets to your end. The difference is what we call loss, and it's power that in one way or another is wasted. Now for you to be able to use the energy that you want, the power station has to put extra on at their end to cover the loss in the middle. The more loss, the more they have to do extra, and the more it costs everyone - especially you and me!

Because of this loss, a lot of research is going on into technologies like high temperature superconductors. A superconductor has much less loss than the cables we use today, which would be much better for the power companies. But there's a problem. For a while scientists have been able to make superconductors at low temperature. Really low temperature. Like a couple of hundred degrees below zero temperature. Which is not very practical if you want to get electricity from Tarong to Brisbane. The aim of HTS research is to find a compound that first of all works at reasonable temperatures (say, anything about zero degrees C) and second of all can be manufactured in the quantities needed to replace the current grid.

So what's spectactular about electrical engineering? Aside from actually generating power and reliably hooking up multiple power stations to users who are constantly turning things on and off, but without having the whole system fall over? Well, one example would be the solar power towers in Spain. They were also featured in Richard Hammonds Engineering Connections, which I mentioned the other day.

What happens when things go wrong in electrical engineering? Well, if you happened to be in a small town in the Ukraine on 26 April 1986, you might not have been very happy with the local power company. That's when the Chernobyl disaster happened. In all fairness to the electrical guys, Chernobyl was a result of many, many things going wrong, but since it's a power plant, it fits with today's theme. Another example - the power grid in the north east US can be a bit unreliable, as massive blackouts in 1965 and 2003 showed.

Tomorrow, we'll find out what makes electronics distinct from electrical engineering.

Tuesday, August 3, 2010

National Engineering Week - Mechanical

It's a coin toss to decide whether mechanical engineering is more or less prevalent than civil engineering. They have some definite overlap - both are dealing with concepts like static and dynamic forces (standing on a bridge versus walking on a bridge), bending moments (what happens if I put this much pressure on a beam which is so-many metres long, with a support at the other end? It bends...), and materials. I guess the easiest distinction is that mechanical engineers are usually more interested in things that move*. It's also been said that civil engineers build targets and mechanical engineers build weapons to break them.

Mechanical engineering shows up all over the place: cars, trucks, trains, aeroplanes, ships, bicycles, escalators, elevators, refrigerators, mining, just to name a handful.

Materials engineering is usually considered a subset of mechanical engineering, and is particularly interesting. Materials engineers do a couple of things. One, they take existing materials and work out what its characteristics are. That is, if I take a rod of material X, will it rust? Will it pass electricity? Will it pass light? How dense is it? Can I crush it? Will it bend or will it break immediately? When it breaks, does it send thousands of deadly projectiles across the workshop? Does it burn/explode/other cool but dangerous things?

Another thing that materials engineers do is to come up with improved compounds for existing materials, or brand new compounds that have certain desirable characteristics. The "composite materials" used in the new Boeing 787 are one example of this.

Like their civil cousins, mechanical engineers do some pretty spectacular things: aircraft carriers, ferraris, or my personal favourite, the Lockheed Martin SR-71 Blackbird.

Also like their civil cousins, mechanical failures can be difficult to hide, like the Hindenburg.

Tomorrow, electrical engineering.

*Not all mechanical engineers are interested in things that move. Where I work, things don't move but our mechanical engineers are very interested in things like how to get heat out, how to make it light but still strong enough to be bolted to an aeroplane, stuff like that.

Monday, August 2, 2010

National Engineering Week - Civil

Civil engineering is arguably the most long-standing of the engineering disciplines. I've been told that the name dates back to when they needed to make a distinction between military work and civilian work, but I don't have a citation for that.

You can't go a single day without relying on something done by a civil engineer. Roads, bridges, water supply, sewerage, shopping centres/office towers - they all fall under the civil umbrella. Even planning the sequence on the traffic lights to keep the traffic moving smoothly is usually a civil task.

Environmental engineering is a growing sub-set of civil engineering. As the name suggests, they usually deal with things like environmental impact statements and water quality.

Civil engineers do some pretty spectacular things, like the Milau Viaduct in Spain (featured in Richard Hammond's Engineering Connections, which just by the way is a fantastic show, even if you're not an engineer).

Of course, they're human and they don't always get things right... Footage of the Tacoma Narrows bridge collapse in 1940 is something that almost every first year engineering student sees.

Tomorrow, mechanical engineering.

Sunday, August 1, 2010

National Engineering Week

This week is Australia's National Engineering Week. In honour of that, I'll be doing a few posts about the different things engineers do. Although my particular field is microwave & photonics I'll also be posting on the contributions of our friends in the civil and mechanical arenas, as well as more about electrical/electronics.

If you've got any questions about engineering, now is as good a time as any to ask them. I can't guarantee that I'll have an answer, but you never know ;)