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, the
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 . . .
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