WHAT TECHNOLOGY WOULD ALIENS NEED TO REACH EARTH?
In 2017 an extraterrestrial object entered our solar system; this object was the asteroid
Oumuamua, a body that did not come from any region of the solar system but the outside.
It was an interstellar object that came from outside the solar system.
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Some scientists like the famous particle physicist Stephen Hawking came to think that this asteroid
was nothing more and nothing less than an extraterrestrial spacecraft that was visiting
our solar system.
However, as soon as the telescopes and radio telescopes were pointed at the extraterrestrial
object to study it better, we realized that it was just an inert rock, lifeless, and did
not emit any strange signals.
In other words, it was identical to an ordinary asteroid.
A few days after entering our solar system, Oumuamua left the Sun's gravitational influence
following its solitary path through the universe.
Although, in this case, it was only an asteroid, many scientists do not rule out that it could
be an extraterrestrial spacecraft at some point in the future.
TECHNOLOGIES FOR INTERSTELLAR TRAVEL
Humanity cannot travel to other stars because our technology does not allow us to do so.
1.
CHEMICAL FUEL
The rockets we use to get out of the earth run on solid or liquid fuel made from chemicals
on the ground.
Usually, a rocket to leave the earth requires an immense amount of fuel which weighs a lot.
80% of the total weight of a spacecraft is the fuel it uses to leave the planet.
With those types of ships, we could go to the moon and the nearest planets.
However, we could not use it to travel to the stars since it is consumed very quickly,
and it is impossible to recover it once it is used.
That is why we can say that aliens would NOT use chemical fuel like the one we use in our
spaceships, but then...
What kind of technology would aliens need to reach earth?
2.
GRAVITATIONAL ASSISTANCE
The fastest spacecraft ever created by humanity is the Parker probe studying the Sun, which
reached a speed of 150 kilometers per second.
(9)
To give you an idea of how fast that is, with that speed, you could go around the earth
in just 4.5 minutes or go from the earth to the moon in less than an hour.
The Parker probe did not reach this tremendous speed with any fuel but with the gravitational
assistance of the sol.
As the name implies, Gravitational assistance consists of taking advantage of the gravitational
field of a celestial body to propel us.
Remember that gravity can be used both to accelerate and to slow down spacecraft.
The gravitational assist is the only method that allows us to reach such high speeds;
unfortunately, the distances in the universe are considerable, and even with this ship's
speed, it would take thousands of years to reach the nearest star.
This method is only helpful within the solar system; once outside, you must fend for yourself;
since there will be no celestial body with which to propel yourself, it is for that reason
that the extraterrestrials will not opt for this method to reach the earth, so it is discarded.
3.
PULSE NUCLEAR PROPULSION
In 1946 the particle physicist Stanisław Marcin Ulam who participated in the Manhattan
Project proposed a novel project called "ProjectOrion" that aimed to build a spacecraft capable of
reaching very high speeds with nuclear energy.
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The Orion project consisted of designing a revolutionary ship that would have cabins
close to the vacuum where a series of tiny nuclear bombs would be detonated one after
another for a short period.
That is why it is called nuclear propulsion repulse.
Since the bombs are detonated, creating small pulses of thrust one after another until the
ship reaches relativistic speeds.
(Note: Relativistic velocity is understood to represent a percentage close to the speed
of light.)
The energy released by the nuclear bombs would be fired by one of the turbines giving the
ship such a significant boost that in a few years, it would be able to reach a tenth of
the speed of light, that is, about 30,000kilometers per second.
In this way, it would be possible to reach the closest star to earth (Proxima Centauri)
in just 40 years approximately, a much more reasonable period of time than the thousands
of years it would take with conventional ships.
According to the Institute for Advanced Study in Princeton, there is currently the technology
to build something like this.
Unfortunately, the partial nuclear-test-ban treaty (TPPEN) of 1963 and the social fear
of nuclear weapons was the finale of this project in the middle of the last century.
If aliens do not have the same social problems as we do and do not have laws preventing them
from conducting nuclear tests, pulse nuclear propulsion would surely be among their first
options for interstellar travel.
However, this technology would only allow them to go to stars near their solar system
since the number of nuclear explosions that the spacecraft could perform would be very
limited and could not go beyond 100 light-years, a very short distance if we considered that
our Galaxy (the Milky Way) is more than 100,000 light-years in diameter.
To make trips beyond the stars near their solar system, the aliens would have to employ
a type of technology that surpasses the technology developed by humans so far.
4.
ANTIMATTER
The first of these technologies would be an antimatter engine.
Antimatter, as the name implies, is a matter with charges opposite to ordinary matter.
That is, if you have a negatively charged electron, an antielectron would be an electron,
but with a positive charge, the opposite of the electron we know.
Antimatter exists, and it is possible to produce it in particle accelerators such as the famous
Large Hadron Collider (LHC), a colossal machine operated by CERN (European Center for Nuclear
Research), which is responsible for producing antimatter particles by colliding elementary
particles at the speed of light.
(8)
The exciting thing with antimatter is that they self-destruct each other upon contact
with ordinary matter, releasing much energy in the process.
To date, the LHC, during its more than ten years in operation, has failed to produce
a single gram of antimatter.
However, suppose it were to one day be followed.
In that case, a single gram of well-stabilized, controlled, and regulated antimatter could
produce enough energy to power a city like New York for several years.
According to Dr. Gerald Smith of Pennsylvania State University, with an engine that could
harness the energy produced when matter and antimatter combine, it takes only one microgram
of antimatter to reach the Oort cloud, the farthest area of the solar system.
(6)
While to reach the nearest stars would only require a few kilos, and stars beyond 100
light-years would need a couple of tons.
Definitely, antimatter is the best fuel for interstellar travel within the Galaxy, Unfortunately
until this date, the human race is not yet able to produce this material en masse, but
if the aliens take us at least 1000 years of advantage indeed for them, it is already
a reality, it may even be their favorite method to propel their spacecraft.
The only downside for them would be that they will find themselves in another galaxy.
So far, we have explored the technologies that an extraterrestrial race could use to
reach earth from any star within the Galaxy, but what about aliens that will not be found
within the Milky Way?
For this case, suppose a civilization at least 10,000 years more advanced than ours, which
will be found in another galaxy, for example, in the spiral galaxy M31, better known as
Andromeda.
If this race of extraterrestrials wanted to travel to earth, they would run into the inconvenience
that the distance between their Galaxy and ours is considerable, more than 2.5 million
light-years.
That is to say that even with a ship that could reach the speed of light, it would take
more than 2.5 million years to reach our planet, that is too much, it is probably here where
they will have to access technologies that for now for us only existed in our imagination.
5.
WARP SPEED
The first of these technologies is WarpSpeed, so you understand quickly.
This idea was first presented in the famous Star Trek television series.
The Enterprise ship used a curvature displacement motor to travel faster than light.
The first to explain how this theoretical design of the WARP system could work was the
Mexican physicist Miguel Alcubierre, who proposes a theoretical model that does not break AlbertEinstein's
law of special relativity.
In this model, the spacecraft would be covered with a bubble of deformed space.
Behind the ship, space-time would extend in the opposite direction, leaving behind the
starting point.
In front of the ship, space-time would be contracted by placing the destination point
closer and closer.
In this way, the ship would move freely within a bubble of space-time; what would move would
not be the ship but the space deformed with the ship enclosed inside.
Matter cannot go faster than light in space.
However, space can go faster than light, so the spacecraft could reach super limunic speeds,
higher than those of light, even reaching 80 million kilometers per second.
We could travel the distance between the Sun and the star Proxima Centauri with that speed
in just three days.
Unfortunately, for now, this technology is totally out of human capacity, there are still
many things about space-time that we do not understand, and even the physicist Miguel
Alcubierre himself states that to create the WARP engine requires an immense amount of
exotic matter, which is a type of fundamental matter that does not exist in large quantities
in the universe.
Could aliens solve this problem and create their own Star Trek-style ships?
If so, it would not be strange for them to visit us in the years to come, but if it is
a race a million years more advanced than ours, it may include the Warp speed is little
for them.
6.
WORMHOLES
Wormholes are cracks in space-time that connect two points in the universe.
These function as portals that serve to move from one place to another, from anywhere in
the universe instantly.
No engines, no fuel, just going into one place and exiting another very far away instantly.
Too good to be true?
Well, you are right; although wormholes are very famous for fiction movies like Interstellar,
the reality is that they do not exist beyond mathematical theories.
To date, there is no evidence that these objects exist, but this does not mean that they will
never exist; many scientists in the field of particle physics think that perhaps in
the quantum foam where matter is found at the subatomic level, there could be micro
wormholes, cracks in space-time that open and close in fractions of a second, perhaps
an alien race far more advanced than us could cause one of those cracks to stay open longer
and enlarge it enough that a big spaceship can pass through it.
However, for now, all that remains in fantasy.
In truth, we do not know what aliens are like or what technologies they would use to reach
our planet; let us hope that whatever technology they use, they come in peace.