When I was in college, we had a workshop with a guest speaker, and I will never forget the words that he started with: "what we're all doing here is trying to achieve perfection in our fields. We've been taught that if we do that, we will be successful in life. But the truth is that perfection is the bare minimum requirement. If you reach a certain point in your careers, all of your competition will also be perfect at their jobs. What you need is to have something unique to offer."
Creating that bare-minimum perfection to me starts with hard work. If you don't have the foundation to back yourself up, it doesn't matter how hard you try to sell it (even if you succeed, you won't last long afterwards). Often hard work requires some inspiration to be sustained, and it sounds like your son is very inspired by math and physics.
The next part of perfection is making your developed skills available to be used (if no one has access to the benefit of what you can do, no one will care). This means 1) offering your skills in relevant situations - whether it's helping move furniture or solving a difficult engineering problem; 2) saying yes when you are asked to contribute your specialized skills (and frankly saying yes if the request is something you're able to do, even if it doesn't specifically require your expertise); 3) following through, which means doing what you say you'll do by your deadlines, and showing up on time (or early) whenever you're expected to show up. In my experience, this set of skills poses some challenges for people on the autism spectrum: obviously it can be hard to volunteer yourself if you have social anxiety, but more than that, there can be strong resistance to the idea of maybe sacrificing some of the desired perfection in the product being created in order to have something that is good enough by the deadline. Also, it's hard to think ahead far enough when planning to be on time for things to organize all of the details (such as where are my shoes/keys/phone, did I eat breakfast, do I have a map, did I lock all the doors etc) which need to be taken care of in order to leave the house on time, and this show up on time. I'm not sure how best to coach your son on these things, but you are probably better equipped than most to be able to figure something out.
The last part is being able to get your skills successfully implemented on a larger scale by being able to 1) accurately communicate your ideas to others (which I would imagine your son is probably rather good at); 2) enroll the listener in the positive potential of the idea (which definitely takes practice for everyone - we often feel like the merits of our ideas should speak for themselves); 3) be able to work with people so that your idea can benefit from the hard work of others, rather than just yourself.
This last part is where most of those social skills come in which were so thoroughly addressed in a previous response, but I'll summarize here: at the very least, it will be problematic if you appear unapproachable or are constantly making people feel uncomfortable. So it's good to have an easy-going and forgiving attitude. At the same time, you don't want that to compromise the quality of the work, but if you are focused and stay on task (which again is probably a strength of your son's), that goes a long way to ensuring everyone else does too.
Dealing with conflict is hard for all people, but maybe more so for those on the autism spectrum. I would say first that it takes practice, and then add a few pointers to keep in mind: 1) calm is always the superior reaction to conflict. If you can't be calm, excuse yourself for a few minutes and then try again (this has been a very hard one for a couple of friends of mine on the autism spectrum). 2) listen, and verbally acknowledge understanding, even if you don't agree (this is hard too). 3) before moving on to resolving the situation, ask if there's anything that anyone still feels they need to say (it's better to air things all at once when a conflict shows up rather than leaving some things to fester for later). 4) during the solution phase, ask for suggestions, and listen to them (even if you ultimately reject them). 5) if there is still disagreement about how to handle the situation, remember that in a work setting there is a hierarchy, and whoever is at the top gets to make the final call, and it is the responsibility of everyone else to accept that decision, whatever it is.
Following these guidelines will help everyone feel like they are respected, which will make them more willing and able to work together, and will make them feel safe in the work environment - but they are not fool proof! Everyone has to at least implicitly agree to interact in a practical and civilized way, or it doesn't work. Just make sure the person refusing to participate isn't you :)
As far as pointers specific to autism...
1) it is ok to ask for clarification ("I don't know if that was a joke or not")
2) people expect specific physical behaviors in conversation - examples are not standing too close together, and that the listener looks at the speaker the whole time they are talking, but the speaker lets their eyes wander (otherwise the listener comes across as inattentive, and the speaker as overtly authoritarian).
3) any time you feel you are in a situation you can't handle, it is ok to say "I need to step out for a minute, but I will be right back" (and it is important to come back and get through the situation in a timely manner).
Getting people to feel like you care about them is harder, and can be worthwhile, but it is always best if this arises from genuine caring, rather than being contrived. If you (your son) does feel genuine caring for people and wants to develop ways of showing it, here are a few suggestions:
1) ask them questions about themselves, like "how are you?" "What did you do this weekend?" "What are some things you like doing?" - and actually listen to the answers :)
Of course, if you're looking to establish an initial rapport (rather than talking to someone you already know), a good approach for your son might be to invite them to play a game and/or ask to join (or watch) a game that is being played.
Also, if someone asks your son a question about himself, or invites him to participate in an activity, it would be good to recognize an attempt by the other person at rapport/friendship building, and to respond positively (accept the invitation/return the question with one of his own).
The bit about having something unique to offer - it seems from my experience that this tends to naturally come from gaining a high level of expertise at something. Once you've mastered all that has already been done, you can't help thinking "but what if..." As long as he's willing to follow that thought through and see what happens, I don't think having a unique contribution will be something your son struggles with.
In summary (because this got SO long), your success in life is primarily based on your ability to demonstrate your value to others, which requires 1) having value, and 2) being able to show it. The first comes from your own hard (and smart) work, the second from your understanding of others and your ability to communicate effectively with them. Being liked etc isn't necessarily necessary, but not being disliked is usually important - but as long as you are a good person (even-keel, reliable, considerate), people are unlikely to dislike you, even if they aren't particularly drawn to you. In general I think that if people are your kind of people, they WILL like you, and if you try to court the others, you're choosing an external locus for your personality, which is ultimately unsustainable (and tends to make you unhappy).
I wish you the very best of luck with this :) ultimately, I think it's pretty hard to motivate a kid to do something if they don't see a reason for it, and you can't always make them see the reason - but I will also say that if he comes to see the reasons later on, he will still be able to draw on any foundations that you lay now, even if it seems like he isn't really taking it in.