
How Long Was Venus Habitable? - rbanffy
https://eos.org/research-spotlights/how-long-was-venus-habitable#.XralmVMHBZM.twitter
======
cletus
So there a few comments scattered around about this so I'll address those
concerns here. Quite a few people are scoffing at the idea of colonizing Venus
("you'll get crushed, dude!") but the idea has had a lot of people put thought
into it and it's not as impractical as you may think. Consider:

1\. Venus is easier to reach than Mars. The Delta-V is 0.4km/s and 0.7km/s
respectively [1];

2\. Mars has practically no atmosphere and really low gravity. It's really not
that much better than colonizing the Moon but a whole lot further away [2].

3\. You wouldn't live on surface of Venus, at least not initially. You'd live
in the atmosphere [3].

4\. Energy will be plentiful on Venus, far more than on Mars or even the
Earth, just from solar energy. [4]

5\. Venus has nearly Earthlike gravity.

So it's actually not as crazy as you might think and shouldn't be immediately
dismissed.

[1]: [https://space.stackexchange.com/questions/2156/does-a-
missio...](https://space.stackexchange.com/questions/2156/does-a-mission-to-
venus-orbit-require-less-propellant-than-a-similar-mission-to)

[2]: [https://qz.com/1105031/should-humans-colonize-mars-or-the-
mo...](https://qz.com/1105031/should-humans-colonize-mars-or-the-moon-a-
scientific-investigation/)

[3]: [https://www.youtube.com/watch?v=BI-
old7YI4I](https://www.youtube.com/watch?v=BI-old7YI4I)

[4]: [https://www.extremetech.com/extreme/196114-nasa-is-
developin...](https://www.extremetech.com/extreme/196114-nasa-is-developing-a-
plan-to-explore-venus-in-a-manned-solar-powered-ariship)

~~~
alistproducer2
I enjoy Isaac Arthur's YouTube channel where he explores topics like
colonizing Venus. Here's the video: [https://m.youtube.com/watch?v=BI-
old7YI4I](https://m.youtube.com/watch?v=BI-old7YI4I)

~~~
keithnoizu
Goes to get a snack.

------
mentos
Anyone else feel the solution isn’t figuring out how to create or find a new
earth but move our consciousness to silicon so that it does not have such a
fragile requirement to exist?

~~~
EdwardDiego
Assuming that's even possible (how are those simulated brains going? As far as
I can tell, we're up to 0.15% of a rat's brain), is a human consciousness
separated from its biological construct still a human consciousness?

We're well out of the realm of science into science fiction, but I feel it's a
valid question to ask - all of our consciousnesses have developed in ape
bodies adapted for the savanna, with a bunch of survival related traits and
sub-processes.

If we remove our "selves" from our bodies, are we still us?

~~~
chispamed
It's really difficult to draw a line between being our "selves" and the
alternatives though.

We are not the individual cells of our body because most of them will be
replaced in the next weeks/months/years. We also don't think of any body with
a knee replacement as any less human. Even altering the genetic code of a huge
part of your body, like after stem cell transplantation, is not commonly seen
as making us less us.

Also suppose it was possible to build a synthentic neuron that behaved just
like the ones inside your brain. If you started replacing your neurons with
the synthetic ones, no individual neuron would "change" you. So were would you
draw the line? At 10% synthetic neurons? At 20%? At 100%?

If we see ourselves as biological beings another interesting point is how you
would view a 1:1 copy of yourself. If we constructed a synthetic human that
had the exact same number of molecules in the exact same place as you, would
that human be you? (Leaving aside that that's basically impossible, just as a
thought experiment)

If you answered the last question with "no", that would also mean that not
even the way we process information and think makes us us, since the 1:1
molecular clone would behave exactly the same as you in the same environment
(in a purely deterministic universe at least, leaving aside probability and
Heisenberg's uncertainty principle).

So are we instead an _uninterrupted_ instance of a thinking process? That
would allow us to differentiate us from the exact clone. However in that case,
would you be another person after being unconsciousness? What about general
anesthesia? This really keeps me up at night.

It's next to impossible to define what we are and that we think of us as
independent, unique beings might just be an illusion.

~~~
lisper
> This really keeps me up at night.

Why? You're pretty close to the right answer:

> are we instead an uninterrupted instance of a thinking process?

No, for the reasons you described. What we are is thinking-processes with a
coherent series of more-or-less-uninterrupted links to the past. When you
undergo general anesthesia you wake up as the same person because you can
_remember_ who you were before anesthesia, and you feel and act like that
person.

The interesting case is not anesthesia (or sleep) but amnesia and traumatic
brain injury or mental illness that changes your personality.

~~~
chispamed
I understand where you're coming from, however I think that remembering the
past is not a very helpful criterium since memories correspond to physical
changes in the brain. In the thought experiment, the 1:1 molecular clone would
have the same memories and think that he had lived through the same things as
the original human for what it's worth. I'm not yet convinced that it is
possible to define one self even though our (physiological) human experience
definitely makes us feel like we were this clearly defined, independent,
conscious thing.

But of course the conditions you mention are also very interesting and make it
non-trivial to define the "true" essence of the person. Another interesting
one would be dementia.

~~~
lisper
> In the thought experiment, the 1:1 molecular clone would have the same
> memories and think that he had lived through the same things as the original
> human for what it's worth.

That's right. Why is that a problem?

Imagine you had this done to you, and imagine that in order to clone your
brain you have to be put under anesthesia (because the process takes time and
you need to capture a coherent snapshot). When you wake up, how are you going
to tell whether you are the clone or the original?

~~~
chispamed
I don’t see it as a problem per-se, it just defies the notion of having a
somehow unique, identifiable _self_ which I understood as a condition for OP’s
question and which I suppose is how most people view themselves.

As far as I’m concerned we might very well be just processes that can in
theory be copied and recreated. In that case the person in the thought
experiment would exist twice at a single point in time and then diverge into
to different persons due to different environments and probabilistic processes
in the body.

~~~
thaumasiotes
> As far as I’m concerned we might very well be just processes that can in
> theory be copied and recreated. In that case the person in the thought
> experiment would exist twice at a single point in time and then diverge into
> to different persons due to different environments and probabilistic
> processes in the body.

This already happens, though before the formation of any memories. We call
them identical twins.

The divergence is more limited than you might imagine. One striking experiment
found that if you separate identical twins and give them the instructions
"just draw whatever comes into your head", they are likely to draw the same
things.

------
rishav_sharan
More fun are the couple of comments in the article. I am still not sure if it
is sarcasm or an actually half-decent theory.

~~~
madaxe_again
I actually kinda like that retrograde moon hypothesis - it’s heavy on
inference and induction, but it largely meshes neatly with observed phenomena
- although if you had had an alien biosphere come crashing into earth, you’d
expect to see that in the tree of life, and afaik there isn’t a sudden
injection of completely novel phyla at 540ma - just evolution of what was
there before.

~~~
rbanffy
If an independently evolved biome were introduced, it'd be on a totally
different tree, sharing very little with our own.

~~~
ramraj07
True unless we assume venusivian and terrestrial life both had a common origin

~~~
ComputerGuru
It would be insanely improbable for independent life to have formed separately
in such close proximity. The odds of that are entirely dwarfed by the far more
likely panspermia scenario.

~~~
rbanffy
Is there any evidence of a panspermia?

~~~
ramraj07
No more than evidence of life forming on earth which is zero. I've thought
about it semi professionally for long, and my bet would be on panspermia.
Heck, my bet would be that all life in our galaxy is probably from the same
origin; it seems fairly easy for at least some microbes to survive on rocks
for really long periods of time, and my guess would be that once one form of
life takes hold in a place other competing forms would probably get fully
eliminated. Thus it stands to reason that panspermia is more probable. This is
supported further by how quickly life seems to have appeared on earth the
moment it was habitable (followed by how it took billions of years after that
to evolve in any meaningful way).

------
m_a_g
I always thought that Venus is a better option than Mars for humans to
colonize if you can cool it down by handling the greenhouse gasses.

Mars can't even retain water vapor.

~~~
mseepgood
First we should turn the Sahara into a lush green forest as an exercise.
Terraforming a remote planet will be a million times more difficult.

Oh, wait, we can't even work together as humanity to contain a virus.

~~~
thysultan
Better to experiment off earth than on it in such planet changing endeavors.
You can afford less attention to (safety)detail in that scenario.

~~~
funnybeam
Or maybe not. Turning the Sahara into a forest would have a massive climate
impact.

I am not a climate scientist but I’d imagine there would be significant
changes to rainfall patterns over most of Europe, Africa, and the Middle East

Edit - sorry, reply was meant to be to parent

~~~
pinkfoot
A fair amount of the phosphorus in the Amazon comes from dust storms
originating in the Sahara.

[1] [https://www.nasa.gov/content/goddard/nasa-satellite-
reveals-...](https://www.nasa.gov/content/goddard/nasa-satellite-reveals-how-
much-saharan-dust-feeds-amazon-s-plants)

~~~
arcadeparade
given that the Sahara is only a couple thousand years old does that mean the
amazon is just as young?

~~~
macintux
An interesting article on how people shaped the Amazon.

[https://www.theatlantic.com/science/archive/2017/03/its-
now-...](https://www.theatlantic.com/science/archive/2017/03/its-now-clear-
that-ancient-humans-helped-enrich-the-amazon/518439/)

------
blackrock
I would think that Venus would have a lot of precious metals: gold, silver,
platinum, titanium, etc. As well as rare earth metals.

It would be a great opportunity to one day build a strip mining colony on
Venus, and ship those metals to Earth, and build future space colonies. But it
might be easier to find some random floating asteroids that contain all those
valuable metals.

I think the most important ingredient that Venus does have, is gravity, that’s
near similar to Earth. This means that humans can live on the ground, and not
be subjected to mass and bone deterioration of living on Mars.

But first, we’ll need to solve some engineering problems, like how to cool the
place down. Maybe throw up some solar shades, and harvest the sun.

~~~
rbanffy
All the minerals on Venus are at the bottom of a gravity well as deep as ours.
Moon is a much better short term goal.

~~~
mLuby
Yeah, even the Moon's gravity well is huge compared to metal-rich asteroids.
They're the low-hanging fruit of space mining.

~~~
rbanffy
True, but the Moon's gravity makes a lot of industrial processes easier to
adapt. Also, it's easier to keep a human crew around for repairs.

------
Koshkin
To the skeptics, read Stapledon’s _Last and First Men_.

------
b34r
The comments on that article are very entertaining

