White noise is what you get when you combine the complete audible spectrum into one incorporate sound. The name derives from white light, made of all the different colours (frequencies) of the visual spectrum. In the same way that a prism or a rainbow separates white light back into its component colours, white noise is a combination of all the different frequencies of sound. You can think of white noise as 20,000 tones all playing at the same time.
White noise is used extensively in electronic and synthesized music. It can be used directly or as an input for a filter to create other types of noise signals. Direct applications include synthesis of instruments such as cymbals which have a high noise ratio in their frequency band.
It is used to generate test tones for concert and performance venues. Short bursts of white noise are sent through a PA system which are then monitored with microphones and spectral analysis so an engineer can tell if the acoustics of the building naturally boost or cut any frequencies. It’s also used for frequency response testing of amplifiers and signal processors. The genre of noise metal also benefits extensively from copious amounts of white noise – a type of music you can only love like you would an abusive husband. Hella, a band hard to get into but harder to get out of.
It’s said that white noise can help aid both rest and concentration, as it can mask irritating noises such as tinnitus. It can sound like a rushing waterfall or wind blowing through trees. Devices known as sleep aids do not produce actual white noise, which has a harsh sound, but pink noise in which power rolls off at higher frequencies. White noise is frequently used to mask other sounds since the brain can not differentiate between the thousands of frequencies and the “voice next door”. Masking devices are often used to protect privacy by screening distant conversations, for example, in a psychiatrists waiting room.
This science lesson we celebrate the half century life of one of the most important inventions of the modern world. Already 50 years old the laser still evokes an air of the futuristic. Vitally important for the industry in which we operate not only does the laser take sound from CDs, read barcodes on tickets and illuminate the Discoteca every sunday but pretty much the whole communications world on which we rely so much is indebted to the use of lasers.
First Ever
On 16 May 1960 the first ever laser was operated by it’s designer and creator Theodore Maiman. A Ruby entwined within the coils of a photographer’s lamp stimulated by its flash released a pulse of pure red light. Because the beam was powerful enough to drill holes in razor blades, physicists measured its power in gillettes, or the number of blades penetrated.
Laser as a Weapon
As soon as the laser became real, military agencies and writers of fiction alike saw the comic-book ray gun made real and began to work on laser weapons. In 1964 arch-villain Auric Goldfinger threatened to saw James Bond in half with this “industrial” laser, at the time pure science fiction. Now with the US and China both with their fingers ready at the trigger of laser defense systems set up to protect against Inter Continental Ballistic Missiles the initial flights of fantasy have been way surpassed by today’s realities.
The Endless Blade
In industry, lasers are the saws and drills that never get dull. The first lasers to earn a wage did so by machining very hard materials, such as diamonds, or very soft ones, for example baby-bottle teats. Low-power lasers can cut and weld plastics; higher-power lasers can cut and weld metals. Early industrial lasers had to be big to be powerful, but new solid-state lasers are impressively small: today a length of thin optical fibre or a poker-chip-sized disc just a fraction of a millimetre thick can generate kilowatts, enough to slice a metal sheet a couple of centimetres thick.
We Love... Grace Jones' Lasers
To begin with, the laser palette was rather limited; the ubiquitous red beams produced using helium-neon and ruby lasers were only accompanied by those producing invisible infrared light for quite some time. The first to emit the rest of the rainbow were ion lasers, which used argon or krypton. Argon emitted blue and green light, krypton several other colours, and mixing the two gases made a laser that could emit across the visible spectrum. From this the laser light show was born evidenced spetaculalry by Grace Jones last year at We Love… Space.
The Ultimate Laser
The most powerful laser ever built comprises of a 192 beam system which when combined can create an energy pulse of a megajoule in a few billionths of a second. Designed to compress and heat nuggets of hydrogen isotopes the National Ignition Facility laser is heading the race for clean energy generation via controlled nuclear fusion.
So to end on a pun… In light of this anniversary lets focus on this video… Sorry.
There is something inherently satisfying about the sound of a pebble breaking the surface of a pond, so satisfying in fact that a few years ago certain DJs and producers encapsulated, mutated and repeated it to create the global phenomenon of ‘minimal’ techno. Having somewhat passed us by we found the sound more befitting of a misty spring morn, camping lake-side in the yorkshire dales than set in an overcrowded nightclub.
A thoroughly satisfying plonk requires a few certain conditions, calm water, a fairly weighty round pebble and a perpendicular entry path. Physicists at the universities of Valencia and Twente have been studying this plonk and have found that a sonic boom is behind it’s well rounded sound. When the stone enters the pond the first reaction is a cylindrical sheet of water called the “crown splash” which is sent up into the air encircling the falling object. Then the stone sinks and leaves in its wake a cylindrical cavity of air. The water surrounding this then begins to collapse in on it, starting at the centre, and creates an hour glass shape. When this form then collapses the result is a jet of air which shoots up the centre of the ever diminishing cavity faster than the speed of sound creating a miniature sonic boom. This combined with the slap of the the water collapsing in on itself gives rise to that sound synonymous with fishing holidays, walks on stoney beaches and, in cases where the falling object is not necessarily a pebble, certain trips to the w.c.
Burchberry Dogwood
It was in the 1950s that aircraft started to break the sound barrier on a regular basis and it wasn’t until 1969 that Concorde took the first supersonic commercial flight. Seen as a barrier there to be broken, Concorde undoubtably did so in the most grandiose manner; but the aircraft was not however the first human invention to cross the supersonic milestone. In fact this invention came from our cat loving friends the Ancient Egyptians in the form of a whip. The tip or a cracked whip will accelerate to speeds way faster than the 340m/s that sound travels at. For the mathematically minded we can see how the thinning and unfurling whip will increases to faster and faster speeds through the equation E = (m(v^2)) / 2. Something which the archaeological crusader Indiana Jones singularly failed to point out even with his copious use of whip and academic background.
And to find the first living thing to break the sound barrier you must venture into the forest covered Canadian Rockies in search of the Burchberry Dogwood, a small plant which spits its pollen out at nearly twice the speed of sound. The force which this plant generates is more than 800 times greater than that which is experienced by astronauts as they leave the earth’s orbit.
Nowadays unmanned craft and missiles can travel upwards of 20 times the speed of sound. Although pioneers in their own right, the designers of the weapons, the masterminds behind Concorde and minimal techno DJs are merely following in the footsteps of ejaculating plants.
This lesson we take a look at the exact science of gambling and probability. Over the years people have obsessed over systems and surefire ways of beating the odds; from Rain Man counting cards in the Vegas casinos to Derren Brown beating the lottery on live tv. Obviously some methods are more effective than others; find yourself a genius human-computer like Rain Man and counting cards at the Black Jack table is a pretty safe bet. Follow the advice of Darren Brown however and you’re more likely to end up trading hand-jobs for a crack fix in Skegness; probably.
If, like most of us, you’re not blessed with a massive calculator for a brain then counting cards is probably out of the question. There are other ways to guarantee a win however. Lets take a walk to the roulette table where a bet on red or black pays out at one to one (a successful bet of £10 will win £10 plus original stake). A spin of the roulette wheel is just like the toss of a coin. Each spin is independent, with a pretty much 50:50 chance of the ball landing on black or red. Contrary to intuition, a black number is just as likely to appear after a run of 20 consecutive black numbers as the seemingly more likely red. This randomness means there is a way of using probability to ensure a profit: always bet on the same colour, and if you lose, double your bet on the next spin. Because your colour will come up eventually, this method will always produce a profit. The downside is that you’ll need a big pot of cash to stay in the game: a losing streak can escalate your bets very quickly. Seven unlucky spins on a £10 starting bet will have you parting with a hefty £1280 on the next. Unfortunately your winnings don’t escalate in the same way: when you do win, you’ll only make a profit equal to your original stake. So while the theory itself is sound, be careful. The roulette wheel is likely to keep on taking your money longer than you can remain solvent. There are more calculated ways of gambling, leaving the casino let’s head of to the bookies.
Although each bookie will stack their own odds in their favour, thus ensuring that no punter can place bets on all the runners in a race and guarantee a profit, that doesn’t mean their odds will necessarily agree with those of a different bookie. And this is where gamblers can seize their chance. Let’s take, for example, the Oxford – Cambridge boat race. One bookie may offer 3 to 1 on Cambridge to win and 1 to 4 on Oxford. But a second bookie disagrees and has Cambridge evens (1 to 1) and Oxford at 1 to 2. Each bookie has looked after his own back, ensuring that it is impossible for you to bet on both Cambridge and Oxford with him and make a profit regardless of the result. However, if you spread your bets between the two bookies, it is possible to guarantee success. Having done the calculations, you place £37.50 on Cambridge with bookie 1 and £100 on Oxford with bookie 2. Whatever the result you make a profit of £12.50. Guaranteeing a win this way is known as “arbitrage”, but opportunities to do it are rare and fleeting. The maths is easiest to do when there are only two possible outcomes, i.e. win or loose. Good places to spot possible arbs are with big football matches where bookies may favour their home team; finals are good as draws are out of the question. The next step is betting at the dogs which will tend to have up to 6 runners meaning the maths is still manageable as apposed to the horses which can have anything up to 15 riders. Online gambling has given a hole new scope to betting with people making a good living from arbitrage.
Before you sack in your day job and start your new career as a mathematician there are a few things you must first consider. Situations where arbitrage is viable are hard to find and once found the maths of calculating what bets to make is quite tricky. In order to see variable returns your stakes are going to have to be quite high, meaning if you make a mistake with your maths your losses can be high too. One massive downfall in the system comes in the bookies’ right to cancel bets. Although not a problem for your average gambler this can result in massive losses for arbers and will undoubtedly lead back to hand jobs in Skegness.
As well as loving Space, the nightclub, we also love space, the final frontier. Today’s lesson has a more historical approach as I take a look at some of humanity’s more ‘off the wall’ efforts to make contact with our universal neighbours. For some, the thought of being alone in the universe seems logical, others feel that if we aren’t alone then our neighbours will come to visit us and then there are the people who are actively extending a hand into the cosmos in the hope that it will be greeted halfway. Just how this hand may be construed by extraterrestrial life has been the subject of much controversy; are we extending an open hand of welcome or a clenched fist?
Star Whores
The first radio message transmitted into space was the Arecibo message sent in 1974 and was a small grid of photos displayed as a 23 by 73 grid. Mathematicians amongst you may have noticed that these are two prime numbers, which as we can clearly see from the film Contact are very important in the search for ET. The message is expected to arrive at it’s destination, globular cluster M13, in the year 26,974. Benign as its content may seem to us, there are many people who fear that other worldly intelligence may not read it in the same way. In fact these people believe that even the way in which the message is sent, a radio pulse directed at a certain place, may be seen to have hostile connotations.
In 1986 Joe Davis sent a message to 2 neighbouring star systems, Eridani and Tau Ceti. The content of his messages was subject to so much controversy that after only a few minutes of transmission the project was shut down by the US air force. Davis, an artist and research affiliate at MIT, had become concerned that no representation of human genitals had been sent into space. To remedy this oversight he led the project which would later go on to transmit the sounds of vaginal contractions to neighbouring star systems. In order to ensure the best sound quality Davis enlisted the help of ballet dancers and their toned contractions. Although the messages will have arrived at their destinations in the late 90s we are still waiting on a reply.
Over the next few decades humanity filled the universe with messages beamed at the locations that scientists believe could support life. One star in particular, Ursae Majoris 47, has been subject to a veritable bucket load of intergalactic spam. One notable example came from a group of Russian teenagers led by Alexander Zaitsev who sent an analogue signal of a piece of electronic music recored on a theremin in 2001. Seven years later in 2008 the star was subject to a 6 hour broadcast of a Doritos advert. Earlier in the year NASA had broadcast The Beatles song Across the Universe to celebrate the agency’s 50th anniversary. What must our neighbours think we do with our time here on earth?
The horse head nebula
Last year Joe ‘vaginal contractions’ Davis made a come back to the scene with a transmission to celebrate the 25th anniversary of the original Arecibo message. Somewhat unfortunately in my opinion his choice of this subject was not the sound of farting in the bath or something similar, but the genetic code of the enzyme RuBisCo which is used in photosynthesis. Davis, always looking to subvert the system reasoned that being one of the slowest and inefficient enzymes, RubisCo was undoubtably representative of life on earth. It is also worth noting that Davis brought the data to be transmitted by a multi-million dollar telescope on his iPhone.
Whether or not these messages will ever be received and what reactions they invoke we may never know. Not having received any messages ourselves may mean, as many believe, that we are alone in the universe. It may of course mean the we don’t have the technology to accept signals that have been sent to us. One thing is for sure, Joe Davis was sending cunts into space long before Richard Branson.
After a lovely roast dinner courtesy of Baxter and Miss W I got to thinking about gravy. One of life’s true pleasures, a good gravy can be delicious, nutritious and also educational. Today I want to concentrate on one of the key ingredients of a good gravy – cornflour.
If you have ever made gravy using cornflour then you will have no doubt encountered its mysterious ways. Mixed with water it creates a Non-Newtonian fluid (another good example of this is instant custard). Under certain conditions a Non-Newtonian fluid will behave just like a regular liquid but also, in other situations, in particular when agitated, it will behave like a solid. This is why when your mixing your cornflour it will sometimes become ‘unmixable’, and also why it is so good at thickening a sauce. These strange properties, which arise form the irregular atomic layout of these materials, give way to some interesting uses. For example the solid like properties of a Non-Newtonian fluid mean that if you had a big enough supply then you could walk quite comfortably across it. (Perhaps an explanation to Jesus’ exploits in Galilee..?) Strange things also happen when you vibrate Non-Newtonian fluids; giving us a use for our old speakers.
The opposite to a Non-Newtonian fluid is a Bingham Plastic; all together less interesting in my opinion. A Bingham plastic will behave like a solid until it is agitated, at which point it will behave like a liquid. A classic example of this is, staying with the food theme, tomato ketchup. Held upside down, Ketchup will remain stuck to the side of the bottle (acting as a solid) but will start to flow (acting as a liquid) when the bottle is tapped. These properties are also put to use in part in the manufacture of paint which is required to flow freely from the brush and also not drip too much when on the wall.
