Defence Science Revealed

Friday was the grand opening of Defence Science Revealed (DSR), an exhibition at the Science Centre Singapore showcasing all the technology used in the modern military!  It was co-organized by DSO National Laboratories, Singapore's research institute for defence science, to celebrate its 40th anniversary.

"40 Years of Serious Fun"

                                          - DSO 40th anniversary slogan

I couldn't exactly escape from work on Friday to go see this, so I made a trip down on Sunday instead, to find SCS surprisingly empty!  Weird.  I've been told the primary school kids are still having exams, and the secondary school / JC kids probably think they're too cool for the Science Centre.  Anyway that meant more space for me to poke around so it's all good.

DSR covered 3 main areas of military technology - Stealth & Surveillance, Aircraft & Bombs, and Armour.  

As part of the Stealth & Surveillance exhibit, there was a spot-the-tank game!  It gave you the option of looking at a scene using visible light, a thermal camera, and a hyperspectral camera to try and spot enemy tanks and howitzers etc.  I clearly have not played video games in far too long because I was beaten by a 6-year-old kid and could only spot 5 out of 12 enemy machines -_-".

Anyway this is cool because a hyperspectral camera is special!  Instead of just seeing in Red, Green and Blue like our eyes or normal digital cameras, it sees in many more wavelengths, including UV, near infrared, thermal infrared etc.  For example, if you try to camouflage a tank by painting it green so that our eyes cannot see it, it may still emit different amounts of UV compared to the trees around it.  So if you look at it with a UV camera, you will be able to see the tank clearly!  By combining many different types of 'cameras' together to form a hyperspectral image, it becomes very difficult to hide a tank.

We can see this very clearly in the next exhibit, where they try to hide a fake plant among real plants:

These all look like plants right?  There's no way to tell which one is fake from so far away... or so you think.

Using a hyperspectral camera, the plant in the bottom left looks obviously different!

In order to discover these hidden and camouflaged equipment from space, Singapore needs to launch a hyperspectral camera into space.  BUT, until last year, 2011, we had never built and launched a satellite into space before!  Our very first home-built satellite, called X-Sat, was jointly built by DSO and NTU, and houses a regular camera that can be used to monitor the weather, but isn't powerful enough to spot tanks in a jungle yet.  Hopefully we'll get there soon :).

Now you see me, and now you still see me, but the camera doesn't.

Here we have yet another example of camera technology: the screen shows an image taken by a thermal camera, the kind they used to scan people for fever during SARS.  In the picture on the left, the 'windows' are blank, giving the camera a clear view of me.  In the picture on the right, I closed a sliding glass window, and suddenly my top half disappears from view in the thermal camera, even though my digicam can see me just fine!  

This is because a thermal camera measures thermal infrared light.  Glass is transparent in visible light, but opaque in thermal infrared light.  It absorbs all the thermal infrared light and prevents my thermal signature from going through and getting picked up by the camera, rendering me 'invisible'.  Spiffy!

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The next part of the Stealth and Surveillance section was Radar.  In case y'all thought radar is a word, it's actually an acronym: RAdio Detection And Ranging.  As anyone who's watched a war / action movie will know, you use radar to tell the location and speed of vessels like aircraft and ships.  But how?

Here's a demonstration on Doppler shift, which also tests your ability to throw balls far, fast and accurate.  All of which my companion and I failed spectacularly at.  Basically you throw the ball, and the camera on top can detect how fast it's moving by emitting one frequency of sound (or I'm guessing it's sound since we can't really throw balls fast enough for light), and measuring the frequency of the reflected sound.  As the ball moves quickly away from the camera, the reflected sound waves get "stretched out", resulting in a lower frequency / pitch.  If the ball were moving toward the camera, then the frequency of the reflected sound gets higher, as you can see in the simplified diagram:

This works the same way for radar, except that it uses radio waves instead of sound waves.  There was even a nice little animation showing how the radio waves reflect off aircraft in the sky, and how the signal changes depending on how many aircraft there are, how close they are, and what algorithm you use to interpret the signal.  You should head down to Science Centre to check it out!

We see it's really hard to identify two separate echos, but with some math magic, it can be done!

Of course, knowing all these ways to find hidden things means we have to learn to hide them better.  Enter the camouflage/stealth materials!  Using a range of materials with different shapes, electronic and magnetic properties, it's possible to reduce the reflection of radio waves, and be a little more 'invisible' to enemies.

 

Modifying the shapes and materials of vehicles can help evade detection by radar, but they must also be compatible with camouflage in other wavelengths of light!

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So all this defence science was getting a bit tiring by afternoon, so at 3pm, we stepped out to watch the daily Fire Tornado show!  It's a visually stunning performance, but honestly not very much science.  Basically if you light a fire under a spinning column of air, the fire will get 'sucked up' the column to make it look like the tornado is really on fire.

You can see a real life example of this when a tornado swept over an Australian bushfire:

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The second section of DSR was "The Science of Flight", which I prefer to think of as Planes & Bombs, but I kind of skipped over it because it was mostly about aerodynamics and very little about defence.  There's a nice activity room in the back that lets kids fold their own paper planes and shoot Styrofoam cups with airzooka guns though!

The third section was about Armour, which you can imagine would be pretty cool if one could actually demonstrate their ability to avoid destruction when faced with all kinds of artillery and bombs.  But alas most of the exhibits were either posters or replicas, with few interactive activities.  

They explain why the fronts of tanks are sloped and why some have cages, and they show animations of all the newfangled artillery which explode and deform in creative ways to maximize penetration through the steel and armour.  Generally not a very happy thought if you were actually in the battlefield, but very cool in theory.

A model tank which housed the video presentation about different armours used in vehicles in combat.

Scale replicas of projectiles designed to pierce through more than a meter of steel.

Bulletproof glass!  Really thick and made up of many layers, like a seashell.

I liked looking at the bulletproof glass because it's very similar to the demonstration teachers often do in high school to show why sea shells are so strong despite being so thin.  If you can find a nice spot of floor at home that won't crack when whacked with a hammer, you can try this at home:

Simulating regular glass:

1. Take a large block of ice roughly tissue-box sized, but half the thickness.
2. Whack it with a hammer.
3. Watch it fracture into smithereens.

Simulating bullet-proof glass:

1. Take the same tray and freeze a ~1cm layer of ice.
2. Lay tissue on top of the frozen layer, then pour another ~1cm of water on top and freeze.
3. Repeat until same thickness as original block used above.
4. Whack it with a hammer.
5. Keep trying.

It's a fun experiment to play with, and a good way to taunt boys when you let a girl hit the first block and a boy hit the second.  Even though both ice and tissue are fragile, the block is incredibly strong, because the layers of tissue prevent the crack from going all the way through and breaking the block.  You thus have to hit the block as many times are there are layers in order to crack through the whole thing, and even then, you may not succeed.

DID YOU KNOW that sapphire is far more useful than as a piece of shiny jewelry?

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There was a good deal more at DSR that I didn't upload, because if I did, you wouldn't have to go see it then, would you?  

The exhibition runs till Feb 2013, so you have plenty of time, but you would want to either go real early or real late to avoid the school holiday crowd.

Join us for some Serious Fun.

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Budget!

Sci. Ctr. + DSR + Candy Unwrapped - $12 (adult), $8 (child up to 12)

Sci. Ctr. + DSR + Candy Unwrapped + Omnimax - $17 (adult), $11 (child up to 12)

Sci. Ctr. + DSR + Candy Unwrapped + Snow City - $20 (adult), $18 (child up to 12)

Notes:  

*If you are a Science Centre member, you still need to pay for a ticket to DSR ($8).

*If you are an NSman with an 11B card, you get into DSR for $2.

*You should get an Omnimax package because Ring of Fire and To the Arctic are awesome.