I will be positive and say YES that technology will advance so that we can leave planet Earth and our Solar System. We are constantly exploring fuels, food production, in the medical field and in new technologies.

The greenhouse effects and climate change impacts are in current review and will be resolved.

There are two main issues to be resolved;

1- Time element. It takes decades to reach the edge of the Solar System e.g. Voyagers 1 and 2. Humans cannot be cooped up in a cylinder for that long. They need food and an infrastructure for their survival. A faster method of propulsion is not here yet. Also, those aboard will need a destination planet where they can thrive.

2- Radiation (Cosmic and galactic) on the human biology needs to be resolved to ensure survival of humans aboard.

The above issues must be addressed before humanity can contemplate such mission with humans on board. Within our reach are the Moon and Mars.

I will be positive and say YES that technology will advance so that we can leave planet Earth and our Solar System. We are constantly exploring fuels, food production, in the medical field and in new technologies.

The greenhouse effects and climate change impacts are in current review and will be resolved.

There are two main issues to be resolved;

1- Time element. It takes decades to reach the edge of the Solar System e.g. Voyagers 1 and 2. Humans cannot be cooped up in a cylinder for that long. They need food and an infrastructure for their survival. A faster method of propulsion is not here yet. Also, those aboard will need a destination planet where they can thrive.

2- Radiation (Cosmic and galactic) on the human biology needs to be resolved to ensure survival of humans aboard.

The above issues must be addressed before humanity can contemplate such mission with humans on board. Within our reach are the Moon and Mars.

Dariusz,

Short of magic, the only known method for carrying a human to another star is through a generation ship.

Can they be built?

With fairly high certainty, yes.

Are they viable?

Hard to say.

Will we survive till we reach a point where such vessels can be built.

Crystal ball cloudy, ask again in 100 years.

An interesting question, but one which opens a dozen cans of worms...

"a man can leave the solar system and, for example, one day he can reach... Alpha Centauri" seems to imply travel from here to there within a single person's lifetime. That would eliminate all the complications (not only technological, as discussed in the first two answers, but also moral) of a "generation ship". (Moral aspect: Presumably all those in the first generation will want to go, but wouldn't many of those in succeeding generations feel that they were deprived of the right to choose what they want to do? Isn't it possible that by the time they reach another star they will want to have nothing to do with the fiends who sent them there?)

However, let us suppose that we want to send someone to another star in a single lifetime. Even though some believe that lifetimes of 150+ years may someday be achievable, the trip would have to be accomplished in under 100 years (presuming the person is "of age" when they start, and still not decrepit when they arrive), and preferably no more than 10 to 20 years. This would require average velocities between 4 and 20% the speed of light, peak velocities of at least twice that amount, and aside from the question of how to avoid having high-g accelerations killing all the passengers, solving the question of how to generate the power required for such flight speeds is more likely to involve millennia than centuries.

There is also the question of the cost of such a project. It is hard to imagine that all the money in the Universe would be enough to pay for either a generation ship or a single-lifetime ship, unless (a) technology has advanced to levels that would make magic seem like child's-play, and/or (b) the Solar System has become no inimical to life that it is either leave or die. The former is unlikely unless we consider time scales of at least thousands or tens of thousands of years, and the latter is a one to three billion-year eventuality.

There is, of course, another possibility. Stars move relative to us, and in a million years of so, one of the Gliese stars (I forget which one) will pass through the outer Oort Cloud, only a little over 50 thousand AUs from the Sun. If that star has habitable planets, the technology of that day might make a trip to one of them quite practical. But of course that isn't actually an answer to the original question.

Nearly Final Note, re the question of whether there are planets where we are headed. Robotic ships (some of credit-card size, based on current plans) should allow us to explore most of the region within a few hundred light years of the Sun within a few thousand years. So long before it is possible to send humans somewhere, we should already know where it would be practical to send them. (Query: If other species have used such "vehicles" to explore the space near them, is it possible that collisions with such near-light-speed objects might be a significant possibility? In other words, would exploring where we want to go make it impossibile to safely get there?)

Final Note: Of course, there are many who believe that within a generation or three, humanity will be replaced by robotically enhanced humans, or simply artifically intelligent robots who have no physical or emotional relationship to humanity. If such robots could think of any rational reason to explore the stars, they might have virtually infinite lifetimes (replacing parts as needed, or moving their AI databanks into newer models), in which case the time required to get from here to there becomes irrelevant. But I think of that as such a dismal outcome that I would rather never be able to reach another star than to do it that way.

It is clear that well before people travel far in the Galaxy, evolved robots will explore and provide to humanity telepresence exactly as we have now such devices on Mars and around other planets. The technology and economics favour, at least now, such a solution.

An other likely path might occur if biotechnologies succeed to evolve conscious, intelligent, and space-adapted living beings, able to use local raw material for reproduction and energy needs.

I propose that Homo Sapiens will eventtually uncover the secrets of transmutation i.e faster-than-light travel (but it will probably won't happen for a few hundred years into the future). This will require a step-change in technological approach. e.g the subject will be dematerialised with the essence of the subject's energy encoded for worm-hole travel, then rematerialised at the destination. This is currently science-fiction, just as a Dick Tracy wrist-watch phone was science fiction in 1950's comic books, but is now a reality. At that future point in time, inter-stellar and inter-galactic travel will become a reality.

Yes. The timing depends on funding, a talented workforce, and taxpayer motivation.

I have to ask why we want to leave this beautiful planet. It is much easier to fix our green house than to go to another planet with a host of unknown diseases, climate and environment etc.

WE may bomb the planet, stave the population etc, but it still may be better than some foreign world "out there".

If a piece of space rock wipes us out, then we are extinc. Full stop.

It is far easier to send unmanned space craft to distant worlds than to populate them with people.

Colin Ayres " If a piece of space rock wipes us out, then we are extinc. Full stop. "

And that, IMHO, is sufficient reason to develop the capability of living off-world, that are not predicated on the stability of this biosphere.

I maintain that we've reached this state by having insufficient awareness of our actions. Planets are simply too big for a curious ape to manage well.

Having to cope with smaller biospheres (O'Neill colonies in cis-lunar space say) will force us to rethink a lot of what it means to live a good life.

So if a sun goes super nova in our surroundings then all is gone. There are too many things that can kill us all, and have reaches far beyond our abilities for space travel. I am not saying that we should not explore, what I am saying is that we should not run away from our commitments we have on earth. Earth is over populated with humans, using too much fossel fuel and poluting our habitation. Would we do any better on another world?

I am not sure whether sending generation ships into deep space will preserve our species anyway.

You are right Colin.

But firstly human endeavour is exploration based on endless curiosity, and the search for space (land). the early migration were based on this. Why send ships to the New World? why circumnavigate the globe explorers like Vasco de Gama, Marco Polo, or Amundsen to the S. Pole?

Firstly we explore and develop the new technologies to do far reaching areas; and if we find anything useful, we use it, including colonization, or just minerals, or satisfy our thirst for "what's it all about"

Nick

Yes, the migration wave of the 17th century etc was to ascape prosecution and move to an environment that was better than they were living in. The same planet with the same systems. But the deseases they carried into this new world also wiped out huge sways of population with small pox etc. If we moved humans to another planet they may have to live in air bubbles. Most planets would not be a lost paradise as storey writers picture.

There has been some work done in this field, and the statisics for finding a habitable planet or moon returns a very low chance of success. My arguements are based of using the money that would be used for these ventures in fixing up our own space ship.

We may also see that in the very short course of time (say 200 years) that technologies will find better ways to defend our space ship and ensure that humans survive.

" If a piece of space rock wipes us out, then we are extinc. Full stop. "

Apologies for the finger trouble in my previous post. What I meant to propose is if a "Space Rock" similar in size to that which caused the Dinosaur extinction, impacted the earth some people would survive. There are a number of individuals and groups who have prepared underground survival shelters, earth-insulated from radiation and thermal changes with sufficient air supplies, food and energy. The earth inhabitants would receive a minimum of one day's notice. This is sufficient time for these persons to become secure in their shelters. Of course the world will be a totally different place.

I was always suspicious of the extinction of the dinosaurs by a meteor. It seamed too species specific. I would think that a desease was also involved in their extinction. Something similar to AIDS.

But the first question has not been addressed.

If we are worried about the end of the human species, we can almost preserve it now. Imagine a space craft carrying enough embryos and support bacteria to repopulate a planet. Kept in limbo for hundreds of years and maintained by robots. Would this be a cost effective way, and ethically acceptable?

If it is a question of survival, ethics will be ignored!

Human species could also be annihilated by an imported disease borne by a meteor. So, humans will keep exploring new technologies as well as new areas/planets, keep them aside in case we need them. the rest is philosophy and endless "what ifs".

Question:

Will man manage to create technologies that will leave the planet Earth, Solar System and reach other planetary systems?

this is a very important issue that requires scientific research.

This question acquires a new meaning in the context of the progressive global warming.

The above discussion inspired me to the following considerations:

More and more scientific research confirms that more and more climatic disasters and weather anomalies occurring in recent years are a derivative of the progressive global warming. More and more often among scientists investigating this issue appears the view that if the average annual temperature at the surface of the Earth by the end of the 21st century will rise by another 3-4 ° C, then man will become an endangered species. If this black scenario was to be realized, in a few dozen years the areas that can be inhabited by people are significantly shrinking globally.

I invite you to the discussion.

Will changing the entire energy, communication and industry to renewable energy sources and ecological technologies significantly slow down the greenhouse effect on Earth?

In a situation, if it succeeded, it might not be necessary for humanity to think about leaving the Earth in the next several centuries.

Does any of you conduct research in this area? Apparently, the greenhouse effect is an irreversible process. the only thing that can be done is to slow down this process and thus adverse weather anomalies, unusual atmospheric phenomena, disasters caused by climate change. The development of industry based on traditional energy sources, ie burning of minerals, still dominates in many regions of the world. In domestic terms, the management of economies often boils down to economic growth, development of the industry without taking into account environmental protection issues and analysis of greenhouse gas emissions. In national economic policies, the tendency of the race is dominating for a higher number of economic growth, and the negative effects of this growth are forgotten. An attitude is assumed that the next generations are worried about how to solve this problem. Such an approach will accelerate only the negative effects of the global greenhouse effect and the emergence of disasters and natural disasters about the sources of climate change in a larger part of the world. More and more often the question is asked: how can we stop this process only as this process of warming up of average temperatures on Earth could be slowed down? What scale of this downturn could be generated if mankind would start to take this problem seriously? Does any of you conduct research in this area? Has any of you developed a theoretical model that would answer the question: Will switching all energy, communication and industry to renewable energy sources and ecological technologies significantly slow down the greenhouse effect on Earth?

Please, answer, comments. I invite you to the discussion.

Following

Dariusz Prokopowicz My understanding is that simply switching to a carbon neutral economy, while keeping CO2 concentrations at ~0.4%, still consigns us to a degree or two rise in temperature by the end of this century.

Removing CO2 from the atmosphere is (I gather) the only route by which the temperature rise seen in the last hundred years can be reversed.

Nuclear-powered CO2 sequestration, anyone?

The (false) assumption that many persons make is that the climate of the last few hundred years is representative of the long term and is therefore used as the baseline for climate predictions.

The geoscience view shows that in the last 800,000 years a Glacial cycle of period of approx 110,000 years exists, and between successive Glacial cycles there is an Interglacial Warming period of about 10,000 years, We are currently in an Interglacial warming period. In the previous Interglacial Warming period, sea-levels were approx. 5 metres higher than current sea-level. Sea-level is considered a proxy for temperature , so temperature was a little warmer than current (perhaps 3 degrees Celsius)- all this without excess fossil fuel burning.

In the previous Glacial maximum approx 30,000 years ago, sea-level was 120 metres below current sea-level, ant temperatures perhaps 6 degrees celsius cooler.

Looking towards the future, the logical forecast is that in the next one thousand years, temperature and sea-level will increase to the levels of the previous Interglacial warming, and then in addition, the increases (whatever they are) of the excess Fossil fuel burning will be superimposed.

Recently, scientists have concluded that the Antartic ice-melt lags temperature change by about 700 years, Currently there is no agreement regarding the future mechanisms and magnitude of Climate Change due to excessive fossil fuel burning (there are many hypotheses).

If the established Glacial cycles are not totally disrupted by the effect of the excessive fossil fuel burning, then the Earth will be in an "ice age" within 30,000 years into the future, and sea-levels will have fallen.

In summary, the long-term geoscience forecast is that the earth will initially become warmer and then become cooler. But as someone who has worked in the heat of Saudi Arabia and in the cold of northern Finland, my forecast is that homo sapiens will survive!

In the unlikely event that we have got the basic laws of physics wrong then we probably could.

So it all revolves on whether we have the laws of physics right or wrong.