[ad_1]
An electromagnetic pulse (EMP) is a burst of electromagnetic energy that can damage electronics, caused by a nuclear explosion or an explosively pumped flux-compression generator. EMPs can disrupt power lines and electronics up to 1,500 km away, but are ineffective against biological creatures.
An electromagnetic pulse (EMP) is a rapid and powerful burst of electromagnetic energy that traverses a significant portion of the electromagnetic spectrum. The most cited source of an EMP is a nuclear weapon. Indeed, the simplest way to generate the energy for an EMP is through a sudden chemical or nuclear explosion, and devices for creating EMPs in the absence of such an explosion are known to be relatively weak.
The general idea of an EMP is that it wreaks havoc on electronics, but leave other physical structures mostly intact. Real-life electromagnetic pulses released from high-altitude nuclear tests have melted power cables, set off burglar alarms, and caused radio, TV and power lines to break as far as 1,500 kilometers (930 miles) away. The source of this disruption is a large-scale, intensely fluctuating magnetic field created when high-energy photons from an explosion knock electrons out of their atomic orbits. This disruption gets trapped in the earth’s magnetic field, leading to a coherent oscillating electric current.
In near-future science fiction, the EMP is seen as a powerful superweapon that disables all sophisticated electronics in a national or even continental region. Because the EMP can extend all the way to the horizon with enough energy, a nuclear weapon detonated in near-Earth orbit could in fact disrupt electronics over a large region. Conversely, a nuclear weapon detonated close to the ground can do little damage with its EMP: for example, aircraft that drop atomic weapons continue to function even if they are in line of sight of the nuclear blast.
To release an EMP capable of damaging a large area, the nuclear weapon that triggers it must be relatively large, in the range of 10 or more megatons, which is nearly three orders of magnitude more powerful than the nuclear bombs of Hiroshima and Nagasaki. To deliver powerful EMP in a smaller area, the explosively pumped flux-compression generator, which uses high explosive to achieve essentially the same effect, has been suggested. Armies around the world have tested prototypes of such a weapon, but it has not been widely used.
The EMP is presented in fiction or games as a weapon suitable for use against machines, cyborgs, or nanobots, but useless against biological creatures. In fact, machines can easily use processing and drive elements based on mechanical and chemical rather than purely electrical principles, making them as immune as a human to an electromagnetic pulse.
[ad_2]