Resonance Cascade

"I never thought I'd see a Resonance Cascade, let alone create one..."

- Scientist

The Resonance Cascade is a cataclysmic quantum event created after the insertion of Xen crystal sample "GG-3883" into the Anti-Mass Spectrometer at Black Mesa by Gordon Freeman, culminating in the Black Mesa Incident.

Overview
According to notes from Gordon's desk, every object has a set resonance. When studied, the object will resonate even more, and sometimes even rapidly. If the object resonates too much, it can open dimensional rifts and portals. The Xen Crystal sample studied at Black Mesa resonated enough to tear a rift between Xen and Earth.

While seeming to be a contained event, it did in fact have repercussions across the entire planet. The Resonance Cascade was the cause of not only the interdimensional rift, but also all the following events. It sparked Portal Storms across the whole Earth, and ultimately led to the Seven Hour War and the Combine invasion of the planet.

The Resonance Cascade is therefore arguably the single most significant event in the entire Half-Life timeline, being the cause of all the games' events.

Half-Life and expansions
The Resonance Cascade caused an aggressive rift to form between the Xen border world, the Race X world and the Black Mesa complex on Earth in 200-. While at first only basic Xen wildlife, such as Headcrabs and barnacles emerged through the rift, eventually other intelligent creatures, such as Vortigaunts, were sent to the other side by Nihilanth, leader of the Xen forces.

The cascade was set to continue until stopped manually, and Gordon Freeman, being the one who caused it, took up the job of closing it. Once the rift appeared to have closed on Earth's side after Freeman had launched a satellite rocket into outer space, the remaining scientists from the Lambda Core discovered that the portal was being held open on the other side by the Nihilanth. Freeman then travelled through a portal to Xen to kill Nihilanth, preventing him from keeping it open any longer, closing it on both sides.

Trivia

 * A resonance cascade is a theoretical possibility. Researchers have theorized that should enough power (theorized to be a electro magnetic beam) come in contact with a certain pure elemental crystal (Xen crystals in this case) it would cause a hole in the fabric of space time, allowing the travel between seperate universes, should other universes exist. They called the element Fromidium.

List of appearances

 * Half-Life
 * Half-Life: Opposing Force
 * Half-Life: Decay
 * Half-Life: Blue Shift