Say you are born on a planet with 1G surface gravity and are of a species adapted to this. Your society has well-established colonies on other planets in your system which have been extensively terraformed to be suitable for life, but these planets are larger and have higher surface gravities.

You grow up to take on some kind of civilian job where you need to frequently travel to these planets, staying upwards of ~1 (Earth-)month at a time, but the majority of your life will still be spent on your home planet.

How noticeable, uncomfortable, or damaging might these short-term, business-trip style stays be on planets with 1.05g, 1.10g, and 1.20g surface gravities respectively? Would your job only be tolerable for well-trained, very fit young people, or can elderly tourists from your home planet go on bus tours on the higher-gravity worlds (at least the 1.05g one?) with little risk? ...What about even higher surface gravities?

(Ignoring the journey; let's say interplanetary space travel has gotten to the point where it's as comfortable and safe as long passenger airline flights in our world)

For my purposes, I'm pretty comfortable with the idea that settlers and people born on these high-gravity terraformed planets would be able to acclimatize. Perhaps the first settlers were even selected for their ability to tolerate high surface gravities, or genetically engineered. However, I'm trying to flesh out the experience of "frequent flyers" as I would like the flow of people between planets to be fairly commonplace.

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    $\begingroup$ there are many questions already about living on higher gravity. Please specify what isn't answered there that you need answered here. That apart, you are asking 4 different questions in a single post. We take only 1. $\endgroup$
    – L.Dutch
    Feb 16 at 4:37
  • $\begingroup$ If you're comfortable that people can acclimatise to sustained living in higher-G then you need to explain how that works in your universe, since you're beyond known science already. In the real world, billions of people have lived practically their entire life in 1G, a handful of people have spent periods between days and a year or so in zero-G and have experienced other G values for seconds (a handful for minutes) at a time. Whether living in other gravity is long-term survivable, let alone able to be acclimatised to, is totally unknown - insufficient data. $\endgroup$ Feb 16 at 5:07
  • $\begingroup$ @KerrAvon2055 Actually people have experienced higher gravity in centrifuges for shorter or longer periods of time in various experiments, so there some evidence about how specific gravity levels affect people over hours, days, or a week or two. $\endgroup$ Feb 16 at 5:17
  • $\begingroup$ Just to be clear: 1.05 g, 1.10 g, 1.20 g are 3 separate questions, plus "what about even higher surface gravities?". Just making the questions bold doesn't change that they are more than 1 $\endgroup$
    – L.Dutch
    Feb 16 at 6:04

1 Answer 1


Not directly the same, but for a first approximation you could imagine that person to carry a (perfectly strapped) backpack with 0.05 times to 0.2 times their own bodyweight (including cloths etc). However they can not put down the backpack ever. Laying down will distribute the additional weight better and you could consider laying under a VERY heavy blanket. But you can never get rid of said backpack.

A young very fit person should not have to many trouble with a lets say 8kg backpack (so 80kg person in 1.10g) but would still be constantly exhausted and need probably more sleep and probably develop problems with their back much faster.

Forcing my grandpa to carry around even a 4kg backpack the whole day and night would just be cruel (considering about 80kg body + cloth weight). Let alone 8kg or 16kg. He would collapse after max 2-3 days and probably not be able to stand up alone anymore.
Though there are some quite fit elders who MIGHT handle 1.05g or 1.1g for a few days to visit relatives. They won't be swinging little kids around though and be quite exhausted when they return. The constant exhaustion will probably also impact their mood negatively. Time for a vacation to rest from the vacation.

I'd recon that for your specific job it would be far more resonable to hire someone growing up and living on one of the planets with high gravity. The slightly lower gravity will just make them feel light on their feet and give them a bit trouble walking around for the first few days. They would look a bit clumsy like seamen that spent multiple months or years on the sea and now return back to land.

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    $\begingroup$ I don't think a backpack is anywhere close to increased gravity: it doesn't make pumping your blood more difficult because the blood is heavier and so on $\endgroup$
    – L.Dutch
    Feb 16 at 9:43
  • $\begingroup$ Thats why I said as a "first approximation". Also for example in 1.05g I don't think the increased blood weight would be that impactful (1.2g however yes there would be additional factors especially in the first time until the body adjusts). Otherwise we simply don't have data of even a single person "living" in higher than 1g. $\endgroup$
    – datacube
    Feb 16 at 10:56

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