It’s 1995 and James Bond enters the modern, post-cold war era with a bang, in Martin Campbell’s derivative, but oddly effective, GoldenEye, as we enter the first (and best) of the Brosnans in BlogalongaBond, subtitled …And Sean Bean.
Aside from a plot that bounces along marvellously, there is some properly intersting science in GoldenEye – no, it’s not whether Xenia Onatop can crush men’s ribs with her thighs – it’s all about that crazy-ass space laser.
But it’s not actually a laser. It’s some sort of EMP generator. What is an EMP, you ask? Well, sit back, grab a cup of tea and 10 rolls of tin foil and I shall explain.
The EMP or Electromagnetic pulse was theorised back in the 1940s when the Americans were performing nuclear tests. Enrico Fermi had insisted on shielding electronics during nuclear testing, as he had theorised that disruption in electromagnetic fields would occur and would majorly fuck shit up. Often, EMPs are encountered in film as a byproduct of nuclear explosions (see John Woo’s Broken Arrow) although non-nuclear forms of EMP generator also exist in the fantasy world of the movies (see Steven Soderbergh’s Ocean’s Eleven).
The example given by M in GoldenEye is a high energy explosion caused by a nuclear device in the upper atmosphere (say 40-400 km above the Earth’s service). This is known as a High-Altitude Electromagnetic Puls (HEMP). While potentially non-nuclear EMP generators exist – governments are pretty hazy on their existence.
A nuclear EMP consists of 3 phases; E1, E2 and E3.
E1 is a very brief intense electromagnetic field generated when gamma rays from the nuclear device knock electrons off atoms in the upper atmosphere. These electrons travel down towards the Earth’s surface. When they pass through the Earth’s magnetic field, the E1 electromagnetic field is generated over a wide area. Here’s some info from How Stuff Works. The problem with this electrical field is that it can rapidly induce very high voltages in conductive materials. Notably, silicon transistors. This fries unprotected computers and communications equipment.
E2 occurs when the neutrons released by the weapon generate scattered gamma rays. This is similar to the EMPs generated by lightening strikes. The major problem is that this can screw up equipment left unprotected following E1.
E3 is akin to an electromagnetic storm – it’s caused by the nuclear detonation moving the Earth’s magnetic field and by the magnetic field reasserting itself. The problem with it is that, like all magnetic fields, it is able to generate currents in long electrical conductors (eg wires). These currents induced in, for example, power cables can lead to damage in transformers which form the infrastructure of the power grid.
Those crazy paranoid Americans came up with the EMP Commission to assess the risks of an EMP, you can see their report here. Among other things, they note the vulnerability of the computer-reliant finance system – curiously, the same plan Trevelyan has for the UK finance system. One does worry that US policy re. crazy Sci-Fi weapons derives entirely from films. What is not really explained in the film is how the GoldenEye generates the EMP, it’s not explained whether it is a nuclear powered device (one assumes not) – I’m not sure the space laser setup they’ve got going would actually work.
How would one prevent damage from an EMP? Well, contrary to what some films have suggested (Spielberg’s War of the Worlds, I’m looking at you) it makes no difference if the electrical device is switched off. Enter Xenia Onatop and her outrageous ‘copter thievery. Onatop steals the Eurocopter Tiger helicopter. Amongst other things, the Tiger is resistent to damage caused by EMPs. This (though an unbelievable flow of logic) leads MI6 to conclude that the Russians actually have an EMP generating space weapon. What is utterly brilliant about the Eurocopter Tiger helicopter is that it actually exists – take a look at the Eurocopter website. What is even more impressive is that the helicopter actually is resistent to damage from EMPs – according to the literature (well, google) the Tiger is protected from the effects of an EMP by a copper/bronze grid and copper bonding foil. This forms a Faraday cage, which encompasses the electronics in the aircraft, thereby protecting them from the effects of environmental fluctuations in electromagnetic fields.
What is a Faraday cage? A Faraday cage is a box or enclosure made of a conductive material. The sides can be solid or made of mesh. The outer conducting materials protect the interior from electrical and, to a larger extent, electromagnetic signals (although it is ineffective at shielding static or slowly moving magnetic fields). Charge collects on the outside of the cage. If the cage is grounded, charge leaves the outside of the cage and goes to ground. From personal experience I can tell you that Faraday cages are good against mobile phone signas and BBC radio waves….
Take a look over here for some pretty impressive examples of how a Faraday cage can protect one from electricity.
I rather enjoyed that – some pretty cool science. I look forward to what the rest of the Bron Hom era has in store for Schiensh. Find out next month when I attempt to watch the thoroughly unmemorable Tomorrow Never Dies.