I recently made a short film for the Royal Institution that tells a story of the miners safety lamp, also known as the “Davy Lamp” – invented by Sir Humphry Davy in the 19th Century.
The lamp was designed to allow miners to safely light their way in the mines using candles or oil lamps – which were previously at risk of igniting flammable gases that leaked from the coal baring rocks, often leading to devastating explosions and large loss of life.
Find out more by watching the video!
This is the first time we’ve explored an archive story through the format of Andy’s Tale’s From the Prep Room series and I really like how the historical narrative is combined with the usual demonstration elements of the series – it’s something we’ll think about doing more in the future.
Riffing off the film’s subject matter, I thought I’d experiment with shooting most of the film in candle light in a pitch black environment – which was made possible by the low light capabilities of the Sony A7s, combined with a very fast vintage lens (Takumar 50mm f1.4). I really love the intimate setting that this creates and it also helped to hide the fact that we shot this in a very dull location (the Ri’s windowless basement lab used for school workshops).
Slow motion footage was captured on the Panasonic GH4 at around 100fps – watching the flames billowing out of the gas filled tube is particularly mesmerising!
Christmas is over – but here’s a very quick film I put out just before the holidays:
The glass baubles (unused props from the 2012 Christmas Lectures) were each sealed with a tiny amount of water inside. As the water was heated under pressure it boils at a higher temperature and when it does evaporate within the sealed space, the internal pressure builds until the glass structure fails. At this point the water (heated beyond it’s normal boiling point under atmospheric conditions) flashes into steam with explosive force and the bauble is shattered into a shower of glass fragments. All this happens extremelyquickly, you hear a loud bang and then see a shower of glass – far too fast to be seen by the human eye (or a camera shooting at 25 fps).
It requires the muscle of a specialist high-speed camera to really catch a glimpse of what’s going on here. For this film we used a Phantom v1610 – which provided extremely high frame-rates, just what you need to get a better glimpse of the action! However, even at a blistering 34,000 fps you can see just how quickly the explosion event occurs – within the space of 1 -2 frames! A rough calculation shows just how fast this is, with one frame at 34,000 being the equivalent of around 29 microseconds in real time, that’s 0.000029 seconds!
You can see the unedited footage below:
As you increase the frame-rate on these cameras, you’re reducing the amount of time each individual frame is exposed, so you need to shine a lot of light on your scene with the higher frame-rates in order to see anything. As you go up to the higher frame-rates you’re also capturing a lot more information and to handle this the camera usually has to lower the resolution – this provides a rather agonising compromise between capturing something at very high-speed and retaining acceptable image quality.
Regardless of this, the results were simply breathtaking and why wouldn’t they be? It’s like being able to slow-time down and observe our world from a totally new perspective. Watch this space for more high-speed footage over the coming year.
One of the great pleasures of working at the Royal Institution is witnessing the frenzy that goes on behind the scenes in the lead up to the Christmas Lectures. This year the lectures cover the chemical elements and are presented by Dr Peter Wothers, a fellow of the Royal Society of Chemistry and teaching fellow at the University of Cambridge.
The lectures themselves are available for a limited period on iPlayer, but will also be available to stream indefinitely on the Ri Channel, the team behind them have done an incredible job and so they’re well worth a watch – you don’t necessarily need any scientific background or knowledge of Chemistry to enjoy them!
Naturally this year’s subject lends itself well to the presentation of scientific demonstrations and there has been plenty of opportunity for loud bangs and fire spewing explosions. However, the lectures have also provided chance to perform some very rare and unusual demonstrations – and it’s these that have formed the subject of a couple of behind the scenes films produced for the Ri Channel:
Reacting Caesium and Fluorine (First time on camera)
Fluorine and Caesium are the two most reactive elements in the periodic table and so for the lectures, Peter was very interested in trying to react them both together. However their extreme reactivity also means that they’re both very dangerous to work wit, so it was important Peter found the right person to work with! Enter Dr Eric Hope a Fluorine specialist at the University of Leicester and so on a grey day in November we travelled up to see how this reaction might work and I think it might be the first time it has ever been caught on camera!
What was particularly nice about this meeting was that Peter had never previously seen Fluorine and Eric had never seen Caesium! This demo features in the second lecture, ‘Water: The Fountain of Youth’.
I was so pleased I got to see this demo with my own eyes, I’d previously heard a lot about cloud chambers and seen a few bits of ropey footage on the internet, but never actually seen one in the flesh (so to speak). It’s essentially a particle detector with a sealed environment that is supersaturated with alcohol vapour and as charged particles zip through the vapour they ionize it, allowing condensation trails to form.
It’s an absolutely beautiful thing to look at, as it makes visible the background radiation that exists all around us and on the last day of recording I was lucky enough to capture this close-up on camera:
This demonstration features in the third lecture entitled ‘The Philosopher’s Stone’.
Testing Hydrogen Balloons
Lastly, the Christmas Lectures wouldn’t be complete without some sort of gratuitous explosion and so here’s a little film about testing different sized hydrogen balloons:
Lighting a match with a single drop of water, sort of…
A break from audio related work – here’s a little video I made recently for the Ri Channel. It’s not exactly the most of significant of experiments, but when someone commented on a previous YouTube video asking whether it would be possible to ignite a match with a piece of Sodium and a single drop of water, we thought we should have a go.
The video was shot in a morning on a single Panasonic AG-HMC151, in the Royal Institution’s legendary prep room with demo Technician Andy Marmery.