In 1960, visionary physicist Freeman Dyson predicted that advanced alien civilizations would one day stop fooling around with kindergarten-level stuff like wind turbines and nuclear reactors, eventually going big and becoming homestars. and proposed to get as much solar energy as possible. Then they used that huge amount of energy to mine bitcoin, create funny videos on social media, Delve into the deepest mysteries of the universe and reap the benefits of an energetic civilization.
But what if an alien civilization… were us? What if they decided to build a Dyson sphere around the sun? How much energy would it take to reconfigure the solar system and how long would it take to recoup the investment? Even so, you have to decide if it’s worth the effort. Can you actually achieve a net increase in energy by building a Dyson sphere?
spherical dyson cow
From the outset, I should state that I am a theoretical cosmologist, not an engineer. We have no idea how to build bridges, let alone the structures that reshape the very face of our solar system. I think. It’s not clear what technological advances would be needed to build a structure that even partially covers the sun. Guess that he is sci-fi. Fun, but not very meaty.
But what I do know is physics, and there are some things I can say about the physics of a Dyson sphere. can. And this is important. Because even if our descendants come up with technologies so advanced that they can tear apart planets, indistinguishable from magic, they still have to face the cold, harsh reality of our physics. Because they can’t get anything for free. If they want to remake the planet, it needs energy. Energy is also required to move a mountain-sized solar panel to another orbit.
For these and many other reasons, a Dyson sphere takes energy. So we’ll look at how long it will take to recoup the building’s energy investment and what the best design is to minimize the initial investment.
We make a lot of assumptions to get some numbers. People like to make fun of physicists for simplifying complex problems. An old joke is that a dairy farmer contacted a nearby university to help figure out why their milk production was low. The reaction from physicists began by assuming that the cow is spherical.
But there is something powerful about this simplification approach, which is why physicists are being trained from day one. First, it allows you to answer the question even if you’re not interested in exact numbers at first. A general sense of feasibility is needed here. Does it require a (relatively) small, moderate, or extreme amount of energy to build a Dyson sphere? helps to hide the If all we’re after is a generic ballpark, a mistake of 1 in 2 (or even 10 or 100) doesn’t really change the overall intuition that the math allows.
Finally, we literally don’t know how to construct a Dyson sphere, so trying to make something more complex means introducing even more assumptions to handle all the details. Each increases the uncertainty of the numbers we generate. That uncertainty can be buried in the analysis rather than simply stated upfront.
