17 August 2010
Opinion - Power (None)
When Stephen Hawking Speaks...
...We should listen
by G B Leatherwood
In a recent interview with Cosmic Log famed theoretical physicist Stephen Hawking declared that humans must be off planet Earth in the next 100 years or face possible extinction.

Hawking said,

"If we are the only intelligent beings in the galaxy, we should make sure we survive and continue. But we are entering an increasingly dangerous period of our history. Our population and our use of the finite resources of planet Earth are growing exponentially….
“Our only chance of long-term survival is not to remain inward-looking on planet Earth, but to spread out into space. We have made remarkable progress in the last hundred years, but if we want to continue beyond the next hundred years, our future is in space. That is why I'm in favor of manned, or should I say, 'personed' spaceflight."

And he's not the first person to say so:

"The earth is the cradle of humankind, but one cannot live in the cradle forever." – Russian rocket pioneer Konstantin Tsiolkovsky, 1895

"Earth is too small a basket for mankind to keep all its eggs in.”
– Science fiction writer Robert Heinlein

"Since, in the long run, every planetary civilization will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring—not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive.” – Astronomer-author Carl Sagan, 1994

"The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!" – Science fiction writer Larry Niven, as quoted by Arthur C. Clarke in 2001

Note that none of these scientists and writers spoke about the human spirit of adventure, or even the search for riches. Instead, each writer points out the need for survival—not voluntary actions of a few brave adventurers, but actions necessary if the human race is to exist.

It is difficult to grasp the immediacy of a situation that may not happen for a century or more, even though we can see the signs all around us. As with other great thinkers, Hawking points out that our population continues to grow along with consumption of our finite natural resources. There is no question about our dependence on fossil fuels, or the limited amount of that vital resource, water.

We can, and do, desalinate seawater, but that takes energy to run the desalination plants. Wind farms are producing electricity, and solar panel technology is improving daily. Both, however, are dependent on capricious sunlight and wind.

The next most promising approach to converting a natural resource into energy is harnessing space-based solar power, in which large orbital stations are located in space where they collect sunlight, convert it to microwave energy, and beam it down to receiving antennas. These “rectennas” would be tied into the power grids here on Earth.

Numerous proposals have been made, patents have been applied for, and at least one contract between a manufacturer and California's power company Pacific Gas and Electric has been signed. But realization of space solar power is still years away.

Will all these problems be solved within the next one hundred years? And even if they are, will that be enough? Not according to Hawking and others, who contend that “saving Earth,” while a worthwhile goal, will get us only so far.

Sure, we went to the Moon, but at this point, only twelve humans have walked there, and neither the US nor any other country (or business) current has the capability to return; in fact, at the moment, we’re unable to travel beyond low earth orbit ( LEO). The International Space Station ( ISS) has only a limited time left and at best can support only seven humans at a time. That won't help get the almost seven billion humans off the planet.

Actually, Hawking’s pronouncement raises more questions than it answers. For example, it is one thing to say that we must leave, but to go where? None of our solar system planets contain those critical elements for human existence—drinkable water, breathable air, fertile soil for food. This means carrying everything we need with us while we search for a place that can sustain us. And let us not fail to mention radiation: without a shielding atmosphere, radiation is a deadly enemy.

One critic of Hawking's statement is University of Michigan astrophysicist Katherine Freese, who says:

"The nearest star [to Earth] is Proxima Centauri which is 4.2 light years away, That means that, if you were traveling at the speed of light the whole time, it would take 4.2 years to get there.
“Unfortunately, at the moment we can only travel at about ten thousandth of light speed, which means if man were to use chemical fuel rockets similar to the those used during the Apollo mission to the moon, the journey would take about 50,000 years…. In addition, the radiation you would encounter alone would kill you, even if you could get a rocket to go anywhere near that fast.”

But let's say that within the next 100 years we develop new propulsion systems, solve the problems of radiation shielding, and perhaps even create vehicles that contain Earth-like environments including gravity. Let's also say that we have at least one favorable destination within reach in a generation or three.

How many, and who of us, would go? How would the selection be made? It has been suggested, facetiously we hope, that the first settlers on Mars be pregnant females to save the weight and supply consumption of males. What about the current divisions of religion, culture, mores, and the human tendencies of hostility, greed, and territoriality? If we are in danger right now of annihilating ourselves with little provocation and even by accident, what hope is there for peaceful and productive settlement on a world unimaginably far from our birthplace?

So where does that leave us—what choices do we have?

Well, we could succumb to the downward spiral of doom and gloom: “It's going to happen anyway, so why bother?” Or we could blithely ignore our dwindling fuel and water supplies, and say, like Alfred E. Neumann, “What? Me worry?”

Perhaps there is another alternative, which may be what the pundits are asking us to consider: Start now. Build on the foundations we already have as starting points.

Hawking said, “We have made remarkable progress in the last hundred years...” Yes, we have, but then he said “...but if we want to continue beyond the next hundred years, our future is in space.”

These are words we need to listen to.
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G B Leatherwood 17 August 2010
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