Anyone who ever had the pleasure of talking to Freeman Dyson knows that he was a gracious man deeply committed to helping others. My own all too few exchanges with him were on the phone or via email, but he always gave of his time no matter how busy his schedule. In the article below, Colin Warn offers an example, one I asked him for permission to publish so as to preserve these Dysonian nuggets for a wider audience. Colin is an Associate Propulsion Component Engineer at Maxar, with a Bachelor of Science in mechanical engineering from Washington State University. His research interests dip into in everything from electric spacecraft propulsion to small satellite development, machine learning and machine vision applications for microrobotics. Thus far in his young career, he has published two papers on the topics of nuclear gas core rockets and interstellar braking mechanisms in the Journal of the British Interplanetary Society. He tells me that when he’s not working on interstellar research, he can be found teaching music production classes or practicing martial arts.

by Colin Warn

Three years ago, I decided to make a switch from being a part time dance music ghost producer to study something that would help advance humanity’s knowledge of the stars. Eventually, I decided that something would be mechanical engineering, a switch which was in no small part due to space podcasts that introduced me to cool technologies such as Nuclear Pulsed Propulsion (NPP): Rockets propelled by small mini-nuclear explosions. The man behind this technology? Freeman Dyson.

Dyson worked on Project Orion for four years, deeply involved in studies that produced the world’s first and only prototype spacecraft powered by NPP. Due to the 1963 Partial Test Ban Treaty, which he supported, humanity’s best bet for interstellar travel was filed away. Yet, something about the audacity of this project resonated with me decades later when I uncovered it, especially when I found out that Dyson was in charge of this project despite not being a PhD.

So, as a bright-eyed and optimistic freshman entering his first year of college, figuring that out of anyone in the world he would have the best insights on what technology would lead humanity to the stars, I decided to send him this email:

Hello Professor Dyson,

My name is Colin Warn, and I’m a freshman pursuing a degree in mechanical engineering/physics.

Had a few questions for you regarding how I should structure my career path. My ambitions are to work on interstellar propulsion technologies, and I figured you might know a thing or two about the skill set required.

If you have the time, here’s what I’d love to hear your opinion on:

1. What research/internships would you suggest I focus on as an undergraduate to learn the skills that will be needed for working on advanced propulsion technologies? Especially in my freshman and sophomore years?

2. For my initial undergrad years, would you suggest that I focus more on taking physics or engineering courses initially?

Thank you so much in advance for your time. Been reading the book your son wrote about Orion. Let’s just say the reactions I’ve been getting from my friends when I tell them what I’m reading about is already quite fun to observe.

Regards,

-Colin

I sent it to his Princeton email, as I’ve sent many emails in the past to fairly high-caliber people, without a hope of getting anything in return.

Two days later, I woke up to find this email in my inbox.

Dear Colin Warn,

I will try to answer your two questions and then go on to more general remarks.

1. So far as I know, the only techniques for interstellar propulsion that are likely to be cost-effective are laser-propelled sails and microwave-propelled sails. Yuri Milner has put some real money into his Starshot project using a high-powered laser beam. Bob Forward many years ago proposed the Starwisp spacecraft using a microwave beam. Either way, the power of the beam has to be tens of Megawatts for a miniature instrument payload of the order of a gram, or tens of Terawatts for a human payload of the order of a ton. My conclusion, the manned mission is not feasible for the next century, the instrument mission might be feasible.

For the instrument mission, the propulsion system is the easy part, and the miniaturization of the payload is the difficult part. Therefore, you should aim to join a group working on miniaturization of instruments, optical sensors, transmitters and receivers, navigation and information handling systems. These are all the technologies that were developed to make cell-phones and surveillance drones. An interstellar mission is basically a glorified surveillance drone. You should go where the action is in the development of micro-drones. I do not know where that is. Probably a commercial business attached to a technical university.

2. For undergraduate courses, I would prefer engineering to physics. Some general background in physics is necessary, but specialized physics courses are not. More important is computer science, applied mathematics, electrical engineering and optics, chemistry of optical and electronic materials, microchip engineering. I would add some courses in molecular biology and neurology, with the possibility in mind that these sciences may be the basis for big future advances in miniaturization. We still have a lot to learn by studying how Nature does miniaturization in living cells and brains.

This email contained more detailed insights to my questions than I could have ever hoped for. Then to top it all off, he still had one more piece of advice for me to a question I hadn’t even asked.

General remarks. In my own career I never made long-range plans. I would advise you not to stick to plans. Always be prepared to grab at unexpected opportunities as they arise.Be prepared to switch fields whenever you have the chance to work with somebody who is doing exciting stuff. My daughter Esther, who is a successful venture capitalist running her own business, puts at the bottom of every E-mail her motto, “Always make new mistakes”. That is a good rule if you want to have an interesting life.

With all good wishes for you and your career, yours sincerely,

Freeman Dyson.

Upon reading this email in 2018, I promised myself that one day I’d put myself in a position to thank him in person. Sadly I’ll never get the opportunity. I discovered watching an old YouTube video featuring him that he died in February of 2020.

So this article is my way of saying thank you to him. For creating literal star-shot projects to inspire a new generation. For being someone who always questioned the status quo. But most of all, for still being down to earth enough to email some amazingly insightful answers to a freshman’s cold-email. I hope one day I’m in a position where I can pass on the favor.