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Wednesday, July 30, 2014

The Atmospheres of the Solar System

The Atmospheres of the Solar System

 
Atmosphere Chemistry of the Solar System Planets
 
We’re heading out of this world for today’s post, to examine the atmospheric compositions of the other planets in the solar system, as well as our own. Practically every other planet in our solar system can be considered to have an atmosphere, apart from perhaps the extremely thin, transient atmosphere of Mercury, with the compositions varying from planet to planet. Different conditions on different planets can also give rise to particular effects.

Mercury
Mercury doesn’t really have an atmosphere in the strictest sense of the word – its incredibly thin atmosphere is estimated to be over a trillion times thinner than Earth’s. Its gravity is about 38% that of Earth, so it isn’t capable of retaining much of an atmosphere, and in addition, its proximity to the sun means that the solar wind can carry gases away from the surface. Particles from the solar wind, coupled with the vapourisation of surface rock as a result of meteor impacts, are probably the largest contributors to Mercury’s atmosphere.

Venus
Venus is similar to Earth in several respects: its density, size, mass, and volume are all comparable. The atmosphere is where the similarities end, however. The atmospheric pressure is around 92 times that found at sea level on Earth, with the main gas being carbon dioxide - the result of previous volcanic eruptions on the planet’s surface. Higher in the atmosphere, the planet also has clouds which are a mixture of sulfur dioxide and sulfuric acid. There is a thick layer of carbon monoxide (DJS note:  should be "dioxide") below these clouds, which subjects the surface of the planet to an intense greenhouse effect. Surface temperature on Venus is around 480˚C – much too hot to sustain life as we know it.

Earth
Earth’s atmosphere is composed primarily of nitrogen and oxygen, which are essential for the life which inhabits the planet. The composition of the atmosphere is a direct consequence of the plant life. Plants take in carbon dioxide and expel oxygen through photosynthesis, and without them doing so, it’s likely that the percentage of carbon dioxide in the atmosphere would be significantly higher.
The greenhouse effect that carbon dioxide is partially responsible for is the result of molecules of greenhouse gases absorbing infrared radiation, which is re-radiated towards the surface of the planet and surrounding atmosphere. Without this natural warming effect, temperatures on Earth would be significantly lower worldwide. The greenhouse effect is not the same as global warming – this is the intensification of the natural greenhouse effect via the emission of further greenhouse gases into the atmosphere by human activities. Venus is an extreme example of the runaway consequences of increased global warming!

Mars
The atmosphere of Mars is, much like Venus, composed primarily of carbon dioxide. Having mentioned the extreme greenhouse effect present on Venus as a consequence of the high carbon dioxide levels, it may seem puzzling that the surface temperature of Mars reaches a maximum of 35˚C. This is because the atmosphere of Mars is significantly thinner than that of Venus, so although the proportion of carbon dioxide is comparable, the actual concentration is much lower. The dustiness of the atmosphere gives Mars its characteristic appearance.

Jupiter
Jupiter is the first of the gas giants, and the largest planet in the solar system. Its atmosphere is, interestingly, fairly similar to the composition of the Sun. Unlike the inner planets, there isn’t a clear point at which the atmosphere of Jupiter stops, and the liquid interior of the planet beings. Around a third of the way towards the planet’s core, the pressure is high enough for hydrogen to exist as a metallic liquid, which can conduct electricity and is responsible for Jupiter’s electromagnetic field. Jupiter’s banded cloud system contains varying amounts of ammonia, water, and ammonia-sulfur compound clouds, and also complex sulfur, phosphorous and carbon compounds.

Saturn
Much like Jupiter, the upper clouds in Saturn’s atmosphere are thought to be composed mainly of ammonia ice, with clouds of ammonia hydrosulfide and water lower down. The sulfur present in the atmosphere gives a pale yellow hue to the ammonia clouds. Although not present on the graphic, Saturn’s moon Titan has possibly the most intriguing atmosphere in the solar system, which is the only nitrogen rich atmosphere outside of Earth’s. It’s the only other body in the solar system on which stable surface liquid has ben confirmed, as well as the only other body where it rains – though the rain is liquid methane, rather than water, and it’s estimated there are centuries between each rainfall at specific locations on the surface.

Uranus
The atmosphere of Uranus is, like Jupiter and Saturn, mostly hydrogen and helium. However, the slightly higher levels of methane, particularly in the upper atmosphere, cause greater absorption of red light from the sun, in turn causing the planet to appear a blue-cyan colour. Uranus has the coldest atmosphere in the solar system, at approximately -224˚C, and its atmosphere contains much more water ice than Jupiter and Saturn as a consequence of this.

Neptune
As with Uranus, the blue colouration of Neptune is partially a consequence of the presence of methane – however, as Neptune is a deeper blue, it’s thought that some unknown constituent of the atmosphere must also contribute towards the colour. As the stratosphere of Neptune contains more gaseous hydrocarbons than Uranus, its temperature is marginally higher. Neptune is also home to the strongest winds in the solar system, with their speeds potentially as high as 600 metres per second.

Pluto
Pluto hasn’t been a planet for a fair few years now, but that’s no reason to leave it out of the fun. On that note, after posting this, I threw this graphic together, so that Pluto doesn’t feel left out in the cold:
Pluto Atmospheric Composition
 
 Here’s the atmospheric composition of Titan, where it rains methane every few centuries:
The Atmosphere of Titan

Wondering About Our Place


Wondering About Our Place

To be, or not to be, — that is the question: —
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune,
Or to take arms against a sea of troubles,
And by opposing end them? — To die, to sleep, —
No more; and by a sleep to say we end
The heart-ache, and the thousand natural shocks
That flesh is heir to, — 'tis a consummation
Devoutly to be wish'd. To die, to sleep; —
To sleep, perchance to dream: — ay, there's the rub;
For in that sleep of death what dreams may come,
When we have shuffled off this mortal coil,
Must give us pause: there's the respect
That makes calamity of so long life;
For who would bear the whips and scorns of time,
The oppressor's wrong, the proud man's contumely,
The pangs of despis'd love, the law's delay,
The insolence of office, and the spurns
That patient merit of the unworthy takes,
When he himself might his quietus make
With a bare bodkin? who would these fardels bear,
To grunt and sweat under a weary life,
But that the dread of something after death, —
The undiscover'd country, from whose bourn
No traveller returns, — puzzles the will,
And makes us rather bear those ills we have
Than fly to others that we know naught of?
Thus conscience does make cowards of us all;
And thus the native hue of resolution
Is sicklied o'er with the pale cast of thought;
And enterprises of great pith and moment,
With this regard, their currents turn awry,
And lose the name of action.

William Shakespeare, Hamlet Act 3, scene 1, 19–28, circa.1600

Bolero by Ravel. An der schönen blauen Donau by Strauss. Rhapsody in Blue by Gershwin. Yesterday I listened to these three pieces of music, among the most beautiful and thrilling that I know of. Each has its own peculiar emotional impact, quite different from each other and yet all calling to me in ways that I am quite sure I could never put words to. I would give anything to know exactly what they have done to my brain and nervous system, which neurons they fire in which sequence, which neurotransmitters – serotonin? dopamine? – they released or absorbed in exactly the right structures and cells of my limbic system and cerebral cortex. There any many other wondrous pieces, from Beethoven to Mozart, to Benny Goodman, the Beatles, and Bob Dylan, and more which provoke the same questions.
There is more. Today I spent several hours driving along River Road in Bucks County, Pennsylvania. The road curvingly parallels the Delaware river in many places, in others the old Delaware Canal. It is carved out of the ancient rock which lines the river, and after several days of rainfall there are numerous small and medium rivulets and waterfalls cascading from the rocks, onto the road surface, and then across it to join the river and its way to the sea. Even without these added splendors, there are the carved, ancient rocks themselves, the trees and other wild flora of May, and the occasional animal, although I did not see any deer, or wild turkey, or any of the other wild animals that inhabit the woodlands on this particular day.

I know – I know as a scientist and as a rational human being – that what I have experienced these last two days would not be possible without millions of years of Darwinian evolution sculpting senses and a nervous system and brain to allow me to experience them. If I were but a rock, I would know none of them. Even if I were a cockroach, perhaps even a fairly evolved organism such a mouse … but because I am human – a sentient being – I experience all of it; all of what gives my life so much of its meaning.

And yet I am missing something.

It is a conundrum that has been known for centuries. One that philosophers have spun and spiraled in their minds to resolve, one that scientists in the relevant fields have grappled with to this day. Some think they have solved it. Yet I beg to differ. Some very straightforward thought experiments show how perplexing it is, how much it defies simple solutions. Theists and other religious pundits think that they solved it long ago, but I believe they are just as deluded. It is the problem of the soul.

What’s this? A scientist speaking of the soul?

Soul is perhaps a bad term. It conjures up the supernatural and the religious, and that, above all, is precisely what we are trying to avoid here too, as in all the previous chapters of this book. Better words are sentience and consciousness. Sentience is somewhat the better of these two because consciousness can refer to the mind and its workings, and what we want to grab hold of is that, however our bodies and minds work, there is an indisputable “we” inside, somewhere, that experiences those workings. This we has a more or less continuous existence, minus deep sleep and any periods of anesthesia or coma we might have had, going back to as far as … well, as far as we have memories of being.

We must concede an undeniable connection to mind and body, for, as I have been emphasizing, without these things there is nothing to experience, and sentience, the experiencer, must have something to experience if it is to exist. At the same time, however, as strong as this connection is, its strength does not reach to identity. Or at least I believe I have good reason for thinking it does not. Naturally, this only deepens the mystery; how can mind / body and sentience be at the same time the same thing and yet two separate things? The answer is that it cannot, yet we struggle mightily to resolve this seeming contradiction.

Don’t think there really are contradictory aspects to it? A few thought experiments should illustrate them nicely. Here’s one: imagine we have a machine, a lá science fiction, into which you step into one booth and out pops in a different booth, by some magical technology we shall in all probability never have, an atom-by-atom exact duplicate of yourself. This, of course, is the basic idea behind matter / energy beaming devices in Star Trek, and though I heartily doubt it will ever be accomplished, it seems at least possible in theory.

Well, what would you expect? Would you still be you? I expect all of you would agree that you would be. But how about this other “person” (I put this in quotes for a specific reason), stepping forth from the other booth? Would you be him / her as well? The answer to this question would seem to have to be an unqualified no, if only for the reason that there are no neural or any other connections between the two brains, which we are quite certain is absolutely necessary for you to experience being two bodies / brains at the same time. On the other hand, if you aren’t both you, then clearly you are the original you and the duplicate, although it would have all your memories, thoughts, and feelings, and be utterly convinced it was the real you, is just as clearly someone else. All this assumes, of course, that they are anyone at all and not a non-sentient simulacrum of you – which can only be true if making at atom-by-atom-duplicate of you is still missing something, something that we have no conception of as of yet. Either way, it isn’t the real you, however identical from a known science point of view it is.

Let me illustrate the problem a different way. I often read by those working in the fields of neurology, psychology, philosophy, and all the ways these fields can be conjoined (neuropsychology, cognitive science, etc.), that sentience is a consequence of brain action, an emergent phenomenon or epiphenomenon, one deriving from brain structure from the macroscopic to the microscopic, from the whole down to neurons and axons and dendrites and neurotransmitters and synapses and, well, and the laws of physics and chemistry as we know them. But there is something wrong with this picture, something, I think, that is actually quite obvious. It is that the Me (hereafter capitalized) that experiences being me does so now in a brain that is different from the brain it experienced being me yesterday, and even more different from the brain it experienced being me a year ago, and ten years ago, twenty, forty, fifty years … all the way back as far as I can remember being sentient.

All I know is this: Richard Dawkins’ statement in his preface to his most inspirational book The Blind Watchmaker, that “Our existence once presented the greatest of mysteries, but it is a mystery no longer because it has been solved,” is both true and false. It is true in the sense that Darwinian evolution, combined with the laws of physics and chemistry in this universe, neatly explains why at this moment some six point seven billion of us humans are running around on the surface of this planet, trying to survive and more, toward what consequences we are both uncertain and afraid of. But it is false in the sense of explaining why we billions experience ourselves doing so – assuming all of us do. Yes, yes, our highly complex and massive brains are part of the solution to this part of the mystery, but – well, is it enough?

* * *
This book being largely composed of scientific ideas and arguments, I wish like anything that I could present some for this most defiant of all mysteries. Alas, I find that after half a century’s worth of reading, exploring, thinking, and probing I cannot. Which leaves me in the position of wishing it would go away, so that it might not torment me, but it refuses to do that either. It is not, mind you, that I am afraid of dying and there being nothing left of either me or Me at all, perplexing and somewhat despairing I find that prospect to be; no, it is a true intellectual riddle, one that has defied all attempts not merely to solve it but even to adequately frame it. At least the reason for this can be stated in a straightforward way. The scientific method is an objective approach to reality, combining observation with hypothesis formation and testing, using both reductionism and holism when appropriate, in the never ending quest to determine just what is out there, all around us, to the ends of the universe. And it is a noble and even, dare I use the word, holy endeavor. But how and in what ways can this method be applied to the subjective reality of experience? How can it explain Me, or You, or any of Us? The answer I keep coming up with is that it cannot, cannot explain Me, You, or any of Us, solely because these are not objective phenomenon “out there” for us to explore and dissect. We can and should dissect and explore brains, and how they work, yes. But in the end, no matter how much we discover doing so I fear we will still not have solved the problem.

The conundrum is very real, and very serious, because we know of no method but science that can reliably reveal truths about reality to us. Mysticism and religion have no chance, in fact don’t even pretend to have a chance however many pseudo-arguments their proponents hurl at us. Yet science and reason can’t will or doubletalk the issue away, either, however.

* * *
Still, I have invited you to read a chapter about this subject, and merely repeating how dumbfounded I am about it is going to wear thin very quickly. So I must make some attempt(s), some approach(es), that have a plausible chance of leading us somewhere toward understanding.

And yet, I must proceed carefully. For example, certain writers, notably Roger Penrose (The Emperor’s New Mind) have suggested that sentience emerges from some of the properties of quantum mechanics. He has apparently even identified structures in the brain, known as neural microtubules, which he claims account for consciousness / sentience in a quantum mechanical brain; part of his argument, as I understand it, is that the human mind is able to solve problems in a non-algorithmic way. While I do not claim to fully understand his arguments, other writers, notably Daniel Dennett and Stephen Pinker, have challenged Penrose, saying that in fact all the things the human mind can do can be reduced to algorithms, albeit highly complex ones, without any consideration of the physical hardware (brains, computers, etc.) that these algorithms are executed in.

Personally, I find both approaches inadequate. We really don’t have any good reason to think that a sufficiently complex computer, one that can fully emulate all the properties of a human brain, will actually be sentient. On the other hand, the mysteriousness of much of quantum mechanics shouldn’t seduce us into thinking it has anything to do with the mysteriousness of our own awareness. That is an argument that sounds powerful on first hearing, but is really quite feeble. Lots of things in this universe are still mysteries, at least to some extent, but that is no reason to assume that they are interrelated simply because they are mysterious.

Of course, this doesn’t prove that quantum processes don’t have anything to do with sentience either, so I don’t want to grind my heel into any such speculations. It’s just that there are so many other mysteries as well. For example, why do so many of the natural constants of nature happen to have the value they have – the “fine-tuning” problem that vexes so many scientists? Why are there four fundamental forces, and why do they have the relationships they have? Why is the speed of light in a vacuum what it is? Why does Planck’s constant have the value it has? And so on. Some people, even scientists, note that all these, and other, constants, have values that are absolutely necessary for intelligent beings like us to exist, so perhaps there is some kind of higher intelligence or will that has ordained them so. Other scientists shake their heads at this kind of semi-mysticism and insist that, as we understand the cosmos and the laws of physics better, we will see how they had no choice to be what they are. Or perhaps there are many, many universes – perhaps an infinite of universes – so some simply had to turn out to have the right conditions; and of course we must be living inside one of those universes, or we would not be here to ask the questions and debate the answers.

* * *
My own personal feeling – and personal feeling is exactly what it is – suggests something else to me. A hundred years ago, at the beginning of the twentieth century, there were certain phenomena that stubbornly defied explanation by the then known existing laws of nature. The structure of the atom, as I have already mentioned, is probably the most famous. The conflict between Maxwell’s laws of electrodynamics and Newton’s laws of motion were another. As was the spectrum of blackbody radiation. The heat capacity of multiatomic gasses, and the photoelectric effect were a third and a fourth.

The solutions to these vexing problems involved, not merely new theories based on the existing laws of physics, but new paradigms, new ways of thinking, which opened up a new universe of laws and theories and hypotheses. These new paradigms were so challenging that many scientists have had a hard time accepting them even to this day, while those who do still sometimes puzzle and scratch their heads at what they really mean. Quantum mechanics. Special and General Relativity. Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD). The expanding universe and the notion of a beginning to everything, the Big Bang (though this is being challenged today in some quarters), and perhaps an end to all things, including time. The idea that space and time, matter and energy, are related in ways that you cannot treat them as separate phenomena. The use of mathematical group theory to explain the plethora of mass-bearing and force-bearing particles in nature, and the relationships between those particles. The idea of inflation in the very early universe, and how it might have led to many universes forming. And now of strings and supersymmetry.

Standing here, at the opening of the twenty-first century, I can envision a similar revolution in paradigms arising to answer the questions I address in this chapter. But as I said in chapter seven, looking at it now, it is science fiction. Perhaps even fantasy. For example, here’s one possibility: perhaps we will create a “super” brain, one composed of electronics and neuronics, that we can all interface with or even become part of. This brain might eventually spread throughout the solar system and then beyond, perhaps to ultimately fill the entire universe. Perhaps this is when humanity learns its meaning and destiny, and all questions are answered. Even those billions who have lived and died may be reincarnated into this star-spanning mind, and not just humans but every other sentient race that has lived and died, here and elsewhere in the universe.

Following this line of prognostication, maybe sentience is something like another property of the universe, one which requires certain conditions, such as those that occur in our brains, to manifest itself. But if it is that, a property, then what kind of property is it? It isn’t a force, or a kind of particle. Something interwoven into the fabric of spacetime itself? But how? And in what way?

* * *
Sometimes I wonder if the Buddhist concept of Maya and Enlightenment can help us here. Maya is the illusion we all experience, that of being separate beings, apart from each other and the rest of the universe, struggling to find our way through life, and ultimately dying in this illusion. The experience of Enlightenment is supposed to be one in which all Maya drops away and you are fully aware of being one with everyone and everything – an experience regarded as impossible to capture in words or any other physical medium. Yes, I wonder if Buddhism is on to something here. It would have to defy explanation by language or any other form of normal communication. One would have to either experience it, or have no idea what it is. That does sound like it has a sporting chance of being right, or at least it does to me.

But if so, then this does imply that there are laws and properties of reality that we do not, and perhaps can never, understand intellectually, because they are not susceptible to scientific analysis? That they work beneath, or above, the radar of our intellects, however hard we try?

If all this is true, however, then what should we do? What can we do?

What we must do, I maintain yet again, is not give in to despair simply because we don’t know the solution to the puzzle, and may never know the solution to it. Also, remember that many mysteries have resisted solution for centuries, only to finally be solved by an application of new paradigms and ways of looking at things. Above all, we must not give up, even if things appear hopeless. A hundred years from now, we may find ourselves shaking our collective heads at our current confusion. I am tempted, however, to call this question – the question of sentience – the ultimate question, to which all others are sublimated. I really do believe that if and when we solve it, there will be a collective sigh of satisfaction greater than the solution to any question that has proceeded it.

* * *
Somehow or other, whether by luck or design or an intermingling of the two, we find ourselves where and when we are. We inhabit a planet orbiting a yellow dwarf star at the edge of a rather typical spiral galaxy. The star is but one among billions in the galaxy it has found itself in, and the galaxy may be one of trillions in a universe many billions of years old and perhaps far, far older. In all that, our individual lives occupy only a few decades of time, a century if we are fortunate. There seems to be nothing particularly special about this where and when we exist, except that is one of the few places we could be in the universe, perhaps the only even, and perhaps one of the few universes we could be in. Maybe the only one. Moreover, we do not know what will happen, not merely to ourselves as individuals, but to us as a species over the next few centuries.

We have spent thousands of years beating our heads against an invincible wall, wondering what the answer to all this is, and for all our pounding still pretty much have no idea. Of course, the answer may well be that “this is all there is”, that once our bodies cease to function that is the end of both us and Us, and no beliefs, religions, philosophies, or wishful thinking can change that. Sad though that is in one respect, even if it is true I believe we should be grateful, grateful for the opportunity to have existed at all and had the opportunity to marvel at this universe we have manifested in. It is even really not so sad either, when you think about it; after all, in the billions or trillions or infinity of years before we existed we suffered not one iota for not being, so certainly after we are gone we will not suffer at all then either. It is only sad, to me at least, in that We will cease to exist with so many wonderful questions unanswered. That, I have to admit, is a bitter pill to force down.

But let us assume that this is not the case. Let us imagine that sentience, while inactive without a brain to model the universe about it, nonetheless still exists in some potential form. I use the word potential with a very specific meaning. We speak of potential energy, as when an object is raised to a certain height, or an elastic material stretched, or as a chemical potential that can lead to an energetic reaction. The energy does not exist in any active form, yet it is still there, waiting to be manifested. Quite possibly, sentience without a brain with which to experience some kind of reality, can be held in an analogous potential form. What would that mean? One possibility is the repeated incarnations of the “soul” as claimed by many Eastern religions, although I am not certain I can believe in that.

I have difficulties with this, because in Eastern religions, the soul can reincarnate as almost anything: another person, an animal, a plant, or even a rock. Yet rocks and plants, and probably even most animals, do not possess the capacity for sentience, as they lack a sufficiently complex brain and nervous system. There are other practical problems as well. Even if we reincarnate as human beings, since the number of human beings on this planet has been exponentially increasing over thousands of years, where are all the new souls to come from to inhabit all these new bodies? There is a disparity here that is hard to reconcile.

There is another tack I would like to try. I am an aficionado of the television series House, which, if you aren’t (fie on you!), is about the brilliant but renegade and rather misanthropic Dr. Gregory House and the characters and cases which spin around him in a mythical teaching hospital between Princeton and Plainsboro, NJ. One of the episodes involves Dr. House temporarily reviving a patient who has been in a coma for ten years, for the purpose of extracting family background in order to save the coma patient’s son’s life (it ends with the coma patient committing suicide in order to donate his heart to his dying son – now you know why I say fie on you if you don’t watch it). Before I begin, I have to say I find the premises of this episode highly dubious at the least: someone who has been in a coma for ten years will have undergone so much muscle atrophy and coordination loss that I doubt he could walk, let alone drive a car to Atlantic City and basically act like someone who has just woken from a short nap. But that is beside the point I want to make.

No, my question is: is the sentience that results from the coma awakening, and spends his last day in a quest for the perfect hoagie then ends by sacrificing his life for his son’s, the same sentience that ended ten years earlier? An even better question might be, does this question even make any sense? The re-awakened father would of course insist that he his in every way conceivable the same person, but how much does that utterly sincere insistence count for? And what possible tests and / or measurements could we make to settle the issue?

I have to confess to something. This is not a mere academic issue to me. I was once in a coma, from which I fortunately awoke after several days. But does that make any difference? Like that father in House, I absolutely insist that I am the same Me that fell into that coma, but how can I, or anyone, really know? And again I ask, does the question even make sense?

Maybe it is an absurd question. Or, not so much absurd as worded incorrectly. Perhaps what seems to happen to Us in those moments, or days, or years, when we still exist but We do not is that time ceases to exist for Us. Just like, according to Einstein’s Special and General Theories of Relativity, time ceases to exist under certain conditions – if we were to ride on a beam of light or (if I understand what I have read correctly) fall into an infinitely deep gravity well – time comes to a complete stop for Us whenever the conditions needed to manifest Us ceases to exist. The question then is, do those conditions exist only within our own brains, for if so, then our current lives are the only ones We can ever manifest in?

* * *
I suspect that I have frustrated and dissatisfied you, dear reader, for I keep promising answers to this deepest of questions, but invariably find myself only circling about and finding myself at my own beginnings, my own head-shaking ignorance and failure of my own imagination and curiosity to solve this most impenetrable of puzzles

Will I give up then? No, first of all because I see no way of letting go of my curiosity and wonder and imagination, without letting go of what it means to be a living, sentient mind in a universe we still have so much to explore within. If there are places and times I have no concept of how to reach, then I am simply going to accept them for the time being, and hope that at some point in the future my eyes will start to open about them. Nor will I relinquish the scientific approach to thinking about reality, for it has served us so well, and has provided answers to what appeared to be impenetrable mysteries, and so I cannot give up hope on it, certainly not at this time and place in humanity’s evolution. Perhaps, of course, these things will lead to my death with so many important questions unanswered, and, yes, as I have admitted, that disturbs me. But, as I said, to stop now and lay down all of the weapons and tools of the mind and surrender to ignorance; that is something I cannot even conceive of doing. I would certainly die of despair if I even so much as tried.

So we have come around and around, and it the end must still admit that this greatest of mysteries has not yielded to science, at least not yet. And yet, that is all right. Mysteries are the lifeblood of science, and indeed of all our wonderings and imaginative escapades. Maybe, like the character in the Monty Python sketch I mentioned early in this book, we even need them, need these challenges to our curiosity, as though they are part of what gives our lives meaning. I know that they have given my life at least a healthy part of its meaning.

* * *

"There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened."
Douglas Adams, The Hitchhiker's Guide to the Galaxy (1979)
"Now my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose."
JBS Haldane, Possible Worlds and Other Papers (1927), p. 286

As I said at the beginning, a large part of this book is about what it means to be human, with curiosity, wonder, and imagination being fundamental parts of the answer. I also stressed the special importance of imagination, supplemented by technology, along with the warning that if we really wish to understand the universe we live in, we must not limit ourselves to our sensory experiences and our intuitions about them. We saw how important that became once we started deviating from the norms of our existence, whether in space or time. When we are dwelling in the world of the ultra-small or large, slow or fast, the laws of physics deviate from common sense in ways we would never have predicted. Phenomena such as the uncertainty principle and the depths of geologic time, time dilation and the bending of spacetime become increasingly important as we move further and further away from the norms of our everyday existence. We found that if we allowed those deviations to take us logically wherever they went then, however strange our discoveries, they could be integrated into the whole of understanding.

We also came to understand that the paths we took were our personal ones, each unique to us even if, ultimately, we all found ourselves in the same place in the end, that end being still finding ourselves facing the same ages old mysteries of our own existence. This is one of the crucial paradoxes of the human condition, I believe; that we all experience our lives as infinitely separated individuals, while underneath we are all tied together by the same laws, the same processes, the same foundations. It is as though each of us perceives ourselves as alone in a tiny boat on the open ocean, winds whipping and waves constantly washing water into the boat, forcing us to bale with all our strength and persistence just to stay afloat, while in fact, ironically, we are all collectively in one huge boat, with each of us making our tiny contribution to keeping the boat afloat and headed for – what land we are uncertain, but whatever it is we shall all arrive there together, in the end.

In the end, maybe this is our place in the scheme(s) of things. I am not the first person to speculate that we may be nothing more than reality’s attempt to comprehend itself. If so however, then we are faced with another mystery, that of how reality can have intentions or goals at all instead of being nothing more than the blind working out of physical laws. A mystery which only becomes deeper if we assume that intelligence, in some form, is itself part of that reality.

I stated at the outset of this book that I do not intend to give in to nihilism or despair, and I will take the time to reaffirm this promise again. Somehow we reasoning, questioning, imagining animals have found ourselves in this universe, and that alone should provoke our minds to keep trying to discover how and why. Indeed it is my view that we are probably still closer to the beginning of our quest than the end. I will also take the time to state my personal gratitude that we are in the middle of it.

We are born as, and grow up into, creatures of curiosity, wonderment, imagination, and rational thought. I do not care what nation or culture you were raised into, what you were taught, or what experiences you have had. Merely by being human, you still have all these traits within you, each one waiting to boil up to the surface at any time. I know that I have been astonishingly fortunate in this respect, in one sense more than most in this world, but at the same time I can’t believe that I have been any more gifted in these things than anyone else. I have just had the good fortune to have these things nurtured and encouraged.

I remember being a child with all these things within me, and nothing gives me more pleasure than today, at fifty-three years of age, to discover that same child just as strong. Though I have spent a half-century’s worth of growing, experiencing, maturing; though I have married, raised children, and known “The heart-ache, and the thousand natural shocks that flesh is heir to” including pain I thought I would never recover from or survive; though I have stared into space and wondered what the point of those pains were … that part of me has never been diminished or defeated in any way.

And so there is nothing more for me to do except present myself as an inspiration, and as a hope. If you have any doubts, then go somewhere where the lights and pollution of the city cannot find you. Wait until the sun goes down, and then lie on the grass, staring skywards at the stars. Stare, and remember that for each one you see, there are trillions beyond your sight, beyond the sight of the most powerful telescopes for that matter. Gaze at the fierce beacons pouring their fires down upon you, and wonder. Though this universe we live in is far vaster than our imaginations can even begin to encompass, I believe you will know what I mean. Though we are but the most mortal of beings, barely eking a century’s worth of experience of the billions of years those beacons have shown, each of us has still our own meaning, our own purpose, whether we know it or not. I believe this will dispel all those doubts.

Why the Solar Revolution is Real

    Ivanpah Solar Thermal Electrical Power Facility (Wikipedia)

I know that, just looking at the title of this argument, some people are already gathering up all their arguments why I'm wrong, foolish, and just don't get why solar can't work.  Others of you might cheer, but not understand why I use the word "Revolution."  I can tell you that it's a perfectly apt word, and there's no foolishness about it.

A caveat, however.  People collectively known loosely as "Greens" have been touting solar power for decades, based the obvious fact that the sun's energy is free and, as long as you don't expose your skin too it for to long (the UV part of its spectrum is causing skin cancer rates to skyrocket), about as clean as you can get.  You might even say,  "It's natural,"  although that doesn't automatically make anything good.

My caveat for all who think that way is that, quite simply, you've been deluding yourselves.  Free and essentially clean it may be, the sun's rays nevertheless have two staring-you-in-the-face disadvantages:  first, it's quite dilute, providing only a maximum of about one kilowatt per square meter even when directly overhead (which it almost never is, so the average intensity is only about 200-300 watts of power per square meter, depending on latitude and climate); second, as everyone knows whether they think about it or not, you only get the energy during daytime, and even then it's often partly obscured by clouds and other atmospheric barriers.  Oh, and there's a third:  your electric washing machine will not work no matter how much sunshine you inundate it with.

No, it hasn't been a lack of political will, or the big, bad oil companies, or short-sighted politicians elected by ignorant voters, that kept solar out of the power mix for so long.  Keep beating one side of your head until those delusions drain out of your ear like tepid bath water.

The real problem, until now, has simply been the lack of scientific and technical know-how to take our star's energy, concentrate it, and convert into electricity.  But here is where we've been fortunate:  the computer revolution over the last 30-40 years has pointed the way to effective solar to electricity conversion.

Before I elaborate on this, I have to point out that there are two different ways of harnessing the sun's energy to make electricity.  One is shown in the picture above.  The Ivanpah Solar Thermal (ST) plant provides, on average, about enough juice to service a quarter of a million homes or so.  It does so when the sun is up by using vast arrays of mirrors to concentrate sunlight onto a molten salt container, which gets hot enough to generate the steam needed to turn the turbines and create the wonder of electric power.  Now, since molten salt is a pretty good retainer of heat (even better materials are being developed), you can even get pretty good output from the plant at night and in inclement weather, to the extent this exists in the desert.

Solar Thermal, while workable under special conditions, has its drawbacks however.  The Ivanpah plant cover about five square miles of desert, and that five square miles was no easy acquisition because a lot of study of the local ecologies of the region had to be made before it could be, barely, approved.  Further, that quarter million households might sound impressive, but it's only a fair sized town.  Imagine powering Los Angeles, or any major city, in this manner:  you'd need ten to fifty times the area, and good luck getting that OK'ed after environmental studies are done.  Then lets talk about an entire state, or part of a state, with several decent sized cities.

ST plants have these limitations, but again the big price is in construction, and Ivanpah needed 2.2 billion dollars to construct (with 1.6 billion being a government loan).  Once in action though, that free solar energy means that, charging only 0.10$ per kilowatt-hour to those households, it should be pay off in (0.10 dollars X 24 hours/day X 365 days/year X 250,000 households = $220 million dollars a year => 10 years to pay off the costs.  If the plant has a lifetime of 30-40 year, it could gross up to six or so billion, minus, of course, operation, maintenance, and repair costs (which, for five square miles, will amount to some serious change).  So it really could work, if those costs are minimized.  And if you could scale the whole operation up, say twenty times (a hundred square miles), Los Angeles might now have to rely on the Hoover Dam any more.  At this point, it's still all a tad iffy, but plants like this, both smaller and larger, are being constructed all around the world.  Improvements to Ivanpah include better heat storing substances than molten salt, and the ability to generate "super critical" steam which increases heat to electricity efficiency significantly.  So it looks as though it is going to play a significant, albeit limited, role in solar's future.

Photovoltiacs -- the Real, Big-Time Player in Solar Power

I mentioned the computer revolution, but little of that has to do with ST.  I'll move on now to photovoltaics, which involves the direct conversion of solar energy into electricity.  I can't tout it without explaining it some, and the explanation involves some science you may not be familiar with, so I'll try to keep it simple without dumbing it down.  Some materials, metals are the most obvious but not the only example, conduct electricity wonderfully.  Why is this?  As Wikipedia has a good article on this, I'll present part of it here for you.  It has to do with conduction bands in the material:
____________________________________________

(Wiki) The conduction band quantifies the range of energy required to free an electron from its bond to an atom. Once freed from this bond, the electron becomes a 'delocalized electron', moving freely within the atomic lattice of the material to which the atom belongs. Various materials may be classified by their band gap: this is defined as the difference between the valence and conduction bands.
  • In non-conductors, commonly known as insulators, the conduction band is higher than that of the valence band, so it takes infeasibly high energies to delocalize their valence electrons. They are said to have a non-zero band gap.
  • In semiconductors, the band gap is small. This explains why it takes a little energy (in the form of heat or light) to make semiconductors' electrons delocalize and conduct electricity, hence the name, semiconductor.
  • In metals, the Fermi level is inside at least one band. These Fermi-level-crossing bands may be called conduction band, valence band, or something else depending on circumstance.

Electrons within the conduction band are mobile charge carriers in solids, responsible for conduction of electric currents in metals and other good electrical conductors.

The concept has wide applications in the solid-state physics field of semiconductors and insulators.
Semiconductor band structure (lots of bands).png
Semiconductor band structure
See electrical conduction and semiconductor for a more detailed description of band structure.
____________________________________________

In summary, in metals and other excellent conductors, the electrons are in bands about the atoms in their crystal arrangement.  Most of the electrons are in filled, so-called valence bands, and being filled, cannot move under an electromotive force (like a turbine or a battery).  But there is a low energy "conducting band" just above the highest valence band, so electrons can easily move into it, thus yielding a partially filled band where a force can make them move, in an electric current.

In an insulating material, either there is no atomic structure giving rise to these bands, or the conducting band is so high above the highest valence band that very few electrons even acquire the energy needed to reach them.  There is a third category, however:  semi-conducting materials.  I suspect you've heard this word, particularly in the context of computers.  Now you get the explanation of them:  unlike conductors, where the conducting band is close enough to the valence band that electrons can easily partially fill it, and insulators, where the band gap is so great that essentially no electrons can make the leap, in semi-conductors the gap is just high enough for a decent energy jolt for electrons to make the crossing.  In computers, semi-conductors lie at the heart of transistors, the basic gizmos (in the very old days, we used expensive things called vacuum tubes which had to be routinely changed at considerably nuisance) that give the computer its speed and capacity, if you can keep making them smaller and smaller, thus closer and closer, on an integrated circuit to communicate extremely rapidly.  What has made the computer revolution possible is the exponential improvements in fabricating smaller and smaller transistors, with better and better semi-conductors, until -- well, until we now have computers that will comfortably sit on your lap which possess far more power and speed than their room-sized ancestors of only a couple of generations ago.

This exponential growth has been fueled by ever newer and newer improvements in materials science, and the chemistry and physics which underlay it.  The advancement has been so profound, so rapid (it has been following Moore's Law, which keeps correctly predicting a doubling in computer speed and power every eighteen months or so) that there appears to be something of a positive feedback loop in progress here, in which each improvement lays the foundation for yet more of the same, all with no clear end in sight -- the precise definition of exponential growth, of which Moore's Law is one example in real life.  The result is that way find ourselves in a position that even a generation ago would have been almost impossible to foresee.  And it, more than anything else, has laid the groundwork for the solar energy revolution we are just beginning to enter.

In what way?  Because the band gap in a semiconductor can now be tuned very precisely to match a specific wavelength of light, or even a significant part of the light spectrum.  This means that solar energy shining on this semiconducting material can directly generate a current of electricity, with a certain voltage.  Again, it wasn't as if the potential wasn't always there, it just needed sufficient STEM to become a practical reality -- and that probably wouldn't have happened without the computer revolution preceding it.

Now the idea of using semiconductors this way isn't new.  But the scientific advances that are making it increasing practical and even compelling aren't stopping, or even slowing down.  Starting with just 2-3% efficiency only some twenty years ago, solar PV efficiencies are now up to 15-20%, and climbing every year, while at the same time costs are plummeting.  At this rate it won't be long before they reach the "theoretical" maximum of around 30%, and then some wise guy will figure out a way to overcome that too.  But even at that thirty percent, it's well within the range of "ordinary" electricity producing plants (30-40%), and since solar cells and panels can be placed almost anywhere, the lack of long distance travel through transmission lines (which use high-voltage / relatively low-current AC to keep losses to a minimum) means even higher practical efficiencies -- if you decentralize the system, which I think is the best, even main, goal.

At this point, you should be about to say,  "Wait a minute.  Again, what about the storage problem you have, because the sun isn't always out and shining.  I understand the solution for solar thermal, but if you want decentralized power, that's probably not going to work for local solar generators.  You're going to need some kind of super battery.  And just how many of these batteries do you think it will take to power NYC or Las Vegas at night? Well?"

Yes, yes, you're right.  A different kind of storage capacity, chemical or otherwise, is probably needed for solar PVs.  But be careful of a certain fallacy I have been encountering over and over again while perusing posts and blogs and comments.  I call it the  "The computer revolution never happened because its too expensive and too damn hard to keep replacing all those vacuum tubes constantly"  fallacy.

I'll again use others' work to demonstrate what's actually happening in the real world:
____________________________________________

New Battery Material Could Help Wind and Solar Power Go Big



Utilities would love to be able to store the power that wind farms generate at night—when no one wants it—and use it when demand is high during the day. But conventional battery technology is so expensive that it only makes economic sense to store a few minutes of electricity, enough to smooth out a few fluctuations from gusts of wind.

Harvard University researchers say they’ve developed a new type of battery that could make it economical to store a couple of days of electricity from wind farms and other sources of power. The new battery, which is described in the journal Nature, is based on an organic molecule—called a quinone—that’s found in plants such as rhubarb and can be cheaply synthesized from crude oil. The molecules could reduce, by two-thirds, the cost of energy storage materials in a type of battery called a flow battery, which is particularly well suited to storing large amounts of energy.

If it solves the problem of the intermittency of power sources like wind and solar, the technology will make it possible to rely far more heavily on renewable energy. Such batteries could also reduce the number of power plants needed on the grid by allowing them to operate more efficiently, much the way a battery in a hybrid vehicle improves fuel economy.

In a flow battery, energy is stored in liquid form in large tanks. Such batteries have been around for decades, and are used in places like Japan to help manage the power grid, but they’re expensive—about $700 per kilowatt-hour of storage capacity, according to one estimate. To make storing hours of energy from wind farms economical, batteries need to cost just $100 per kilowatt-hour, according to the U.S. Department of Energy.

The energy storage materials account for only a fraction of a flow battery’s total cost. Vanadium, the material typically used now, costs about $80 per kilowatt-hour. But that’s high enough to make hitting the $100 target for the whole system impossible. Michael Aziz, a professor of materials and energy technologies at Harvard University who led the work, says the quinones will cut the energy storage material costs down to just $27 per kilowatt-hour. Together with other recent advances in bringing down the cost of the rest of the system, he says, this could put the DOE target in reach.

The Harvard work is the first time that researchers have demonstrated high-performance flow batteries that use organic molecules instead of the metal ions usually used. The quinones can be easily modified, which might make it possible to improve their performance and reduce costs more. “The options for metal ions were pretty well worked through,” Aziz says. “We’ve now introduced a vast new set of materials.”

After identifying quinones as potential energy storage molecules, the Harvard researchers used high-throughput screening techniques to sort through 10,000 variants, searching for ones that had all the right properties for a battery, such as the right voltage levels, the ability to withstand charging and discharging, and the ability to be dissolved in water so they could be stored in liquid tanks.
So far the researchers are using quinones only for the negative side of the battery. The positive side uses bromine, a corrosive and toxic material. The researchers are developing new versions of the quinones that could replace the bromine.

The Harvard researchers are working with the startup Sustainable Innovations to develop a horse-trailer sized battery that can be used to store power from solar panels on commercial buildings.
The Harvard researchers still need to demonstrate that the new materials are durable enough to last the 10 to 20 years that electric utilities would like batteries to last, says Robert Savinell, a professor of engineering and chemical engineering at Case Western Reserve University. Savinell wasn’t involved with the Harvard work. He says initial durability results for the quinones are promising, and says the new materials “without a doubt” can be cheap enough for batteries that store days of electricity from wind farms. And he says the materials “can probably be commercialized in a relatively short time”—within a few years.
____________________________________________

 See what I mean?  I could go gallivanting about the Web, gathering more data for the solution of solar PV energy storage, but this one example should suffice.  We've are making great progress, have been making great progress, and will continue to make great progress.  By great, I mean computer revolution great, for it is all still founded on materials sciences, and an enormous body of knowledge is already available thanks to computers.

The computer revolution, to date at least, has taken some two generations to reach where it is today.  I see no reason, either in principle or in practice, why the solar energy revolution can't race along the same curve.

Urine may make Mars travel possible -- student.societyforscience.org

Urine may make Mars travel possible

A new recycling system turns pee into drinking water and energy

Astronauts aboard the International Space Station toast people back home with water recycled from their urine. A new system not only would turn pee into drinking water but also produce energy.

Every day, you flush a liter or two of urine down the toilet. But if humans are going to get to Mars, they won’t be able to afford throwing out this yellow water. Indeed, they are going to have to drink water from their own pee. Scientists have now built a recycling system that can turn astronauts’ urine into both clean drinking water and energy.

That two-step process could be important in making long-distance space travel possible, report chemist Eduardo Nicolau of the University of Puerto Rico, in San Juan, and his colleagues. They described their new pee-recycler in the April 7 issue of Sustainable Chemistry & Engineering.
The International Space Station would be a likely first place to try out such a system. It already recycles pee using a complex process to filter out the water and purify it. “It makes yesterday’s coffee into today’s coffee,” astronaut Don Pettit said when it was installed.

Before the space station, astronauts didn’t harvest pee. The Russian Mir craft had a recycling system that accepted urine. It was known for breaking down, however. In the end, it didn’t produce much drinkable water. NASA’s space shuttles jettisoned urine into space. This created lovely “shooting stars” of pee that were visible from Earth. (Fortunately, the shuttles brought home the solid wastes, which otherwise could have made for a really disgusting type of space junk).

Astronauts report that the water made from recycled urine on the space station tastes great. But the system, installed in 2008, keeps breaking down. It also takes a lot of power to run. What’s more, the system uses some filters and other materials that can’t be recycled. These will add to a spacecraft’s trash, notes Nicolau.

The system his team has come up with not only would remove water from pee, but also its urea. A nitrogen-rich chemical, urea is used as a fertilizer and as a raw ingredient in some fuel systems. Harvesting it from urine might reduce some of the weight and space that must be allotted for a spacecraft’s fuel, Nicolau says. Indeed, some chemicals recycled from pee can be used to generate electricity, according to his team (which includes NASA scientists).

The new recycling system relies on chemistry to pull pure water out of urine. Through a process called forward osmosis, it uses a concentrated salt or sugar solution. This draws the water from the urine and across a membrane barrier. A tank, called a bioreactor, uses enzymes to convert the leftover urea into ammonia. That ammonia is used to drive a fuel cell, which uses chemicals to produce electricity.

No shortage of raw materials

People urinate about 50 percent more each day than they drink, notes Sherwin Gormly. That’s crazy, you’re thinking: How could you pee out more than you take in? Well, for one thing, your body turns some of your food into water. (When you burn carbohydrates, your body makes energy with a side order of carbon dioxide and water.)

Gormly knows about such issues. As an engineer at NASA’s Ames Research Center in Mountain View, Calif., he helped design the system to recycle urine on the International Space Station. He now works for Desert Toad Water Technology Research in Carson City, Nev.

Surendra Pradhan of Finland’s University of Kuopio shows off cabbages whose growth was boosted by fertilizing them with human urine.
J. Holopainen/Univ. of Kuopio

Managing water — including pee — ends up being one of the biggest obstacles to supporting people on a trip to Mars or any other distant space destination. Without urine recycling, water for a trip to Mars could take up 80 to 90 percent of the mass on a spaceship, Gormly says. Launching something into space can cost up to $10,000 per pound. So shooting mega-tons of water into space quickly becomes crazy expensive.

Any recycling system that people will rely on for months or years has to be extremely efficient. The space station’s system can reclaim 93 percent of the water on board. The new system that Nicolau’s team has developed still needs tweaking. But even in its early stages, it too recovers more than 90 percent of the water going into it.

It’s only generating a tiny trickle of electricity right now. In the lab, filtering one liter (or quart) of urine in eight hours produced about as much electricity as the static charge produced by rubbing a balloon on your hair. “Still,” says Nicolau, “our system is a proof of concept.” Now it’s up to engineers to make it work even better. Eventually, he says, it might produce enough power to run itself.

Another limitation: The system requires small amounts of oxygen to make that electricity. And oxygen, of course, is something else you’re going to need to travel in space. “We are using some breathable oxygen from the cabin,” Nicolau says. So the system would require another process to make up that lost oxygen. This might require breaking down water (via electrolysis) to recover some of its oxygen, or using other chemical processes.

The new recycling process does produce drinkable water. At least in theory it does. Nicolau admits that his team has not yet sampled any. The reason: It has not yet been tested for bacteria and other germs. He promises a photo, though, once he and his team are able to gather around the bioreactor and toast each other with glasses of a beverage made from recycled urine.

Closer to home

We could even get energy-producing urine recyclers here on Earth. “You could deploy this in developing countries where water is scarce,” Nicolau says. It also might appeal to military troops sent to remote desert sites.

If a future in which you drink water made from urine doesn’t sound attractive, think of it this way: Your drinking water already comes partly from the entire planet’s pee; it’s just been recycled a lot more slowly.

Yet one more use for urine at home and in space: growing food. Several years, ago, Finnish scientists reported fertilizing veggies with human pee. Their cabbages grew bigger — and had fewer germs — than those treated with regular fertilizer.

Power Words

ammonia  A colorless gas with a nasty smell. Ammonia is a compound made from the elements nitrogen and hydrogen. It is used to make food and applied to farm fields as a fertilizer. Secreted by the kidneys, ammonia gives urine its characteristic odor. The chemical also occurs in the atmosphere and throughout the universe.

astronaut  People trained to travel into space for research and exploration.

carbohydrates  Any of a large group of compounds occurring in foods and living tissues, including sugars, starch and cellulose. They contain hydrogen and oxygen in the same ratio as water (2:1) and typically can be broken down to release energy in the animal body.

carbon dioxide  A gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. This colorless, odorless gas also is released when organic matter (including fossil fuels like oil or gas) is burned. Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.

chemistry   The field of science that deals with the composition, structure and properties of substances and how they interact with one another. Chemists use this knowledge to study unfamiliar substances, to reproduce large quantities of useful substances or to design and create new and useful substances.

engineer  A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

fertilizer     Nitrogen and other plant nutrients added to soil, water or foliage to boost crop growth or to replenish nutrients that removed earlier by plant roots or leaves.

fuel cell  A device that converts chemical energy into electrical energy. The most common fuel is hydrogen, which emits only water vapor as a byproduct.

International Space Station  An artificial satellite that orbits Earth. Run by the United States and Russia, this station provides a research laboratory from which scientists can conduct experiments in biology, physics and astronomy — and make observations of Earth.

mass  A number that shows how much an object resists speeding up and slowing down — basically a measure of how much matter that object is made from.

National Aeronautics and Space Administration   Created in 1958, this U.S. agency has become a leader in space research and in stimulating public interest in space exploration. It was through NASA that the United States sent people into orbit and ultimately to the moon. It has also sent research craft to study planets and other celestial objects in our solar system.

recycle     To find new uses for something — or parts of something — that might otherwise by discarded, or treated as waste.

space shuttles    The world’s first reusable vehicles, NASA’s five space shuttles (Columbia, Challenger, Discovery, Endeavor and Atlantic) ferried astronauts and cargo into orbit, including to service satellites (like the Hubble Space Telescope) and the International Space Station. The first shuttle launched on April 12, 1981. On July 21, 2011, a shuttle returned home for the last time. After that trip, the program was retired. In all NASA’s shuttles tackled 135 missions.

urea  A nitrogen-rich chemical that the bodies of many animals produce after breaks down proteins, amino acids (the building blocks of proteins) or ammonia. People excrete excess nitrogen from the body — as urea — in urine. But many other mammals, amphibians and fish make urea as well. Synthetic urea is often a nitrogen source of plant fertilizers. In 1828, German chemist Friedrich Wöhler for the first time created urea in the laboratory. This discovery would lead to the widespread use of synthetic fertilizers in farming.

Oklahoma Moms Stage Mass Breastfeeding In Public Park -- ThinkProgress

Oklahoma Moms Stage Mass Breastfeeding In Public Park

Posted on
 
"Oklahoma Moms Stage Mass Breastfeeding In Public Park"
Breastfeeding Photo
CREDIT: Atlanta Journal-Constitution

More than 30 mothers challenged societal norms last weekend at an Oklahoma park when they synchronically pulled out one of their breasts and publicly fed their infants for one minute. The event counted among several gatherings taking place around the world as a part of “The Big Latch On,” an annual effort to promote public breastfeeding.

The Big Latch On launched in 2005 in New Zealand in observance of World Breastfeeding Week, which falls on the first week of August. It has since grown in worldwide popularity, reaching the
United States in 2011 when members of La Leche League of U.S. helped organize mass latch ons in several American cities and towns.

“Get with it. Let’s realize that this is going to be normal,” Carrie Fulgencio, head organizer of Monday’s event, said in the Atlanta Journal-Constitution. “I should not have to take my baby into [a restroom or any other] unsanitary place to feed them, and neither should any other mom. You don’t go eat your lunch there, so why should I take my child?”

Experts say breast milk serves as a unique source of nutrients that infants need to grow and strengthen their immune system. Children that breastfeed in their early years often stave off a host of ailments – including juvenile diabetes, multiple sclerosis, heart disease, and cancer – before the age of 15. Breastfeeding also lowers mothers’ risk of breast, uterine, and ovarian cancer and assists in the loss of weight gained during pregnancy. The American Academy of Pediatrics suggests that breastfeeding an infant within its first year of life ensures fewer doctors’ visits and lower healthcare costs throughout the youngster’s life. Mothers have increasingly become aware of breastfeeding’s health benefits. Data compiled by the Centers for Diseases Control and Prevention shows that breastfeeding among new mothers has increased by more than 60 percent within a 10-year span.

While there’s little question about breastfeeding’s benefits, debates about the manner in which mothers conduct the natural bonding activity have taken place in state legislatures, public gathering places, and online forums for years. In 2003, Jacqueline Mercado and her husband lost custody of their two young children after a clerk at the local Eckerd reported the mother to Child Protective Services in Richardson, Texas upon his discovery of photos that showed Mercado breastfeeding her then one-year-old son. The local district attorney charged the couple with “sexual performance of a child” before dropping charges six months later.

In 2006, Vermont mother Emily Gilette filed a complaint against Freedom Airlines and Delta Air Lines after she said airline officials removed her from a Freedom Airlines flight for not covering herself while breastfeeding her child. In 2010, Jessica Swimeley rallied the support of breastfeeding advocates after she said that administrators at the Ronald McDonald House, a center for sick children based in Houston, threatened to remove her from the premises for breastfeeding her 17-month-old son, then recovering from brain surgery, during an elevator ride.

In June, a Hawaii homeless shelter allegedly threatened to remove a woman from the premises after she refused to cover up while breastfeeding. Earlier this month, a Utah middle school came under fire after its principal wrote a letter to breastfeeding mother Andrea Scannell asking her to “discretely feed the baby, whether with a small blanket or in a more private area while the lunch program is taking place,” citing complaints from parents and other patrons. The incident prompted Scannell to post the letter on social media and stage a nurse-in at the school with the help of Breastfeeding Mama Talk, a breast feeding advocacy organization.

“This kind of shaming, this kind of bullying, it prevents other breastfeeding women from going out in public, from feeding their baby,” said Scannell, according to the Huffington Post. “Not to mention that women can legally breastfeed in public in all 50 states, Utah included.”

Scannell’s right. Today, laws protecting public breastfeeding exist in every state. According to the National Council for State Legislatures, 46 states, the District of Columbia, and the Virgin Islands have laws that allow women to breastfeed publicly. Twenty-nine states – including Arizona, Florida, and Utah – exempt breastfeeding from public indecency laws. The Affordable Care Act also includes provisions that require employers to allow a reasonable break time for an employee to nurse her child for up to one year after its birth.

Dinosaurs doing well before asteroid impact (phys.org)

Dinosaurs doing well before asteroid impact

21 hours ago by Hayley Dunning in phys.org 

Dinosaurs doing well before asteroid impact
Artist's impression of the impact. Credit: John Sibbick.
A new analysis of fossils from the last years of the dinosaurs concludes that extra-terrestrial impact was likely the sole cause of extinction in most cases.
Although some groups of were declining in certain populations, dinosaurs in general were doing well before the impact of a 10km-wide asteroid or comet.

The impact caused huge tsunamis, earthquakes and wildfires. Everything over 25kg went extinct, paving the way for small birds and mammals to flourish in the aftermath.

Other pressures

The impact is well-established as the final cause of the demise of the dinosaurs. However, several other major changes were occurring on Earth at the time, leading to the suggestion that dinosaurs were already declining, and that the impact was the final straw.

Dinosaurs went extinct at the end of the Cretaceous period, 66 million years ago. Over the last few million years of the Cretaceous, environmental changes included huge temperature variations, sea-level swings and massive outpourings of volcanism in India.

Using the most up-to-date records of assemblages occurring in the last 18 million years of the Cretaceous, a team of researchers from some of the top institutions and dinosaur museums around the world, including Dr Paul Barrett from the Natural History Museum, conclude that in most cases the impact was the 'smoking gun for the cause of the extinction.'

Dinosaurs doing well before asteroid impact
Some large herbivores, such as triceratops, may have been declining in certain areas.
 Little decline

In some regions, there was evidence of certain groups of large herbivores declining in species diversity, which could make the communities that depend on them for food more vulnerable to extinction from external pressures such as an impact.

Overall, though, dinosaur species diversity appeared to be relatively stable despite the large-scale changes occurring over the last few million years.

New fields of study

However, the work is based largely on sites in North America, where the most complete and continuous dinosaur fossil records from the end of the Cretaceous have been described.

'It is unusual for so many experts from a consortium of world-leading intuitions to reach consensus over a big question like this,' said Dr Barrett.
                                  
'Having this agreed view helps to set an agenda to guide palaeontologists interested in finding more evidence regarding the speed and structure of the extinction.' This agenda includes looking at regions with the potential for the same detailed records as in North America, including sites in Spain and China.

Zooming in on the cause

The timing of the impact also coincides with a pulse in volcanic activity from India. The dinosaur fossil record is not yet complete enough to say what effect the increase in dust, sulphur and carbon dioxide in the atmosphere from the volcanism would have had on dinosaur communities immediately prior to the impact.

With focused research on this time period across the globe, Dr Barrett is hopeful we can gain an even clearer understanding of the timing and tempo of the .

'This will give us a much clearer picture of our past and perhaps even an understanding of the environmental and ecological factors that could cause or accelerate extinctions in the future.'
Explore further: Dinosaurs fell victim to perfect storm of events, study shows

New molecule puts scientists a step closer to understanding hydrogen storage

New molecule puts scientists a step closer to understanding hydrogen storage

Jul 25, 2014 by phys.org

The Chinese Puzzle Molecule -a twenty eight copper fifteen hydride core wrapped in dithiocarbamate
Australian and Taiwanese scientists have discovered a new molecule which puts the science community one step closer to solving one of the barriers to development of cleaner, greener hydrogen fuel-cells as a viable power source for cars.

Scientists say that the newly-discovered "28copper15hydride" puts us on a path to better understanding hydrogen, and potentially even how to get it in and out of a fuel system, and is stored in a manner which is stable and safe – overcoming Hindenburg-type risks.
"28copper15hydride" is certainly not a name that would be developed by a marketing guru, but while it would send many running for an encyclopaedia (or let's face it, Wikipedia), it has some of the world's most accomplished chemists intrigued.

Its discovery was recently featured on the cover of one of the world's most prestigious chemistry journals, and details are being presented today by Australia's Dr Alison Edwards at the 41st International Conference on Coordination Chemistry, Singapore where 1100 chemists have gathered..
The molecule was synthesised by a team led by Prof Chenwei Liu from the National Dong Hwa University in Taiwan, who developed a partial structure model.
The chemical structure determination was completed by the team at the Australian Nuclear Science and Technology Organisation (ANSTO) using KOALA, one of the world's leading crystallography tools.

Most solid material is made of crystalline structures. The crystals are made up of regular arrangements of atoms stacked up like boxes in a tightly packed warehouse. The science of finding this arrangement, and structure of matter at the atomic level, is crystallography. ANSTO is Australia's home of this science.

ANSTO's Dr Alison Edwards is a Chemical Crystallographer at the Bragg Institute (named after William Bragg and his Australian-born son Lawrence, who were pioneers in this field). She explains the very basic (elementary, if you will!) principles behind the discovery, and the discovery itself:

"Anyone with a textbook understanding of chemistry knows the term 'hydride' describes a compound which results when a hydrogen atom with a negative charge is combined with another element in the periodic table," said Dr Edwards.

"This study revealed that mixing certain copper (Cu) compounds with a hydride of boron (borohydride or (BH4)) - created our newly discovered "Chinese Puzzle molecule" with a new structure that has alternating layers of hydride and copper wrapped in an outer shell of protecting molecules.

"Using our leading KOALA instrument – we identified that this molecule actually contained no less than 15 hydrides in the core - which is almost double the eight we were expecting.

"This new molecule has an unprecedented metal hydride core – it is definitely different and much more stable than many previous hydride compounds, in fact it is stable in air, which many others are not. So, we see there is probably much more yet to learn about the properties, and potential of hydride."

The discovery puts us one step further along a path to developing distribution infrastructure - one of four obstacles to hydrogen fuel-cell technology as a viable power source for low-carbon motor vehicles, as cited by Professor Steven Chu, Nobel Laureate and former Secretary of Energy in the United States.
 The four problems in using hydrogen as fuel can be broadly understood as:
  • Efficiency, because the process of obtaining hydrogen - H2 - costs some of the actual energy content already stored in the source of the hydrogen;
  • Transportation and a lack of adequate mechanism to store large volumes at high density;
  • The fuel cell technology is not yet advanced enough; and
  • The distribution infrastructure has not been established.
ANSTO's KOALA has been uniquely placed in developing a scientific understanding of hydrogen and the potential of hydrides, because the neutron source allows us to see the precise location of hydrogen in structures which is effectively invisible with X-rays.
"This improved understanding of one aspect of the nature of hydride provides an improved fundamental understanding of an aspect of hydrogen which underpins potential technological developments – you cannot have a well-founded "hydrogen economy" unless you understand hydrogen!," said Dr Edwards.

"No one is claiming hydrogen-powered cars are imminent. Perhaps this puts us a step further down the road, but we don't know how long the road is. What this research shows is hydrides may yet help us get in and out of a fuel system, stored in a manner which is stable and safe – overcoming the Hindenburg-type risks.

"As I said before, the implications from the research are actually broader and have impacts beyond car power sources.

"The same synthetic chemistry is being applied in the areas of gold and silver nanoparticle formation, which are currently believed to have wide-ranging potential applications in fields such as catalysis, medical diagnostics and therapeutics."

"Our result suggests there could be much more going on in gold and silver nanoclusters than is currently understood – or at the very least, there is more to be understood about the processes of nanoparticle formation. Through understanding the process, we have the prospect of controlling and even directing it."
Explore further: A new solution for storing hydrogen fuel for alternative energy


Bayesian inference

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Bayesian_inference Bayesian inference ( / ...