Hello everyone!
So yesterday, I was watching Godzilla (The newer one, 2014) for about the fourth or fifth time(Yes, I loved it).
There are a lot of references to Electromagnetic Pulses in that film. The MUTO (Massive Unidentified Terrestrial Organism) is born from a cocoon in a fury of EMP pulses and has the uncanny ability to release EMP pulses at will. This EMP burst also brings down a lot of planes from the sky in one of the climax scenes of the movie. That’s all right in fiction, but can this happen in real life? What is EMP exactly?
EMP exists in real life per se. EMP by itself is portrayed in a plethora of fiction movies, games and books as a surge of electric energy which destroys any electric circuits in its range, leaving destruction in its wake.
EMP is correctly portrayed as a short burst of electromagnetic energy which can destroy and disrupt electronic circuits and cause a lot of destruction to our daily life. But, even larger bursts of energy can cause damage to buildings as well! EMP can be generated by nuclear detonation, electronic transmitters, solar storms and even lightning!
Why is EMP so destructive? When an EMP encounters any conducting material, it sends through it a very high voltage pulse within a microsecond, essentially frying almost any circuit! This effect is even more devastating if it is done high above the ground, above 20000 meters or so. The pulse sent thus can overcome surge protection device capabilities and cause permanent damage to electronic devices. The high voltages can cause ionising of air around the blast and cause lightning.
Most electromagnetic pulses are uncontrolled energy bursts and hence, exist as a mixture of wave forms in multiple frequencies. There are 3 major types of pulses : E1, E2 and E3.
E1 pulses are very fast and brief. They are the major component in nuclear EMPs and cause a lot of destruction. The E1 component is produced when gamma radiation from the nuclear blast knocks off electrons out of the atoms in the upper atmosphere. The electrons begin to travel in a generally downward direction at relativistic speeds (more than 90 percent of the speed of light).
In the absence of a magnetic field, this sudden stream of electrons would produce a large pulse of electric current vertically in the upper atmosphere over the entire affected area. But, the Earth’s magnetic field acts on these electrons to change the direction of electron flow to a right angle to the geomagnetic field (Fleming’s Right Hand Law). This interaction of the Earth’s magnetic field and the downward electron flow produces a very large and very brief, electromagnetic pulse over the affected area.
E2 pulses are pulses initiated immediately about 1 microsecond to 1 second after the original electromagnetic pulse. E2 pulses are typically similiar to those caused due to lightning strikes. Electronic devices are easily shielded from these pulses by commercially available lightning protectors. However, during nuclear detonation, the immediate formation of these pulses after the E1 pulse can damage the electronic devices that were left intact.
While E1 and E2 pulses are brief and highly intense pulses, E3 pulses are slower pulses spread out over 500+ seconds. E3 pulses are similiar to the electromagnetic interference caused by solar storms. I will not emphasize on what are solar storms right here and save that for a future article. The only thing to note here is that complex interactions between the magnetic field of the Earth and the magnetic field of the released pulse cause electromagnetic interference over a longer time duration, interrupting communication and power generating devices in the vicinity.
All the 3 EMP components are present in a Nuclear EMP.
In a nuclear weapon, the strength of each of the components of the pulse will depend upon
- the strength of the geomagnetic field in the region,
- the altitude of the detonation, and
- the size and details of construction of a particular nuclear weapon.
In fact, the exact waveform of an EMP will reveal many details about the construction and content of a nuclear weapon. Military documents about nuclear EMP that have been declassified over the years have had the exact EMP wave-forms deleted before the report was released to the public for this very reason.
Have you seen the Auroras that are observed at the poles? Nuclear EMP and their interactions with the magnetic field also produce such vibrant Auroras for the same reason as the naturally formed Auroras: Variable scattering of the light. These Nuclear Auroras can last for upto 15 minutes after the triggering of the nuclear weapon.
Since EMP can be weaponised, it definitely poses some threat to the population in a country. The major cause of such a threat is the use of electronics in almost everything we interact with today. Electronic circuits are everywhere in today’s world: cars, clocks, computers, petrol pumps, cellphones and the list goes on and on! The vulnerability of modern systems can not be emphasized anymore!
As to the question of planes falling from the sky in an EMP attack, it definitely is possible as almost all commercial and military planes today employ a “fly-by-wire” system which means their flight control systems are electronically controlled!
I would like to conclude this post by stating the following facts.
The probability of major, modern cities being affected by a nuclear EMP attack is very much unlikely in today’s peaceful military/political situation across the world. However, if an all-out war does occur, EMP will probably be one of the very first modes of warfare to be employed, simply because of its drastic electronic disabling abilities.
- For more reading on this topic, I would like to highly recommend checking out this site http://www.futurescience.com/emp.html which is dedicated to Weaponisation of EMP and is full of actual, declassified data on EMP.
- The page http://www.futurescience.com/emp/emp-protection.html shows you how to prepare for a EMP attack or a major solar storm.
I hope you enjoyed reading this post, I definitely enjoyed writing and learning about EMP. Until Next time! 🙂
PS- Godzilla and MUTOs can still appear out of nowhere and destroy mankind and all life on Earth. So, be on the lookout!
iamchaitanya 