Sunday, November 30, 2014

Universe teeming with life? Not so fast, say physicists


This NASA Hubble Telescope photo shows 10,000 galaxies.
Of them, 9,000 are dead and lifeless, say research astrophysicists.

New study: gamma ray bursts make life impossible in 90% of galaxies
This is a peer-reviewed article from Science, one of the most prestigious peer-reviewed journals. It speaks to the fine-tuning of the galaxy for life.
The article says:
Of the estimated 100 billion galaxies in the observable universe, only one in 10 can support complex life like that on Earth, a pair of astrophysicists argues. Everywhere else, stellar explosions known as gamma ray bursts would regularly wipe out any life forms more elaborate than microbes. The detonations also kept the universe lifeless for billions of years after the big bang, the researchers say.
Another relevant discovery: "Invisible shield above the Earth protects us from electron threat."
A team led by the University of Colorado Boulder has discovered an invisible shield some 7,200 miles above Earth that blocks so-called “killer electrons,” which whip around the planet at near-light speed and have been known to threaten astronauts, fry satellites and degrade space systems during intense solar storms.
The "shield" is related to the Van Allen Belt, an electromagnetic ring around the earth that was discovered in the mid-1950s. The VAB is the product of the fact that earth's core is made up mostly of iron, the outer layer of which is liquid. The Earth's rotation produces convection about the core that in turn creates a magnetic field around the entire planet. The convection is itself produced by loss of heat from the core, and this heat loss comes from plate tectonics that, over enormous periods of time, churn the earth from the outer core to the near-surface and back again. Without plate tectonics, says Joseph Kirschvink of Cal Tech, there would be no convective "cells" to generate the magnetic field.

"Without our magnetic field," write paleontologist Peter Ward and astronomer Donald Brownlee in Rare Earth: Why Complex Life is Uncommon in the Universe,
Earth and its cargo of life would be bombarded by a potentially lethal influx of cosmic radiation, and solar wind "sputtering" (in which particles from the sun hit the upper atmosphere with high energy) might slowly eat away at thew atmosphere, as it has on Mars.
Even in the 10 percent of galaxies that  "can support complex life like that on Earth," the radiation problem remains at the planetary level: does an otherwise-suitable planet have the necessary shields against lethal, non-gamma radiation? Unless the planet is highly ferrous, it won't. Unless is is highly ferrous and rotating fairly rapidly, it won't. Unless it is highly ferrous and rotating fairly rapidly and features plate tectonics, it won't. And none of these features have been found on any extra-solar planet.

Bookmark and Share

Wednesday, November 12, 2014

Why physicists' heads explode

Phys.org:
One problem is that conventional physics doesn't really account for why the universe is so large, Arkani-Hamed said.

Albert Einstein's theory of relativity showed that a huge amount of energy exists in the vacuum of space, and it should curve space and time. In fact, there should be so much curvature that the universe is a tiny, crumpled ball.

"That should make the universe horrendously different than what it is," Arkani-Hamed said.

But quantum mechanics also poses a problem. The theory is good at describing the very small realm of particle physics, but it breaks down when physicists try to apply it to the universe as a whole.

"Everything that quantum mechanics is, is violated by our universe because we're accelerating (referring to the idea that the universe is expanding) – we don't know what the rules are," Arkani-Hamed said. "When you try to apply quantum mechanics to the entire universe, quantum mechanics cries 'uncle.'"
But fear not! The reason that our universe acts in ways that physicists don't understand is because they are simply living in the wrong universe! There are trillions and trillions of other universes, they claim, and perhaps if Arkani-Hamed lived in one of them it would make perfect sense to him. 

But he doesn't, nor do any others, so they mentally invent them. It's called String Theory, the idea that there are indeed trillions and trillions of other universes, and lucky us! we inhabit this one. As I have written before, advanced cosmologists have started writing science fiction, not science, although they use equations for their fiction rather than prose.
All their equations may work out, but that don't mean they actually know more than before or that reality has been discerned to a greater degree. Hawking admitted that postulating a universe of three or four dimension did not resolve mathematically. In fact, using up to 10 dimensions didn't work. So they tried 11 and presto! X = 0. Or something. To paraphrase Groucho Marx, "These are our equations. If they don’t work, we have others."
But back to the multiverses. Prof. Arkani-Hamed (he teaches at Harvard) and some others insist that there is a real problem with living in a universe that appears so finely tuned to support our lives when such fine tuning has no scientific explanation. So they say that there are, minimally, 10^500 other universes because that is the minimum number to make our universe's fine tuning feasible. Author Donald Johnson explains,
Koonin explains, "In an infinite multi-verse ... emergence of highly complex systems by chance is not just possible but inevitable. That this extremely rare event occurred on earth and gave rise to life as we know it is explained by anthropic selection alone." The anthropic illusion basically says we just lucked-out in that our Universe appears to be designed "toward man" (anthropic). The fallacy is that we're considering the only universe that we know exists (ours), and the fine-tuning that is evident in it. Speculation of innumerable other universes does not explain our Universe's fine-tuning.   
Others note that "String Theory" is not a scientific theory since it cannot be observed, tested, or falsified. "Alternative universes, things we can't see because they are beyond our horizons, are in principle unfalsifiable and therefore metaphysical." "The trouble is, proponents have not produced an iota of empirical evidence for strings. That's why University of Toronto physicist Amanda Peet--a proponent--recently called string theory a faith-based initiative'. "No part of it has been proven and no one knows how tо prove it'.   
"Because our Universe is, almost by definition, everything we can observe, there are no apparent measurements that would confirm whether we exist within a cosmic landscape multiple universes, or if ours is the only one. And because we can't falsify the idea, ... it isn't science '. "If ... the landscape turns out to be inconsistent ... as things stand we will be in a very awkward position. Without an explanations of nature's fine-tunings we will be hard pressed to answer the ID critics'. It is clear that string theory is not science, but a philosophical belief. (Italics original)
So the physicists' dilemma is either to accept that, "In the beginning, God created the heavens and the earth," or find some way, however screwy and fictional, to deny it. 

Kaboom!



Bookmark and Share

Tuesday, November 11, 2014

Not all wounds have scars . . .

Just because you cannot see any scars does not mean they are not wounded.


I cannot put it any better than Army wife Rachel Latham:
I have stood by and seen my husband off to war three times. Three times I have wondered if he would return home. Three times he has stood, along with others, to offer himself in the name of freedom.

I have felt the presence of God push me to my knees in prayer, only to find out later that the timing matched the exact hour of a firefight. I have seen both beauty and fear in those lonely days and nights.

I have stayed awake through the nights, unable to sleep, the reality of my comfortable secure  bed paid for at the price of those standing on the front lines.

I have calmed the fears of children, spoken words of strength and comfort into their hearts, when I felt so little in my own heart. A mother’s love can do that- offer what isn’t even always there in order to bring peace to a worried little one.

I have felt the joy of the return, knowing how so much has changed, but eternally grateful for the opportunity to learn each other again. Not everyone is allowed this, and I do not take it for granted. 
The war doesn’t leave and I have seen the burden carried by our vets as they recall those moments- the fights, the fears, the victories and the losses. I see them standing at monuments, a vacant look in their eyes as they remember, as their fingers drag along the discovery of a name on the monument. They can’t forget, and neither should we, the price that was paid.

I have seen the veterans in the hospital, seen the camaraderie that spans the generations of war…bonds that only those who have lived through could understand. I could never understand, not really, but that isn’t what I have been called to do. I can, however, be thankful.

I have seen and felt the thrashing in the night, of memories that will remain forever, relived only in nightmares.
 
I remember through this how precious our freedom is, how without those who have chosen to serve, we would have nothing. That freedom we enjoy is paid with this price. It isn’t paid only once though, but repeatedly by those who willingly serve. 

Thursday, November 6, 2014

What are the odds of life? Beyond mere astronomical

 Lecompte de Nouy
The French biophysicist and mathematician Lecompte de Nouy was an internationally-regarded scientist whose work on surface tensions and other properties of liquids is still studied today. 

During his work, which started in World War One in trying to mathematically describe the healing of wounds, he examined the laws of probability for a single molecule of high dissymmtery to be formed by chance. De Nouy found that the time needed to form one such molecule worked out to be 10^253 years, or countless trillions of years. (This in a universe that scientists today say is a mere 14.5 billion years old.)

"But," continued de Nouy, "let us admit that no matter how small the chance it could happen, one molecule could be created by such astronomical odds of chance. However, one molecule is of no use. Hundreds of millions of identical ones are necessary. Thus we either admit the miracle or doubt the absolute truth of science." 

I posted before a lecture by James Tour, one of the 10 most cited chemists in the world, whose particular specialty is making molecules from scratch, ab initio, from atoms. 
… I will tell you as a scientist and a synthetic chemist: if anybody should be able to understand evolution, it is me, because I make molecules for a living, and I don’t just buy a kit, and mix this and mix this, and get that. I mean, ab initio, I make molecules. I understand how hard it is to make molecules. I understand that if I take Nature’s tool kit, it could be much easier, because all the tools are already there, and I just mix it in the proportions, and I do it under these conditions, but ab initio is very, very hard.
Think about this: the simplest form of life is the single-cell creature. There is, after all, no such thing as a "half-cell" creature. Of such organisms, prokaryotes "are the earliest and most primitive forms of life on earth." 


As organized in the Three Domain System, prokaryotes include bacteria and archaeans. Prokaryotes are able to live and thrive in various types of environments including extreme habitats such as hydrothermal vents, hot springs, swamps, wetlands, and the guts of animals. Prokaryotic cells are not as complex as eukaryotic cells . They have no true nucleus as the DNA is not contained within a membrane or separated from the rest of the cell, but is coiled up in a region of the cytoplasm called the nucleoid. 
Study that diagram and try to answer Dr. Tour's simple question: 
How do you get DNA without a cell membrane? And how do you get a cell membrane without a DNA? And how does all this come together from this piece of jelly?” We have no idea, we have no idea.
Prokaryotes did not evolve. Taking Dr. Tour's point, the cell's DNA contains the coding for the  formation and structure of the cell wall. But the cell wall could not have come after the DNA because without the cell wall to begin with, the DNA could not have either formed or survived its environment if it had formed. The DNA and cell wall had to have formed simultaneously, but how could that be if forming any organic matter at all is nothing but random chance combinations of atoms that have, in some vital cases, one chance in 10^253 to have formed at all? 

A prokaryote cell cannot have come into existence bit by bit because no bit could have survived without the rest of the cell to support it and give it life. And scientists have neither discovered nor described a potential, simpler pre-prokaryote. No, such a cell not only came into existence all at one time, it had to do so already capable of reproduction through binary fission, else the first would have been the only. 

And of course, this all happened by random chance, right? Which begs the question, What are the odds? 

No wonder that Freeman Dyson, one of the most celebrated scientists of the last 100 years, wrote in his essay, "How We Know," 
The public has a distorted view of science, because children are taught in school that science is a collection of firmly established truths. In fact, science is not a collection of truths. It is a continuing exploration of mysteries. Wherever we go exploring in the world around us, we find mysteries. Our planet is covered by continents and oceans whose origin we cannot explain. Our atmosphere is constantly stirred by poorly understood disturbances that we call weather and climate. The visible matter in the universe is outweighed by a much larger quantity of dark invisible matter that we do not understand at all. The origin of life is a total mystery, and so is the existence of human consciousness. We have no clear idea how the electrical discharges occurring in nerve cells in our brains are connected with our feelings and desires and actions [boldface added].
Then we have this observation by GK Philip & SJ Freeland, NASA Astrobiology Institute, University of Hawaii, in considering that of the 80 amino acids that could be used to build genetically encoded protein polymers, nature uses a “standard set” of 20 identified amino acids.
“Specifically, we show that the standard set of 20 amino acids represents the possible spectra of size, charge, and hydrophobicity more broadly and more evenly than can be explained by chance alone.” (emphasis added)
Amino acids, of course, are the building blocks of proteins, without which there is no life. But, "What are the odds of getting a functional protein by chance?" Well, see for yourself:
  • BONDING: You need 99 peptide bonds between the 100 amino acids. The odds of getting a peptide bond is 50%. The probability of building a chain of one hundred amino acids in which all linkages involve peptide bonds is roughly (1/2)^99 or 1 chance in 10^30.
  • CHIRALITY: You need 100 left-handed amino acids. The odds of getting a left-handed amino acid is 50%. The probability of attaining at random only L–amino acids in a hypothetical peptide chain one hundred amino acids long is (1/2)^100 or again roughly 1 chance in 10^30.
  • SEQUENCE: You need to choose the correct amino acid for each of the 100 links. The odds of getting the right one are 1 in 20. Even if you allow for some variation, the odds of getting a functional sequence is (1/20)^100 or 1 in 10^65.
The final probability of getting a functional protein composed of 100 amino acids is 1 in 10^125. Even if you fill the universe with pre-biotic soup, and react amino acids at Planck time (very fast!) for 14 billion years, you are probably not going to get even 1 such protein. And you need at least 100 of them for minimal life functions, plus DNA and RNA.
But the difficulties of "random chance" continue. E.V. Koonin and A.S. Novozhilov, National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, wrote:
A real understanding of the [genetic] code origin and evolution is likely to be attainable only in conjunction with a credible scenario for the evolution of the coding principle itself and the translation system.
Which is to say: 
  • The origin of the genetic code is unknown
  • The code operates according to a coding principle but no one knows how the principle started
  • No one understands how the coding principle could have preceded the code itself, or even whether it did so.
But it all started randomly and uncaused, right? It just happened. Lucky us! British cosmologist (and ETI enthusiast) Paul Davies observed that there are just three possibilities of how life started on earth: 
  1. A fluke (random chance), 
  2. Unknown laws that make life a cosmic imperative, 
  3. A miracle (that is, intentional acts by an outside agency)
Of number 1, Davies says this is the "ultimate just-so story." Of number 2, there is no evidence at all and of number 3, well, he doesn't say much. 

I am going with number 3 myself. I do not have enough faith to believe the other two.


Bookmark and Share