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.
Presumably these delta-v numbers are from some form of earth-orbit. These tend to make a lot more sense, because getting to LEO is mostly not about orbital mechanics, which is where delta-v is the most useful concept.
That said, looking at that wikipedia page these numbers don't match up with any kind of LEO-mars or LEO-venus transfer. Numbers seem to be off by an order of magnitude.
But no matter how you slice it, Venus is easier to get to than Mars, if for no other reason than that aerobraking is a lot easier when your destination has a thick atmosphere so you don't have to carry as much propellant for orbit insertion.
Mars has more than enough atmosphere for aerobraking on arrival (see all mars landers). After that, for subsequent orbit lowering, the density of the atmosphere doesn't matter as you only ever use the upper wisps anyway.
The reason is that you can do lowering incrementally across multiple orbits, but insertion requires a huge delta-V on a single pass. It might be possible in principle, but the engineering challenges are daunting. I don't believe it has ever been attempted.
>>It is used for orbit lowering but not for insertion.
It is not used for insertion of orbiters because strapping some rockets to them is easier/lighter than the heat shields and other equipment that would be needed for braking. They would also have to retract solar panels and do a bunch of other things. The martian atmosphere is more than thick enough to handle the ~1km/s for insertion. All the landers shed more than that (3km/s) on entry from orbit, a maneuver that only uses 1/2 the braking potential of the atmosphere.
Turns out there's a distinction between aerocapture (which is possible but has never been done) and aerobraking (which has been done but it not common).
But there is a place where you are correct. Atmospheric density does put an upper limit on payload density. Mars can slow down objects the size of cars or large trucks. But for very large things the heat shield needed to create enough drags becomes huge.
Think the scene from "2010: The Year We Made Contact" where very large spacecraft aerocaptures in Jupiter's atmosphere. That probably wouldn't be possible at mars, not without hitting the ground. Or 'Independence Day'. Those giant spacecraft arriving at earth surrounded by fire could not possibly have aerocaptured/braked in earth's atmosphere.
I believe humanity will colonise the open space way, way earlier than it would colonise another planet.
Really, if you are already in space with all that infrastructure, and economy needed to support settlement on another terrestial body, you would have to already have at least few megalopolises in the orbit.
Why? You don't have in space anything which you didn't bring there from a surface. On a planet you have resources at least. Also you have radiation shielding and no necessity to tie all small things from floating away.
In order to make anything in a space station, you have to bring something from outside. Not so on a planet.
The point is one of bootstrapping. IF you must build up a critical mass of space-based infrastructure in order to colonize a planet - do you still need to colonize the planet, or just continue on with the space based infra? Especially if you can capture sufficient resources from the asteroid belt.
Capturing resources from asteroids could be more expensive than from the planet, given the infrastructure on the planet.
So you may make an investment - spend initially to make a planet base, then enjoy smaller expenses.
Maybe the question is of comparison - how big space infrastructure one need to colonize the planet comparing to returns from planet base. Is it obvious that planet returns are smaller?
Considering the difficulty of aerial operations on Earth (namely balloons/zeppelins are vulnerable to weather and using airships as aircraft carriers extremely risky and tricky) I think you're underselling the practical difficulty of living in the Venusian atmosphere. We should be able to master these matters on Earth before trying it on another planet.
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?
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?
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.
> 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.
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.
> 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?
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.
> 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.
> If we remove our "selves" from our bodies, are we still us?
But answering this is now a straightforward thought experiment. You just approach it incrementally.
If you replace your limbs with prosthetics, are you still you?
If you get a heart-lung transplant, are you still you?
If you get an artificial heart, are you still you?
etc.
> a somehow unique, identifiable self which ... is how most people view themselves
Well, yeah, but that's a limit of our present technology, not necessarily a fundamental aspect of what it means to be human. Technology redefines the answer to that question all the time.
For what it’s worth, I think that in the process of gradual replacement of human organs with their “mechanical” equivalents, the brain will not be the last one to be replaced.
There is the idea that consciousness cannot be expressed as a computational process (at least not a classical one) because computation is deterministic. We are a part of nature and nature seems to be unpredictable at the quantum level. Quantum states can not be predicted even when taking the whole past history of the universe into account.
I think the free will lectures from John Conway also go in that direction: because some properties cannot be predetermined, free will must exist. Something must make a decision in order to have an outcome.
This all goes far over my head and I may have misinterpreted the great John Conway. In that case I beg your pardon and would love to hear your thoughts on it.
I think we'd be much further along if we kept our wet ware and learned how to program our existing DNA and proteins. We already have a functioning system that does what we want and a whole planet full of example code. The molecular machines even do all the work for you if you give them the right instructions. How happy would you be if I offered you functional nano technology capable of producing self sustaining macro structures from elements and energy scavenged from the environment? It's literally under our noses and almost nobody has noticed.
In the great scheme of things, making environments safe for human levels of tolerance is extremely wasteful. You need the right atmosphere, temperature, radiation freedom, freedom of toxic materials (and guess what, many chemical processes create tons of them), noise freedom, etc. This causes huge costs already now because industrial processes need to be engineered in ways to reduce emissions, it makes nuclear energy unavailable, people not wanting to live near airports, etc.
Even gravity is an extremely wasteful thing. In order to have it, you need a giant planet full of precious construction material for dyson spheres, anything->iron fusion/fission reactors and hawking radiation matter->energy converters, all unavailable because some individuals chose to colonize the surface of it...
The optimal approach for intelligent life is to architect computers that can run in the vacuum of space with minimal shielding and then deploy them across the galaxy to convert the available energy into intelligent thoughts and experiences. What the computers will run is up to us.
Yeah, there's a good chance that what we think of as humanity will be different 500 years from now. As such, trying to find ways to get today's humanity to live on other worlds (a questionable proposition even if things remain relatively static) might be about as useful as the tower of babel would have been to space exploration.
Personally I think this is what’s going to happen. Why put up with the limitations of our physical body? With games, TV and internet we have already disconnected from the physical world to some degree and I think this trend will just continue
If you could put your mind into an octopus, could you learn to use your 8 tentacles? Probably not without no longer being a human mind and becoming an octopus mind.
Our bodies (and culture & environment) are part of our minds. They cannot be separated without destroying that mind. Also, most of what we think is our own “intelligence” actually exists outside our brains, in our culture & civilization.
“Uploading our minds” only seems plausible if you have a cargo cult understanding of what is actually happening.
Humans learn to drive cars, fly aircraft, operate robotic arms, and play video games quite well, to the point where they consider those things "extensions of themselves." I wouldn't say a pro StarCraft player who's soldier management clicking has become muscle memory isn't really a human mind anymore. And likewise humans whose bodies have crippled or dismembered are still fully human despite sometimes barely being able to move or sense.
Because their minds are all still inseparable from their bodies.
You make my point, we are not just our mind, but a mind dynamically interconnected with a civilization in amazingly complex ways. Whether its the medieval catholic church, the interstate highway system, WoW, or the Internet.
Cognition scientists are pretty sure that we think with our bodies, not just our brain. If you totally separated the human body from the human mind, it is by definition not a human anymore. At best it would be closer to the ghost we leave behind online after we die. Just a shadow or footprints. I dont expect us to ever do better than making really convincing animatronic ghosts.
and even if it were, it'd be a consciousness copy, not a consciousness transfer. you'd get a software simulation of yourself but you, the real you, would still be dead
The sci-fi novel The Resurrected Man asks that question about teleportation technology. The teleporter itself is referred to as "a murdering twinmaker".
cgp grey has made a nice video about it. "trouble with transporters". The question is: if you go to sleep and wake up, is it really you? or is it a new consciousness?
That's what bugs me about uploads. If you clone your brain by some means, and the second copy comes online, presumably your original "you" will stay in the original body, and you won't perceive sensation/thoughts of the clone. It may as well not be a copy but a completely different individual.
This is getting off the rails into of science fiction I guess, but it raises the question of how do you transfer the "you" into the new brain? That way you could destroy the body or let it die and still have continuity. It's not clear that merely making a "bit-for-bit" copy is enough.
The problem is, if the 'from' entity is destroyed, it has no agency any longer, and the 'to' entity, if a perfect copy, won't notice anything different, it'll be like waking from sleep.
There's no loss for the rest of the world. What if actual sleep is analogous to that? The you that wakes in the morning is a fresh copy with memories up until you 'died' last night.
Definitely digressing into sci-fi thought experiments.
> how do you transfer the "you" into the new brain?
Yeah this is the big question: what constitutes as "you"?
Your body? You can lose a limb or parts of your brain and still remain "you". Your memories? they are constantly re-forming with people forgetting things and new memories being made. Your way of thinking? Neurons are extremely long lived cells.
Unless you believe in souls (which many religions do), the experience of "you" is entirely defined by the matter of your body and maybe your surroundings.
Let's assume we can build machines that can fully emulate human minds. Let's assume this emulation is good enough to also emulate the self-ness experience we are interested in.
Your question was (and the question of LoSboccacc), that if you have this technology, can you somehow transfer the self-ness so that the real, legitimate, "you" gets there, and not a copy? How do you know it's really you?
I'd argue that consciousness and self-ness is weirder than humans usually experience it: it can do more things than you'd think.
Let's take Bob, someone born in the simulation, that is, he has spent his entire life being simulated in silicon. For all purposes, his self-ness is the only true legitimate one. There is no difference in legitimacy between his simulation and a human in flesh and blood. That's just a simple conclusion of the basic assumption that there are machines that can do this.
Now if we have such a machine, then it runs some kind of program that can at least store Bob's state as a finite set of bytes. Whether it's a petabyte (less likely) or a yottabyte (maybe) is less relevant, what's more important is that it's a set of bytes.
Now you can do interesting things with this data. What happens if you pause the emulation, save the data to disk, and then decide to either a) stop the emulation and load it from the saved state or b) delete the saved copy and resume the emulation. In both scenarios a and b you'd resume with the same state for Bob as in a) you load the same data you just stored and in b) you just create a disk backup and delete it. Nothing would really change. It would be the same Bob afterwards in both scenarios.
In the next experiment, you save it to disk, turn off the emulating computer for a day, then turn it on, loading the disk again? It would be the same Bob, right?
Let's combine the two experiments. Let's pause the emulation, save the data to disk, and then decide whether to either a) turn off the computer for a day or b) resume the emulation and run it for a day. After the day concluded we power cycle the computer and load the data we stored to disk yesterday. Now my argument is that it's still the same Bob in both scenarios. Scenario a) is our second experiment. As for scenario b), at the point of the pausing, we haven't decided yet about whether to choose a) or b). So clearly, the Bob stored on disk must be the legitimate one, otherwise a) would end up "killing" Bob. So it follows that in scenario b) it's the same Bob as well.
Next I'd argue that whether there is a decision or not isn't really relevant for which data is being stored. It'd be the same Bob if you always chose b). In the fourth experiment, you'd just always go with b).
If we apply this thought experiment to the boundary between emulated and incarnated minds, the conclusion to be drawn is that the cloud copy is always [1] legitimate, whether the original host dies during the copy, after the copy, or not at all.
This conclusion is a bit humbling and it's understandable that people are critical, in fact I'm myself. But I believe this is just because the way we experience life on earth as separate individuals and consciousnesses, simply because our bodies are made like that. Our perception of what a consciousness is is blinded by the fact that each human starts with a blank set of memories and has their own way of deciding things, own skills etc. But once we get the ability to copy entire brains, those new experiences with consciousnesses in our society will fold the perceptions of individuals. Of course there will always be people who still believe in souls, and maybe there are in fact souls we just don't have the detection technology for. But 100 years ago people were superstitious of being photographed as they'd think you are stealing their soul. Maybe in 100 years we'll think that the old kind of thinking about consciousness is the same kind of superstition.
I'd say it's an artifact of our self-preservation drive. Of course it's very important to quality control whether the simulation is really doing what's promised.
To conclude, I think it's much easier to believe in life after death if you've seen your friends and family do it before your own eyes. Even Thomas ended up believing!
Uhh the comment has gotten a bit longer than I anticipated.
[1]: Note that this opens the question: can you just make any kind of copy and call it legitimate? Of course not. Consciousnesses are even weirder. The transition between legitimate and illegitimate is fluid. I'd consider someone who had a stroke and can't talk or walk any more as a weakly legitimate copy of the person pre-stroke. My argument assumes legitimate copies, but of course people can have different opinions/standards on what constitutes a legitimate copy. The question will become especially interesting if billionaires will get access to different copying methods than poor people.
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.
Yeah but it also talks about "oversized moons" and then cites Titan and Triton as examples of oversized moons of Saturn and Neptune. Why is that worong?
Titan is not oversized, in comparisson to Saturn. It's a normal, larger-than-Selene (Earths moon, but not that much larger really). Compared to Mercury, it is larger in radius, but less massive (about 1/3rd the mass). Now let's look a bit at Selene. It's an "oversized moon" at a bit more than 1% our planets mass. If that was the criteria for oversized moons, then Saturn would require an Earth-like planet orbiting around it to be considered to have an "oversized moon".
Another thing to consider: if we're thinking 1% mass as the parameter, it would've required a far larger moon to crash (from a retrograde orbit) to change Venus's rotation from prograde to retrograde.
Now on to Triton... it didn't form with Neptune. It's suspected of being a Kuiper Belt Object captured by Neptune that will eventually disintegrate from tidal forces once its retrograde orbit gets it close enough to the planet. If it had been formed 4 billion years ago with the planet, that would've already happened.
All in all, I'm not a astronomer nor planetary scientist, just a software engineer who really likes astronomy and got a few math and physics class at uni. But this "twin planets with oversized moons" theory has very little substance.
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.
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).
Deserts are great for shedding heat into space (highly reflective in the visible, highly emissive in the infrared, low moisture in the atmosphere).
We had a theory (not yet published, so take it with a grain of salt) that desertification might buffer the radiative forcing effects of CO2. Unfortunately, when we analyzed the last 20 years of satellite data, the opposite is happening--people have been watering the desert like crazy, leading to a net reduction on the order of ~100-200,000km^2.
There is a nice article about some paper modeling the climate if all the Sahara was covered with solar panels and wind turbines.The temperature on the Sahara would actually increase on average.rain would also
There's a theory that the Sahara alternates between desert and green every X thousand years, dramatically altering the Mediterranean, European, and African climates.
And BTW our species is conducting its largest peaceful "mobilization" ever to deal with this virus; it's actually quite inspiring.
> a theory that the Sahara alternates between desert and green every X thousand years, dramatically altering the Mediterranean, European, and African climates.
This is a funny way to phrase the causation. The state of the Sahara is surely not exogenous -- the transition must be caused by the climate. (It can then contribute further, but why attribute the changes to an intermediary effect?)
If you have the industrial capacity to handle metallic lead precipitation and strip away 92 times as much atmosphere as the total on planet Earth, dissenting voices are of less relevance than the contents of your spam folder.
Mars can retain water vapor just fine. It occasionally snows lightly.
Without a magnetic field (which could be built easier than terraforming), over 100 million years, it can slowly lose atmosphere, but nothing like a relevant rate for humans. The sun is also getting significantly hotter on a similar timescale, which makes habitation on Venus (And Earth, for that matter) significantly harder and dependent on active geoengineering methods.
If you blocked all incoming sunlight, how long would it take for the surface to cool to human-tolerable temperatures?
Or more extreme, how long would it take to cool it down to the freezing point of CO2, then build some sort of maglev launch system and lob solid CO2 to... Mars maybe, that planet could use more atmosphere.
And how much stuff would you need to launch to spin up Venus? Months long nights are not fun. Can you launch stuff to yield more spin, then have it sling around Earth or Mercury, and then have it hit Venus again, resulting in more spin up, i.e. getting twice the rotational acceleration from a launch?
Venus isn't a better option. Mars is ready for human shelters on day one, venus would crush and melt anything we're sending there for hundreds of years. It'd be far easier to warm Mars than cool Venus, as we're discovering on earth, warming is much easier to cause.
For mars, You could crash nitrogenous asteroids into the surface, make GHG production facilities that emit CFCs or HFCs, and hopefully soil carbon gets released in a runaway effect. Thermonuclear weapons over the pole is impractical but a fun idea.
For venus, it's so tough, you'd have to block solar radiation and then fix the massive amounts of carbon with co2 capture... maybe if we develop co2 capture for dirt cheap on earth, we could make sky cities with carbon fixers on venus, after a few hundred years it'd be colder...
Fun to think of, but ultimately we need to terraform earth towards cooling, as our current warming is too successful
If I were a very determined, ultimate Bond villain* who set out to destroy the whole universe, what are my options? How bad can I fuck it up for all ? Back-to-back mega nuclear explosions occurring simultaneously on all planets within reach? Could that start chain reactions around our galaxy that'd bring it all down? What else?
* Funnily enough, I just started reading 'From Russia with Love' whose first few chapters deal with the unusually vicious nature of our henchman.
10 million is too long a time frame on human scale, given that humanity looks so drastically different even compared to 50k years back, and agriculture is also some 14k years old. If humans manage to survive on mars for 10 million years, they would be advanced enough to be out of it.
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.
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...
[2]: https://qz.com/1105031/should-humans-colonize-mars-or-the-mo...
[3]: https://www.youtube.com/watch?v=BI-old7YI4I
[4]: https://www.extremetech.com/extreme/196114-nasa-is-developin...