During the Golden Age, humanity still faced real threats as we expanded our influence in the solar system. I think the answer to this question is clear: We faced the Vex.
Ghost tells us that the Vex ruins on Venus predate humanity by eons. The structures on mercury line up with this idea as well - The Vex have been doing work on the planets in our system for a very long time. The Ishtar Collective arrived on Venus, and began to study the Vex structures.
Humanity appears to have first encountered the Vex on Venus. Possibly the Vex were in some sort of stasis, like the ones that we find inside the Black Garden. But other signs point to the idea that the Vex began to appear as humanity began to study the ruins.
This is supported by the name of the Vex we fight in the black garden - the Sol Progeny - or “Children of Sol”. This leads me to my first point, remember this: The Vex were the threat that Golden Age humanity had to contend with.
With that established, let’s take a look at the Vex entries in the Grimoire. The 4 ghost fragments that talk about the vex tell a story of a group of Ishtar Collective scientists that are studying a captured vex specimen. In Vex 1, the scientists realize that the mind inside the Vex is advanced enough to simulate its local reality. That is, it can run a complete and accurate simulation of the universe around it, and that is how it decides how to act when not being fed orders from a hydra.
In Vex 2, the scientists come to a stark realization. If the Vex can simulate reality, then the odds are that THEY THEMSELVES are simulated. This is a reference to a philosophical concept called the Simulation argument, proposed by Nick Bostrom in 2003.
Bostrom argues that, if it is even POSSIBLE to simulate reality, then the probability that you exist in a simulation is astronomically high. The reasoning behind this is simple: Let’s say that we call Reality, actual physical reality, “prime”. Advanced beings create an accurate simulation of “reality prime”, within “reality prime”. So now we have Reality Simulation A, inside “reality prime”.
But if Reality Simulation A is truly an accurate simulation of reality, then inside of that there must be a “reality simulation B”, and a “reality simulation C” inside of that one, and D and E and so on (to infinity!). Even if we assume that this continuing string of simulations stops at 100, we have a pretty large number. Let’s say that it stops at 227, you’ll see why later. Now, how many of these realities is actually reality? Just one. Reality prime. Therefore, If you exist, and are thinking, and have a reality that you perceive, the odds are 227:1 that you are in a simulated reality.
Hoping that you all have wrapped your minds around that, we can press on.
Continuing the story of the Vex we are discussing - The Ishtar scientists capture a vex, and discover to their horror that the vex can create an accurate reality simulation. Knowing Bostrom’s argument, they know that the odds are high that they themselves are simulated. That makes them freak out a bit.
ESI: It controls the simulation. It can hurt our simulated selves. We wouldn't feel that pain, but rationally speaking, we have to treat an identical copy's agony as identical to our own.
SUNDARESH: It's god in there. It can simulate our torment. Forever. If we don't let it go, it'll put us through hell.
DUANE-MCNIADH: We have no causal connection to the mind state of those sims. They aren't us. Just copies. We have no obligation to them.
ESI: You can't seriously - your OWN SELF -
SHIM: [profane] idiot. Think. Think. If it can run one simulation, maybe it can run more than one. And there will only ever be one reality. Play the odds.
DUANE-MCNIADH: Oh...uh oh.
SHIM: Odds are that we aren't our own originals. Odds are that we exist in one of the Vex simulations right now.
ESI: I didn't think of that.
So our scientists need to decide what to do about this. They plan to make a move - they are going to call in a warmind.
SUNDARESH: If we're sims, we exist in the pocket of the universe that the Vex specimen is able to simulate with its onboard brainpower. If we're real, we need to get outside that bubble.
ESI: ...we call for help.
SUNDARESH: That's right. We bring in someone smarter than the specimen. Someone too big to simulate and predict. A warmind.
SHIM: In the real world, the warmind will be able to behave in ways the Vex can't simulate. It's too smart. The warmind may be able to get into the Vex and rescue - us.”
In Vanilla Destiny, this is where the story left off. However, House of Wolves included a new vex card, Vex 4. This card, in my opinion, is RIDDLED with clues as to what’s going on here.
Maya, Chioma, Duane-McNiadh and Shim decide to have a picnic before they send themselves into infinity.
Up here they have to act by biomechanical proxy. No human being in the Ishtar Academy has ever crossed the safety cordon and walked the ancient stone under the Citadel, the Vex construct that stabs up out of the world to injure space and time. It's not safe. The cellular Vex elements are infectious, hallucinogenic, entheogenic. The informational Vex elements are more dangerous yet— and there could be semiotic hazards beyond them, aggressive ideas, Vex who exist without a substrate. Even now, operating remote bodies by neural link, the team's thoughts are relayed through the warmind who saved them, sandboxed and scrubbed for hazards. Their real bodies are safe in the Academy, protected by distance and neural firewall.
But they walk together in proxy, pressed close, huddled in awe. Blue-green light, light the color of an ancient sea, washes over them. Each of their explorer bodies carries a slim computer. Inside, two hundred twenty-seven of copies of their own minds wait, patient and paused, for dispersal.
"I wonder where it came from," Duane-Mcniadh says. Of course he's the one to break the reverent silence. "The Citadel. I wonder if it was here before the Traveler changed Venus."
This is interesting - Duane-Mcniadh is wondering if the vex were always here, or if the traveler changed venus somehow and they appeared. Note: Duane-Mcniadh is directly specified as a male here.
"It could have been latent," Chioma Esi suggests. She's the leader. She kept them together when it seemed like they faced actual, eternal torture. She pulled them through. "Seeded in the crust. Waiting for a period of geological quiescence, so it could grow.”
Note: Chioma is directly specified as a female here.
Dr. Shim shrugs. "I think the Traveler did something paracausal to Venus. Something that cut across space and time. The Citadel seems to come from the past of a different Venus than our own. It doesn't have to make any sense by our logic, any more than the Moon's new gravity.”
Dr. Shim believes that the Traveler pulled this venus from a different reality. I also like the little shout out to the moon’s gravity, as that was one tiny Destiny mystery that was never brought up
Maya Sundaresh walks at the center of the group. She's been too quiet lately. What happened to them wasn't her fault and maybe she'll believe that soon. "What could you do with it?" she murmurs, staring up. "If you understood it?”
Note: Maya is directly specified as a female here.
Chioma puts an arm around her. "That's what we're going to find out. Where the Citadel can send us. Whether we can come back."
"They're not us any more." Maya looks down at herself, at the cache of her self-forks. "We're not going anywhere. We're sending them. They're diverging."
They rescued themselves from the inside of a Vex mind, two hundred and twenty-seven copies of themselves, untortured and undamaged. Those copies voted, all unanimously, to be dispatched into the Vex information network as explorers.
227? Hmm. Where have I heard that number before?
When Maya and Chioma look at each other they can tell they're each wondering the same thing: how many of them will stay together, wherever they go? How many fork-Mayas and fork-Chiomas will fall out of love? How many will end up bereft, grieving? How many will be happy, like them?
Chioma tries a little smile. Maya smiles back, haltingly, and then, sighing, unable to stop herself, grins a big stupid grin, an everything-is-okay grin. Shim makes a loud obnoxious awwww at them. Duane-McNiadh is still thinking about paracausality, and doesn't notice.
Maya and Chioma are in love. Golden Age tolerance for the win!
They climb. When they find the Vex aperture they plan to use, they overlay the luminous stone and ancient brassy machines with images of sun and sand. They set up the transmitters and interfaces that will translate two hundred and twenty-seven simulations of the four of them into Vex language, into the tangled pathways of the Vex network, to see what's out there, and maybe come home.
In the metaphor they've chosen, setting up the equipment is like laying out the picnic. In the metaphor they've chosen they look like themselves, not hardened explorer proxies. Like people.
Our scientists plan is revealed here. They have rescued 227 copies of themselves from the simulated realities they were stuck in, and all of those copies of themselves are accurate simulations - THEY ARE REAL PEOPLE. Those copies have decided that, since they are simulations, they can probably be translated into the Vex network and explore, and try to get information back for humanity. This is where the story takes an interesting turn.
"Do you think," Duane-McNiadh begins, halting, "that you could use this place to change things? If you regretted something, could you find a way through the Citadel, go back, and change it?"
"I wish I could go back and change you into someone else," Dr. Shim grouses. Chioma's shaking her head. She knows physics. "Time is self-consistent," she says. "I think it's like the story of the merchant and the alchemist. You could go back and watch something, or be part of something, but if you did, then that was the way it always happened."
"Maybe you could bring something back to now. Something you needed." Maya runs a hand across the surface of the Vex aperture, feeling it with sensors ten thousand times as precise as a human hand. These proxy bodies are limited— they crash and need resetting every few hours, they struggle with latency, they can't hold much long term memory. But they'll get better. "Or go forward and learn something vital. If you knew how to control it, how to navigate across space and time.”
The scientists begin to think that they can use time travel to change something. Maya and Chioma are taken by this idea. but maya’s paragraph is particularly interesting. these proxy bodies are limited, they crash and need resetting, struggle with latency, can’t hold much long term memory. BUT THEY’LL GET BETTER. SHE IS CONSIDERING SOMEHOW TIME TRAVELLING TO CHANGE THE PAST AND FUTURE INSIDE A MORE ADVANCED PROXY BODY. This is super super important.
Note: the Story of the Merchant and the Alchemist was a very interesting read. Released in 2007, it's a short story and i recommend it. basically the theme is that Time travel in Destiny is done "LOST" style: what happened happened and events can't be changed, because they always happend that way.
"So it's just a way to make everything more complicated." Duane-McNiadh sighs. "It doesn't fix anything. Nothing ever does! I should've taken that job at— "
"You would've hated it at Clovis," Dr. Shim says. "We both know you're happier here." Duane-McNiadh stands stunned by this courtesy, and then they both pretend to ignore each other.
The four of them set up the interface. Their stored copies wake up and prepare for the journey, so that as they work they find themselves surrounded by the mental phantasms of themselves: two hundred and twenty-seven Mayas and Chiomas knocking helmets and smiling, two hundred and twenty-seven Dr. Shims making cynical bets with each other about how long they'll last, two hundred and twenty-seven Duane-McNiadhs blowing goodbye kisses to the sweet golden sun, two hundred and twenty-seven of them shaking hands, smiling, making ready to explore.
That’s what we have so far on the vex. so how does this tie into the exo?
Here’s my theory. The Exo were created during the golden age to allow humanity to combat the Vex.
Here’s the exo card:
Built for a long-forgotten struggle, Exos are self-aware war machines so advanced that nothing short of a Ghost can understand their inner functions. They remain ciphers, even to themselves: their origins and purpose lost to time.
Whoever built the Exos fashioned them in humanity's image, gifting them with diversity of mind and body. Many of the City's Exo citizens live and work alongside their organic brethren. But others fight again, re-forged in the Light of the Traveler to serve as Guardians.
The Exo are specifically designed to be a cipher. This ‘encryption’ is a defense against the vex. We know from the card that the vex basically have thought weaponry, and the exo is probably hardened against that type of thing.
The Exo are an advanced form of the “proxy bodies” that our intrepid scientists were utilizing in Vex 4. Golden age humans could be installed in these ‘robot bodies’, enabling them to fight the Vex. But there’s even more here.
The Exo Stranger is either Maya Sundaresh or Chioma Esi. My suspicions lean on Maya. Maya is wondering if you could use a proxy body and the power of the citadel to go back in time. Maya is also from the Golden Age, and knows a lot more about what’s going on in the solar system than anybody else. I think that Maya is working with Chioma or Duane-Mcnaidh, our intrepid scientists are orchestrating everything to try and change the past (their future)
The Stranger meets you on the moon, and immediately directs you to go to the Ishtar Collective on venus to introduce you to the Vex. The stranger does everything she can to change the timeline, and she doesn’t even have time to explain why she doesn’t have time to explain. And on top of everything else - the stranger KNOWS YOU.
Do you remember the only scientist in our group whose gender was never specified?
Which brings us to yet another clue. In “The Archive” story mission, when you descend into the ishtar collective’s data archive, the archive computer snaps on and says “Welcome Dr. Shim”. We get a nice little quote from Ghost here. he says: “Dr. Shim? NEVERMIND THAT…”. Not “Dr. Shim? What is she talking about?” or “What does that mean?” but “Nevermind that.”
We are Dr. Shim. maybe not his/her personality, or him/her specifically, but we are a guardian occupying Dr. Shim’s body. Maya (the stranger) recognizes us. That’s one of the reasons she is so interested in tracking us. She is trying to figure out what the traveler is trying to do with Dr. Shim’s body.
I’ll wrap this up here for now, but I’m interested in hearing your thoughts on this. Here’s a TL;DR