Comments on: One answer to the Fermi Paradox that I don’t think people consider as seriously as they should

By: RL

RL — Sun, 19 Dec 2021 16:43:39 +0000

We know that putting humans in zero gravity CAN have serious long term impacts to their physiology… but- as Raoul points out- those can be potentially overcome…

What I find surprising is that removing gravity is not more IMMEDIATELY fatal – that in over 3 billion years not one single essential metabolic process evolved a critical dependence on gravity, or the physical processes that gravity enables.

Convection, separation of fluids by density, gravitational organization
of the distribution of fluids and solids in the body… apparently none of that is critically important to our ability to live. Sure there might be some effects that could shorten lifespan, not a lot of long term data, but people have spent over a year in microgravity and survived. In fact, not one person has died from a health issue in orbit.

I find it surprising the effects are so benign.

Probably my surprise is simply a result of my lack of knowledge about biology- because it isn’t just humans that can survive zero gravity- pretty much any Earth organism seems to be able to survive it with varying degrees of impairment… The processes of life must be, for some reason I don’t understand, fairly agnostic to gravity- I find that odd, given it is pretty much the ONLY constant in our over 3 billion years of evolution.

In over 3 billion years, something as fundamental as the way fluids of different densities behave when mixed in the presence of gravity NEVER became critical for cellular functioning.

I find that rather shocking… which probably means I am overlooking something obvious, I would like to know what that is. It certainly seems to be the case that it’s just not that critical for Earth life- but is that just an astronomical fluke? It seems easy to come up with countless ways evolutionary shortcuts on other planets might lead to a life form that cannot survive even brief exposure to zero-Gravity…

By: Raoul

Raoul — Sun, 19 Dec 2021 10:42:04 +0000

It might be we need a world with gravity and not necessarily 9,81 m/s/s. Why not imagine exoskeletons for those who have been living too long on Mars and would like to visit their parents on Earth? Or a space station with wheels creating various acceleration fields so that those from Earth can visit those from Mars for a few weeks, only not on a planet but in a station? Earth and Venus have roughly the same gravity. Mercury and Mars have exactly the same gravity. The Moon, Ganymed, Europa, Titan, Triton have roughly the same gravity.

By: ER

ER — Wed, 15 Dec 2021 05:42:32 +0000

I once feared that if prolonged exposure to zero-g was toxic to the human metabolism, then manned space travel would never happen. In fact, early space explorers and planners feared this too. It was one of the “hazards” of space travel (like meteor strikes)that never fully materialized, but were anticipated with dread.

I guess the answer lies in that living organisms are essentially bags of colloidal solutions, and chemical reactions occur just as easily whether or not in the presence of a gravitational acceleration. Still, we do know there are long term negative metabolic effects of prolonged exposure to zero-g, even if they are not immediately fatal.

By: podrock

podrock — Wed, 15 Dec 2021 03:07:05 +0000

in my opinion. What is the record for a human’s time in space?

When there is a human born in zero G, raised in zero G, and then gives birth in zero G…

Then we will see the true effects.

And would such humans, born to space, ever be able to survive in gravity?