Could a device, maybe a beam from an aeroplane, cause explosives to detonate spontaneously? This would include firearms as well as missiles and drones?
This is a question of physics and engineering. The answer is yes, in principle, and some relevant technologies already exist in early or partial forms.
Explosives detonate through rapid energy input, heat, shock, or electrical impulse. Firearms discharge when a primer is struck or electrically ignited. So we now ask if you can deliver sufficient energy remotely and precisely to trigger these mechanisms.
High-powered microwave (HPM) weapons are real and deployed. The US military's Active Denial System and various counter-drone HPM systems work by depositing energy into electronic systems, causing them to malfunction or fry. Directed energy weapons can already disable drone electronics. The step from ‘disable electronics’ to ‘ignite an electrically-primed system’ is not enormous in principle.
Laser systems can already ignite certain materials at a distance; this is straightforwardly demonstrated by high-powered laser demonstrations.
The engineering challenges are substantial. Explosives are specifically designed to be insensitive to accidental initiation, and modern military munitions go through extensive ‘insensitivity’ testing to resist heat, shock, and bullet impact. Triggering them remotely would require overcoming those design features. Range and atmospheric absorption are major problems because beams diffuse and lose energy over distance, especially through cloud cover or humid air. Targeting moving objects such as missiles or drones in flight with enough precision and time to deposit sufficient energy is extremely hard.
Modern firearms typically require mechanical primer strikes or specific electrical pulses. A beam capable of generating that level of localised heat inside a chamber from a distance would be formidable, but physically conceivable with a sufficiently powerful focused laser or HPM system at short range.
A practical airborne system capable of reliably detonating a variety of munitions across tactically useful ranges does not exist yet, but it is not science fiction either. It sits in the category of ‘hard engineering problem with no known physical law prohibiting it.’ Military research into directed energy is active and accelerating, and counter-munitions and counter-drone applications are among the most actively pursued areas under investigation.
Were such technology to become available, it would have a major effect on asymmetric warfare. If a power with sufficiently advanced technology, could destroy the armaments of opponents, detonating their missiles and drones, and exploding their bullets, it would create an imbalance of technological ability similar to that employed by the allies in the first Gulf War, Desert Storm.
Madsen Pirie