Alternatives To Elusive Dark Matter

from KHouse Newsletter January 2014

The Universe is made up primarily of a mysterious substance called dark matter, a mesh, a spider web of space. That’s what popular science says, at least. Astrophysicists insist that dark matter is there; the indirect evidence is substantial. Yet, after multiple millions of dollars have been spent on trying to track down the actual physical particles that make up dark matter, science continues to come up empty. Maybe the astrophysicists need to try another approach in order to finally detect the elusive substance, or maybe they just need to adjust their current models about the nature of light, time, and the Universe itself.

It all started with the spinning of distant galaxies. A Swiss astrophysicist named Fritz Zwicky postulated in the 1930s that invisible stuff he called “dunkle Materie” hid inside the galaxies he was studying, because they spun too fast to contain only the visible stars and gas he could account for. Scientists observe the same puzzling phenomenon today. Based on spectral line data, it appears that the outer rims of spiral galaxies are moving at the same rate as the insides of the galaxies – and that doesn’t make any sense. The galaxies should fly apart from spinning that fast.

This problem caused Zwicky to hypothesize the existence of dunkle Materie—large amounts of invisible material that provides the gravitational pull to hold the galaxies together. It’s what physicists think dark matter is – neutral, uncharged particles that interact with visible material by massive gravitational force.

There is also the matter of gravitational lensing. Starlight through space if often seen to bend and warp around unseen massive objects. The Hubble space telescope can often produce two or three images of the same galaxy in one single picture. The individual images may be different sizes but contain the same features, as though space were a hall of mirrors. As beams of light from the same galaxy bend around objects in space, they reach the earth from slightly different angles, giving the appearance of coming from different locations. Clumps of invisible dark matter between us and these galaxies are blamed for causing the distortions.

Cosmologists have a variety of reasons for embracing the idea of dark matter. The problem is that its existence is inferred from physicists’ current interpretations of data; nobody has been able to directly detect the stuff yet. The physicists are confident that dark matter comes in the form of a particle, a weakly interactive massive particle (WIMP) that creates gravitational effects but otherwise ignores normal visible particles. The trick is to get it to get some WIMPs to show themselves by hitting visible matter into them and making them say, “Ow!”

Rick Gaitskell of Brown University has been hunting for dark matter for 24 odd years and heads the team that turned on the Large Underground Xenon (LUX) experiment in South Dakota. A mile underground in the Homestake Gold Mine, the LUX particle accelerator shoots xenon particles past ultra-sensitive detectors. If the xenon particles smack into one of these WIMPs, it should give off a little flash of electricity that the detectors can catch and record.

So far, though, the LUX hasn’t found anything. Gaitskell told Popular Science this past autumn, “Every experiment has reported essentially negative results. No one even knows for sure if the d- stuff really exists.” If dark matter really does make up five-sixths of the matter in the Universe, it certainly does an excellent job of hiding itself.

A Dark Herring

Of course, dark matter may not exist after all. In his own PowerPoint slides on dark matter posted on the Brown University website, Gaitskell tells his students, “It has been a Problem in Cosmology that astrophysical assumptions often need to be made to interpret data/extra parameters.” It’s true. Scientists create models they use to interpret the information that space gives them. The models are based on certain assumptions, and if those assumptions are incorrect, the data gets interpreted wrongly.

Possible Alternatives

If dark matter is just an illusion, though, what is causing the observed phenomena? What does hold spinning spiral galaxies together and cause the bending of light through allegedly empty space?

First of all, it is odd that so many spiral galaxies appear to have the same issue – the matter across their diameters all appear to be rotating at the same rate – all without flying apart. It may be that that the light information coming from them is interpreted incorrectly. The redshifts that are treated as a sort of Doppler effect – light appearing to lengthen as its source moves away from us – may have another explanation.

In the 1970s, William Tifft at the University of Arizona noted that his redshift measurements didn’t show gradual, smooth shifting to the red. Instead, they were quantized – the measurements made small jumps as though going up a flight of stairs. Two astronomers from Scotland, Guthrie and Napier, tried to disprove Tiffts quantized redshift ideas in the 1990s, but they finally confirmed his results.

Professor José Senovilla, Marc Mars and Raül Vera of the University of the Basque Country, Bilbao, and University of Salamanca, Spain proposed in 2011 that the redshift isn’t caused by a Doppler shift but by the slowing of Time itself. Dark energy supposedly permeates the Universe, causing the outer edges of space to expand at an accelerating rate. That’s the wrong way to interpret the light wave data, suggest these scientists. Senovilla and Vera argue that the better explanation is the opposite, that Time has been slowing down and we see its effect in the apparent stretching of light waves. The light reaching the Hubble telescope from distant galaxies might not tell us as much about the rate the galaxies are spinning as about the nature of Time itself.

The speed of light itself may be slowing. Physicists insist that light speed is a constant, but they may have made that determination prematurely. The speed of light may not be dropping very quickly, but a variety of papers have been written in the past several decades that suggest light speed is not a constant after all. Paul Davies, currently of Arizona State, argued in 2002 that the speed of light may be slowing down, and physicist Barry Setterfield has written extensively on the subject.

Yves-Henri Sanejouand from the University of Nantes in France in 2010 showed a possible slowing of the speed of light by about 0.02–0.03 m/s per year. That’s not much, but it demonstrates the real possibility of a much faster speed of light in the past. “The constancy of the speed of light is one of the fundamental pillars of contemporary physics,” explains Sanejouand, “so the possibility that it may instead vary (even at a slow rate) has far reaching consequences (although mostly on the theoretical side).”

It may also be that spiral galaxies haven’t had time to fly apart. If the speed of light has been slowing, methods for dating the age of the Universe might be way off. The age of the Universe itself may have been overestimated.

While dark matter is credited with causing gravitational lensing, Anirudh Pradhan of Hindu P. G. College in India suggests that the observed bending of light might be caused by the refraction of light as it hits the gasses around various astronomical bodies. We see the refraction of light all the time in everyday life. The fisherman who goes to stab a fish in the water cannot aim directly at the image of the fish, because the light changes direction as it leaves the denser water and hits the less dense air. The refraction of light makes the fish look like it’s in a spot that it isn’t. The same thing can happen in space. As light shoots through the vacuum of space, it hits clouds of gasses that cause it to change direction so that when it reaches us, multiple images of various sizes are produced – and we can’t be certain of where they actually originated.

The nature of the Universe is an involved mystery, a deep subject that requires a great deal more study. Yet, the hunt for dark matter highlights the importance of examining one’s assumptions in the pursuit of scientific truth. Assumptions are required to interpret data, but a great deal of time and money can be spent to prove incorrect interpretations when the underlying assumptions are faulty.

Further Reading

• Dark Matter Search Leaves Scientists Questioning Basic Theories
— Scientific American

• Dark Matter Still Hiding: Latest Experimental Sweep Comes Up Empty
— Scientific American

• Evidence For Dark Matter
— Brown.edu

• Refraction-Based Alternative Explanation for:Bending of Light Near a Star, Gravitational Red/Blue Shift, Gravitational Lensing and Black-Hole
— UPM.edu.my

• What is Gravitational Lensing?
— CFHT LenS

• Einstein’s Relativity Theory Hits A Speed Bump
— The Age

• Is Light Slowing Down?
— Optics and Photonics Focus

• Dark Energy Is A Fiction: The Appearance of Acceleration Is Caused By Time Itself Slowing Down
— Daily Galaxy

• Too Much Dark Matter in Galaxy Cluster? ‘Dark Core’ May Not Be So Dark After All
— Science Daily

Quantum Theory: is the Universe not gravitationally but electrical?

from K-House

Ever since the birth of Quantum Theory there has been speculation—some privately held, some very public—of what the implications of the existence of quanta really means. As measuring devices improved dramatically, they provided more clarity to the issue. Today it is an accepted “truth” that everything is quantized. Energy (as well as length, time, and mass) exists in discrete quantities, divisions if you will.

There are also other side-effects to this discovery. Everything is “connected.” All particles on the quantum level know what the other particles are doing, regardless of distance, instantaneously. Let that sink in. Also, there is a size at which, when dividing the particle in half, it becomes “non-local.” It is nowhere and everywhere. Every measurement of the universe in which we reside has a “quantum limitation.”

Since what we know of reality is based solely on our perception (what we see, hear, feel, taste and smell), it appears there is a foundational structure upon which all of the details “hang.”

If we entertain the idea that the Universe is not gravitationally based but is electrical, it certainly would fit even our most common understanding of a computer-generated simulation. Because of the many difficulties with the gravitational model of the universe, many physicists are being convinced of an electrical model. Many of the issues concerning missing mass, celestial interactions, black holes and the abnormality of temperatures on our own Sun dissolve with the electrical theory.

There is a movie from a few years back (The Thirteenth Floor) in which the simulated characters of a simulated world are confronted with the fundamental limitations of their “reality.” Because of the limitations of structure, they were forced to conclude they were living within a “program” created by an outside source.

Ironically, this is where the physicists of our time find themselves. Disregarding what the Bible has said all along, of course, they are seeking to quantify and confirm the obvious, yet unwanted, conclusion to where the evidence is leading them. Like all good “scientists” they are trying to creatively foster any explanation other than a Creator that loves them and has been trying to inform them in every way possible.

The more they learn about the foundations of our reality, the more the idea of an underlying structure to space/time is confirmed. Millions of dollars are being spent in preparation for the design and construction of experiments to “test” the simulation theory.

Right now at the University of Bonn, nuclear physicist Silas Beane and some of his colleagues have come up with a test that exploits this feature of simulations; their need to be discretized, or quantized.

Beane and company believe we can test to see if the universe behaves the way we expect from theory, or the way we’d expect in a discretized model like a computer simulation. If the latter is true, it would provide evidence that we are all stuck in a simulation:

“In our universe, the laws of physics are the same in every direction. But in a grid, this changes since you no longer have a space-time continuum, and the laws of physics would depend on direction. Simulators would be able to hide this effect but they wouldn’t be able to get rid of it completely.”

Beane and company are testing by creating their own simulations. They are presently simulating quantum chromodynamics (QCD), which is the fundamental force in nature that produces the strong nuclear force among protons and neutrons, and to nuclei and their interactions. In place of the space-time continuum, they have designed tiny, tightly spaced cubic “lattices.” They call this “lattice gauge theory.” After observing their models, they then compare them to real world observations.

Interestingly, the researchers consider their simulation to be just a beginning. As computational development takes place, they envision more powerful versions in which molecules, cells, and even humans themselves might someday be simulated. But for now, they’re interested in creating accurate models of cosmological processes — and finding out which ones might show evidence of an underlying lattice.

On the possibility that we do live in a simulation he says, “There is a famous argument that we probably do live in a simulation. The idea is that in the future, humans will be able to simulate entire universes quite easily (approximately 500 years). And given the vastness of time ahead, the number of these simulations is likely to be huge. So if you ask the question: ‘Do we live in the one true reality or in one of the many simulations?’ the answer, statistically speaking, is that we’re more likely to be living in a simulation.”

The interesting analysis that drives them is that we have “noticed” that our reality has limitations. It is not a foregone conclusion that if some alien culture is behind this simulation, it would be constructed in a way we could understand it. Since we can, at least so far, understand its limitations, this means one of two things; either the designer is like us or it is constructed for our discovery. Either scenario causes secular scientists headaches. How could “they” be like us when they are capable of such technologies? And why would they care that we can discover limitations that should be invisible to the participant?

Many are seeing this edge of reality as an obstacle to be overcome. They talk of entering into the “real world” by their own intellect and effort. This is vaguely reminiscent of the Tower of Babel. As man stumbles forward, the higher probability is of misstep. If God acted at Babel to halt their development capabilities, what more could He have in store for us now?

Related Links:

  •   Physicists Devise Test To See If We’re Living In ‘The Matrix’ - The Verge

  •   Physicists Say There May Be a Way to Prove That We Live in a Computer Simulation - io9

  •   Physicists May Have Evidence Universe Is A Computer Simulation - Huffington Post

Announcement of the discovery of the Higgs Boson, often called the "God particle

From KHouse

Scientists waited in a line 1000-persons long Tuesday night to witness the long-anticipated announcement of the discovery of the Higgs boson, often called the "God particle." The elusive Higgs cannot be observed directly, but physicists at the European Organization for Nuclear Research (CERN) believe they have gathered enough evidence of the particle's traces - its subatomic-sized "footprints" - that they can say it does exist. 

STANDARD MODEL

The Higgs boson is fairly large as far as subatomic particles go, approximately 130 times heavier than a proton and 500,000 times heavier than an electron. The difficulty is that it breaks down too quickly to be directly observed, and only its "shadow" can be seen. Yet, it is believed that the Higgs is the particle that unifies all the forces seen in the physics of the Universe, the substance of the invisible force field that gives all subatomic particles their mass in the first place, that gives them inertia, that makes it possible for atoms to hold together. 

Physicists working at the Large Hadron Collider at CERN's laboratories deep under the Alps believe they have actually found the invisible Higgs, or at least a particle that behaves a lot like they thought the Higgs would act. There might not be just one Higgs particle, though, but a whole variety of flavors, just as there are a wide variety of quarks. "If the boson really is not acting standard, then that will imply that there is more to the story - more particles, maybe more forces around the corner," Neal Weiner, a theorist at New York University, wrote The New York Times in an email, "What that would be is anyone's guess at the moment." Particle Physics 101: The Standard Model in particle physics attempts to explain how all the fundamental particles of the Universe interact with each other. 

The model, which is often compared to the Periodic Table of Elements used by chemists, consists of the various particles that make up all matter and force in the Universe. When our children study about protons, electrons, and neutrons, they are learning old information. Particle physicists have developed the categories of subatomic particles a great deal since the neutron was discovered in 1932. Protons and neutrons now fall into the category of hadrons, particles that are made up of combinations of quarks. Electrons and neutrinos are both types of leptons. 

All the above particles, which make up the fundamental building blocks of matter, are called fermions. In contrast to fermions, bosons are particles like photons, gluons and the Higgs boson that do not make up actual matter; they are considered force-carrier particles. Two fermions cannot occupy the same place at the same time; they bump into each other. Bosons, however, are not actually matter and can move right through one another. Scientists like to talk about the fabric of time and space. 

The fabric of space? By definition, isn't a "space" an emptiness, the hole between two objects? Isn't space that vast black nothingness between the stars? In 1964, a physicist by the name of Peter Higgs, currently professor emeritus at the University of Edinburgh, proposed that empty space is not really empty at all; it is filled with a background energy field, like a lattice through which all other particles have to move. Wherever a particle moves through this field, the field gets distorted and hugs around the particle. The Higgs boson is that "hug" of the field - like a crowd of people around a starlet. 

The particle is given mass, making it harder for it to change direction, speed up or slow down, like the crowd-clustered starlet trying to move across the room. People surround the famous woman as she moves, making it harder for her to speed up or slow down. In a similar way, it is believed that subatomic particles get their mass - their inertia, their resistance to changes in motion - through interactions with the Higgs Field. That was Peter Higgs' idea. 

Since a field cannot be seen, scientists are looking for the hugging clusters, the uncharged particle that would interact with every other subatomic particle to give them all mass. Since then, scientists have been scrambling to find this particle, the Higgs boson. It's difficult to prove the existence of an invisible particle that disappears before you can grab it. Physicists working at CERN's Large Hadron Collider said Wednesday that they had built up enough evidence to declare that a Higgs boson-like particle did indeed exist, and already the scientists are working to learn more. 

From here they want to detail the nature of the Higgs and its possible siblings and hunt for dark matter, parallel universes and the other stuff of science fiction. "The fact that both our teams have independently come to the same results is very powerful," Oliver Buchmueller, a senior physicist on one of the research teams, told Reuters. "We know it is a new boson. But we still have to prove definitively that it is the one that Higgs predicted."Peter Higgs received a standing ovation when he entered the CERN auditorium. His eyes filled with tears as he spoke to his fellow researchers. "It is an incredible thing that it has happened in my lifetime."

  •   A New Particle Could Be Physics' Holy Grail - The New York Times
  •   "It's A Boson:" Higgs Quest Bears New Particle - Reuters
  •   What Is The Higgs Boson? - BBC News
  •   Higgs Boson 'We Have It' - BBC News

Solar Flares, Radioactive Decay, and The Age of the Earth

From Koinonia House

From their first books on dinosaurs, our children are told that life was evolving "millions of years ago." The majority of geologists today tell us that radioisotope dating has narrowed the age of Earth to about 4.5 billion years, give or take 330 million. Recently, two dating methods have been updated, and scientists say the earth might not be as old as they thought it was, but they may not recognize how "off" the dating methods truly are.

How accurate is radiometric dating? Should we accept the "millions of years" scenario that easily, or are there alternate possibilities that get rejected because they don't fit an evolutionary model of origins?

The Grand Canyon:

The age of the earth is not a purely academic matter. The deepest held values and beliefs of many people are tied into whether the earth has been around billions - or only thousands - of years. The Bible says God created the physical universe in seven days. That doesn't leave a lot of time for life to evolve from primordial amino acids.

Where does the evidence honestly lead? On one hand, Hadrian's Wall has survived the erosional forces of wind and rain and ice for nearly 1900 years. With that in mind, it is obvious the Colorado River would have required a great deal more than 6,000 years to scratch out the Grand Canyon. On the other hand, perhaps the mighty Colorado River did not carve the Grand Canyon at all. Consider, mud flows after the eruption of Mount St. Helens gouged sizeable canyons through solid rock in just a few days…

Radioisotopes: 

The measurable breakdown of radioactive isotopes, like the Grand Canyon, appear to give an ancient age for the Earth. Measuring the amount of uranium-238 parent material as well as the lead-206 daughter material in a zircon theoretically allows geochronologists to date the zircon in which these "before" and "after" materials are found. By comparing the derived date to that produced by U-235 and Pb-207 in the same sample, geochronologists believe they can get fairly close results.

The age-dating methods are not perfect, however. There is far less U-235 than U-238 in natural uranium, and by consensus, geochronologists have long used a U-238/U-235 ratio of 137.88 to simply calculate the amount of U-235 in a zircon rather than try to measure it. The original consensus ratio was determined to have some flaws, however, and researchers from the British Geological Survey and the Massachusetts Institute of Technology recently did do some careful measuring. They found the average ratio to be a more accurate 137.818 ± 0.045.

"Firstly, the consensus value of 137.88 couldn't be traced back to international standard units like the kilogram. Secondly, the old consensus ratio had no uncertainty assigned to it, [and] thirdly, the previous measurements were made on materials like uranium ores — and not on naturally occurring minerals that are routinely used for U-Pb dating studies," wrote Joe Hiess, a Marie Curie ITN Experienced Researcher.

This ratio adjustment would take a few hundred thousand years off the widely accepted view of the planet's age. That's not much, but it does raise a question: how many other dating method particulars have been accepted by consensus while including glaring flaws?

Humans Were Human Earlier Than Thought

From Koinonia House

Science artists love to depict early humankind as intelligent apes – standing upright, but hairy in a specifically primate-looking fashion, eyes and ears high on the head.  Yet, as paleoanthropologists uncover more information about ancient humans, the evidence consistently points toward a race of beings that were intelligent and capable, different from anatomically modern humans primarily in that they camped out in caves.  Recent discoveries show that fire was tamed by the earliest of humans, and they used it for more than just keeping warm.

Researchers from Boston University found ash and bone remnants in Wonderwerk Cave in the Northern Cape province of South Africa, according to details published in the Proceeding of the National Academy of Sciences.  The ash and bones and been heated to nearly 1000 degrees Fahrenheit (500 C) in what appear to be a consistent series of controlled fires 100 feet inside the cave.  The site has been dated to the early Acheulean period, about a million years ago, a time when Homo erectus (Homo ergaster in Africa) was busy making tools.  Whether the dating of the site is absolute or relative in the timeline of human history, it does offer strong evidence that humans were using fire to cook their food much earlier than previously thought. 

Prior to this discovery, there were indications that humans used fire as early as 1.5 million years ago, but most paleoanthropologists agreed that only the 400,000-year-old use of fire could be well-established.  It is well known that Neanderthals and modern humans used fire; it appears that early Homo erectus was able to control fire as well.

Paleoanthropologists commonly place H. erectus at between 1.9 million and 143 thousand years ago, when these early humans lived in groups found in spots from Indonesia and China all the way to the southern tip of Africa. Because the brain cases of H. erectus were on average smaller than the brains of people today (yet within the modern-day range of brain size), with thicker face and jaw bones, artists often portray H. erectus with ape-like features.  Yet, the evidence has long demonstrated that these early men were just as human as the humans of today.  We cannot go back in time and have a conversation with them, but we can examine the tools they left behind, and they were not the handiwork of a people who were intellectually defective.
 
Tool-Making
Homo erectus craftsmen chiseled tools from stone in a distinctive teardrop or oval shape, chipping stone hand axes and other cutting tools from the earliest time of their known existence.  The cutting tools were used to butcher the large animals they hunted.  The H. erectus people are always described as hunters and gatherers, yet their tools also included picks, which means they also spent time digging in the ground.  While the "cave man" has long assumed to have been intellectually weak, the sophistication of the artifacts indicates otherwise.  

Communication
While there has been question about whether H. erectus could communicate as we do today, this people did have a human hyoid bone.  Also, the Broca's area of the H. erectus brain was like that of modern humans, according to studies of skull endocasts done by Thomas Wynn.  Scientists have been slow to agree that H. erectus communicated just as well as we do (perhaps better), but the paleoanthropological community has also been reluctant to agree that Neanderthals sat around chatting, and Neanderthals had larger brains than modern man.  Considering their sophisticated tool production, sufficient brains and a hyoid bone, there seems to be little reason to believe that H. erectus did not use spoken language, except for the same assumptions about early man that cause the artists to draw him looking like an upright chimpanzee.

Red Deer Cave People
Even modern man gets sketched as ape-like because he is determined to have "primitive" features.  A recent article on the Red Deer Cave People in Southwest China published in last week's China Daily shows a fine ape-man pencil drawing at the top, even though the Red Deer Cave People were dated to less than 15,000 years ago, nearly 60,000 years after the time when scientists say men were using fire to blacksmith tools.  According to the common paleoanthropology timeline, these are young humans who should look anatomically modern, yet they have "archaic-looking" parietal lobes, large molars, and thick skull bones – qualities that H. erectus also shared. The most important difference is their lack of a strong modern human chin.  "They look very different from all modern humans, whether alive today or in Africa 150,000 years ago," Darren Curnoe of the University of New South Wales told the BBC.

The Red Deer Cave People were also tool makers that used shovels and stone hammers. Even pyramids and quartz stone-cutting tools have been found in their isolated Asian home.

"It is not rare to see fossils that carry both early and modern Homo sapien traits. In the same era, there were many human groups in China. Red Deer Cave people could just be ordinary Chinese," an anonymous paleoanthropologist in China told reporters.

The skulls of modern humans are relatively similar, but that does not mean that ancient people who had different skull characteristics were any less human than we are.  It simply indicates that certain human family groups died out while one group lived on. 

Related Links

  •   Latest Fossils Shed Lights On Evolution And The Migration Of Man - China Daily

  •   Humans Tamed Fire by 1 Million Years Ago - Scientific American

  •   Stone Age Man Used Fire To Make Tools - 50,000 Years Earlier Than We Scientists Thought - The Telegraph

  •   Microstratigraphic Evidence Of In Situ Fire In The Acheulean Strata Of Wonderwerk Cave, Northern Cape Province, South Africa - National Academy of Sciences

  •   Homo Erectus - Smithsonian National Museum of Natural History

  •   Oldest Homo Erectus Tools Found, Early Humans Had Tools Way Earlier Than Previously Thought - The Huffington Post

  •   Becoming Human: Homo Erectus - Institute of Human Origins

  •   Language Capabilities of Homo erectus & Homo neanderthalensis - Laboratorio de Lingui­stica Informatica

No Missing Link! Peoples Is Peoples... And Apes Is Apes

from  Koinonia House

There were once a much wider variety of human beings on this planet than there are now, according to new genetic analyses of Neanderthals in Europe and Denisovans in East Asia. Modern humans once interbred with these other groups, apparently sharing genetic material that includes the ability to fight off certain diseases. Yet, not all creatures designated as "hominids" are related to humans. 

In 2008, a piece of bone and a tooth of what is believed to be a young girl were found in Denisova Cave in southern Siberia, along with stone blades and body ornaments. Twenty years ago the small bone and a tooth would not have been much to go on. These days, however, 40 mg of real bone from a fossil can tell researchers a great deal of information - if the bone contains enough genetic material for researchers to sequence the DNA. 

Researchers were able to compare DNA all around, and it turns out that the Denisovan girl and Neanderthals are related, but not directly. According to comparisons of genetic code, the Denisovan shared a common ancestor with Neanderthals and modern humans. 

"It amazed me that we found this other extinct group of humans," evolutionary geneticist Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology at Leipzig, Germany, told LiveScience. "When we got this little finger bone from Siberia, I was totally expecting it to be either Neanderthal or modern human. When it was something else, that was totally surprising and shocking to me." 

Ancient humans might bear some superficial physical differences from modern homo sapiens, but they were all still humans and able to breed with one another. In fact, interbreeding between modern-form humans and Neanderthals may have given us modern humans certain genes that helped boost our immune systems.

At the least, Neanderthals share key immunity genes with us, namely the HLA (human leucocyte antigen) class 1 gene. HLA proteins are important in helping the body defend itself against new infections. A variant called HLA-B*73 is found both in modern humans and Denisovans. 

There's quite a bit of Neanderthal DNA floating around out there in the population. According to researchers, up to four percent of Neanderthal DNA and up to six percent of Denisovan DNA have survived in modern humans. It's been known for some time now that Neanderthals bred with the people whose descendants are now found in Europe and western Asia. Denisovan genes can also be found in the population of Europe and especially in the people of Asia and the oceanic islands. 

THE GRAND CANYON FORMATION - ALTERNATE THEORIES

From Koinonia House - June 15, 2011

The Grand Canyon is a geological wonder, a vast chasm stretching 277 miles west to east through northern Arizona. The canyon offers one of the best geological cross sections in the world, with nearly 30 distinct layers found from the bottom to the top; its mesas, buttes, colorful slopes and spires illustrate the geological story of the great American southwest. School children are fed a simple tale about how the canyon was formed, but as any honest geologist will admit, nobody knows exactly how it got there. 

The true cause of the Grand Canyon is still hotly debated among geologists, and all recognize there's no solid answer. There are too many missing pieces. The basic park ranger explanation is that the Colorado Plateau - 130,000 square miles covering northern Arizona, southern and eastern Utah, western Colorado and northwestern New Mexico - began to rise up 50-70 million years ago, causing the existing Colorado River to downcut. After millions of years of steady uplift, the Colorado River carved out the Grand Canyon. The higher the plateau rose, pushed upward by magma from deep in the earth, the more powerful the erosional forces of the river proved to be. 

The Colorado River was tamed a great deal when the Glen Canyon Dam was finished in 1966. The dam controls the flow of the river now. The Colorado's flashfloods once carried boulders the size of VW Buses, and it transported an estimated 160 million tons of sediment every year, scouring the canyon bottom. Still, many people consider the vast expanse of the Grand Canyon and despise the Colorado as an underfit river, one that could not have possibly hauled out all the necessary sediment. 

A Few Puzzles:

The simple explanation does have serious geological issues. The Colorado River flows into the Gulf of California – the Sea of Cortez - which contains sediments from geologically young Pliocene layers - not older layers.  It appears that the eastern part of the Grand Canyon is much older than the western part of the Grand Canyon, but nobody knows exactly what happened. 

The western end of the canyon is fairly young. Local sediments come from the Basin and Range area to the west of the Canyon and are from Miocene layers. No river could have carved through there until after the Miocene. There's also no evidence that an older Colorado River ran through the Grand Wash Cliffs at the western end of the canyon. There is therefore an upper Colorado River system to the east that did not originally continue west of the Colorado Plateau. 

Alternate Theories:

The first thought, of course, is that the deposits were carried away by a different route. Perhaps the canyon was carved by a river that flowed down through Marble Canyon through what is now the Little Colorado River, draining into the Rio Grande. According to the theory, another small but steep and vigorous river rushed westward across the Basin and Range. It moved eastward by headward erosion until it ran into the upper Colorado. It "captured" the Colorado , caveman style, and the two married and carved the Grand Canyon in 4-6 million years, dumping into the Sea of Cortez like today. 

There's a problem there, though. The Continental Divide would have prevented the Little Colorado River from reaching the Rio Grande, and the sediment evidence is not there. 

Some argue that the old river flowed south at Peach Springs Canyon, until the river burst through whatever blocked the way to the western part of the Grand Canyon. Some argue that the Colorado Plateau tipped one way and then the other as it rose so that the Colorado River flowed in the opposite direction. Some argue the river flowed underground, or flowed northwest, draining into lakes in Nevada and Utah. 

The deposits to prove these drainage systems haven't been found.  That's part of the problem; there is a lot of data that is just plain missing.