In the beginning, there was darkness.
And then, bang!
Giving birth to an endless, expanding existence of time, space, and matter.
Every day new discoveries are unlocking the mysterious, the
mind-blowing, the deadly secrets of a place we call the universe.
Thousands of witnesses have claimed to see UFOs.
And their accounts are often strikingly similar.
You have a crashed saucer, but also some crashed bodies.
You have government cover-up.
Mainstream science says the evidence just isn't there.
Oh, my God.
It's a big jump between a UFO and an extraterrestrial spacecraft.
But if UFOs were really extraterrestrial craft, what kind of mind-bending technologies would we find under the hood?
You'd have to have some sort of technology that was capable
of canceling the effects of inertia.
When it comes to Unidentified Flying Objects, what is the real deal?
For millions of believers, it all began on June 24, 1947.
A businessman and pilot named Kenneth Arnold is flying solo near Mount Rainier, Washington.
Suddenly he sees a group of nine aircraft moving at incredible speeds.
They were highly reflective, and they were flying at supersonic speeds, in formation, changing course abruptly.
The speeds were unattainable at the time.
This was before the age of jets and certainly supersonic jets.
Being a trained pilot, he did several things to corroborate their existence to make sure he wasn't seeing some kind of atmospheric effect.
He changed his-- his head angle.
He changed the aircraft angle.
He even positioned the aircraft such that there was a light snow in the background behind the objects, and they appeared dark against a light surface.
Before Arnold can maneuver closer, the objects are gone.
It was basically unprecedented in modern times.
No one had seen anything like this.
In the days that follow, newspaper reporters misquote Arnold, as he tries to make sense of the incident.
In fact, he said it moved like saucers skipping on water.
Now, of course, the reporter kind of messed that up in
reporting it and said that they looked like saucers.
The term "flying saucer" is born.
And Arnold's encounter launches the modern UFO phenomenon.
Weeks later, in the summer of 1947, perhaps the most famous
incident involving an Unidentified Flying Object is reported near Roswell, New Mexico.
Roswell's become the poster child of the UFO phenomenon,
because it has all the necessary ingredients.
You have a crashed saucer, but also some crashed bodies.
You have government cover-up.
There was some sort of cover-up.
There was misinformation given out by the authorities.
The original account put out by the air force at the time was
that this was a flying saucer of alien origin.
And then later, very quickly, was denied, and the story then
was that this was a weather balloon which had crashed and
that there were no occupants on board and that there was nothing extraterrestrial about it.
Other witnesses claimed to have seen actual pieces of a crashed spacecraft-- Materials that are reportedly unknown to science.
Both Arnold's sighting and the Roswell incident remain
officially unconfirmed and highly controversial.
Just about every year, there are thousands of reported sightings mostly in the sky, of objects that they assume are extraterrestrial craft-- So-called UFOs.
The "U" is important, of course. They're unidentified.
I personally have seen a bright light start at the horizon and shoot off into the clouds.
Now, strictly speaking, that was a UFO.
It's a big jump between a UFO and an extraterrestrial spacecraft.
Scientists argue that most UFO sightings either have Earthly origins-- Like satellites, balloons, and aircraft-- Or cosmic origins, such as meteors, comets, or even an especially bright planet Venus.
But when a UFO sighting has no known explanation, could it be an extraterrestrial craft?
And if so, what kind of technologies could possibly explain the behaviors that witnesses actually report?
How would such craft be built?
And what problems would they have to overcome?
A lot of the behavior of UFOs that people have reported are
things that are beyond our current level of physics--
Extreme rates of speed or extreme acceleration, extreme
turn rates, things that just we're-- we're not capable of
doing without extreme harm to a pilot or destroying a spacecraft.
Eyewitness accounts of super fast accelerations, lightning turns, and sudden stops seem to violate known laws of physics, but could aliens find a way around these laws?
So what we have to keep in mind here is the principle of inertia.
That principle, stated first by Isaac Newton, says that an
object at rest or in motion tends to stay at rest or in motion unless acted on by an outside force.
So, to generate these kinds of crazy changes in inertia, you'd
really have to act on that object with an immense amount of force.
Following the same logic, a fighter pilot traveling near the speed of sound, attempting to make a 90-degree turn at the same speed, would experience something close to 300 "g"s of force.
The most that a human pilot wearing a pressure suit can
manage without blacking out is around ten "g"s.
If his physiology were remotely similar to humans, an
extraterrestrial pilot undergoing a 300-g maneuver would instantly perish.
His internal organs would continue moving forward and
crush against the skeleton.
If they were similar to us, they'd probably have to have a way of injecting fluid-- Internal fluid-- Inside their bodies so that they dealt with this problem of their organs floating around inside, and if they were strapped in properly and cushioned properly, uh, end up not having internal damage when they accelerated and decelerated.
To effectively cancel the inertial effects on the craft itself, the pilots might switch on a technology that is beyond the reach of modern humans.
So, in order to cancel out the effects of a 300-g turn and
not be squished by that amount of force, you'd have to have
some sort of technology or a device that was capable of
canceling the effects of inertia.
The device would have to manipulate the force of gravity, using a type of force field to counteract the gravitational forces that rule the entire universe.
This device, you could turn on if you wanted to, then turn
it off if you wanted to, or maybe it would come on and off automatically.
This is high technology that's out of sight.
But if science can't yet explain how these craft could overcome the deadly problem of inertia, can it help explain their shapes...
Particularly the most famous shape of all, the flying saucer?
In the late 1950s, the U.S. air force tested the Avrocar, but the design had poor stability and few aerodynamic advantages, proving that high speeds are unattainable for saucer craft in Earth's atmosphere.
The delta wing, or wedge shape, is a far stronger candidate--
A fact that is well known by modern military aircraft designers.
In fact, the percentage of UFO sightings reporting a wedge-shaped craft have increased in recent decades, a trend that mirrors the emergence of swept-wing jets and even flying-wing designs like the B-2 stealth bomber.
The shapes that people have reported over the years have
changed, with the most recent ones being more wedge-shaped.
So, really, people's accounts tend to reflect the most advanced aircraft of the time.
Beyond movement and shape, any attempt to explain the science of UFOs has to deal with the noise factor, or rather, the lack of noise.
UFO reports consistently claim that the objects moved without making any sound.
Almost all of these sightings, it's a real rule-- There's no noise, which you would expect to hear from any fast-moving craft in the Earth's atmosphere.
You would hear it.
What actually happens is that you get what's called a sonic boom, and that's a special pressure wave that sweeps
through the atmosphere along with the craft.
So you're on the ground, and that huge sonic boom is the
result of that pressure difference between the front of the aircraft and the back of the aircraft as it pushes through the atmosphere.
Could an alien craft somehow cancel out the enormous pressure wave that supersonic flight generates?
The answer could lie in the technology used in the latest
generation of digital noise-canceling headphones.
So there is such a thing as a sound-canceling technology,
where you take a particular sound that you're interested in
canceling and kind of broadcast the negative of that sound to cancel it out.
Now, I'm not aware of any technology that's capable of
doing that with shock waves.
Canceling out the ear-splitting, body-shaking effect of a sonic boom would certainly require some advanced engineering skills.
And if there is silence, what about invisibility?
Some reports claim that UFOs simply disappear into thin air.
One promising human technology currently being researched might explain such phenomenon.
There is a technology on the horizon which might change things visually.
And that is a kind of light-bending technology.
As a class, they're called metamaterials.
If you want to think about popular movies, think the
invisibility cloak in the Harry Potter movies.
Metamaterials use combinations of polymer substrates, gold, and copper to forcibly bend electromagnetic waves around an object.
The light is guided around the object rather than being
reflected or refracted.
But advanced materials, stealth capability, and mind-bending
maneuverability would all come to nothing if our visitors were unable to get to Earth in the first place.
I'd say that the chances of another civilization making it
here to visit us are pretty miniscule.
But if they did make it, it would mean that they had solved a whole bunch of problems, including material-science problems that we don't have answers to.
So they'd have technology far beyond ours, perhaps even beyond what we've dreamt of at this point.
But scientists can imagine several ingenious technologies that could bridge the seemingly unbridgeable distance between the stars, including one explosive propulsion source that's so
apocalyptic, we might see them coming light years away.
For decades, countless UFO reports have surfaced from cities and countries around the globe.
But not all UFO sightings have been reported from the surface of planet Earth.
On July 19, 2009, viewers of a NASA video feed from the space shuttle Endeavor reported seeing a disc-shaped object hovering above the shuttle's mechanical arm.
Space-based UFO sightings like this have purportedly happened throughout the history of manned spaceflight.
Unspecified cosmic phenomenon, or could it suggest the
possibility that huge extraterrestrial starships are cruising the Milky Way galaxy?
Space travel between the stars-- It's a staple of science fiction, right?
You see it every night on television.
You see it in the movies all the time.
But could we really do it, or could any species really do it?
Well, the distances between the stars are enormous-- Really enormous.
Interstellar travel doesn't violate physics.
It isn't that you can rule it out and say, "there's absolutely no way they can come here."
It's just that it's very, very hard.
Just traveling from the Earth to Alpha Centauri, our closest neighboring star at nearly 4 1/2 light years, is beyond the reach of our most powerful rockets.
If an advanced civilization were to visit us from a distant
star system, we can pretty much rule out that they would use
chemical rockets to get here.
Despite the impressive pillar of fire and smoke that we see
during Apollo, Saturn V, or shuttle launches, chemical
rockets don't get you very far in a solar system.
To give you some context for that distance, our furthest
known space probe is Voyager 1, launched in 1977.
It's been flying for 34 years at 38,000 miles per hour, and it's
only now starting to leave our Solar System.
If its destination were Alpha Centauri, it would take over 56,000 years to reach even the closest star system.
To engage in interstellar missions on time frames of a
human lifetime, around about 50 years, we can see that we need to increase the speed that we can travel by at least a factor of 1,000.
Scientists have determined that the speed of light is a mind-blowing 186,000 miles per second.
A spacecraft traveling the star systems would have to reach a
significant percentage of that speed even to reach the nearest star.
The biggest obstacle is weight.
A chemical rocket exacts a huge weight penalty, because its
entire fuel supply must be carried on board.
We can calculate that even to reach 6% of the speed of light
using chemical rocket fuel, you would need more rocket fuel than exists mass in the universe.
So we really know that it's actually impossible to reach
another star system using chemical rocket fuel.
If extraterrestrial visitations are even possible, their spacecraft must solve this problem.
In 2011, NASA's Nanosail-D became the first solar sail to orbit the Earth.
The ultra-thin 100-square-foot sail uses sunlight, or photon
pressure, as a source of propulsion.
One of the immutable limitations of rocket propulsion
is the fact that any rocket has to carry its fuel with it.
A solar sail can take advantage of the naturally occurring
resources, namely photons emanating from the sun, which
can be used to propel that solar sail.
Similarly, a hang glider can fly without any fuel or an engine
just by taking an advantage of the natural resources we're
surrounded by, namely the atmosphere and the laws of aerodynamics.
To achieve sufficient speeds to tow a spacecraft supporting life forms, the sail would have to be huge, up to hundreds of miles in diameter.
And because the photon pressure from a star would decrease the further the sail traveled, some have envisioned a concentrated laser beam directing energy at the sail.
Eventually and sadly, this hang glider and all hang gliders at some point have to land, but a solar sail riding a beam of laser energy could conceivably travel to the stars.
The max speed of a solar sail-- About 10% the speed of light.
Travel from Earth to Alpha Centauri using laser-generated photons-- About 45 years.
Currently, NASA and other space agencies have plans for
launching more solar sails.
But there are other, more powerful sources of propulsion in the universe.
In the 1960s, a method of propulsion was proposed where a
spacecraft would literally drop a series of explosive charges
out the back, and the force of the explosions would push the
spacecraft forward.
The prototype was called the "Orion Drive," and there were
actually a series of experiments done with conventional charges to show that it would work.
The Orion Drive, however, was proposed to use nuclear charges.
In order to simulate an Orion-style propulsion system,
Paul and Jim here are rigging up a demonstration where they're going to put a small chemical charge inside this barrel, and we're going to lift this off the ground 50, 60 feet in the air.
We're going to actually calculate the energy released in
this explosion and compare it to a nuclear charge you might
find on an actual Orion Spacecraft system.
Our Orion spacecraft simulator is rigged and ready to go.
We're going to light off the charges inside, blow the can up
into the air, and compare that with the energy release from a
typical nuclear explosion that would be used on an Orion-style drive.
The Orion Spacecraft, studied at Los Alamos in the late 1950s, proposed nuclear fission as its propulsion source.
Fission energy is produced when the nucleus of an atom splits into smaller parts, producing free neutrons and protons that release tremendous gamma-ray energy.
The explosive charge in this 35-pound barrel lofted it about
60 feet in the air.
A small nuclear charge in the Hiroshima range would liberate
about 27 million times more energy.
Clearly, that's a practical propulsion drive for interplanetary or even interstellar travel.
Because of the huge explosions that an Orion Drive would
require, on the back of the spacecraft, you would have a
huge, thick metal plate that would absorb the thrust of the
explosion and a series of shock absorbers to keep the crew from getting jolted each time the charges went off.
The max speed of a nuclear-powered fission spacecraft-- About 5% the speed of light.
Travel time from Earth to Alpha Centauri-- About 90 years.
Despite its powerful fuel source, the fission craft is actually slower than a solar sail.
Boosting speed would mean turning to another, more intense nuclear reaction.
Fission technology is well known and understood.
And we've been using it to generate power here on Earth
for decades, but there's another kind of nuclear technology, and that's nuclear fusion.
Fusion is the power source of the Sun.
In the core of our Sun, the temperatures are so high, atoms
are moving so fast that they slam into each other, creating
new elements and liberating energy.
The opposite of fission, fusion energy is produced when two atomic nuclei fuse together to form a single, heavier nucleus.
The result is a huge liberation of energy.
A fusion-powered spacecraft was proposed in a 1970s study called "Project Daedelus."
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