The Pull of Half Life - Guns & Gravity - Extra Credits

Rise and shine, EC viewers. Rise and shine. Oh, um excuse me. Welcome everyone to the Black Mesa Research Facility. I'm your trusted administrator, Matthew Kroll, who currently has a gleaming record of two whole days without a dimensional incident. Thank you very much. And with us again is PhD in astrophysics, educator, science consultant for Star Trek, and writer of this episode, Dr. Erin Macdonald. The most important thing though is that her PhD is specifically in general relativity and how gravity works. And that's definitely going to be relevant for your briefing today. Throughout the Half-Life series, Gordon Freeman gets to use a lot of awesome weapons. And while it's the crowbar that usually gets all the meme glory, the weapon we've always thought was the coolest is the mighty zero point energy field manipulator, or gravity gun for short. But, how does zero point energy relate to gravity? And how could this gun actually work? Well, let me tell you. If you didn't have opinions about quantum field theory versus general relativity before this episode,

Well, we'll see about that. Time to choose. Thanks so much to NordVPN for sponsoring today's episode. To take control of your internet security, save 68% off a two-year plan, and get four months free, use code extra credits at nordvpn.com/extracredits. Before we get into the physics of how this gravity gun works, let's break down its in-game mechanics. It has two fire modes. The primary mode gives the object it targets a massive kick, launching it away from the user, which is great for clearing your way. Then the secondary mode allows the user to pick up an object and hold it just in front of the gun. Then these held objects can either be dropped or flung away from you with the primary fire mode. Now, in the story, it was designed for handling hazardous materials, but of course we know it can be used for so much more than that. Yeah, it's a fun gun. Of course, outside of science fiction, we don't have that kind of technology, so let's start to science this by examining

the weapon's name, the zero point energy field manipulator. Mhm. You know, that smells like something referencing quantum field theory. So, strap in because we're going to be dealing with a quantum level of minutia here. In quantum field theory, we break down the universe into matter fields and force fields. The matter fields are made up of fermions like quarks and leptons, which when combined make up the components of an atom, protons, electrons, etc. But then force fields are made up of bosons, which are the fundamental particles representing fundamental forces such as the photon for electromagnetic force, i.e. light. And quantum mechanics treats these fields as having zero point energy or the lowest possible energy a quantum system may have. Now, if that all sounds confusing, that's probably because I read it pretty fast in hopes I sounded like I fully understood it. But in all seriousness, Erin assures me, if we're a little lost, we aren't alone. It's still an area of physics that's pushing the boundaries of research and understanding and lots of theories still about. But how does this concept of zero point energy tie to gravity and our favorite

yeet cannon? Well, there's a theoretical particle associated with gravity called the graviton. You may have heard this word a lot in science fiction, and though there's currently no evidence that the graviton exists, it's at least a theoretical physics construct. Just like how photons are the particles of electromagnetic force, if you think of gravity as a fundamental force in quantum field theory, then the graviton would be the zero point energy field equivalent for gravity. Now, of course, that's a big if because there are a lot of problems with gravitons in the theoretical quantum physics realm. But if we were to get into all of them, then we'd start throwing around jargon like second order tensors and spin two fields, and frankly, most of us would just be begging for Gordon to open the portal to the aliens already. So, here's the TLDR. Zero point energy is a quantum field theory concept that explains the source of fundamental forces, which in some theories includes gravity. Now, let's step away from the name itself and just look at what the gun does. Another way of explaining gravity manipulation is through Einstein's general relativity. Like we talked about back in

our science of Mass Effect video, which you should go check out because Ezo is neat and Garrus is a dreamboat, essentially the presence of mass warps the fabric of space-time like a bowling ball on a trampoline, creating a gravity well. So, if you want to bend space-time and build a gravitational well without the presence of, you know, a planet, you could use an equivalent amount of energy. So, positing that the gravity gun generates a gravitational well that causes objects to fall toward it kind of works when dealing with a super secret underground research facility that's playing with alien technology. Because the amount of energy needed would need to be a lot in order to compete with the gravitational well of the planet the gun was being used on. But, remember the pulling of objects toward you is only the secondary function. The primary one pushes things away from the gun with a sort of anti-gravity, if you will. And if gravity is due to the presence of mass, then anti-gravity would have to come from anti-mass. And the whole Black Mesa incident in the first Half-Life did start with playing around with an anti-mass spectrometer and Zen crystals. So, yeah. They've set up the idea of

anti-mass in the Half-Life universe from the beginning. So, having it be a component of the gravity gun works pretty well narratively. In our reality, though, we haven't discovered anything called anti-mass. And frankly, after seeing what happened at the resonance cascade, I'm kind of okay with that. Despite quantum field theory and general relativity being pretty incompatible, each offer some theories on how our favorite zero point energy field manipulator could function. Granted, the weapon's name implies it uses quantum field theory to manipulate gravity, despite little evidence that that's possible under our current understanding. But, we can leave the quantum field physicists and general relativists to fight. I mean, uh work together to figure it out while we do our part to fight back against the Combine in a video game. See? We're helping. And while I wish I could do more than explain theories with the aid of scary sci-fi tech to smooth out the impossible edges, we all must prepare for

unforeseen consequences and YouTube comments THAT OKAY, I'M SORRY. I'LL STOP BEING CREEPY AND CRYPTIC. Just put me down, please. No, not like that, Erin. Zoey, that's not what I meant. Once again, thanks so much to NordVPN for sponsoring this episode. If you're looking to protect your online activity from prying internet eyes, then you've got to give NordVPN a try. With thousands of servers in over 60 countries, military-grade onion over encryption technology, and a user-friendly lightweight Chrome extension, you could be browsing securely in seconds. Plus, if you act now and use the code extra credits at nordvpn.com/extracredits, you'll get 68% off a two-year plan. That's under four bucks a month for 24 months if you're doing the math, with a 30-day money-back guarantee. And you'll receive four extra months of double encrypted protection absolutely free. So, secure your online self with NordVPN and never be scared about your internet security again. Oh, I didn't see you there, Ahmed Ziad Turk, Alicia Bramble, Casey Must Dominic

Valenciana, Gunnar Clovis, Kyle Murgatroyd, and Orioles 1. It's so nice I can thank you all in one place.