Wednesday, August 24, 2016

Top 10 Unsolved Mysteries of Astronomical Proportions

10. Closer than Mercury?
In 1781, the solar system doubled in size literally overnight when William Herschel, professional musician and amateur astronomer, discovered a seventh planet from the Sun, the first planet discovered since antiquity, and the first planet discovered with a telescope. Its existence confirmed, the seventh planet, eventually to be named Uranus after much controversy, would become the target for many astronomers. However, with all the study, a problem emerged: Uranus did not orbit the Sun as Newtonian physics predicted it should, which implied a more distant, eighth planet tugging on Uranus and altering its orbital path.

Taking the observations and translating them to numbers, French mathematician Urbain LeVarrier made a bold prediction of where the hypothetical eighth planet would be found. In 1846, using LeVarrier's math as a guide, German astronomer Johann Gallee discovered the eighth planet, Neptune, exactly where LeVarrier predicted where it would be located. With his discovery, Gallee proved that mathematics could be used to find planets and thus began the true marriage of theoretical math and practical observation.

In the years following Gallee's discovery, the planets and their orbits would continue to be a focus of study for astronomers. During years of observation and calculation, another unexpected finding emerged: Mercury's already known to be highly elliptical (for a planet) orbit also exhibited precession of perihelion, which suggested that a planet inside Mercury's orbit was tugging on what was thought to be the first planet. Buoyed by the confidence of predicting Neptune, LeVarrier entered the picture again in 1859, coming up with calculations to where this hypothetical planet he preemptively christened “Vulcan” (after the Roman Gods' blacksmith and from whose name 'volcano' would originate) could be found. Later that year, Edmond Modeste Lescarbault reported seeing a planet that wasn't Mercury or Venus transit the Sun, seemingly confirming the existence of Vulcan. LeVarrier and Lescarbault would triumphantly present their 'discovery' the French Academy of Science in 1860, where they were showered with honors.

Needless to say, other astronomers were eager to see this tiny new planet, too. Unfortunately, look as they might, no set pattern emerged to reported sightings of Vulcan for over 50 years. The tiny planet was a celestial phantom of sorts, appearing seemingly at-will before disappearing into the blackness of space. However, the search would continue until around the time of World War I, when Einstein's Relatively explained the oddities observed in Mercury's orbit, thus negating the need for the gravitational tug of a a planet between Mercury and the Sun at all. It was at this point that the vast majority of astronomers concluded that a tiny planet inside the orbit of Mercury named Vulcan simply didn't exist.

But what of the observations? Surely so many experienced astronomers couldn't have mistaken a sunspot for a planet, could they?

Well, it is now believed that something was seen, but that that thing wasn't a planet.

The inner solar system is loaded with asteroids, space rocks left over from the formation of the solar system. As of today, it is estimated that there are over 1 million asteroids, with the vast majority residing in the Main Asteroid Belt between Mars and Jupiter. However, there are other asteroids zipping about the inner solar system in random orbits that they were nudged into by collisions and/or gravitational encounters with larger bodies. In all probability, it was asteroids transiting the solar disc that accounted for all of these sightings of a 'planet' within the orbit of Mercury.

9. The Day the Sun Fell to Earth
The morning of June 30, 1908 dawned like any other in the Tunguska region of Siberia, Northern Russia. The region was sparsely populated and few people witnessed the event that was soon to unfold. However, those who witnessed what happened would never forget what they saw.

Shortly after 7am, a fireball described by witnesses as every bit as bright as the Sun was seen to streak across the sky, then explode in a fireball that was so powerful that it flattened over 1,000 square miles of trees and created a shockwave that traveled around the world three times. The only thing more amazing than the power of the explosion is the belief that, thanks to the remoteness of the region, no one was killed in the event.

While the event was of immense curiosity thanks to the seismic shocks and nights that were as bright as day as far away as London, no scientist made it to the area until over 20 years later. However, when Russian Leonid Kulik finally made it to the site in 1929, the scene was breathtaking: trees flattened out in a butterfly pattern as far as the eye could see except for at the center, where the trees remained upright but stripped of limbs and scorched to cinders. Expecting to find a meteorite (a controversial idea in 1929 as meteor craters were then almost universally thought to be extinct volcanoes), Kulik was shocked to find no crater.

Not deterred, Kulik and his team braved the wilderness, weather, and mosquitoes in order to pump several swamps dry in a search for the meteorite that their leader was convinced lie beneath. Coming up empty in 1929, Kulik led further teams to the site throughout the 30s, coming up empty every time. Science was put on hold by WWII and Stalin's purges and would not resume at Tunguska until the 1960s but, when it did, the mystery only deepened.

One thing Kulik could never explain was why trees were left standing at the epicenter of the blast. Come the 60s and atomic tests, the answer became clear: whatever caused the explosion exploded in mid air.

But what caused the explosion?

Scour the boreal forests as they might, scientists have come up empty in their search for definitive pieces of whatever object caused the explosion. For most scientists, there are only two choices: asteroid or comet. Unfortunately, both theories have holes. The asteroid theory is weak on the fact that no abnormally large concentrations of materials characteristic of an asteroid have been found in the region, which seems to point to the comet theory, except that the comet hypothesis is weak on account of the fact that current theories don't seem to point to comets having the tendency to self-destruct in mid-air.

With neither mainstream hypothesis having any real evidence going for it, all sorts of fringe ideas have sprung up, including but not limited to: mini black holes, an exploding alien spacecraft, antimatter impact, a death ray, and a naturally occurring nuclear explosion.

8. “Wow!”
Over 50 years after it began in 1960, the Search for Extraterrestrial Intelligence (SETI) continues without any confirmed contact from intelligent aliens. For this reason, government funds were pulled in the early 1990s and, to this date, SETI programs continue on private donations, which are increasingly strained thanks to a rough economy. However, it was nearly 40 years ago that SETI may have come closest to reaching its goal.

It was on August 15, 1977 that a tantalizing signal was intercepted at the Big Ear Radio Telescope, located in Dublin, Ohio and operated by Ohio State University. The man at the printout machine that day was Jerry R. Ehman, who, upon seeing the unexpectedly long signal, circled it on the printout and wrote “wow!” on the page. The name has stuck but the question remains: was this an intelligent transmission or some unusually long, naturally occurring event?

Well, it's hard to say for sure.

Pointing to the signal being artificial (and thus of intelligent origin) is the fact that it was a narrowly-focused signal. The Big Ear was scanning across 50 channels simultaneously and, at the time the Wow signal was being recorded, there was no other interference, not even the tiniest trace of static, on any of the other channels, as would be expected with a naturally-occurring source. Another plus going for the signal is that it rose and fell during the 72 second recording time, peaking at the 36 second point. A final point making the case for the Wow signal being alien: it was broadcast at 1420MHz, a “protected spectrum” forbidden for use on Earth and reserved for astronomical purposes.

Going against it? Well, there's one big problem: the signal never repeated. Immediately following the signal, astronomers at the Big Ear were able to determine its celestial origin and began the search to find it again without luck. Even in the following years, the search continued to no avail, which begs the question: why would aliens beam out such a signal never to do so again? It is for this reason that many doubters point to Earthly origin, whether it be an unintentional transmission or deliberate mischief on the part of Earthly radio operators.

In the end, all we can do is wonder . . .

7 A Sign From Above?
It is one of the most universally recognized images of all time but no one knows exactly what it was. For 2000 years, the Star of Bethlehem has captivated people the world over. Described in the Bible as the star that led the 3 Magi to the infant Christ, little else is related about the Star, leaving a lot of questions, and just as many possible answers to its true identity assuming that the whole story of the Star was not made up by the Biblical writer (the Star only appears in the Gospel of Matthew).

One problem that must be confronted right before we can even start to narrow down the possible identities of the Star is this: no one knows exactly when Jesus was born. Our current calendar is based on the birth of Christ in that His birth separates the B.C./A.D. eras. However, it is clear that the dating is wrong as the Bible describes how the Holy Family fled to Egypt to avoid the wrath of King Herod, a well-documented historical figure who died in 4 B.C. Thus, 4 B.C. is the last possible year in which Jesus could have been born. It is now generally thought that Jesus was born anywhere between 8 and 4 B.C.

Now that our time frame has been narrowed down, we can start looking to the sky.

There are two schools of thought about the Star of Bethlehem: it was either astronomical or astrological. Astronomical possibilities include supernova, planets, comets, and conjunctions. However, with historic records available from all over the world from the time of the Star, no unusual events were recorded anywhere by anyone, leaving astrology as the more likely explanation to the Star story.

People at this time were almost universal believers in astrology. A notable exception here were the Jews, who were forbidden to practice astrology at numerous spots in the Old Testament. As far as everyone else was concerned, heavenly bodies had special meaning.

One thing we know was that the Magi came from the East. Considering the geographical location of Judea, “East” almost certainly meant Persia. In Persian language, the word “magi” referred to Zoroastrian priests, who practiced medicine and magic (“magic” comes from “magi”), which could also include astrology, at which the Persians were very sophisticated. Coincidentally, it is this astronomical focus of the Persians that can cause the traditional astronomical explanations for the Star to be discounted.

One particular passage in Matthew can greatly narrow down possible candidates for the true Star of Bethlehem. According to the Gospel, “the star which they had seen in the East went before them till it came and stood over where the young Child was.” If this is to be believed, the Star was a planet. Over the course of months, a star's position will change as it rises about four minutes earlier each night. Stars don't stand still, but planets do.

Observe a planet over the course of a year (Mars is best as it is closest), noting where it is in the constellations. For most of the time, it moves with the background stars. However, there are times where it stops, reverses course, stops again, then continues forward with the stars once more. This apparent change in direction called retrograde motion is an optical illusion caused by the Earth passing the slower planet as both orbit the Sun. A comparison can be made to passing cars on the highway. As you pass, the slower car seems to travel backwards. The same is true of planets.

Besides retrograde motion, there is more. Planets and constellations had different significances. Jupiter was widely considered to be associated with kingship. The constellation of Aires the ram was often associated with Israel/Judea. Putting this information together with the knowledge that the Star of Bethlehem was almost certainly a planet allows one to start putting the puzzle together.

In 6 B.C., an astronomical/astrological event that fits the bill very nicely occurred. In that year, the planet Jupiter (planet of kingship) moved into the constellation of Aires (the constellation for Israel/Judea). Thus, this could be interpreted as a sign that a new king of Israel was born. To add even more weight to the hypothesis, Jupiter first appeared as a morning object in the East. At this time, the Sun was also in Aires (Jupiter was rising just ahead of the Sun). In astrology, any constellation is at its most influential when the Sun is in it. Also, it was believed at the time that planets were at their most powerful as they emerged in the East after a period of invisibility in the Sun's glare.

As it would have taken the Magi months to reach Bethlehem from Persia, this also explains the motion of the Star. As time progressed, the Magi could have observed Jupiter slow down and stop before going into retrograde motion. The stoppage could have coincided with the arrival of the Magi in Bethlehem after stopping in Jerusalem and being told of the prophecy predicting the Messiah's birth there.

In the end, though, the Star of Bethlehem will probably remain a matter of faith.

6. Death Star?
When one thinks of death from space, the event that comes to mind for most people is the asteroid impact in the Yucatan Peninsula 65 million years ago that brought about the extinction of the dinosaurs. In geologic terms, the 65 million year ago dinosaur killer was a recent event. For older events, pinpointing a cause can be even more difficult.

Of all the mass extinctions whose cause remains a mystery, one of them, during which roughly 70% of all species died out (only the Permian event was worse), may also have a culprit from the heavens: a gamma ray burst.

Roughly 440 million years ago, there was a mass extinction event that has since been used to denote the boundaries of the Ordovician and Silurian Periods. At the time, life continued on a its brisk pace of evolving into increasingly more complex forms. Then, suddenly, the vast majority was wiped out, leaving a complex puzzle in its wake.

The Ordovician extinction is thought to have been brought about by a sudden global cooling and resultant drop in sea levels (at the time, all life was still in water) brought about by water freezing into ice. The problem here: what brought about this sudden drop in global temperature? So far, science has yet to detect any evidence of an impact or major upsurge in volcanic activity, both of which could cloud the atmosphere and cause a sudden drop in global temperature. The absence of evidence for either of these obvious causes brought about a third, controversial hypothesis: a gamma ray burst.

A gamma ray burst (GRB) is a sudden burst of gamma rays in an extremely focused beam that occurs during a supernova explosion of an extremely large star that travels at nearly the speed of light. Most of these blasts are so powerful that they will release, in a matter of a few seconds, more energy than the Sun will in its entire 10 billion year lifetime. These are extremely rare events, estimated to take place only a few times per galaxy per million years. So far, all GRBs observed have taken place outside of the Milky Way.

The catch: so far.

There is no reason that a GRB couldn't take place in the Milky Way. Why? All that's needed to create a GRB is the explosion of an extremely massive star, of which many exist in the Milky Way. The key wild card: distance from and duration of the burst. Currently, most estimates state that any GRB within 3,000 light years of Earth could pose a serious danger to life on Earth.

Should a GRB hit Earth, the results would not be pretty.

The danger posed by a GRB is caused by its namesake: high-energy gamma rays. If a GRB were to hit Earth, the first result would be the depletion of the ozone layer thanks to the fact that the gamma rays would shatter the ozone molecules. End result: even at 3,000 light years, the ozone layer could be depleted by 50% and would take decades to recover to normal levels. In contrast, the much-publicized “ozone hole” over Antarctica was a depletion of roughly 5%. Without the ozone layer to block high-energy radiation from the Sun, Earth and all life on it would get a bath of dangerous solar radiation. Then things get worse.

If the fact of increased exposure to radiation, which would make cancer almost a certainty and disrupt the mechanics of life at the cellular level, weren't bad enough, the atmospheric troubles would be far from over with the depletion of the ozone layer. The GRB would also create nitrogen dioxide, which is essentially smog. This nitrogen dioxide would block the sunlight and initiate a sudden global cooling, which would cause massive plant die offs, and thus disrupt the food chain, on a global scale. If that weren't bad enough, nitrogen dioxide is water soluble and would precipitate back to surface as acid rain.

At the time of the suspected GRB, all life was still confined to the ocean, but not all ocean-dwelling life was equally susceptible to the ill effects of a GRB.

Two keys regarding any given species' odds of survival were the following: how much time it spent in the water and at what depth. For animals at the time, odds of survival would favor those that lived at great depths and/or lived at the bottom of the ocean in sediment as both distance from the surface and ocean mud would offer greater protection from the GRB's ill effects on the environment. Coincidentally, the vast majority of life forms that survived the extinction were deep water dwellers and/or creatures that lived on the ocean floor.

While not proof positive of a GRB taking place 440 million years ago, what is known about what happened and what is hypothesized about what a GRB could do make this an idea worth further scientific study.

5. Where Did We Come From?
Science is an amazing tool we utilize in our pursuit of knowledge. To date, science has developed to a point where it can explain just about every known happening by way of natural laws.

Key words: just about.

Right now, science can explain everything perfectly well right back to the nanosecond after creation. The big problem: the act of creation remains a topic of hot debate because everything we see around us on Earth and in the sky had to be created somehow but the idea of something coming from nothing makes no logical sense at all.

It is only in regards to this question that science still cannot offer any more of a provable idea than faith. While the religious offer the solution that God/the gods created the universe and scientists ridicule this idea as a cop-out, the scientists are still left having to explain how everything in the universe just spontaneously created itself.

However, there are ideas.

Currently, the most widely accepted idea for the origin of all the matter and energy in the universe has its basis in quantum mechanics, which is the study of subatomic particles. According to this theory, the universe started as a “quantum vacuum,” which isn't a vacuum at all. The catch, in quantum mechanics, there is no such thing as zero energy as there is always wiggle room for energy to fluctuate from zero. The theory continues that these energetic fluctuations from zero are caused by instability and, if the instability is great enough, the fluctuations will grow, the instability growing with it in a sort of subatomic push-pull snowball effect.

The current thought is one of these fluctuations of energy from absolute zero grew, and along with it the level of instability, which fueled more energetic variation from zero. In time, this bubble of energy exploded the universe as we know it into existence in the event called the Big Bang. The key concept that needs to be accepted for this theory to explain the origin of the universe (and one that many people will undoubtedly have a hard time grasping): there is no such thing as absolute nothingness. That being said, the universe didn't originate from nothing as there is and never has been such a thing at all as the energy that fueled the Big Bang always existed and what the Big Bang really created was the matter that makes up the universe. Recently, scientists have addressed this problem by stating that the universe evolved out of “quantum nothingness,” which is almost nothing, with the tiniest amounts of energy constituting “something.”

Obviously, the idea that there is no such thing as zero energy is a difficult concept for most to grasp, especially when combined that tiny amounts of energy combined with instability built up until they fueled the Big Bang, which created all matter in the universe. The above theory has its root in mathematics which, combined with physics and quantum theory, has successfully explained the universe and all contained therein. With today's technology, there is no way to test a creation theory, which means that it will, at least for the foreseeable future, remain in the realm of theoretical mathematics and physics. However, so far, the marriage between the two has a very good track record and the equations used as the basis for the above theory make everything outlined above possible.

Perhaps this is the greatest of all mysteries in that, more so than any of the others presented in this list, it stands the lowest chance of ever being solved.

4. More than Meets the Atmosphere?
Is there more to the weather than the atmospheric conditions on Earth? According to some, yes. It has long been known that the daily weather and weather patterns spanning longer periods of time, known as climate, can fluctuate wildly over geologic time. In the past, Earth has been everything from a global tundra to a planet-wide greenhouse and everything in between, often in cycles.

The big question: what sets the whole change in motion? One potential hypothesis: the Sun.

Man didn't start recording his musings on the heavens until the advent of writing around 5000 years ago in the earliest areas to develop the written record. The start of truly detailed observations of the celestial bodies surfaces? That only began in the last 400 years with the advent of the telescope. However, that beginning of up close astronomy coincided with a major shift in climate called the Little Ice Age, which lasted from 1350 to around 1850 and saw the average global temperature drop 2 to 4 degrees Fahrenheit in just decades. Coincidentally, the coldest part of the Little Ice Age coincided with an abnormally quiet period on the Sun (even for that time) known as the Maunder Minimum, which lasted from the mid 1600s to the early 1700s, during which virtually no sunspot activity took place.

Before the Renaissance, quantitative scientific measurements had yet to come into play, but historic anecdotal evidence goes to suggest that the climate was warmer in Europe, where the historical records are the most complete. In Europe, the Earth is still cooler than it was before the Little Ice Age. Proof? Until the 1200s, England had a booming wine industry. As of 2016, England is still too cool to accommodate the vineyards needed to produce fine wines. In the age of the Vikings, settlers inhabited Greenland in the 11-1200s, but had to abandon their new colony because it became too cold to grow crops, which is how it remains to this day. In more practical matters, the sudden drop in temperature resulted in crop failures, starvation, war over resources, and shifting weather patterns that made disease, most notably Plague, more prevalent.

Historically speaking, the road to linking solar activity to climate has been a long, bumpy ride as the first scientists to suggest that solar activity had a link to climate were G.W, Sporer and E. Walter Maunder. Unfortunately, these men simply noted that there was a drop in temperature that coincided with a drop in solar activity. Result: with no mechanism suggested to explain the change, the correlation was forgotten for almost a century.

During the late 1800s and into the 1960s, the discovery of the 11-year solar cycle and better, more standardized weather data combined to create a series of events that would send the study of solar activity-climate linkage into disrepute. The pattern: someone would look at weather and sunspot data, find a connection, and make a bold prediction. Problem: these predictions always failed to materialize. By the 1960s, there had been so many failed predictions that most scientists refused to go near the topic for fear of being branded a crank. However, a few scientists continued their research, now focusing on much longer time scales than the 11-year cycles that served as the basis for so many failed predictions. As for all of the failed predictions, these scientists reasoned that predictions failed for one reason: there's no way to forecast solar activity years into the future.

By the 1970s, inarticulate pieces of evidence had emerged to show that the Sun did indeed have an impact on Earthly events. In 1976, Jack Eddy published a paper that brought everything together, bringing the once disreputable practice of linking solar activity and Earth climate together back to the scientific mainstream. In his paper, ironically initially intended to study solar stability (or at least behaved according to patterns), Eddy examined old records of sunspot observations and discovered that the Sun was anything but stable. Independent of Eddy, other researchers had already shown that there were spikes of carbon 14 in trees during periods of low sunspot activity. It was Eddy who linked the carbon 14 levels, solar activity, and temperatures together.

In the years since Eddy, more research has been conducted into this still controversial topic. Taking the known carbon 14/sunspot/climate correlation deeper into the past, other scientists examined ice cores dating back over 10,000 for carbon 14-climate connections. Other studies looked for connections between the strength of solar rays and amount of cloud cover and UV rays' interaction with stratospheric ozone, all with varying results. As time progressed and warming continued (during consecutively weakening sunspot cycles 23 and 24), the focus has shifted to man-made, vs. Sun-made global warming.

Still, despite the wide scientific consensus that man-made greenhouse gas emissions are fueling the rise in global temperature, scientific evidence taken from ice cores around the world and dating back 425,000 years show a curious pattern: inexplicable, sharp spikes in global temperature that seem to occur regularly every 125,000-150,000 years. We are currently at the peak of such a spike that fits the established pattern that has thus repeated 5 times. So far, no one can explain such findings, which also coincide with spikes in carbon dioxide levels.

However, one thing is certain: in today's political climate, civil debate often turns into outright name-calling and, with big money from special interests with political and/or economic aims, science with an agenda may become the norm in the climatology field.

3. Is Anybody Out There?
There are estimated to be anywhere between 200 and 400 billion stars in the Milky Way, most of which probably have planets based upon what we now know about stellar formation, which tends toward the creation of planets based on mechanics of star formation alone. Even taking the low estimate of 200 billion and assuming that, on average, every star has just a single planet, that's an unimaginably large number of worlds upon which life could take hold. These massive numbers combined with nearly 14 billion years time to evolve in the cases of low-mass stars, it seems almost a certainty that there is life somewhere out there.

Or is there?

Ever since the age of science dawned, writers have take an interest in speculating upon other worlds and life inhabiting them. Unfortunately, the reality of things stands in stark contrast to writers' imaginations as, so far, there is no tangible evidence whatsoever of alien life, whether it be technologically-advanced or single cell.

In 1960, pioneering astrobiologist Frank Drake proposed his now famous equation that anyone can use to calculate how many intelligent, space-faring civilizations exist in the Milky Way. The problem: there's no answer as the Drake Equation serves a thought experiment. Yes, many of the early values are pretty concrete (number of stars in our galaxy, fraction of stars with planets, fraction of planets that can support life) but, on the other hand, the latter ones (fraction of planets where life develops , fraction of planets that develop intelligent life, fraction of civilizations that develop technology that can communicate through space, fraction of time in a planet's existence that it is graced by such a civilization) involve a lot of speculation and can hugely throw the final result from optimistic to pessimistic in outlook.

Perhaps the biggest factor to answering this question is the last value: the fraction of a planet's existence during which it is populated by a technologically advanced civilization that is capable of interstellar communication. For us here on Earth, that's just over 100 years with the advent of wireless radio. For the record, Earth is nearly 4.5 billion years old. Needless to say, that's a very, very, very (can't emphasize the 'very' enough!) tiny fraction of time, which is made more complicated by another problem: can technologically-advanced civilizations use their technology wisely and survive or are they doomed to use it foolishly and self-destruct? Addressing this problem is the Fermi Paradox, which states that, given the vastness of the cosmos and course life took on Earth, there should be ample evidence of alien civilizations yet there is not the smallest trace at all of a single one. The unwritten assumption of the Fermi Paradox is advanced civilizations tend to self destruct shortly after gaining technological mastery, which Fermi defines as having nuclear technology.

Having teetered on the edge of self destruction during the Cold War and current madness in the Middle East, this question over the tendency of a civilization to destroy itself is a valid one.

Another problem: the sheer vastness of the Milky Way itself. On Earth, we've been beaming our radio waves into space for just over 100 years, enough time to travel just over 100 light years. In contrast, the Milky Way is about 100,000 light years across, meaning that our broadcasts have only gone a stone's throw out into our home galaxy.

Perhaps our nearest neighbors just live too far away to have picked up our broadcasts yet. On the other hand, they may have already done so, not liked what they have picked up, and changed the channel. . .

2. The Reality of Things
For centuries, the universe was defined as everything we saw and this universe was presumed to be infinitely old and static. This comfortable, simple notion of reality changed abruptly thanks to Albert Einstein, whose relativity allowed for a dynamic universe that gained a beginning and possibly an end. A few decades later, things got even more complex with quantum theory which, among other things, said that there was variability to everything and the whole concept of zero/nothing wasn't quite as it seemed. These two branches of physics, studying the universe on the scale of the very large and very small, respectively, changed the way we perceive our universe.

The idea that we may not be living in a universe, but a multiverse, first originated with Hugh Everett's doctoral dissertation at Princeton, which was titled “the Theory of the Universal Wavefunction.” Although Everett's work was obviously of sufficiency to earn him his Ph.D., it was met with a lot of criticism in the wider scientific community with one objection being that it was unscientific for the simple fact that it was untestable and couldn't be proven false. Another problem: the idea of multiple universes violates the principle of Occam's Razor, which states that, when presented with two possible explanations that explain a given phenomenon, choose the simpler as the natural world tends toward the simple. Result: for about a decade after its proposal, the idea that there could be multiple universes was largely discounted by most scientists.

In the 1970s, things changed when Bryce Dewitt again revisited the idea that there could be multiple and/or parallel universes. A key difference between Everett and Dewitt's presentation: Dewitt was more accessible to the general public in that he used the term “multiple worlds” in place of “universal wavefunction.” This, combined with new theories in physics, has produced a wide variety of variations to the original multiverse theory, the most popular of which are outlined below.

The Inflationary Multiverse.
In this theory, t
he Big Bang, specifically the inflationary period that followed, could have set in motion a series of Big Bangs creating an infinite number of universes, whose creation continues even to the present. For those unaware, inflation was the event that started a fraction of a second after the Big Bang during which the universe expanded almost as fast as light in all directions. While this seems absurd that the inflation of our universe could set forth other inflationary events that could create other universes due to the massive amounts of energy that would seemingly be required, science says that this isn't necessarily so. In fact, it is thought that inflation does not require a lot of energy thanks to the fact that the process can possibly pull energy from a reservoir of energy contained in the gravitational field. Result: for inflation to continue and continue popping out universes like bubbles, very little energy is needed to get the process going thanks to the energy reservoir. To determine if this model is accurate, scientists look for evidence of disruptions in the cosmic background radiation left over from the Big Bang caused by bubble universes either gravitationally interacting with and/or bumping into one another.

The Quilted Multiverse
In this theory, the universe is infinite and contains infinite variations and copies of everything. The idea behind this theory: if space-time is flat rather than curved, then it will extend out to infinity but there's a problem: particles can only be arranged so many ways before the possible ways to put them together runs out, which means that if the universe is infinite, arrangements will eventually start to repeat and create a quilt-like patchwork of infinite universes. In researching this possibility, scientists need to determine whether the universe is infinite or not. If the universe is finite, there could be traces of this visible to the human eye. One possibility: multiple images of far away galaxies should be visible in deep sky photos because the light coming from them would travel multiple times around a finite universe, thus leaving multiple images in a single picture. As of now, this is the most practical way in which scientists search for evidence of a multiverse because, after all, the same galaxy should not appear in two areas of sky simultaneously.

The Membrane Multiverse
Derived from string theory, this theory states that there could be membranes separating multiple universes in a way that scientists compare to how gaps separate slices in a loaf of bread. The idea behind this theory is that we live in a 4 dimensional universe (3 directions plus time) but what if there are other dimensions we don't know about? String theory doesn't provide for a limited number of dimensions and also states that there could be other plains of existence, albeit separated by the membranes. Interestingly, science has just recently developed a way to test the validity of this theory the Large Hadron Collider offers potential to prove this theory reality. The idea is this: if you collide protons in our universe, debris might be ejected into another universe, which would be measured as a drop in energy of the output. However, technology is not fool-proof. Remember a few years ago when it was reported that neutrinos were measured to be traveling faster than light only for it to later be found that instruments were out of calibration? Well, no technology is perfect but it is tantalizing to know that the technology to prove or disprove this theory currently exists.

The Quantum Multiverse
Perhaps the wildest of all multiverse theories is that of the quantum multiverse, which is based on the idea of quantum uncertainty, which inherently makes a multitude (in fact an infinite number) of universes possible. The idea that makes this theoretically possible is a cornerstone of quantum theory, namely that, in quantum mechanics, there is no way to predict with certainty the outcome of a measurement before it is made and that each quantum system exists within a “superposition” of states, which contains a multitude of possibilities. Therein arises a problem: how can one universe emerge out of infinite possibilities? Answer: it's impossible, as is any current way to test this theory, which holds that every possible time line and every possible course of actions that could have happened in this universe but didn't happen can exist in their own universe.

And if that wasn't weird enough, things get stranger still . . .

What is reality itself? Is reality as we perceive it even real? This question is both ancient and philosophical. Around 2,000 years ago, Chinese philosopher Zhuangzi posed a question after awaking from a dream wherein he was a butterfly: am I a man dreaming of being a butterfly or a butterfly dreaming of being a man? Similarly, ancient Greek philosopher WHO is credited with the famous expression “I am because I think I am.” Needless to say, people have been questioning the nature of reality for a long time but, until recently, these people lacked the science and technology required to get any concrete answers.

So, is reality everything it seems to be or is reality just real to us because we're living in it?
A Technological take on this question came in 2003 when Nick Bostrum of Oxford posed an interesting scenario. Bostrum calculated that it would take a computer 1036 calculations to create a simulation of all of human history that was indistinguishable from reality. Additionally, he also theorized that this was well within the capacity of a planet-sized computer with current (as of 2003) technology and that simulating the observable universe as part of a computer program would not be a huge undertaking for a creator that could build such a computer in the first place. In fact, Bostrum postulated that such an advanced civilization could create far more simulated people/beings in their virtual reality than have ever lived here on Earth. Conclusion: odds are that we're living in virtual reality, and that our creators may in fact be living in another, higher civilization's simulation, and so on and so on.

So far, this is the most detailed take on the question of whether we're living in simulated reality and what it would take in order to create such a fake universe. Perhaps the only thing weirder than the whole idea itself is that science has undertaken projects to determine whether this seemingly crazy idea just may be true.
As of today, there are a couple trains of thought when it comes to determining if we live in virtual reality. First up, while our computers can come nowhere near simulating the universe, computer simulations we can do all create virtual reality within a lattice framework. According to researchers, if our distant descendents are running a simulation that we are part of, there should be traces of such a lattice in the universe. One idea: if we are living in a lattice-based virtual reality, there should be limitations in the energy levels exhibited by cosmic rays caused by how they interact with the hypothetical lattice.
Another less abstract train of thought is to look for glitches in the software and/or software patches to fix these glitches, which would manifest themselves as violations of the laws of physics as we understand them. In a similar vein, one may recall in The Matrix that such patches caused the sensation of deja vu.
In the end, if science determines that we are living in virtual reality, it leaves a big question: if we're virtual reality (and if virtual reality extends through many levels of creation), who programmed the computer(s), where did the computer programmers come from, and could our universe end if some supreme being just decided to shut the whole thing off?
These are big questions that of yet have no answers as everything outlined above remains purely hypothetical.

1. Where Are We Going?
If origin of the universe is perhaps the greatest mystery of the past, the question of what will eventually happen to everything contained within our universe is something that is still shrouded in darkness, literally, too.

At the most basic level, the fate of the universe depends on how much matter (which all has mutual gravity) is in the universe. The problem: no one knows how much 'stuff' there is is the universe, which makes finding the ratio of the expansive force of the Big Bang to the compressive force of mutual gravitation all but impossible.

Why? Blame the darkness.

The whole question about the ultimate fate of the universe revolves around two mysterious factors: dark matter and dark energy. As for what they are, we aren't exactly sure. However, we do have guesses. According to current theories, dark energy is a mysterious force that is held responsible for causing the universe to expand at a quickening rate (in stark contrast to predictions that expansion set in motion by the Big Bang should be slowing). Needless to say, the amount of this dark energy can play a crucial factor in determining future behavior of the universe. The other factor, dark matter, is 'missing matter' in the universe that can't be accounted for by all the things we see. Long story short: theories predict a certain amount of matter in the universe but the measurements show that the predictions are consistently short on their estimate. The 'missing matter' that we can't see was conveniently dubbed 'dark' for this very reason. Again, the amount of matter in the universe directly impacts on how the universe will behave as a whole in the future.

In the end, there are three basic scenarios for the fate of the universe:

1. The Big Crunch: The actual density of the universe is greater than the critical density. In short, the mutual gravity of all the matter in the universe is greater than the expansive force set in motion by the Big Bang. The process: expansion of the universe will start to slow and will eventually come to a halt before reversing into a collapse wherein the gravity of everything contained within the universe will start attracting all the matter back unto itself. End result: the universe will eventually collapse into itself, eventually reaching a black hole-like singularity like at the point of the Big Bang. As an addendum, some theorists believe that such a contraction could result into another Big Bang, thus creating an oscillating universe.

2. The Big Freeze/Heat Death: The actual density of the universe is equal to that of the critical density. In short, the expansive force set in motion by the Big Bang and the mutual gravity of everything in the universe is equal and cancels out the other. The process: expansion starts to slow and eventually comes to a stop. The process involving the births and deaths of stars continues to the point where the universe eventually becomes so filled with heavy elements (iron and heavier) that stars no longer have enough fusible matter with which to form. The result: in time, all of the existing stars burn out and the universe goes cold, eventually reaching a temperature near absolute zero.

3. The Big Rip: The actual density of the universe is less than the critical density. In short, the expansion not only continues, but picks up speed over time because the expansive force set in motion by the Big Bang is stronger than the mutual gravity of everything that exists in the universe. The process: expansion of the universe accelerates in an uncontrolled manner. The result: expansion eventually becomes so fast that the very atoms that create the universe itself will, at the last moment before the universe is destroyed, be ripped to shreds by the expansion.

What will happen?

As of now, it's hard to say. However, there is growing agreement based on the latest data that the Big Crunch/Oscillating Universe is looking more unlikely than it was seen to be in the past as current data suggests either a universe with density equal to (Big Freeze) or less than (Big Rip) critical density. On the other hand, as instruments become more precise and theories revised, this may change again in the continually-updating process that is science.

Bottom line: stay tuned . . .