The Science Behind Half-Life: Weapons

25th April 2015

Welcome to the second part of The Science Behind Half-Life. In the first part, I looked at the game names and this article looks at some of the weapons.

I’d like to mention that I’m not going to cover all the weapons used in the game, just the ones with science connected to them.

Gluon Gun

“The Gluon Gun was developed in the Weapons Section of the Lambda Reactor Complex in Black Mesa’s Sector F and first discovered by Gordon Freeman in a Test Firing Chamber right before the Lambda Reactor Coolant System. Upon entering the Test Firing Chamber, Gordon is met by the weapon’s designer himself, who is unwilling to use it on living creatures. He then deems Gordon less hesitant to kill things and gives the gun to him.”

Essentially, Gluons are massless particles that help other particles bind together, hence the idea “glue”. In the Feynman Diagram, the gluon is represented as a helix, which is probably why when you fire the weapon in the game, the beam has straight line beam AND a secondary helix around it.

The gluon gun simply stops the gluons from working within atoms and the object it hits loses its nuclear strong interaction and falls to pieces. I would have been cool if this also worked with inanimate objects as well as living objects but then you have to worry about destructible walls etc. Clearly for 1998, the engine was just not capable of that detail.

The CombineOverwiki also refers to this as the “Egon gun” and it is possibly a reference to Dr. Egon Spengler from Ghostbusters who invents the Proton Pack which is designed to weaken ghosts through some sort of atomic manipulation.

Tau Cannon

I love this weapon and you probably do too. It’s powerful, accurate and versatile. So let’s get to the science.

Tau is another Greek letter, just like Lambda. In this case it’s a particle, just like the gluon, (it’s sometimes called the Tauon) but unlike Gluons which are part of the Bosons family, the tau is a fermion. Due to their mass, at very high energies that are described as “potentially highly penetrating”. So what we have here is a weapon that fires Tau particles. It does it in two ways; 1. short bursts of limited particles and 2. when the charged can be stored in spinning capacitors. The second method gives some recoil which can be used to jump.

This weapon is the most accurate of all weapons in Half-Life partly because the environment has no effect (distance, wind etc) and partly the beam is perfectly straight.

The CombineOverwiki has a nice detailed overview as well as some background information about its development from a different sort of weapon.

Zero Point Energy Field Manipulator

We know this as the gravity gun.

Quantum mechanics tells us that it’s possible to know the vector of a particle within an atom but not it’s location. Or you can know exactly where it is but not its vector. Basically, it’s one or the other: position but not speed or speed but not position.

So, what would happen if you could get an atom down to absolute zero, that’s minus 273.15 Celsius to you and me.

Well, before we do that why is important? For us, temperature IS movement. The hotter something is the more the atoms are moving. Therefore if we can “stop” all movement, we can measure both, right? Wrong, no we can’t because even at absolute zero there is some movement, some energy in the system. That energy is called Zero-point energy.

So where does the energy come from? It comes from the various fields within a vacuum. Essentially, it pulls energy out of nothing.

Einstein’s General Relativity theory tells us that mass and energy are equivalent; both produce a gravitational field. SO it may be possible that through some clever manipulation of the zero-point energy field we could control gravity. Well, that’s the idea.

Valve are’t the only ones to use the idea, Stargate has the Zero-point module and probably others.

Anyway, it’s cool to know that it’s not just a made up phrase. You can learn more about it on the Wikipedia article.

Displacer Cannon

Okay, it’s at this point that things get a little murky. Any player of the Half-Life series knows that teleportation and portals are a key element in the gameplay and story of those games but how they work is not so obvious.

In the case of the Dsiplacer Cannon, it creates portable portals that can be used as a weapon and as a means of transportations. Iain M. Banks wrote in one of his Culture stories that technology is more like a wall than a ladder. There are various ways to reach the same level and in the case of portals within the HL universe that seems true. Both the Combine and Race X have their own portal technology.

The word itself comes from 1931 and uses the Greek Prefix “tele”, meaning “at a distance” (telephone, telecommunication, television etc) and the latin verb “portare”, meaning “to carry”.

But how does it work?

Firstly, we need to distinguish the difference between transporting information and transporting atoms. In something like Start Trek that destroy the original thing and transfer the information somewhere and create an exact replica of that thing. Which is, I suppose, why they also have a replicator in the show. The information is stored in a file somewhere and used to create a cup of coffee. If that’s the case, why don’t they have copies of the people and just replicate them when they die – minus the memories between being replicated and when the died?

Here is the same thing but done with inanimate objects and two 3D printers!

Portal technology seems to take an area of space and somehow move the whole thing to a new location. This is bets to call displacement.

There’s also something called Quantum Entanglement. This means that when two or more particles are created at the same time you can’t describe each separately. Imagine one is spinning clockwise then the other one is spinning anticlockwise. ANy changes to the first particle are “mirrored” in the second irrespective of the distance involved and with no known way for the information to be communicated. It seems that some scientists believe this could be the way forward for making teleportation real.

So where does that leave us? To be honest, I’m not sure. There is certainly science behind the vague concepts but nothing that could be described as “possible”.

Dark Energy

Dark Energy should not be confused with Dark Matter which is a hypothetical matter potentially inhabiting 70% of our universe (or maybe multi-verse!) that we can’t actually see – that’s why it’s called “dark”.
Dark Energy on the other hand seems very similar to zero-point energy in that it permeates the universe and is connected to the Cosmological Constant (Which Einstein described as the “biggest blunder” of his life and is referred to by a capital Lambda!). It’s also believed to be responsible for the expansion of our universe.

The CombineOverwiki mentions that the reason why the Gravity Gun was not dissolved with Gordon’s other weapons was because the device used to dissolve them used Dark Energy and that’s why the gravity gun because the SUPER gravity gun! DUN, DUN, DURRR!

Dark Energy is used in the game as Energy balls, which can be fired with the gravity gun or used to power other technology and the secondary fire of the Overwatch Standard Issue Pulse Rifle. Even Striders are armed with Dark Energy cannons that are so powerful that they visually distort space when used.

Biological Weapons

Whilst not science in the sense of “physics”, the biological weapons seen in Half-Life are pretty cool too. Essentially, they are living things turned into weapons. I don’t mean in the sense of the Combine Synths (a combination of biological and technological), I mean animals uses as weapons.

We have the Shock Roach (one of my top 3 weapons from Half-life games), the Hivehand, the Barnacle Grapple and finally the Spore Launcher which has the great animation of the hand soothing the animal. It’s probably too powerful though. All of them amazing but totally invented.

Well, there you have them

I hope you learnt and enjoyed this article and if you feel I missed a weapon or misexplained something please feel free to post a comment, but please keep your comments on the topic of weapons.

The next article in this series will be about chapter and soundtrack titles.

Thanks for reading.


  1. I would love to see some pictures in this article, it would really make it more interesting.

    1. I consciously decided against it. I know it looks pretty and can break up the article but I wanted it to be about the content. To be honest, they would just be screenshots from games anyway.

  2. Hec

    Displacer Cannon: The Black Mesa version of the Aperture Science Portal Gun? It seems that this BM is way to inferior to its adversary one.

    1. I wouldn’t say that. They have the same basic function: moving from one place to another but that’s all.

      1. Hec

        Yeah; You’re right I guess so far all of that is non canon interpretation. Although I’d love to see some official reference of a related connection between this 2 rival developments maybe in HL3 or, Portal 3??

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