4 of 4 people found the following review helpful:
5.0 out of 5 stars
Restoring Earth: The Space Imperative, May 13, 2010
This review is from: Paradise Regained: The Regreening of Earth (Hardcover)
I've heard of Dyson spheres and Dyson swarms, but what exactly are Dyson 'dots'? As coined by Greg Matloff, C Bangs and Les Johnson in their book Paradise Regained, the term refers to a type of solar sail. These sails are not meant for moving things around the Solar System, but for reducing the amount of solar radiation hitting the Earth. The authors imagine large numbers of the Dyson dots placed near the L1 point, using the momentum from solar photons to maintain their position. Imagine thousands -- maybe millions -- of these sails equipped with sensors to receive the instructions of their builders, communicate with each other, and make changes in the configuration of the swarm.
Could you use a sail array like this to cool off the planet? From the book:
"...using reasonable middle values for the parasol parameters -- 80 percent reflectivity or albedo, mass 53 grams per square meter, positioned 2,100,000 kilometers from Earth -- we would need almost 700,000 km^2 of sunshade area to achieve a reduction of 0.25 percent in the solar constant, that is, some 37 million metric tons."
And let's put this into perspective:
"...bear in mind that the United States alone burns about one billion tonnes of coal every year. One supertanker of the many hauling petroleum around the world's oceans weighs about half a million tons fully loaded; and 37 megatonnes is roughly just 3 days' supply of crude oil... If each Dyson dot has an area of 10 km^2, then our array, or school, would consist of 70,000 units."
Now back into an even deeper perspective, which is what Paradise Regained is all about. The authors advise us to look to extraterrestrial resources, to mine the heavens as a way of reducing the industrial footprint on Earth and restoring the planet's ecological balance. Think space for resources, then, and realize that the 37 million tonnes referred to above amounts to the mass of a single, small stony-iron asteroid some 300 meters across, which is a class of rock so small that we're only now starting to look for them.
Paradise Regained is a bracing study of what we might do in the near future to make life better, and that includes asteroid missions that could help us protect the Earth via methods like 'gravity tractors' and solar 'parasols' as well as missions to exploit their resources. In this context, the word 'exploitation' has less bite than it does on Earth, for resources in the Solar System are vast, and exist in an environment so deadly that there is little humans can do to degrade it. Moreover, a small asteroid 1 kilometer in diameter might contain 2 billion tons of iron ore, enough to meet the annual global demand for one year.
The asteroid 16 Psyche may contain enough iron ore to take care of our needs for millions of years. Moreover, many asteroids contain nickel, cobalt, copper, platinum and gold. Thousands of Near-Earth Objects (NEOs) exist in the 100-meter range or bigger, providing an all but limitless pool of raw materials. Needless to say, the authors also throw into the mix the possibilities of tapping the Sun's energy output -- 3.86 X 10^26 watts every second of every day. The infrastructure needs are huge, encompassing spacecraft, solar arrays, antennae, ground support equipment and more. Can we afford to build it?
"...that all depends on the cost of energy and how much of a value we place on the environment. The cost of energy production is not as simple as dollars, euros or yen. What is the cost to the planet of the strip mining required for the coal we burn in our thousands of power plants? What is the payoff in reduced defense spending that will result from us not having to depend on the volatile Middle East for oil to generate electrical power? How much is it worth to eliminate the acid rain associated with the burning of fossil fuels? What benefits will we reap from a power system that produces no greenhouse gases? The authors contend that when the real societal costs are considered, as well as the real monetary cost from end to end, space-based solar power begins to look like a winner."
From mining to fusion, Paradise Regained covers the numerous options that space affords our species. As for the latter, helium-3 gets interesting because it's a potential fusion fuel that, while rare on Earth, seems to be plentiful in the lunar regolith. If we can ever make fusion viable, a mixture of deuterium (heavy hydrogen) and helium-3 is a desirable fuel choice because it produces little residual radioactivity. Some estimates of helium-3 on the moon run to about a million tons, a potential solution to our energy needs for centuries.
Because it is stuffed with possibilities, it's tempting to keep racing through this book popping out facts and prescient speculations, but I don't want to ignore the moving, poetic side of it, reinforced by C Bangs' lovely artwork, which harkens back to a pastoral world of the imagination even as it embeds itself in the cosmos. Thus the lovely Shakespeare quote from the introduction:
"I know a bank where the wild thyme blows,
Where oxlips and the nodding violet grows;
Quite over-canopied with luscious woodbane,
With sweet musk-roses and with eglantine."
That's from A Midsummer Night's Dream, and it conjures up a vernal Earth we'd like to preserve even as we spread the benefits of technology and industry to the less advantaged. Myths of a 'golden age' are just that, reflecting a time-honored nostalgia for a past that never truly was, but there is a sense that we can 'regain' that dreamed of Earth by creating it for ourselves, using our technology wisely to offload industrial activities to nearby space. Buy two copies of this book and give one to your local school library. The ideas are spread out here in dazzling profusion, a chastening reminder to those who see no value in space exploration and believe such funds should be spent here on Earth. Here we learn that the space payoff may be huge, transforming our planet even as it feeds our dreams.
Help other customers find the most helpful reviews
Was this review helpful to you? Yes
No
3 of 3 people found the following review helpful:
4.0 out of 5 stars
A thought provoking plan to save our planet., March 28, 2010
This review is from: Paradise Regained: The Regreening of Earth (Hardcover)
Although interested in the subject matter I began to read this book with great trepidation due to what I shall refer to as 'Cosmos Syndrome'. You see, when I was but a tween my aunt gave me a copy of the book 'Cosmos' by Carl Sagan. I loved that book, particular the pictures the likes of which I had never seen before, but most of the detailed commentary just flew right over my head. So when I read the inside cover of this book and seen it was written by a Doctor of Physics, a NASA Project Manager and a NASA Faculty Fellow I could do nothing other than think I was in for some very tough reading. As it happens I need not have worried as the book is written in a clear, concise and easy to understand manner.
Cover to cover 'Paradise Regained' is only 180 pages long yet due to the concise nature of the writing it is crammed with information and ideas. This is something I found refreshing as too many books nowadays, whether fiction or non-fiction, flesh out their work for no apparent reason other than to up the page numbers and make it appear as if one is getting more bang for their buck. In fact they're getting unnecessary wordage that just slows or dulls down the overall content.
The book is split into three parts each dealing with a different aspect. The first part deals with the formation and resources of earth and the solar system and is very much background information for the next two parts. The second part of the book deals with the here and now and the ecological challenges facing our planet. The third, and final, part of the book puts forward potential solutions to our problems through the development of space and its resources.
Overall, I very much enjoyed reading 'Paradise Regained' and found it to be very educational. The solutions put forward to our ecological problems were well thought out. Although, given that we live in a world where governments are far more willing to spend money on war and destruction than they are on saving the planet I found myself doubting whether the actual cost of instigating some of these potential solutions would ever be forthcoming by governments. However, the authors are dealing with solutions to problems and not the costs of those solutions and in that respect they have put forward some compelling and thought provoking scenarios.
Help other customers find the most helpful reviews
Was this review helpful to you? Yes
No
4.0 out of 5 stars
Against Stupidity, The Gods themeselves, contend in vain, January 15, 2011
This review is from: Paradise Regained: The Regreening of Earth (Hardcover)
The premise of this book is that space technology and resources can solve our most pressing threats to the earth and it's development. This isn't a new idea, as the authors acknowledge. What the authors try to demonstrate is that space is the best way to both create a rich economic future for all humanity, whilst not destroying the earth's environment in the process, and that these goals should be compatible with the aims of the "greens" who have traditionally been somewhat anti-technology and those of technologists who see the benefits of space for earth.
The vast majority of earth's population will remain on earth, so the expense of space development should yield direct benefits. This is very much in the tradition of existing satellite programs for communications, weather and earth resources.
It seems almost inarguable that we need to develop the technology for asteroid deflection. While the likelihood of a major impact is very low, the potential effect is so devastating that we cannot really ignore it. As the author's then state, if we can move an asteroid, why not also harvest it's resources? While logically attractive, the economics are not explored and may well be non-viable. One has to consider would better earth based mining practices be a better solution? And even if major destructive extractive technologies were sourced in space, what about the problems of pollution from downstream manufacturing and waste disposal?
Similarly with space based solar power. The potential is inarguable. But the costs seem currently prohibitive even when using those same asteroid sources for the materials. If they could be made economic, it would be difficult to find another energy source that is both so non-polluting and has so much potential growth.
Finally the Dyson Dot sunshades at L1 to reduce insolation and mitigate global warming are a very expensive way to achieve this, and of course are only a stop gap because CO2 emissions will destroy much the current ocean environment in unchecked. But they do offer an elegant, non-intrusive technology for global climate control.
If I had to make a prediction, I would say that none of these technologies would be developed, because of the high costs and free rider benefits. The very same problems that plague global action on climate change today. If we cannot even seriously agree on meaningful CO2 emission targets, what hope for asteroid deflection or Dyson Dots?
As a vision of what might be possible, this book is a good start. What I would like the authors to tackle in future is how to make that path economically compelling. What would be needed to make asteroid deflection a "no brainer". What space technologies would make asteroid mining attractive and how best to deploy those resources? Should they primarily be used for solar power and Dyson Dots, or should much of the material be dropped back to the earth's surface? Once the economics start to make sense, the powerful drivers to develop resources will be harnessed. It cannot have escaped the authors' notice that if asteroid mining were profitable, asteroid impact mitigation might be just a side effect of that development. As we've seen with geo-engineering proposals for global warming, there has been a lot of interest from corporations who want to offer cloud forming ships for profit as a relatively cheap earth based mitigation approach. Gerard O'Neill tried to offer an economic rationale for space based solar power as a way to pay for the huge expense of building his orbital space colonies. Unfortunately, this was a ass backwards approach. If space solar power is profitable using space resources, then they would be much more profitable not having to support the costs of a space colony.
To date we seem to have a bootstrap problem to jump start the ideas presented in this book. If we can overcome that, it seems to me that it might be possible to develop a large, economically viable space infrastructure to provide the resources and services envisioned in this book.
Humanity currently seems to be the stupidity that is defying the gods. Perhaps we can harness humanity's strengths to ally ourselves with the progenitors of a regreened future earth.
Help other customers find the most helpful reviews
Was this review helpful to you? Yes
No
