consistenthistorian

That made me think of this for some reason, I assume this is a fairly accurate depiction.

Of course, that doesn't solve the problem of the gravity, since as Ross mentioned if you're orbiting something then you're in free fall and you don't notice any gravitational pull. I think it's safe to assume the platforms are floating somehow, powered by who knows what. The best indication of this is probably the platforms spinning round the spikes, which look purposeful and clearly are powered by something. As to how, well I don't have any theories. The Arthur C Clarke quote about any sufficiently advanced technology being indistinguishable from magic comes to mind here of course, but a more interesting question is maybe this; Imagine someone from 200+ years ago suddenly transplanted to the modern day. Sure they'd be overwhelmed by the technology, but the interesting question is whether they'd be most interested or impressed with the things that are the most technologically advanced. I can imagine that someone in that situation might not even recognise the significance of computers, but they could spend ages worrying about how street lighting worked... It's not just that advanced technology looks like magic, it's that it becomes hard to appreciate the relative significance of technology when it gets really advanced. I think there's a danger that we focus too much on the stuff that looks visibly different from what we're used too. Floating platforms in this episode, and momentum conservation by teleporters in a previous one are good examples. Who knows whether with the technological ability the aliens possess these things are exciting or mundane? We might be worrying about the metaphorical street lighting and missing the really important differences.

Possible, sure, but it feels too much like a Deus Ex Machina. You can solve anything by saying the physics is different. Plus of course, if gravity is different that might just about be ok, but if pretty much any other physics is different then Gordon wouldn't survive. Eg the molecules in his body are held together by electrostatic forces, you go and change the electro-weak force any and Gordon is suddenly going to find himself with a larger, much less attractive volume... FWIW I always assumed the platforms were orbiting a gas giant, something like Jupiter or Saturn. When you look in any direction you don't see infinity, just a sort of haze in the distance. Locally being somewhere in the atmosphere of a gas giant is probably going to look like an interestingly coloured haze.

Also, in answer to this: Ok so your centre of mass momentum is the sum of the momentum of all your constituent atoms. Actually doing the sum would be horrific because, as you say, you'd need to know the motion of every atom in your body. But here's the thing, you can get the result very easily from other means. Assuming you know the (GR) stress energy tensor at a few points round the teleporter*, you should be able to read off your centre of mass momentum easily enough, even though you can't know the motion of all the constituent atoms in your body. It's a bit like how the gravitational attraction of the earth on an orbiting satellite has contributions from every mountain, molehill and speck of dust on earth, but as far as the satellite is concerned the net effect looks like a point particle located at where the centre of mass of the earth is with a single fixed mass. (I'm talking about Gauss' law here.) If you were hovering somehow above's the earth's surface you could compute the sum of the masses of everything below you by dropping a ball and seeing how fast it accelerated. Thus it's very very easy to compute the sum of all the masses of the stuff that makes up earth, even though it's very very hard to actually know all the individual masses themselves. It's a broadly similar thing for momentum, knowing the individual momenta - very very hard, knowing the sum (i.e. centre of mass momentum) very easy. As I mentioned in a post above, being able to change this centre of mass momentum is essential if you want a useful teleporter (i.e. can teleport you to places on earth more than a few miles apart), so you have all the ingredients here to read and cancel your centre of mass momentum, without having to know or adjust the momenta of your constituent atoms in the frame where the centre of mass momentum is zero. * This is about the minimum you'd need to know to actually teleport anything.

Okay this goes back to the "multiple breakthroughs" line again. I considered that maybe it only detects motion on a certain level, but what level? At the cellular level, who knows fast your cells are moving? Hell I think sneezes are at 100mph. Nerve connections and the brain in general must move pretty damn fast as well. I guess the thing is I don't see how you would cancel one type of momentum, but not the other; additionally I don't see how there would be technology to DISTINGUISH the two or even DETECT the difference in the first place. I really tried to think this one out and I couldn't come up with any scenario where momentum is cancelled AND you come out alive on the other end short of having some positional tracking and computational system way, way beyond anything we could dream about. Let us not forget, Black Mesa still uses giant tape reels on their computers. Ok, so maybe it's just masochism, but I'll try and persevere with this! The biggest problem we have in trying to understand this technology is that it's obvious that in order to produce a working teleporter there must have been some kind of major discovery that changes the laws of physics as we currently understand them. Quantum teleportation as we currently understand it won't cut it here, mainly because you need a way of communicating a huge amount of classical data between sender and receiver. This might just about be feasible between two points on earth, if you allow near unlimited computational power, but it's not going to let you send anything to Xen because you'd need a pre-existing communication channel. Unfortunately, it's hard to avoid the temptation to use a 'breakthrough in physics' as a deus ex machina, which just let's you do anything you want to. So let's try and see if we can't agree some assumptions about what sort of physics we have in the half-life universe, and then work from there. You can criticise these assumptions, but at least I'm being definite. 1) Quantum Theory as we know it is basically correct. If this doesn't hold I have basically no idea how to do physics. Incidentally, it's a theorem of quantum theory that you can't clone Freeman's (http://en.wikipedia.org/wiki/No-cloning_theorem) so no multiple Gordon's I'm afraid. 2) Lorentz Invariance holds at least on scales that matter (I mean here from subatomic up to solar system scale.) There is very good experimental evidence for this of course, but it is just an assumption. 1) + 2) mean any physical theory (apart from gravity) is going to be expressible as a quantum field theory. That's useful because it rules out any sort of quantum teleportation explanation for teleporters. (Not just because of the problem highlighted above, but also because of other limitations of relativistic quantum information like the No-Summoning theorem http://arxiv.org/abs/1101.4612). So given that, any teleporter technology is going to have to be based around gravity. Here's the part where things get sketchy of course, since we are now speculating about the details of unknown 'future' physics! The easiest way for a teleporter to work would be if there were extra microscopic dimensions that could connect different points in 'our' space (a bit like wormholes.) (Incidentally string theory won't generally get you this since the extra dimensions are usually tensor product-ed onto ours, so moving around in the extra dimensions doesn't change your co-ordinates in our dimensions any.) Anyway, regardless of how it works, any working teleporter is almost certainly going to be able to cancel centre of mass momentum, but leave the random motion of atoms etc (i.e. temperature) alone. I say this because teleporters are going to have to do funny things to your momentum anyway in order to be useful, since suppose, e.g. I wanted to teleport to the other side of the world, the teleporters might be stationary in the labs at either side of the world, but they will be moving relative to each other at about 2000 mph! (http://image.gsfc.nasa.gov/poetry/ask/a10840.html) If I teleport from one to the other it's important that I come out stationary relative to the right teleporter! So a useful teleporter is going to have to be able to at least adjust your centre of mass momentum by an arbitrary amount anyway, so I don't see why it couldn't also add or subtract any momentum relative to your input teleporter. Of course I have no idea how this might work in practice, and that's part of the 'future physics' stuff that's just speculation. Still, I think we can still usefully rule some options out, and that gives us a better idea about what sort of new physics we might be dealing with.

Awesome episode again Ross, good job. Re Momentum and teleporters, I think Freeman has got a bit muddled. There are two types of momentum to consider here, the momentum of his centre of mass (CoM) and the momentum of his constituent parts in the frame where his CoM momentum is zero. Freeman has experience so far that teleporters don't conserve CoM momentum, but that doesn't mean they kill ALL momentum. I can't see an obvious problem with teleporters cancelling CoM momentum*, so "speedy thing goes in, stationary thing comes out", but there are some big problems with cancelling ALL momentum (someone already mentioned that motion of particles is basically temperature, so Freeman would freeze solid, but there's also the issue that it would violate the Heisenberg uncertainty principle...) * I mean, you'd need to shunt it somewhere, but this seems the least of your worries if you were actually trying to design a teleporter...

I have to agree with a previous poster that I'm not 100% sure about this episode (or the previous one for that matter.) I think Ross has done a good job with the dialogue as always, but I'm less convinced by the ideas. I think one of the strengths of FM is that it feels pretty original in general, but the drugs idea was done very well in Shepard's mind, and teleportation is the kind of 'amnesia' of the mind series world, i.e. a convenient plot device used by pretty much everyone to shoehorn in pretty much anything they feel like. I'm interested to see where Ross goes with this, but I think I would have preferred fewer gimics. Ross's writing is good enough that he doesn't need them.

I enjoyed this episode, though I agree some of the corridor wandering doesn't lend itself well to entertaining video. I do actually quite like the claustrophobic feel of some of this section of the game though. More generally as we get closer to Xen I'm intrigued about how Ross is going to address Freeman's motivation for making that jump. For most of the game you're pretty much wandering aimlessly with your only objective being to escape the current location you're trapped in, and I think the way Ross has developed Freeman so far works well (doesn't really care about anyone else, only interested in escaping etc.) However the further through the game you get the more your objective starts to be to get TO the lambda complex, rather than just AWAY FROM wherever you are now. So the further through the game Ross gets the more the motivation of the Freeman he's created diverges from the player's motivations. There have been a couple of moments so far where this has been obvious, the journey from the surface down into the lambda complex, culminating with the scientist who let's you into the complex proper really feels like you're heading somewhere definite. Ross doesn't have Freeman comment about going back underground, or try any of the other doors, or mind that the way out of a huge loading bay is probably not a tiny door up a ladder... That really comes to a head at the end of this chapter when you're given the lowdown on the plan to save the world, and you have to make a pretty positive decision to jump into that portal. I mean, I know there are actually no other exists from that room, but the whole sequence is designed to make you feel like you're deciding to help. So is Ross still going to have Freeman as 'just trying to escape'? That's going to feel pretty forced surely? Or will Freeman have some kind of realisation that he's going to have to help, if only for his own sake? We haven't really had any hint of that so far, unless I've missed something. I'm interested to see how the next few episodes pan out.

Hi Ross (and everybody else), I've just made a small donation to the cause, but I wanted echo a couple of other posts in saying I'm not hugely fussed about HD. I'd much rather you took the money and used it to set your finances on an even keel and avoid money-related terror sweats... I think it's a real shame that talented and dedicated people like yourself can find themselves in a position where they're struggling for money to make ends meet. I mean, I'm a researcher in a UK university and I'm currently writing this 'at work' sat on the sofa in my flat, so I understand that 'doing what you love' for a job can have its perks, but I also understand that it can come with a lot of financial and other uncertainties. For that reason your ongoing saga with The-Company-Who-Must-Not-Be-Named makes me so angry I feel like I'm going to start throw-up crying every time I think about it. If my donation helps make your life easier that's good enough for me, HD or no HD. Anyway it looks like I'm not the only one here that thinks this, I hope the donations make your (and MAGDA's) life a little easier, and remind you of just how many appreciative fans you have. Keep up the good work, and get started on those Robot Attack Dogs!