Debunking Interstellar Travel: Separating Fact from Fiction

[enorbet]

Since I have been guilty of pessimism (to me it seems painful but healthy realism) in this thread and since someone asked that we "slow down", I think I should expand a bit. Although I strongly suspect we are 1000+ years away from practical Interstellar Travel, in no way do I support slowing down. In fact I am all for speeding up.

It has been mentioned in qualifying points of difficulty that "barring serendipity in the form of a major breakthrough" is needed to qualify any manner of timeframe predictions. Regarding smarter predictions or progression graphs I mentioned those of G. Harry Stine (if you don't know of the man you really should explore his contributions in many areas...possibly start here - https://en.wikipedia.org/wiki/G._Harry_Stine ) though I used his in that case to point out the dangers of assuming past change rates will or even can continue indefinitely.

The reverse is true as well in that it is not trivial nor rare that breakthroughs can occur suddenly and at almost any time. However, they do not happen so often "in a vacuum" though, so even pure research is exceptionally important from my POV. It amazes me how ignorant most people are of the myriad spinoffs from Apollo and other "noble" Science causes (please forgive my cynical quotation marks. It's just to show that the real motivation behind the Moon Race was as mundane as it gets but wise politicians knew The Public needed to be "sold a Bill of Goods) . Even those who are aware of microelectronics, medicine, food, textiles and so many more advances that without Apollo our lives would be vastly different, often overlook the valuable lesson of corporate and National cooperation in addition to just competition that changed how we do business and even think of each other. Those changes are much harder to even identify let alone quantify.

OK so I'm biased in favor of Scientific Exploration but it does seem we grow in important ways when we engage in it and tend to fall behind when we don't.The simple fact remains that if we don't follow dreams of discovery the likelihood for unexpected breakthroughs is diminished. It's not like the silly adage "You can't win The Lottery if you don't play" since iirc the odds of anyone winning top prize are somewhat less than being crushed by a meteorite. The odds of beneficial applications from Scientific experimentation and exploration are considerably better and unlike the one-time Lottery win can continue to spawn 2nd, 3rd and 4th, etc. generation benefits. The "game" gets forever changed.

Frankly we waste money on so many ridiculous "investments", both personally and collectively, it makes perfect sense to me to spend more on Science, even if we just start with those with better odds ( a few examples http://cen.acs.org/magazine/93/09322.html and don't forget Obama's increased funding for new alloy research as a high likelihood, high ROI endeavor). Back (more specifically) On Topic, it seems to me that while there is still much to be discovered here on Earth (especially undersea) the key to Interstellar Travel is cheap power and the quantities we are talking about whichever ends up being the means of the moment seem more likely to be found and experimented with Out There instead of Back Here. Just learning to survive higher levels of radiation could possibly result in major benefits. The odds of a permanent settlement on the Moon or Mars may still be less than compelling but those are far more achievable in a reasonable time (and cost) than Interstellar Travel and they do constitute a step in the right direction.

 

[AgentCachat]

The inactivity of muscles will turn the humans to Jello. Humans are too lazy to exercise long and hard on a daily basis to maintain their musculature..

They exercise long and hard on the ISS on a daily basis.

 

[Jenab2]

About the only way I can see humans colonizing exoplanets is to send them in digital/data form, and have a computer-controlled replicator print them, either as sperm/egg sets, or as fertilized ova, or as embryos, or, perhaps, as full-term babies. They'd have to be cared for by machines until they could look after themselves.

If the replication process was good enough, which is to say very good indeed, fully mature adults could be printed, copies of original humans who never left the solar system, with the same memories and education and skills.

A journey though interstellar space at 0.001c, or 300 km/sec, would require tens of thousands of years to reach its destination. The speed is, after all, one light year per thousand years. During transit, cosmic rays would occasionally damage software in even shielded computers. So each starship would need to have redundant computers with identical software, which would wake up every century or so and check each other for errors. Whenever a location in any computer's memory was found to have deviant contents, the computers would vote on which version of the content at that location was the true copy, and the largest plurality would correct all of the deviant computers into compliance.

When the computers were finished correcting themselves, they would begin checking out each of the items held as data, including the data instructions for printing colonists. Again, deviations would be corrected to a norm determined by the largest plurality of the copies.

With that done, the computers would agree on their next wake-up time, and shut down.

 

[DrStupid]

About the only way I can see humans colonizing exoplanets is to send them in digital/data form, and have a computer-controlled replicator print them, either as sperm/egg sets, or as fertilized ova, or as embryos, or, perhaps, as full-term babies.

When they are uploaded into some kind of highly advanced hardware, why should they download to old-fashioned wetware again?

 

[ebos]

They exercise long and hard on the ISS on a daily basis.

Quite agree... but they still can't walk when they get back home and that's after a few months. Imagine being in space for hundreds of years.

 

[mfb]

They can walk - not for very long, but the human body quickly adapts back to Earth conditions. You don't need to go to space for that, being in a hospital bed for several weeks to months has a similar effect.
Anyway, artificial gravity, if necessary, is just a minor issue.

 

[newjerseyrunner]

A private venture is possible, but I think not many people with serious financial means would invest in an interstellar exploration project with an unknown result.
They got rich anyway by investing in things of which the outcome would probably be profitable.

No... but their children might. ;)

Look at history, when gold was discovered in CA in the late 1840s plenty of rich people from the east coast migrated in hopes of expanding their fortune. After the discover of the Americas, there were many old-money morons who set sail for just a chance at riches beyond their dreams... and an equal chance of being slaughtered by natives.

 

[PeterC34]

I agree with Dr. Stupid and Jenab2 that it makes far more sense to launch tiny interstellar craft made with replicators. Digital human 'maps' including brain states, nano-replicator repair of systems (recreating new pieces as replacements), then, upon arrival, the replicators use the mass of a nearby asteroid for molecules and the local sun for power to create landing craft (many, for redundancy), human-capable habitats, as well as food, water on the surface. The replicators would then build people and say, "Thank you for flying with us on Interstellar Space Lines. Hope your luggage made it, too. Have a nice day..."

A fascinating look at assemblers and replicators can be found in Eric Drexler's book Engines of Creation. It alludes that once we are able to manipulate molecules via self-replicating assembler nanobots, the entire 'game' of life changes forever. I agree.

Even without nanotechnology, humans only have about 100 years of so left on Earth, IMHO. It will likely become possible to decode the genome sufficiently to create custom DNA pairs and birth the first Human 2.0 models, immortal like jellyfish, immune to disease, strong and efficient, smarter by an order of magnitude than the average booger-eating human, and (possibly) with a digital interface for backing up consciousness, to assure immortality. Once Human 2.0 is 'in production', what point will there be to continue to make Human 1.0 models anymore? Brave new world will eventually become brave new WORLDS...

 

[Budgie2016]

As I see it . . .
The problem, seeming one of distance and speed is actually a problem of time. Even traveling at the extremely slow, relative to the distances to be overcome, speed of light, much of our own galaxy let alone the universe is beyond travel in a reasonable human scale time frame. Massive multiples of the speed of light are needed even to begin a proper exploration of the universe.

If one could go back in time, launch, cryo travel, return forward in time then at least your colonies (if any) are existing within the “relative time” of the mother planet, an actual meaningless point as communication Twix and tween would be next to impossible over vast distances.

As time seems to stop at a black hole’s threshold, one might wonder if all elements of past time are available beyond said threshold.

Impeccable conversion of matter data to energy back to impeccable matter data recovery (teleportation) coupled with a though examination of why the light speed is so slow and if there are any changes we could make to energy to increase this would also be of some help.

Coupled with nano technology – possibly anything is possible.

However – at the least – terra forming of our sister planets, ring world tech as well as human bio engineering to exist in other planetary environs still offer us enough challenge and living space to keep us busy until our technology matches our universal exploratory ambitions.

 

[phinds]

a couple of comments:

As time seems to stop at a black hole’s threshold, one might wonder if all elements of past time are available beyond said threshold.

Since, as you correctly stated, time only SEEMS to stop at the Event Horizon, the rest of your sentence does not follow.

... a though examination of why the light speed is so slow and if there are any changes we could make to energy to increase this would also be of some help.

c is what it is; it cannot be changed. Not sure why you think it is "slow".

 

[rootone]

If by any means interstellar travel became feasible, staying well away from black holes would be a priority.

 

[newjerseyrunner]

If by any means interstellar travel became feasible, staying well away from black holes would be a priority.

I'm sure, but absurdly obvious. That's like saying when driving a car, it's advisable to avoid driving off of a cliff.

 

[mfb]

I'm sure, but absurdly obvious. That's like saying when driving a car, it's advisable to avoid driving off of a cliff.

To take the probability into account: When driving a car, avoid hitting elephants that have penguins on top.
Is it a good advice? You certainly should not hit elephants with penguins on top, but the probability to do so at random is negligible.

 

[Jenab2]

When they are uploaded into some kind of highly advanced hardware, why should they download to old-fashioned wetware again?

Because that's what we are. We make machines to serve us, not to replace us. Thought might be the best part of being human, but it isn't the only good part of being human. And there's really no guarantee that machines would even think our way.

Anyway, humans wouldn't depart Earth aboard a starship as androids any more than they would go as living passengers. Instead, the data necessary for the 3D printing of human fertilized ova from data-encoded descriptions of their DNA and some means to turn it into babies and some means to provide protection, food, and instruction for them until they are grown.

 

[nikkkom]

Er... where is my [Alien invasion alert] card?

Apparently, aliens in globular clusters, not we, are best positioned to master interstellar travel.

I've found this: http://arxiv.org/abs/1601.03455
"Globular Clusters as Cradles of Life and Advanced Civilizations"

"Globular clusters are ancient stellar populations with no star formation or core-collapse supernovae. Several lines of evidence suggest that globular clusters are rich in planets. If so, and if advanced civilizations can develop there, then the distances between these civilizations and other stars would be far smaller than typical distances between stars in the Galactic disk. The relative proximity would facilitate interstellar communication and travel. However, the very proximity that promotes interstellar travel also brings danger, since stellar interactions can destroy planetary systems. However, by modeling globular clusters and their stellar populations, we find that large regions of many globular clusters can be thought of as "sweet spots" where habitable-zone planetary orbits can be stable for long times. We also compute the ambient densities and fluxes in the regions within which habitable-zone planets can survive. Globular clusters are among the best targets for searches for extraterrestrial intelligence (SETI). We use the Drake equation to compare globular clusters to the Galactic disk, in terms of the likelihood of housing advanced communicating civilizations. We also consider free-floating planets, since wide-orbit planets can be ejected and travel freely through the cluster. A civilization spawned in a globular cluster may have opportunities to establish self-sustaining outposts, thereby reducing the probability that a single catastrophic event will destroy the civilization or its descendants. Although individual civilizations within a cluster may follow different evolutionary paths, or even be destroyed, the cluster may always host some advanced civilization, once a small number of them have managed to jump across interstellar space."And naturally, when they're done settling every usable real estate in their cluster, they will have a very advanced interstellar ships and they come to us. Run for your lives! ;)

 

[mfb]

We should mention Breakthrough Starshot here. Produced quite some news, although several components are significantly beyond current technology it could deliver a probe to Alpha Centauri within the 21st century.

 

[Borg]

We should mention Breakthrough Starshot here. Produced quite some news, although several components are significantly beyond current technology it could deliver a probe to Alpha Centauri within the 21st century.

I saw the interview with Hawking on the news yesterday. It was nice to see him crack a smile when answering the question of how he felt to be a pop icon. His response was that he wouldn't consider himself a pop icon unless he was on the Kardashians. Please no Stephen, don't do it.

 

[DrStupid]

Because that's what we are.

That's what we are today. But we are talking about a distant future.

Instead, the data necessary for the 3D printing of human fertilized ova from data-encoded descriptions of their DNA and some means to turn it into babies and some means to provide protection, food, and instruction for them until they are grown.

The question remains: What is the benefit of a biological body compared to artificial hardware? With a biological body a human is just a human and can only live in an environment which is habitable for humans. In a sufficiently advanced simulation space he can be be a human or everything else and with suitable hardware he can exist almost everywhere.

 

[nikkkom]

As you will get old, you'd *wish* you can replace your failing body parts with artificial ones.
Do you really require legs made from bones and muscles, or do you need legs which merely "feel okay" and more importantly, which perform their function: move you around as needed?

 

[newjerseyrunner]

Because that's what we are.

No, we aren't. We are an entity of consciousness. The fact that that consciousness emerges from our biology in no way makes you dependent on that biology once it's going. Our consciousness requires hardware to run, biology is not the most efficient hardware. If I were given the opportunity, I would consider transferring my consciousness myself, especially the older I get. All human religions have invented afterlives to fulfill human's desire for immortality, technology can actually provide such an experience: a lifetime as a biological being, followed by an eternity as an metaphysical entity.

It'll start slowly of course, instead of having a hearing aid boost sounds for you, it'll connect directly to your neural pathways. Instead of letting the memory deteriorate with age, we'll enhance it. Enhancements will lead to new innovations which will cause old systems to become obsolete. We are no were near the ability to replace any part of the brain right now, but 500 years ago, if your heart stopped beating, you died. Now we either add a pace-wire, replace it with a donor, or in the not too distant future, 3D print a new one out of stem cells.

I don't think there are any humans living right now that'll live past the age of 1000, but it's within the grasp of the generations in our immediate future.

 

[mheslep]

Necessity is the mother of invention. The tone of the article suggests we should've stayed in Africa, a voyage to another continent would be extremely dangerous ...

If the state-of-the-art amounts to no more than a raft made from sticks and palm fronds, suitable for crossing a large river at most, then yes stay at home and keep improving for another 100 generations. Crossing the 10 mile wide bay is dangerous in such craft, crossing the ocean is impossible. If crossing the ocean is 4000 times harder than crossing a mile wide river, then a 10 light year manned journey is 300 million times harder than going to the moon.

 

[mfb]

If the state-of-the-art amounts to no more than a raft made from sticks and palm fronds, suitable for crossing a large river at most, then yes stay at home and keep improving for another 100 generations. Crossing the 10 mile wide bay is dangerous in such craft, crossing the ocean is impossible.

It is impossible until someone does it.

Difficulty does not scale linearly with distance.

 

[mheslep]

It is impossible until someone does it.

Difficulty does not scale linearly with distance.

Well the pre Columbian's that might have built a Kon Tiki like sail powered craft were, what, 20,000 years out of Africa and river crossing rafts.

Granted distance dies not scale linearly with difficulty, though they are correlated, and distance provides a shorthand for showing that interstellar travel is not a few times harder than going to the moon but many orders of magnitude harder.

 

[phinds]

Well the pre Columbian's that might have built a Kon Tiki like sail powered craft were, what, 20,000 years out of Africa and river crossing rafts.

Granted distance dies not scale linearly with difficulty, though they are correlated, and distance provides a shorthand for showing that interstellar travel is not a few times harder than going to the moon but many orders of magnitude harder.

I agree. I think the leap from our Solar system to interstellar is likely to be more of an exponential change than a linear one.

 

[sophiecentaur]

I cannot claim to have read all the posts in this thread (144!) but I feel I have to comment on the limited way in which the 'enthusiasts' seem to look at the problem. The technology is only a small part of this problem. More important are the phyiology and psychology of humans. Whatever speed of travel we can postulate, we are talking in terms of timescales involving many human generations. That would take us as far into the future as prehistoric Man is in the past and what earth-bound organisation is likely to spend what would be virtually their total resources on such an uncertain investment? How could we predict how the passengers of such craft would feel and would they still want to continue on a mission on which they find themselves through no choice of theirs.
Then, what would be the motivation for such a project? Governments, these days do not get involved in projects with timescales more than one or two periods of office. There is no motivation, afaic. I cannot see the attraction of sending human 'spores' out in different directions, in the hope that even one of the many 'expeditions' could reach a suitable destination. Who would benefit from such an exercise? The genes of some humans other than myself? Where's the profit in that? Jam today vs someone else's jam tomorrow.
I admit that discussions about exotic technologies are fascinating but the Star Wars / Star trek / Dan Dare meets the Wild West and Kontiki scenarios are just fanciful.
If and when Earth gets threatened by some imminent and inescapable disaster, the place we would be going would be along the lines of Mad Max and a very sad decline until the remnants all expire. That's the way humans work and we need to accept that - but we won't.

 

[Rubidium_71]

Crossing the 10 mile wide bay is dangerous in such craft, crossing the ocean is impossible.

The thing about humans is, they actually like to take on what is dangerous. Humans also like to defy what is considered impossible.
I still don't think it is out of the question that a Generation Ship (or a ship of some other type) might someday make such a perilous journey to another star. Dangerous? Absolutely. Impossible? Not necessarily.

 

[phinds]

The thing about humans is, they actually like to take on what is dangerous. Humans also like to defy what is considered impossible.
I still don't think it is out of the question that a Generation Ship (or a ship of some other type) might someday make such a perilous journey to another star. Dangerous? Absolutely. Impossible? Not necessarily.

But you are talking about some thing that is significantly different that "dangerous". Yes, it IS dangerous but more importantly it is boring and for the immediate crew, personally pointless. Altruism is all well and good but I mean really? Dedicating your whole life so that someone ELSE can someday land on another planet while you spend your in a relatively small spaceship? Do NOT sign me up.

 

[nikkkom]

How could we predict how the passengers of such craft would feel and would they still want to continue on a mission on which they find themselves through no choice of theirs.

Well, you are on a "spaceship" Earth. You were brought into it without anyone consulting you whether you want it or not. The situation is similar. How do you, a passenger of this "craft", feel? The situation is: most people don't care about how you or I feel about it. If we feel okay, we live here, likely have children and thus the "crew" reproduces. Whoever feels miserable, can kill hiumself (or more likely, continue to feel miserable for years on end).

Then, what would be the motivation for such a project? Governments, these days do not get involved in projects with timescales more than one or two periods of office. There is no motivation, afaic.

It was hardly different at any other time in human history. Columbus had hard time raising cash for a 1-2 years exploratory trip.

I cannot see the attraction of sending human 'spores' out in different directions, in the hope that even one of the many 'expeditions' could reach a suitable destination. Who would benefit from such an exercise? The genes of some humans other than myself?

Exactly. That's the reason of existence of any lifeform: to spread (minimally: to survive). Lifeforms which don't do that, die out - the ultimate form of failure.

 

[mheslep]

The thing about humans is, they actually like to take on what is dangerous. Humans also like to defy what is considered impossible...

Sure. A manned mission to the moon was, is, dangerous. Interstellar travel with today's technology and physics is like jumping off a cliff with a garbage bag as a parachute. My guess is interstellar travel remains jumping-off-a-cliff out of reach for the next century even with on trend, incremental but non-revolutionary improvements in technology. Currently (i.e. through 2200) an interstellar project is not simply dangerous but pathological, as the Sci American article labels such projects.

With some revolutionary discoveries in physics, tech, and human civilization, who knows.

 

[mfb]

The technology is only a small part of this problem. More important are the phyiology and psychology of humans.

They are not separate problems. The technology chosen influences everything alive on the spacecraft . Concerning the lack of choice, see nikkkom: We don't have the choice today either. Launching such a spacecraft would give some humans a choice: stay on Earth, or travel into the huge interstellar void. Some concepts reach ~10% the speed of life, sufficient to get to the closest stars within a human lifetime, even with today's life expectancy. Improvements in medicine could significantly extend the human lifespan, improvements in spacecraft designs could increase the speed.

The genes of some humans other than myself?

It is still 99.95% your genes.

Governments, these days do not get involved in projects with timescales more than one or two periods of office.

ISS, ITER, LHC, the global investments in photovoltaics, a few agreements on reducing CO2 emissions, ... it happens.

That's the way humans work and we need to accept that - but we won't.

We (as species) survived an ice age and the Toba volcano with primitive tools. We can do so much more with today's technology, and even more with future technology.