We can definitely travel to other stars, basically for sure

Eerik Wissenz
6 min readSep 17, 2021
Photo credit space

In “Why There Are No Space-Faring Civilizations” Allan Milne Lees argues, as the title suggests, it’s argued it’s impossible.

I am not a space “fanboy” Allan Milne Lees decries.

I definitely view current money’s (investor or private) for humans in outer space is a complete waste of money and distraction.


  1. We have a planetary emergency right now.
  2. Although (as I’ll argue below) we can colonize space, it’s simply impossible anytime soon.
  3. Even when it becomes possible it may take centuries of technological dependence (replacing those 3D printer and laser heads and computer chips and so on) before there is a self sustaining space colony anywhere.

Therefore, if you want humanity to become space faring, you should first put all your effort into making sure humanity is decently earth-faring.

Nevertheless, although I understand the negative sentiment about our current billionaire fetish contest, and also the negative sentiment of all the fans distracted by this circus rather than focusing on something important, I don’t like bold statements that are simply false.

Credit where credit is due: people in the comments to the article in question have pointed out a lot of criticism and faults already, such as basic physics misconceptions, AI would have no biological problems and not ruled out by the authors , so feel free to go to the article I’m rebutting and check out those comments (I have not checked since). So, please visit the article and check out the comments for a lot of existing criticism.

If they are solvable for humans, then things distributed in bell curves as they are, if there are other technological civilizations there’s going to be some that it is even easier to solve. For instance, any species that floats in water may have little problem with zero g’s in space at all.

As for the solutions

It is definitely true that constant acceleration to simulate gravity is completely impossible. Author is correct on this point.

The author is also correct that humans would have a hard time in a rotating

This is true as well.

However, there is zero evidence currently that humans can’t simply adapt to the physics of a rotating platform. It maybe dizzying only at first, or only to some people. Fighter pilots can sustain long period of difference forces that would make any “tourist” vomit. Likewise, sailors can compensate all the motions of the rough seas with ease to do their work while a large part of the passengers are sea sick.

From planes and ships, the strange forces of a rotating maybe harder to adapt to (but some people manage) or may actually be easier, as it’s at least constant and predictable compared to a boat in a storm or a fighter jet in a dog fight.

If the rotation solves all the heart and muscle mass problems, then the remaining adaptation to dizziness seems like a small obstacle.

It maybe simply an easy problem that most people just get used to relatively quickly, or there’s simply enough people not bothered by it to easily form space crews.

What if it’s harder?

It could be harder, we don’t know. It’s difficult to check on earth since a whole G force of rotation would add to the normal G force of being on the earth; and 2 G forces wouldn’t be a good short term test as it’s very different to a 1 G force in space, and a long term test may give all the subjects heart failure.

And, this experiment has been done and I’ve participated in it.

When I was a kid, the “gravitron” was still a thing and not illegal. I assume it’s illegal, well at least in Europe, as I haven’t seen one in a long time.

The gravitation was just a cylinder that spun you around until you could walk on the walls (if you had a “cool” teenager controlling the thing that couldn’t care less what you did). It was weird, for sure, but puking in it was unusual. Some kids would get overwhelmed with nausea, but most of us would sit up, crawl around, try to reach the center of the thing (again, if a cool teenager was in charge). In was honest amazing and I wish I had one.

OMG. Stop the presses! Yes, Gravitron has injured children, several times, according to Wikipedia, but it’s still operating around the world. Even one in Finland! At Tivoli. So, I will go and report back.

And here’s a wikipedia picture of the Gravitron in all it’s glory.

Photo credit Lzcracker

Point is, after experiencing the gravitron and all the wonky effects being stuck to the inner side of rotating cone has, it’s pretty difficult to imagine that making it only 1G of force in space would suddenly create the catastrophic effects the author describes.

It could be more difficult to adapt to rotating conditions.

However, the space station has demonstrated fairly long term survivability of micro gravity.

Even staying in micro gravity we basically have a single generation of technology. With more experience, technology and tricks, maybe years of micro gravity is doable.

I would, however, agree that the order of magnitude improvement for surviving micro gravity for any stellar travel do seem likely undoable.

However, combining improvements in surviving micro gravity and a rotating artificial gravity seems a fairly easy solution to implement.

Maybe “working” in the centrifuge is as difficult as the author describes, in which case people can just sleep, sit, do basic exercise in the centrifuge, but need to exit into micro-gravity to get any work done.

There’s lot’s of other problems, but they can all be solved by shear mass and huge amounts of energy. Simply more mass would protect from cosmic rays, provide centuries of fuel, protect from micro impacts, and so on.

As for gravitational problems of colonizing something at the end of the trip, that’s easy to solve by simply going to moons and planets with close to the same gravity as earth.

Going to other start is possible with today’s technology

It would just take literally centuries of building space stations and space bases around the solar system and building an absolutely massive space ship that is truly self sustaining (may need to be a small city) in which people can live (and reproduce the technology they need to live) for decades if not centuries.

It would not be so difficult to design such a craft right now directly into a large asteroid, comet or small moon in the solar system (provide all that mass to solve all the problems), but actually building such a thing could be a millennia scale project, but we could get there with a sustained effort.

If any of the breakthrough that space junkies like to talk about happen, it would be even easier than that.

Of course, our technological civilization does not have a millennia on it’s current trajectory.

So, if you want to “save the species” you should probably focus on saving our current habitat.

Where the author is correct is in the basic conclusion that space fairing, Space fairing

Since it’s just annoying, I’d also like to simply solve the engineering problems the author presents for humans.

One more thing

I can’t help but mention that any species that evolves in a small amount of gravity, especially in a particular sweet spot, would have an incredibly easy time of exploring space (assuming they’re a technological civilization as the author posits).

If evolved on something like asteroids or small moons … they would essentially be already adapted to space, so only need an artificial energy source to replace their natural one and they’re good to go.

The author flippantly casts them aside as potential space fairers because they can’s experience much acceleration.


Slow acceleration is what’s most efficient in space, so our aliens need only find a smaller rock in their solar system and turn it into a spaceship and accelerate slowly so it’s unnoticeable. Since it’s space, fuel tanks can be placed far away from the mother ship so their decrease in mass (which maybe substantial depending on the distance) over the trip doesn’t affect the gravity of the mother ship. Problem solved. Slow acceleration over a long period of time is what’s most efficient with current technologies anyways.

Case. Closed. Or is it?

You decide, by criticizing my criticism of criticism of “space travel fans”.