In the last video, we looked at a mature Type 2 civilization of the Civilizational Range
Scale. If you haven’t seen the previous videos on this topic, do check them out, the
link is provided for you in the description below. Today, we will be looking at the next
step from a fully mature Type 2 civilization. So, let’s dive right in and explore some
of the defining characteristics of an Immature Type 3 under the civilizational range model!
Zubrin believes that “interstellar travel is the holy grail of astronautical engineering.
The challenge is daunting, but the rewards are potentially infinite”. For example,
distance is the biggest challenge that a civilization must overcome in order to become “Starfaring”.
So, any Mature Type two civilization that has conquered its entire stellar system and
is ready to expand beyond, must really consider inventing or innovating space flight technology
that could support long-distance interstellar travel. This is because distances to even
the nearest known stars are tens of thousands of times greater than those to the farthest
planets in our solar system. To put this into perspective, the distance from the Sun to
the earth is roughly 150 million Kilometers, or 1 astronomical unit or AU. Planet Mars
to Planet Neptune all fall between 1.5 to 30 with Pluto at about 39.5 AU. In comparison,
the nearest known stellar system to us, Alpha Centauri, which is a triple star system, is
about 4.3 light-years, or 270,000 AU. Now that is quite the jump in distance!
But currently, humanity has managed to speed up its fastest spacecraft, Voyager, to about
17 km/sec using multiple gravity assists from the 4 outer giants of our solar system. But
as fast as this may seem, it would still take more than 79,000 years for Voyager to reach
Alpha Centauri! So, “if such a probe had been launched from Earth the day Homo sapiens
first set foot in Europe, it would still have another 30,000 years to go”. Moreover, the
problem is not just the vast distances between stars, it is also the fact that there are
virtually no supporting resources along the way such as sunlight or any other form of
fuel that could be utilized for such long journeys. For this reason, many people believe
that interstellar travel may be impossible without the exploitation of exotic or fantastical
physical phenomena such as wormholes, space warps, cosmic strings, and so forth. However,
for Zubrin, “while orders of magnitude more difficult than interplanetary travel, interstellar
travel is fundamentally feasible using currently understood engineering approaches”. So,
what are these approaches, and how can humanity, or any other Mature Type 2 civilization overcome
these challenges and advance to an Immature Type 3 status? Well, there are a few possibilities
that Robert Zubrin suggests in order to advance to a young ‘Starfaring’ Type 3.
The first on the list to becoming ‘Starfaring’ is our very own chemical propulsion systems.
The idea of our current hydrogen/oxygen rocket systems accomplishing interstellar travel
may seem absurd, but it may not be all that bad. According to Zubrin, the maximum possible
exhaust velocity of our current rockets is 5 km/sec, but “the maximum practical velocity
increment that can be delivered by a rocket engine to a spacecraft is about twice the
exhaust velocity” giving a final push of 10 km/sec. With this speed, reaching the Alpha
Centauri system would take approximately 135,000 years. But this is without considering the
multiple gravity assists we could use to speed up our spacecraft similar to what we have
done with the Voyager spacecraft before. Using the gravity assist from the outer giants and
the Sun, we could achieve a departure speed of 110 km/sec reducing the travel time to
get to Alpha Centauri to only about 12,300 years! Now that is quite an improvement, but
it gets better! Zubrin believes that if we pushed our engineering to wild extremes along
with numerous carefully planned stages, we should be able to achieve a final departure
velocity of 175 km/sec, or 7,700 years to arrive at Alpha Centauri. This, he believes,
is the limit of chemical rocket technology. So, to use this method of traveling to nearby
Stellar Systems wouldn’t be an ideal choice for humanity as it would require many human
lifetimes to complete just one mission. Naturally then, we must come up with something better!
One way to obtain faster speeds would be to turn our attention to fission propulsion systems.
In the past, there have been several proposals for nuclear fission-based rocket systems such
as Project Orion, or the Nuclear Salt Water Rocket (NSWR) proposed by Zubrin himself.
The idea behind Project Orion was pretty simple: use a series of atomic explosives behind a
rocket ship to push it to extremely high speeds. But of course, the risks associated with this
are high as well. For example, one wrong explosion could evaporate the entire ship within seconds,
or a lethal dose of gamma rays could kill the entire crew on board! Perhaps this is
why Project Orion was halted in 1963. In contrast, Zubrin’s Nuclear Salt Water Rocket dissolves
fissionable material, such as uranium bromide, in water as a salt and uses a similar method
of detonation as chemical combustion rocket systems. But because the uranium is ‘watered-down’
the exhaust velocity achieved by this method would be about 3000 km/sec, or 1% the speed
of light similar to Project Orion but without the need for mass-produced nuclear bombs.
Now, since a spacecraft can generally be designed to obtain a change in velocity equal to twice
its exhaust velocity, starships driven by such systems might be able to attain 2% lightspeed,
allowing Alpha Centauri to be reached in about 215 years! But that is not all, an Immature
Type 3 civilization would be able to develop perfect fission drives that are capable of
accelerating up to 8% lightspeed, reaching Alpha Centauri in just about 54 years! But
even if we mastered these fission drives, the amount of fissionable uranium-235 or plutonium-238
needed to fuel such systems would be enormous. So, a civilization of this caliber might explore
a more potent source of energy for their starship propulsion: thermonuclear fusion.
Nuclear fusion is a much better alternative when it comes to interstellar rocketry with
high exhaust velocity. Not only can a fusion reaction propel our spaceships with more power,
but it also produces energetic neutrons which can be used to produce onboard power. There
are several designs for these fusion propulsion systems. For example, the National Ignition
Facility (NIF), is a laser fusion system that can use a set of high-power lasers to focus
on a very small pellet of fusion fuel, thereby heating, compressing, and detonating it. There
are other alternatives to this that require no lasers, or bombs, instead relying on large
magnetic confinement chambers to contain a large volume of reacting thermonuclear fusion
plasma. Zubrin predicts that this type of system would be used to produce fusion power
in the future. Using Deuterium and Helium-3 as fuel, along with advanced engineering methods,
we, or any other Immature Type 3 civilization, could theoretically produce an exhaust velocity
of over 26,400 km/s, or about 10% the speed of light! This would allow a one-way trip
to Alpha Centauri in no more than 43 years which is quite an improvement from the 54-year
trip using the fission propulsion systems! But even 43 years can be a very long time
in terms of the human lifespan. So, can we do better than this? Robert Zubrin definitely
thinks so!
While D-He3 may be one of the best sources of fuel found in nature, there is an artificial
material that is much better! It is called antimatter, and we have been able to create
it in labs. Antimatter is mass with the charges of the subatomic particles reversed. So, in
ordinary matter electrons are negative and protons are positive while in antimatter,
electrons are positive, and protons are negative. This causes matter and antimatter particles
to be attracted, which results in total annihilation, transforming their combined mass into energy
in accordance with Einstein’s famous formula E = mc^2. So, if we could freeze anti-hydrogen
gas, and use this material as fuel on a starship, annihilating it with ordinary hydrogen to
produce energy, “a single kilogram of antimatter annihilating with a kilogram of ordinary matter
will release as much energy as 40 million tonnes of TNT. The maximum theoretical exhaust
velocity of an antimatter rocket would be the speed of light.” But of course, in practice,
nothing can travel at the speed of light. But this method is far more promising than
any other mentioned so far. A system called a photon rocket, that uses antimatter and
matter annihilation as fuel, is said to attain anywhere from 50 to 90% the speed of light!
This means that a spacecraft of this caliber could get to the Alpha Centauri system within
five years, although it will seem like three years to the crew of the ship due to the effects
of relativistic time dilation. Now that would be pretty impressive for any civilization
to be able to achieve!
Apart from these methods, Zubrin also considers light sails and magnetic sails. Although very
cheap, and effective, these methods are best used without any crew onboard since they rely
on simple sail designs to be pushed by man-made lasers, sun-light, or solar winds. But as
we already know, it is simply not enough to send small probes to nearby stars such as
Alpha Centauri to be considered an Immature Type 3 on the Civilizational Range Scale.
An Immature Type 3 civilization is one that is capable of traveling to its nearby Stellar
Systems to colonize and extract all the useful resources. So, what happens when humanity
or any other Mature Type 2 civilization starts to conquer its nearby Stellar Systems? How
will they advance from here to become a fully mature Type 3 civilization? And what can a
mature Type 3 civilization even accomplish? Well, that is a discussion, best left for
another time!
If you enjoyed this video, do leave a like, share, and subscribe to our channel for more
content like this! Will humanity ever advance to this level? Let us know your thoughts in
the comments down below. Until then, we’ll see you in the next one!