Time to Go Says Hawking

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Time to Go Says Hawking

 http://www.huffingtonpost.ca/2011/11/18/stephen-hawking-space-exploration_n_1101975.html?ref=mostpopular&just_reloaded=1

 

“We are entering an increasingly dangerous period of our history," said Hawking, who has Lou Gehrig's disease, leaving him almost completely paralyzed and unable to speak.

"Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill. But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million.

"Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space."

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Why space is not an option

Reaching the stars simply isn't feasible says Prof. Murphy (an astrophysicist at UCSD), in this interesting blog article he recently wrote:

"Why Not Space?"

Prof. Tom Murphy wrote:

"Ask a random sampling of people if they think we will have colonized space in 500 years, and I expect it will be a while before you run into someone who says it’s unlikely. Our migration from this planet is a seductive vision of the future that has been given almost tangible reality by our entertainment industry . . . I’m not going to claim that this vision is false: how could I know that? 

But I will point out a few of the unappreciated difficulties with this view. The subtext is that space fantasies can prevent us from tackling mundane problems whose denial could result in a backward slide.  When driving, fixing your gaze on the gleaming horizon is likely to result in your crashing into a stopped car ahead of you, so that your car is no longer capable of reaching the promised land ahead. We have to pay attention to the stupid stuff right in front of us, as it might well stand between us and a smart future.

By the way, I highly recommend his blog "Do The Math" from which this article was taken.  I think everybody should have a look at it.

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Do The Math
jrf29 wrote:

By the way, I highly recommend his blog "Do The Math" from which this article was taken.  I think everybody should have a look at it.

I'll second that emotion......  it's one of the best blogs I've ever read, and I point people to it ALL THE TIME.  His "energy trap" post is a classic.

Oh, and Hawking's lost it IMHO...  you'd think he'd know better!

Mike

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 Ditto. Honestly, you'd

 Ditto. Honestly, you'd think Stephen Hawking was one person who would have done the 'math'!

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beauty to behold

Hawking is brilliant but he's also a bit of a savant and wrong about some of the most important things.  I'm sure he thinks this beauty is just a random biological occurrence.

http://player.vimeo.com/video/27920977?title=0&%3bbyline=0&%3bportrait=0href

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 It isn't going to happen.

 It isn't going to happen.  There is no where to go and no way to get there.

What I think people are missing is the chance he represents.  When Stephen Hawking tells us that we are running out of resources you can use that as a teachable moment.  

Yes, seeking the ability to leave may cause you to miss the ability to fix what is wrong here.  But, I get frsutrated with people who dismiss every possible fix or possible movement in the right direction because it is not the right fix or not enough movement.  Research into space and terraforming can bring us fixes for what ails us here.  Well respected scientists announcing that we are running out is a wonderful opportunity for us to say - "Hey he agrees we're running out.  He agrees we are not able to go anywhere yet so we'd better get busy fixing what is wrong here."

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what gets me........

What gets me every time this idiot talk of moving to the stars comes out is that for anyone to do it, they would need to live hyper sustainably, recycling EVERYTHING, food, air, waste, energy...... and of course you can forget multiplying on a small space ship too!  Yet NOBODY's talking about the fact that if we did this right here on Earth, well we wouldn't need to go anywhere now would we!

Mike

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Ditto
Damnthematrix wrote:

What gets me every time this idiot talk of moving to the stars comes out is that for anyone to do it, they would need to live hyper sustainably, recycling EVERYTHING, food, air, waste, energy...... and of course you can forget multiplying on a small space ship too!  Yet NOBODY's talking about the fact that if we did this right here on Earth, well we wouldn't need to go anywhere now would we!

Mike

It get's me too! I see this idea of moving to the stars as a failure of the global community to tackle true sustainability here on earth. It's almost as if a smaller community of people could achieve what the larger body couldn't. This is a falsehood however. The "Super committee" should show us that smaller doesn't mean more functional. It's like fractals. No matter how much you zoom in, or minimize the view, the shape and structure stays the same.

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I think some of you may be

I think some of you may be reading a little more into Hawking's statement than is really there.  From the article it didn't seem like Hawking was presenting space travel as a solution to our energy or resource problems here, but rather as insurance against human extinction or indefinite collapse of technological human civilization in a era of increasing societal volatility.  Diversification in a time of great uncertainty, as it were.  That seems prudent does it not?

I concur with Land2341.  Space science & exploration is not going to cure our problems down here, and we can't and shouldn't count on a space-based Hail Mary pass that fixes our problems on Earth or as a way of running away from the problems here.  But neither of those was ever the point behind space exploration, were they?  It's about expanding the frontiers of human knowledge and experience.  Sure there are ways space resources and technologies can provide us with benefits down here, but those were really secondary reasons that were overshadowed by the urge to explore and expand our boundaries.  What Prof. Murphy said in his article is that space is not a cure or solution for our energy and resource problems down here, and that expanding space exploration and colonization is much more difficult than most people assume.  And I wholeheartedly agree.  But that is not the same as saying that manned space exploration, travel, and colonization (at least within our solar system) is infeasible, or that the attempts should not be made.  Prof. Murphy's article is a great moderating counter-balance to excessively enthusiastic pie-in-the-sky assumptions about space exploration, but not an argument of its futility. 

The sad thing is that I think if we played our cards right, we could continue to have and make progress in space exploration in a "world of less", and I would argue that we should.  But most nations are doing the wrong things, increasing the chances of such great global upheaval that space eventually falls out of our collective reach.  Our scientific and engineering ability is there, but many of our societial priorities are f***ed.  It's like watching a scientific or artistic prodigy killing himself with drugs; the ability was there, but all for naught because of bad decisions. 

What gets me every time this idiot talk of moving to the stars comes out is that for anyone to do it, they would need to live hyper sustainably, recycling EVERYTHING, food, air, waste, energy...... and of course you can forget multiplying on a small space ship too!  Yet NOBODY's talking about the fact that if we did this right here on Earth, well we wouldn't need to go anywhere now would we!

Mike

DTM/Rihter-

You guys are actually making a good argument for trying such a thing.  I know I've said this before, but how better to increase awareness of resource limits and utilization than to live in an environment where bad decision-making and poor impulse control leads to immediate and sometimes severe consequences?  It's in adverse conditions where we see human beings either step up, or step aside.  So on the contrary, it may be quite possible a smaller group can do what the larger group does not.... not because they're smarter or 'better', but simply because they're put in a drastically different environment that constantly forces them to re-evaluate their priorities and be more aware of the consequences of their actions.  We don't see that kind of self-aware behavior down here so much because we don't have that forcing pressure.

Yet. 

(cue ominous music... Bum Bum BUUMMM!) 

 

- Nickbert

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Fatalism

The notion that we "can't" is absurd to me.
We are the most adaptive creature on this planet, and we're capable of producing technologies that could easily ferry us to planets nearby in our solar system, and create isolated, self-sustaining habitats or colonies.

This babble about "with what fuel!?" Is ridiculous.
We're not out yet, ladies and gentlemen, and it seems pretty important to start developing our species beyond this earth, unless we want our species to just perish.

While I know there probably a few people out there nodding their heads, and thinking that's for the best, I'd make mention of two things:

1. We're an extremely young species, and like all adolescents, we're prone to mistakes, and;

2. Though we've had our dark ages, we've also had our renaissance, and this cycle will progress, here or elsewhere.
Personally, I'd like to see our community thinned by diversification of planetary holdings... but maybe I read too much Heinlein.

Cheers,

Aaron

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There's dreaming & there's the hard realities of Thermodynamics

 There's nothing wrong with dreaming as long as you keep one foot in reality....

 

Kiss space goodbye : Pharyngula

Charlie Stross examines the economics and physics of colonizing other planets, and he isn't at all optimistic. Forget going to planets around other stars — the distances are absurdly excessive. But also forget about colonizing planets in our solar system: not only is it ridiculously expensive just to put a human being on another planet, it isn't even an attractive proposition.

When we look at the rest of the solar system, the picture is even bleaker. Mars is ... well, the phrase "tourist resort" springs to mind, and is promptly filed in the same corner as "Gobi desert". As Bruce Sterling has put it: "I'll believe in people settling Mars at about the same time I see people settling the Gobi Desert. The Gobi Desert is about a thousand times as hospitable as Mars and five hundred times cheaper and easier to reach. Nobody ever writes "Gobi Desert Opera" because, well, it's just kind of plonkingly obvious that there's no good reason to go there and live. It's ugly, it's inhospitable and there's no way to make it pay. Mars is just the same, really. We just romanticize it because it's so hard to reach." In other words, going there to explore is fine and dandy -- our robots are all over it already. But as a desirable residential neighbourhood it has some shortcomings, starting with the slight lack of breathable air and the sub-Antarctic nighttime temperatures and the Mach 0.5 dust storms, and working down from there.

Sterling is being optimistic there — no way is it only 500 times more expensive to go to Mars rather than the Gobi.

I love to read space opera, but face it, it's about as realistic as your goofiest high fantasy novel with elves and gnomes and magic swords. It's not going to happen, ever, but it is still fun to dream.

Safewite said it best here:

As our resident science fiction writer/editor (my magazine Abyss & Apex is here; the book I edited with our Best-Of is here), allow me to chime in on the whole terraforming and leaving earth subject.

Those of you who are not aware of the amount of energy it takes to break out of earth's gravity, please take note. Here is a rather succinct explanation.  Long story short? It takes a lot of energy, as does the whole manufacturing process to make what you are bringing up out of the gravity well (the space ship and "stores" to bring with you.) Distance to Mars, the only viable candidate in our solar system, is ...prohibitive, as are conditions there. Distances to other star systems, where we might be able to infer a Jupiter-sized planet (with no guarantee of any world in the habitable zone) by the perturbations of a star's gravity are...well, there is a reason that we use the term "astronomical." It might take several generations to get there, where ever there might be. And then our descendants, if they  even make it there, may not find a usable world.

So, leaving earth as a mass migration or even as a select few, and then terraforming (another subject, and you really do not want to go there) that world? Ain't gonna happen; it's not only impossible for cash-strapped debt-ridden governments but peak oil mitigates against it on a global scale. There's a reason science fiction is labeled "speculative" - most of it cannot happen in real life. We are very much stuck on this planet with the one world we have. Our world is not disposable; neither is it replaceable.

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Yeah o.O

And... where does the "hard reality of thermodynamics" say it's impossible?
The fact that these articles are highlighting the difficulties says that it's possible.

Difficulties are not physics based impossibilities, and I don't like the assertion that physics are creating an impossibility, when traveling to distant celestial bodies is something we have already done. We've got rovers on Mars, sensors, there's no reason we couldn't have satellites.
There's no reason we couldn't establish an outpost on the moon, a place where significantly less gravity would create a situation that is perhaps more conducive to launch.

In short, I see "won't" where you see "can't".

Also, please, XRM! For the love of whatever you find holy - post something that is your own thoughts and words!

Cheers,

Aaron

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Have you paid attention to what's going on around you???????????

 I find it hard to believe that any rational person who has really paid attention to CM's crash course, let alone the myriad of other energy studies available, would even entertain the idea that humankind is going to colonize other planets, considering the vast distance to be traveled, the harshness of those barren alien worlds, as well as the outrageous amount of cheap energy required to get there and maintain such space colonies. But such people are, I suppose, in good company because the subject of this post, Hawking, believes its our only chance for survival:

"Life on Earth is at the ever-increasing risk of being wiped out by a disaster such as sudden global warming, nuclear war, a genetically engineered virus or other dangers ... I think the human race has no future if it doesn't go into space."

I think Hawkings is right in his assessment of the precarious future the human race has dug for itself, but he's unrealistic in what it should do to save itself. Facing up to the self-created problems in the here and now on planet Earth before even dreaming of seeding outerspace with our kind would seem to be a mandatory rule. Nevertheless, we'll entertain the idea of space colonization despite the crushing weight of civilization-collapsing factors occurring here on Earth.

Since there are no hospitable planets within our solar system, we would need to be able to travel interstellarly. The stars visible from Earth are 50 to 100 light years from us, our galaxy being 100,000 light years across. What kind of energy would fuel such travel? How would you sustain the humans on such ships at such great distances over such long time spans? The astronauts would likely be dead of old age before they reached any habitable destination. Do you see how silly and incomprehensible such ideas are? Barring the discovery of some new form of free energy, along with resolving other seemingly impossible barriers, space colonization is just a fantasy of sci-fi stories.

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Re: Have you paid attention to what's going on around you???????

Well I have been in space for yearsssssss.

It can be done but I'm not telling my secrets.

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Wowww Mannnn I'm Flyyyyiiinnnnn'''''''
Johnny Oxygen wrote:

Well I have been in space for yearsssssss.

It can be done but I'm not telling my secrets.

I know a few peope who have been in space for years as well. And I know what there secret is. It involves controlled substances.

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Absurd?
Aaron Moyer wrote:

The notion that we "can't" is absurd to me.

What's REALLY ansurd is that we would even contemplate polluting the rest of the Universe.....

 

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with what fuel!?
Aaron Moyer wrote:

This babble about "with what fuel!?" Is ridiculous.

Is it?  I remember once reading that every time the shuttle takes off, it uses as much energy as all the cars in LA consume in one year.....  and that's just to get into ORBIT!  Never mind going to Mars or another star......

Yes, it's ridiculous alright, and the question stands.

Mike

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Go to the moon?

Who wants to go to the moon anyway? There's no oil there or natives to take advantage of.

On the other hand there isn't any global warming there either.

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Thermodynamics?

xraymike-

Please do tell, what law of thermodynamics does space colonization or exploration violate?  Last I checked such things do not involve perpetual motion machines, reversing a normally irreversible process, or absolute zero temperatures.  Or perhaps you're referring to the inherent energy properties of various fuels making such things impossible?  But wait, we've already demonstrated several propellant/oxidizer combinations CAN send earthbound objects to distant orbital bodies, and in recent decades we've developed propulsion technologies that can do so with vastly greater efficiency.  Did your statement about thermodynamics have a point?  I hope you weren't just throwing around that word in an attempt to show off.

Furthermore, the article you reference was from a biologist, not an engineer.  What are the odds he even knows the simple rocket equation, or the typical delta-V requirements to reach and land on other orbital bodies?  About the same odds of an engineer like myself knowing the detailed internal anatomy of a South American tree lizard.  In other words, very slim.  And that's to be expected... the two fields are very different.  So it's non-expert opinion, nothing more.  And the blog that the biologist referred to?  That's from a sci-fi author (presumably more knowledgable but still without an engineering or physics background), and the article is actually similar to the Do the Math article in that it highlights the difficulties in reaching distant bodies and colonization, but does not dismiss the possibilities or state it can't happen.  And even then some of the statements or assumptions are questionable, such as the one you quoted saying "I'll believe in people settling Mars at about the same time I see people settling the Gobi Desert."  Well news flash, but people HAVE been settling the Gobi for a long time now.  It's a funny coincidence, but in fact my wife's relatives on her mom's side happen to be among them.  I've been there myself, and while it's far from my first choice of places to live (too hot in the summer) there is a kind of beauty to some of the region. 

For any partially or fully self-sustaining manned outpost or colony beyond Earth, you ultimately need 3 things: to be able to get there (already demonstrated in part by the Apollo program and numerous probes), available energy (solar and nuclear are available options in most cases), and water or water ice (already demonstrated to be present in several other planetary bodies).  You could probably include soil and mineral deposits for agriculture and materials for construction or industry to that list, but in all likelihood any hypothetical colony would be located on or near such things.  And to get objects out of the Earth's gravity well, as long as you have some small industrial base, a source of energy to create hydrogen (you could use solar), and the proper skillsets you can do it.  Cheap energy is helpful, but not a necessity.  We were sending things into space decades ago when the economy and per-capita energy consumption was a fraction of its current size, so economy and energy shrinkage alone is not a valid argument against a functioning space program.  To be perfectly clear.... I am not saying that further space exploration & colonization WILL happen, I am only saying it CAN happen.  As Aaron put it, it's really a matter of "won't do it" rather "can't do it".  At present the larger obstacles are politics and societal priorities (or lack thereof) & dysfunction, not the limits of engineering.  To be fair, the political, economic, and social dysfunction obstacles are very substantial, but none of us know how these will develop and to what degree they will be present in the future.  It's premature to call space exploration "dead" when we still don't know what the end state of society will be like.

So xraymike, why then should we take your statements of the absurdity of it all at face value?  Do you have any expertise or background in this topic to validate your claim?  Because so far all you've come up with is we can't do it "because it's hard".  Well, so was the development of powered flight, or the mapping of the human genome.  It looks to me like your opinion or belief here is based on either preconceived notions or a failure of imagination (or both), not on actual knowledge.

 

For anyone who wants to dig deeper, I recommend The Case for Mars (you can preview part of the book at that link).  It's written by an aerospace engineer but most parts are written for the educated layperson.

 

- Nickbert

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Who wants to go to the moon anyway?
Johnny Oxygen wrote:

Who wants to go to the moon anyway? There's no oil there or natives to take advantage of.

On the other hand there isn't any global warming there either.

This one's for you

 

- Nickbert

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nickbert wrote: Johnny
nickbert wrote:
Johnny Oxygen wrote:

Who wants to go to the moon anyway? There's no oil there or natives to take advantage of.

On the other hand there isn't any global warming there either.

This one's for you

 

- Nickbert

Thanks Nickbert

What a great promo! I'm getting my ticket now.

Oh...I didn't care for that collision part but I guess you have to take the bad with the good.

 

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Thermodynamics and the Fantasy of Space Colonization
nickbert wrote:

xraymike-

Please do tell, what law of thermodynamics does space colonization or exploration violate?  Last I checked such things do not involve perpetual motion machines, reversing a normally irreversible process, or absolute zero temperatures.  Or perhaps you're referring to the inherent energy properties of various fuels making such things impossible? ... Did your statement about thermodynamics have a point?  I hope you weren't just throwing around that word in an attempt to show off.

- Nickbert

Please do tell, you say???

As I stated in my previous post, we would need to be able to travel light years in order to 'maybe' find a habitable planet for humans since there are none in our solar system. But even if we travel at speeds less than the speed of light, we would get roasted alive. I'll let Ben Crowell explain. He has a PHD in Physics from Yale University....

 

It's getting a little warm in here.

If we really are restricted to slower than light (STL) travel, what kinds of stories can we tell while staying within the bounds imposed by the laws of physics? The next pesky problem comes from the laws of thermodynamics: it turns out that even if the Galactic Federation wasn't worried about your STL spaceship's awesome potential as a weapon of mass destruction, you'd still get roasted alive by your own engines. Here's how it works. If a spaceship is going to travel at an appreciable fraction of the speed of light, then the amount of energy it needs to carry along is on the same order of magnitude as Einstein's E=mc2, and this is the amount of energy you could produce by converting the entire ship's mass into pure energy. In other words, the only fuel that's going to have a high enough energy density is a supply of antimatter, which you can annihilate slowly as you go along. That means your ship's drive falls into a very broad category of devices known as heat engines — devices that turn heat into mechanical work. The laws of thermodynamics place strict limits on the efficiency of heat engines. These are not just technological limits that might be surpassed by clever engineers someday, they're fundamental limits that come from the basic laws of physics.

Now let's say your spaceliner, with a mass of 100,000 tons, is going to spend ten years accelerating up to one tenth of the speed of light, a speed at which it would take most of a human lifetime to get to the nearest star. That means your engines have to have a power of 1011 horsepower, or about ten times the output capacity of the entire U.S. energy infrastructure. If your engines are fifty percent efficient, then half of that energy isn't going into propelling your ship, it's going into heating it — and remember, there's no air in outer space, so you can't use a fan to blow air over a radiator. Your ship will melt down in a fraction of a second from its own waste heat. What if we make the engine more efficient? The theoretical maximum efficiency of a heat engine according to the laws of thermodynamics is given by 1-Tc/Th, where Tc is the cold temperature of the environment into which the engine can dump its waste heat, and Th is the temperature at which the heat is produced by burning the fuel. Letting Th be a million degrees Kelvin (and assuming we can contain something that hot!), and letting Tc be room temperature, we get a theoretical maximum efficiency of 99.97%. That still leaves 0.03% as waste heat, and that waste heat is still enough to kill the crew faster than you can say "well done."

He's got a lot of myth-busting ammunition in his essay Why Space Opera Won't Fly, but my favorite tidbit is this one:

...We're all familiar with the earthbound tropes represented by Horatio Hornblower, Captain Hook, or Stanley and Livingstone, so why not just translate all those tired old storylines into outer space?

Well, there are a lot of good reasons why not. Let's start with energy scales. The U.S.S. Enterprise of Star Trek fame is about the same size and tonnage as the Queen Elizabeth 2, so if it was moving at half the speed of light, its kinetic energy would be something like 1024 joules. That's equivalent to about a hundred billion Saturn V rockets, or about a thousand times the total megatonnage of the world's nuclear arsenals. In other words, the Enterprise is the ultimate weapon of mass destruction. If you accidentally crash it into a planet (didn't that happen in one of the movies?), it's more than enough to destroy everything alive....

We humans have the ability to descend thousands of feet down into the sea where the oceanic pressure would crush you to death if you weren't in a special pressure sphere, but would any sane person want to build a city down there and live their life in such a life-threatening environment? The same holds true for the crazy idea of building hermetically sealed space colonies on inhospitable planets like Mars. It ain't gonna happen.

What would happen to you if your precious space suit failed?

 

Outer space is an extremely hostile place. If you were to step outside a spacecraft, such as the International Space Station, or on a world with little or no atmosphere such as the moon or Mars without the protection of a space suit, then the following things would happen:

  • You would lose consciousness because there is no oxygen. This could occur in as little as 15 seconds.
  • Because there is no air pressure to keep your blood and body fluids in a liquid state, the fluids would "boil." Because the "boiling process" would cause them to lose heat energy rapidly, the fluids would freeze before they were evaporated totally (There is a cool display in San Francisco's science museum, The Exploratorium, that demonstrates this principle!). This process could take from 30 seconds to 1 minute. So, it was possible for astronaut David Bowman in "2001: A Space Odyssey" to survive when he ejected from the space pod into the airlock without a space helmet and repressurized the airlock within 30 seconds.
  • Your tissues (skinheart, other internal organs) would expand because of the boiling fluids. However, they would not "explode" as depicted in some science fiction movies, such as "Total Recall."
  • You would face extreme changes in temperature: sunlight - 248 degrees Fahrenheit or 120 degrees Celsius;shade - minus 148 degrees Fahrenheit or minus 100 degrees Celsius
  • You would be exposed to various types of radiation (cosmic rays) or charged particles emitted from the sun (solar wind).
  • You could be hit by small particles of dust or rock that move at high speeds (micrometeoroids) or orbiting debris from satellites or spacecraft.

You would die quickly because of the first three things listed, probably in less than one minute. The movie "Mission to Mars" has a scene that realistically demonstrates what would happen if an astronaut's space suit were to rapidly lose pressure and be exposed to outer space. So to protect astronauts, NASA has developed elaborate space suits.

http://science.howstuffworks.com/question540.htm

 

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Damnthematrix wrote:Aaron
Damnthematrix wrote:
Aaron Moyer wrote:

This babble about "with what fuel!?" Is ridiculous.

Is it?  I remember once reading that every time the shuttle takes off, it uses as much energy as all the cars in LA consume in one year.....  and that's just to get into ORBIT!  Never mind going to Mars or another star......

Yes, it's ridiculous alright, and the question stands.

Mike

Mike-

I'm not sure where you read that, but it doesn't appear to add up.

The shuttle's external tank contains about 534900 gallons (or roughly 2 million liters) of liquid hydrogen, with an energy density of 10.1 MJ/liter, for a total of 2,000,000*10.1=20,200,000 MJ.  The two solid rocket boosters contain about 1110000 lbs (about 500000 kg) of solid propellant with an energy density of roughly 31 MJ/kg, for a total of 500,000*31*2= 31,000,000 MJ.  Add that up and you have 51,200,000 MJ of energy.

The best link for California gas consumption I found was here, and they approximated 10 barrels (1590 liters) per year.  The energy density of gasoline is 34 MJ/liter, making a total per-person consumption of around 54,060 MJ.

Divide 51,200,000 MJ (for the shuttle) by 54,060 MJ (for yearly consumption of one driver), and you get 947 persons worth of consumption.  Last I checked there were a few more than 947 drivers in the LA area  .  

Don't get me wrong that is still a helluva lot of energy, but nowhere the total gas consumption of LA in a year.  These are just very rough approximations mind you (and done in a Thanksgiving dinner over-eating induced stupor ), but even if the source data is a little off it still shows the scale of energy use is much different from what you stated.

As to your question of what fuel, it is quite possible to use solar energy to create hydrogen for use as propellant (which actually happens to be one of the best performing propellants).  Right now we use fossil fuels to do so because it is currently easier/cheaper, but we can do the same with solar and an available water source.  It would take a little time to create 2 million liters worth of liquid hydrogen, but then again rocket launches are not an everyday occurence either.  Like I said before, cheap energy is really helpful, but not necessary.  If people want it badly enough, it's possible to do.  I'm not saying they WOULD make that decision, only that it remains an option should they so choose.

- Nickbert

 

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xraymike79 wrote: nickbert
xraymike79 wrote:
nickbert wrote:

xraymike-

Please do tell, what law of thermodynamics does space colonization or exploration violate?  Last I checked such things do not involve perpetual motion machines, reversing a normally irreversible process, or absolute zero temperatures.  Or perhaps you're referring to the inherent energy properties of various fuels making such things impossible? ... Did your statement about thermodynamics have a point?  I hope you weren't just throwing around that word in an attempt to show off.

- Nickbert

Please do tell, you say???

As I stated in my previous post, we would need to be able to travel light years in order to 'maybe' find a habitable planet for humans since there are none in our solar system. But even if we travel at speeds less than the speed of light, we would get roasted alive. I'll let Ben Crowell explain. He has a PHD in Physics from Yale University....

It's getting a little warm in here.

If we really are restricted to slower than light (STL) travel... (snip)

 

(sigh) You mischaracterize my position by trying to redirect the conversation and arguing against one of the most extreme examples of exploration & colonization (i.e. interstellar), an example I never even mentioned much less argued for.  Not only that, but using an example involving antimatter as a fuel, the energy source least likely to be used for any energy or propulsion any time this century, if ever (we can only create handfuls of atoms at a time and only with great effort).  And to deviate even further, the next part of your counterargument goes on a tear about space opera cliches ala Star Trek.  Again, a mischaracterization of my position.  Nowhere did I say we're going to be flying around ala Star Trek or Star Wars.  None of this has anything to do with exploration of our closer neighbors in this solar system.  Nice try but no dice... I'm not going to argue a position that you're trying to create for me. 

Again, do you have evidence that thermodynamics is a barrier to exploration and colonization beyond Earth (and yes this includes our own solar system not just distant stars)?  You have not mentioned any personal credentials or background in this area, but lest you think I'm blowing smoke I will disclose mine.  I have a B.S. in aerospace engineering with 5+ years of professional experience at a major aerospace company working with simulations and models of a space-based system.  The professor I worked with my senior year happened to be the one who developed an in-situ atmosphere processor for creating oxygen from the Martian atmosphere, and my independent study under him involved proving the feasibility of a Martian sample return vehicle using a hybrid rocket in combination with aforementioned atmosphere processor.  Now I will readily admit I am FAR from being the most experienced or knowledgable engineer in this area, but I do at least have a grasp of the fundamental difficulties and technologies involved.  Any difficulties with space travel and habitation I am very likely to be at least very familiar with, if not formally educated in or being part of my work.  And while many are formidable, I have yet to see any that definitively bars us from doing such things.

Quote:

We humans have the ability to descend thousands of feet down into the sea where the oceanic pressure would crush you to death if you weren't in a special pressure sphere, but would any sane person want to build a city down there and live their life in such a life-threatening environment? The same holds true for the crazy idea of building hermetically sealed space colonies on inhospitable planets like Mars. It ain't gonna happen.

What would happen to you if your precious space suit failed? (snip)

And here you are changing the direction of the debate again, this time instead of saying we "can't" now you're trying to say we "won't".  But I'll humor you this time.

Since you question the sanity of anyone willing to try a life in such places, it's obvious you don't think much of myself and numerous other aerospace and science professionals because there is actually no shortage of such willing to try it.  And yes the difficulties and hardships are enormous, but so are the potential opportunities.  Think of the biologists who get to explore for evidence of ancient microbial life on Mars, or the geologist that gets to study geological formations larger and more ancient than anyone before?  Think of the engineers who get to be on the forefront of developing and implementing new technologies, or the entrepreneurs who get to develop new frontiers or build industries where none existed before.  In short, some people like a challenge, at least when there's incentives and opportunities.  If you want an example of such, look at the researchers who live and work in Antarctica.  Similar to your space suit example; without the benefit of certain technologies and special equipment, in certain seasons a human will not live that much longer than he would exposed to vacuum.  There is a certain percentage of the population that are natural explorers and risk-takers, who will take a chance where most others "play it safe".  Their reasons may vary, but the behavior is there.

I get the sense you think the whole notion is a waste of time.  And if that's your opinion then that's cool, and you're entitled to it.  But don't assume everyone thinks like you do, and also be very careful when saying it "can't" or "won't" be done, because then you're in a position to prove something is impossible.  And history is littered with critics who said "it's impossible" only to be proven wrong.  It wasn't long ago many people we're saying the breakup of the Euro was impossible.  Think in terms of probabilities, not just in terms of "will happen" or "won't happen".

- Nickbert

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I think the work you do is the pinnacle of our civilization
nickbert wrote:

 (sigh) You mischaracterize my position by trying to redirect the conversation and arguing against one of the most extreme examples of exploration & colonization (i.e. interstellar), an example I never even mentioned much less argued for. ...Nice try but no dice... I'm not going to argue a position that you're trying to create for me. 

- Nickbert

Nickbert,

     I'm taking the position that Hawkings proposed. What on earth was he talking about when he said:

"Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space."

And what were you talking about when you said:

nickbert wrote:

xraymike-

Please do tell, what law of thermodynamics does space colonization or exploration violate?

But your work is invaluable, despite what I have said.

nickbert wrote:

Since you question the sanity of anyone willing to try a life in such places, it's obvious you don't think much of myself and numerous other aerospace and science professionals because there is actually no shortage of such willing to try it. 

...I get the sense you think the whole notion is a waste of time. 

Having answered your question in my last post, I also have to say that NASA and space exploration would be one of the last areas I would defund if I had any say in the matter. I was just answering the practicality of colonizing alien worlds with humans at the present time. Gotta eat turkey now. Happy Thanksgiving. 

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land2341
land2341 wrote:

 http://www.huffingtonpost.ca/2011/11/18/stephen-hawking-space-exploration_n_1101975.html?ref=mostpopular&just_reloaded=1 

“We are entering an increasingly dangerous period of our history," said Hawking, who has Lou Gehrig's disease, leaving him almost completely paralyzed and unable to speak.

"Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill. But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million.

"Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space."

Hawking is talking about civilization having a [very] long term goal because we can't solve our problems here.  Because of who we are.  What do you think, is that true?

In the near term, say the next hundred years, we shouldn't be working on manned space flight or going to Mars.  We should be mining asteroids and the moon because, as has been pointed out enough, we are running out of resources here.

I've posted about this before.  And the responses struck me as the same skepticism that greeted flight in the 1890's.  So I will go ahead and cherry pick a few paragraphs from the Wikipedia article:

"Some day, the platinum, cobalt and other valuable elements from asteroids may even be returned to Earth for profit. At 1997 prices, a relatively small metallic asteroid with a diameter of 1.6 km (0.99 mi) contains more than 20 trillion US dollars worth of industrial and precious metals.[1] In fact, all the gold, cobalt, iron, manganese, molybdenum, nickel, osmium, palladium, platinum, rhenium, rhodium, ruthenium and tungsten that we now mine from the Earth's crust, and that are essential for economic and technological progress, came originally from the rain of asteroids that hit the Earth after the crust cooled.[2][3][4] This is because, while asteroids and the Earth congealed from the same starting materials, Earth's massive gravity pulled all such siderophilic (iron loving) elements into the planet's core during its molten youth more than four billion years ago[5]. Initially, this left the crust utterly depleted of such valuable elements[6]. Asteroid impacts re-infused the depleted crust with metals."

...

"Economic analyses generally show that asteroid mining will not attract private investment at current commodity prices and space transportation costs.[11] However, based on known terrestrial reserves and growing consumption in developing countries, there is speculation that key elements needed for modern industry, including antimony, zinc, tin, silver, lead, indium, gold, and copper, could be exhausted on Earth within 50-60 years.[12]"

...

"Near-Earth asteroids are considered likely candidates for early mining activity. Their low Δv location makes them suitable for use in extracting construction materials for near-Earth space-based facilities, greatly reducing the economic cost of transporting supplies into Earth orbit."

There are challenges of course, but there are many technological, social, jobs, etc.,benefits to having a clear goal.  And successfully carrying it out.

DTM is right that getting a rocket out of earth's gravitational well is expensive, which is why the base of operations will have to be the moon or a space station.  But think about it this way:  if it costs $ 2T to get $ 20T isn't that a good return on investment?

 

 

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xraymike79
xraymike79 wrote:

Nickbert,

     I'm taking the position that Hawkings proposed. What on earth was he talking about when he said:

"Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space."

The position he took was simply to have human settlements beyond the Earth, which can mean anywhere from Earth orbit on out.  The context of his statements in the article was that we're heading into a century of extreme uncertainty and volatility, and his mention of aggressive and selfish instincts implies potential for major conflict or strife of some kind.  Given our military and scientific capabilities, this could result in either our extinction or an indefinite disappearance of anything resembling an advanced civilization on the planet (though one might say at present we only "resemble" an advanced civilization given our poor decision-making and management of resources ).  So from that one would assume that the intent behind his proposal is not to fix said problems on Earth, but rather preserve something of advanced civilization if not our species itself in case the worst happens.  And though he does not mention this, I happen to think there is also potential to improve ourselves through these endeavors.  As I mentioned in my first post, the degree of cooperation, forethought, and resource management required to live off-world just might diminish some of our more aggressive and selfish instincts.  As you rightly point out it's an incredibly hard endeavor, one that wouldn't tolerate the degree of those aggressiveness and selfishness that we sometimes see down here.  We still wouldn't be perfect, but we may at least learn some self-control over our more self-destructive instincts.

Quote:

And what were you talking about when you said:

nickbert wrote:

xraymike-

Please do tell, what law of thermodynamics does space colonization or exploration violate?

By your subject title in your original post ("the hard realities of thermodynamics"), you imply that the principles of thermodynamics are a barrier to what Hawking proposed, i.e. expanding manned space exploration and colonization in space.  The only way that happens is if such things violate one of the four laws of thermodynamics, or that the application of thermodynamics can prove that the methods used to get there or live there produce insufficient useful work to get the job done.  I was saying that this cannot be true, since we have already demonstrated the ability to both get beyond Earth orbit and to survive, and it is actually application of thermodynamics that allows us to do these things.  This is why I'm saying your mention of thermodynamics didn't make sense.

Quote:

But your work is invaluable, despite what I have said.

nickbert wrote:

Since you question the sanity of anyone willing to try a life in such places, it's obvious you don't think much of myself and numerous other aerospace and science professionals because there is actually no shortage of such willing to try it. 

...I get the sense you think the whole notion is a waste of time. 

Having answered your question in my last post, I also have to say that NASA and space exploration would be one of the last areas I would defund if I had any say in the matter. I was just answering the practicality of colonizing alien worlds with humans at the present time. Gotta eat turkey now. Happy Thanksgiving. 

I happen to agree that right now would probably not be a prudent time to embark on greatly expanding manned presence in space.  The US and the world is in such a precarious situation that efforts should be focused on damage control and triage, and regarding space it would be wiser to focus on preserving and building resiliency in the capabilities we already have.  Embarking on such a project that requires very long term commitment in the face of an imminent fiscal & debt crisis would be a little like deciding to build an extension to your house during a hurricane.  But eventually the debt/fiscal hurricane will run its course one way or another and society will adapt to the new economic situation.  THEN it would be a good time to propose such a project on both public and private levels, while we still have some of our dwindling fossil fuel energy bounty left and before the race for resources gets even uglier.

One thing that gives me hope for the world's space programs is the example of the collapse of the Soviet Union; despite horrendous political, economic, and budgetary chaos, they still managed to keep their space program alive.

- Nickbert

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james_knight_chaucer
james_knight_chaucer wrote:

 Ditto. Honestly, you'd think Stephen Hawking was one person who would have done the 'math'!

Hawking has likely done the math. However, I don't believe Murphy is competent to do so: Murphy's Mangled Math

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So the Kepler planets?

 We also could,  nay should, be using the technology we're developing to deal wit space to deal with deep sea exploration.....

 

We don't have a planet B,  but assuming we've got the "space thing" figured out and so should stop exploring is hubris.  I think it is from physics that  our next big transformative push will emerge.

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If Thermodynamic Physics were not enough of a limiting factor

Space travel 'may damage eyesight', brain study shows

 

...

Professor Larry Kramer, lead author, said, "The MRI findings revealed various combinations of abnormalities following both short and long-term cumulative exposure to microgravity also seen with idiopathic intracranial hypertension."

Kramer said the impact of space travel on astronauts' brains and eyes represented a "potential limitation to long-duration space travel."

...

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