As a newcomer to this forum, I would like to play devil's advocate and suggest that humans traveling in space and colonizing other worlds is an idea whose time has come .. and gone.  I believe there is a distinct possibility that we humans will never, ever venture far beyond our own planet.  My reasons for this conclusion are as follows:

1.Interstellar distances are as we know vast, perhaps too much so.  As near as I can find on the internet, the man-made object that has traveled faster than any other was a Helios space probe that achieved a speed of 153,800 mph. That's really fast - equivalent to the distance from the Earth to the Moon in 100 minutes!  Yet were we to use a solar fly-by to achieve this velocity for a probe sent to Proxima Centauri, the star nearest to Earth, it would arrive in the vicinity of its target sometime in the year 20,320 A.D.  The good news is that should anything on board still be functional after its 18,313-year flight, we'd begin to receive its signals in a mere 4.2 years. 

   But of course we will not launch such a probe with today's technology.  We need to go much faster.  Estimates of velocities needed for interstellar travel on the order of 0.1c are bandied about - at that rate, we'd reach Proxima Centauri in only 42 yrs.  However, 0.1c is 3,672-fold greater than our Helios achieved.  To put it in perspective, that improvement in speed is the same as that of our Helios compared to a Model-T Ford (~40 mph).  And we must consider the energy per gram of payload (the Helios vs the Model-T) needed, as well as the technology.  What will be the cost of the energy?  It is a daunting task.

  I throw these numbers out to illustrate what most of us are already aware of at some level:  the unimaginable gulfs that separate us from our neighbors in space.  Perhaps these difficulties can easily (!) be overcome with worm holes or hyperspace drive, the old sci-fi reliable.  But to date these are little more than fanciful ideas.  When we navigated blue-water oceans or broke the sound barrier, nothing in physics said we couldn't.  Einstein's special laws of relativity, however, have stood a century of rigorous testing.  There is a distint possibility that they are valid and that for all practical purposes, a directed craft containing human passengers will be never be able to approach or exceed the speed of light.  Familiar stars like Antares (600 l.y.), Deneb (~3000 l.y.) and even Arcturus (87 l.y.) are beautiful to look at, but may be forever unreachable.

    I've decided to make this post in 2 parts.  In the second I will describe what I believe are more significant reasons why human space travel may never occur:  a) the success of un-manned space probes; b) elevated human awareness.

I can't argue with your logic, Al.

Dave Mitsky

 Hi Al:

Thanks for keeping it real in your great post. As far as humans in space, it's as simple as doing the math. The VAST distances between stars is something most minds can't begin to fathom. Low-Earth Orbit is like a window to the Universe and we need to make the best of it.

-Mr. Jackson

Human engineered spaceprobes will travel to other stars within 100 years.  These stars will be in the 4-15 ly range.  I will bet the impetus will be terrestrial planets in habitable zones with biotic atmospheric signatures discovered by the first generation of dedicated space and Earth-based planet-finder telescopes.  These discoveries will begin pouring in between 2014-2025.  Expect HUNDREDS of terrestrial planets, and dozens with biota signatures. The interest and enthusiasm around the world will be overwhelming.

  I'll put $10 on that one.

  Improvements in propulsion technology might increase the horizon out to 20-30 lys with the next generation of craft.  If you consult a galactic map, you will see this area encapsulates several G type stars.

 While human travel does not seem feasible with current tech, a second generation technology might make human flight to the nearest stars possible.  However, the round trip would lilely take 40-50 years!  A working lifetime....  Personally, I see no benefit to such a mission, beyond saying we did it.  A fucntioning spaceprobe can image and do remote experiments in solar orbit just as well as human beings.

  volunteers?

Let us not forget that as one of the leading nations in space explorations , we are too busy policing the world and the moneys that could go to something like this is being poured out into stupid programs.

  hey Astronig!  Let's not get political!

  Some of the membership voted for the representitives that voted for those stupid programs!

    Have some respect!   (;< )

  Anyhow, given how things are going with the US economy, and our ever increasing national debt, we might have settle NASA serving as a space-ride revenue venture for the government!

cyberpatzer:

While human travel does not seem feasible with current tech, a second generation technology might make human flight to the nearest stars possible.  However, the round trip would lilely take 40-50 years!  A working lifetime....  Personally, I see no benefit to such a mission, beyond saying we did it.  A fucntioning spaceprobe can image and do remote experiments in solar orbit just as well as human beings.

  volunteers?

If we assume a long-term future for human civilization (another 10,000 to 50,000 years) the benifit would be in relocation and colonization after we've populated and polluted ourselves off this planet.  I don't say that to be pessimistic, it's just that our civilization consumes huge amounts of resources and , IMO, we won't be able to find alternatives forever.  Also there is the fact that at some point (probably not within the 10K to 50K year time frame, but eventually) the Earth will become inhospitable to humans just as has happened on Mars and Venus.  Those two planets, at some point in the solar system's history, apparently had conditions conducive to supporting life.  How long will our own planet maintain its friendly nature, even if we don't run ourselves out?

Yea , sorry 'bout the political aspect of my post , but somehow it just happens to all blend into the scheme of the topic and I didn't necessarily intend for that to happen but at the same time , you can't ignore the truth.

   Another bet:

   Within 100 years, there will be worldwide policy on population control.  World wide population will be held to 10-12 billion people, give or take a billion.  or a lower quota could be set (6-7 billion--to be achieved by, er, 'peaceable attrition' (natural death).  Current population increases will not be sustainable within 100 years.  Prevailing logic has 13 Billion as a cap on how many people the Earth can support.  This doesn't; include changes in available land for farming, coastal erosion, water shortages, etc.. from inevitable, if moderated warming.  Keep in mind millions of Africans die from malnutrition every year, right now (among other areas....)  So, maybe we mean how many nice people like us can Earth support ('Pale' westerners?) at other nations expense?

  We will have also solved the energy problem and global warming in this time frame, or it will handle the population control issue without our input!

   This is how sentient, intelligent, and wise beings might behave--soving problems, not working around them.  If humanity or humanity's leadership is too short-sighted to handle these problems, my personal feeling is that we don't deserve to populate other worlds, having proved ourselves such abyssmal stewards, acting like a horde of ravenous rats, mindless and instinct-bound.

  Controling our numbers is 'humane', logical, and imperative.

  Short of a human engineered (or non-engineered?) end, we could expect another 1 billion really solid years on Earth.

  (P.S.:  As long as we are imagining:  If we can travel to other stars, we could certainly solve population and energy problems, and likely must....)

Maybe this population control is something that should have been put into play a long long time ago as there is a lack of accountability and responsibility for the most part anymore.

  Yes, perhaps population control earlier might have been an idea.  However, I remember China being villified for imposing birth limits not too long ago.  It appears limitless procreation is felt to be a basic human right by many.   Paradoxically, perhaps, this feeling doesn't change when you tell the proud parents:  YOU WILL NOT BE ABLE TO FEED YOUR CHILD. (Of course, this syndrome appears everywhere...)

   Clearly, many places in the world are lacking basic housing, education, healthcare, and industry (And I am not talking about the US!...Duh!).  Some moderate level of development will be necessary prior to policies of any impact in these regions.  And, we're not talking about not having any children, just one....or two...here and there....

Should we ask to move this thread to "Off Topic" if we want to keep it going?

It's funny whereas I was asked not to get political on this topic that it still sounds like there are political overtones within it.   But ya gotta admit , that it is hard for a topic such as this not to have political overtones. Just myworth.   And hey!......Who loves ya baby!

  I was only being sarcastic, astronig!

   I am the most political/naughty/censored/locked threaded

     person on this site!

   Rock on!   Power to the People!

I know it cyberpatzer! , I could tell by the shape of the letters in your post! lol Believe me , there aint nothin' wrong with a little light hearted humor here and there! I think most of us can handle some messin' around once in awhile!...But seriously , this UFO threat is real and needs to be addressed and the official that I voted for went weak in the knees on it!..There needs to be some money spent on the UFO problem!  (Undocumented Fleeing Offenders)    Is that not politically correct or what!?   lol   lol   Dave

OK, I guess I am going to be the saviour of this thread. Initially I considered the vast amount of distance involved in solar system flight let alone interstellar flight to be fairly insurmountable without resorting to SciFi solutions. However, after watching The Universe last night I am going to be a little more open minded about it. The very old idea of the space elevator is now quite closer to being feasable than once was thought due to the advances in materials strength and elasticity. If we could build one the tremendous cost of using chemical rockets to boost things into earth orbit would no longer be an issue. All sorts of money then could be spent on solar system exploration. When looking at interstellar flight there is a long ways to go but those on the cutting edge of theoretical physics now do not seem to be so negative about either a matter/anti-matter warp drive or even better a Tachyon Drive. Also mentioned were ramjets, an old idea once again, as well as ion engines which we already have used, and solar sails. Many of these things are old staples of classic SF by Clarke, Asimov, and others. Unfortunately I fell asleep and missed the last 10 minutes of the program but perhaps, just perhaps, humans in space is not such a far fetched idea.

BTW, while human space flight is probably a 20th century yearning, other than going to the Moon of course, and certainly one of man' greatest achievements, Pigs In Space is certainly a twentieth century laugh fest! Hee Hee

A future of humans NOT flying in space is a bit like a future where humans no longer climb Mt. Everest, or study Antarctica, or the sea-depths, but rather they send robotic surrogates in their stead to do all the field work.   It just doesn't FEEL right, and I know how un-scientific that statement is.  Believe me, life ain't all explainable by scientific means.  We're Humans and we Explore. 

PS  Is it true that even a million kilogram spacecraft that is accelerated by a one- Newton thruster can achieve tremendously large speeds (interstellar?) over months and years.  Followed by an identical, but opposite, deceleration, and you'll have visitors to nearby stars in decades, not millenia. 

Al, loved the post, i understand how you view the distances of objects in our Universe.  We should first focus on the reachable objects in our nieghborhood: our solar system.  The Mars Missions are soon to come and from there we can develop new knowledge.  The show Universe in the History Channel also describes faster ways to zip along the galaxies. For example, harvesting the power of Tachyons, which are viewed as energy being that use the speed of light as a speed limit.