Is Space Battleship Yamato‘s Journey to Iscandar and Back in One Year Feasible?
Text by Rikao Yanagita
Illustrations by Yutaka Kondo
“Warp, even in space, hurry up!”
When I think of a big project with the fate of mankind at stake, the first thing that comes to my mind is the “journey to Iscandar” depicted in Space Battleship Yamato.
In 2199 A.D., Earth is on the verge of extinction due to a planet bomb attack by the planet Gamilas. A message from the planet Iscandar in the Large Magellanic Cloud (footnote 1) tells them to come and get a “radioactivity removal device.”
The Earth Defense Fleet has been destroyed. The former Battleship Yamato is converted into the Space Battleship Yamato. Captain Okita and 114 others are on board, and they depart for the planet Iscandar.
However, the distance between Earth and Iscandar is 148,000 light years. Yamato has to travel this vast distance and back within a year. On top of that, Gamilas, the planet attacking Earth, is a binary (twin) planet with Iscandar, where Yamato is headed. The closer they get to their destination, the more fierce the attack becomes.
It’s a very exciting story, but when you think about it, it’s really desperate.
The success of such a journey is due to Captain Okita’s leadership, Shima Daisuke’s calm, Shiro Sanada’s intelligence, Dessler’s selfishness, Susumu Kodai’s good luck, and so on. There are many factors involved, and the most technologically significant one is the “warp.”
Iscandar provided blueprints for the Wave-Motion Engine. Thus, Yamato is the first Earth spacecraft to achieve “faster-than-light” navigation technology. In this paper, I would like to consider it from a scientific point of view. If warp navigation becomes possible, will we be able to travel as far as 148,000 light years?
296,000 times the speed of light!
It is 148,000 light years to Iscandar in the Large Magellanic Cloud. The round trip is 296,000 light years. This is a distance that would take 296,000 years even if we traveled at the speed of light. That said, it’s hard to understand. How great is this distance?
Let’s think about it in terms of real-world vehicles. For example, if the 320 km/h Tohoku Shinkansen Hayabusa ran continuously for one year, it would travel 2.8 million kilometers. Since the distance from Earth to the moon is 380,000 km, it is three and a half times that distance.
However, light travels the same distance in only 9.4 seconds. And even that fast light would take 296,000 years to travel to Iscandar and back. A round trip on a bullet train would take 998 billion years! It is still too great a distance for our senses to comprehend.
Yamato must make a round trip of such a great distance in just one year. Is it really possible?
Simply put, if it takes 296,000 years at the speed of light, we would need to travel at 296,000 times the speed of light. Unfortunately, according to Einstein’s Special Theory of Relativity, no matter how fast an object accelerates, it cannot exceed the speed of light. This is because “energy needs increase rapidly as we approach the speed of light, and at the speed of light it becomes infinite.”
In other words, no matter how much energy is poured into an object, it will never reach the speed of light.
However, special relativity also reveals the following: “The closer you get to the speed of light, the slower time moves for objects in motion.” In other words, if Yamato accelerates to just below the speed of light, time will move much more slowly on board Yamato.
I calculated that if Yamato traveled at 99.999999943% of the speed of light, the travel time would be reduced to 1/296,000 (footnote 2). So Yamato could return in one year! Great! But no, it’s not great. Time will only move slower on board Yamato. For the people aboard Yamato, only one year will have passed, but on the Earth, 296,000 years will have passed without fail.
By the time Yamato returns, the human race will be long gone! After that, Gamilas aliens would have moved in and flourished. I wonder what will have become of them…
In this way, the speed of light is a barrier to space travel.
How warp navigation works
In Yamato, this problem is solved by “warp,” a technology that allows us to travel great distances in an instant. What kind of principle is this warp, which is made possible by the “Dimensional Wave-Motion Engine”?
To summarize the in-story explanation, “We compress and convert cosmic energy into tachyon particles.” A tachyon is a particle that is said to move faster than the speed of light. It was proposed by a German physicist in the early 20th century, but its existence has not been confirmed. However, this particle is assumed to exist in Yamato.
In Episode 4, science team leader Sanada says, “Warping is a way to travel faster than light, to jump across the time axis without passing through it.”
(1) Space is curved. If you can imagine it as a plane, think of it as a curved surface.
(2) In normal motion, we can only move along this curve.
(3) However, if you move in a straight line from point to point on the curve, you can shorten the distance. This is warp navigation!
If this is possible, we may indeed be able to take a shortcut.
It is a fact that outer space is curved. When a solar eclipse occurs and the moon blocks the light from the sun, we can observe the stars on the other side of the sun. It is because space is bent by the sun that we can see stars that should not be visible.
So does this mean warping is a reality, and we can take an amazing shortcut?
Even if the space between here and Iscandar is as distorted as the space around the sun, the distance that can be shaved off is only 0.0000005 light years. It is the mass of matter that bends space. The sun is 300,000 times more massive than the Earth, but the distortion is still very small.
So, the warp that Sanada is describing must be a completely different method.
In the remake version Yamato 2199 (footnote 3), which was released in theaters and aired on TV in 2013, Sanada (whose character is slightly different from the ’74 version) explained how to use a “wormhole” (footnote 4).
It also uses dark energy (footnote 5), which is more understandable to me. If you are interested, please read the footnotes section.
Traveling through space in a hurry
Here, let’s assume that the Dimensional Wave-Motion Engine is now able to achieve warping without a hitch. However, this engine is not a panacea.
It is not possible to reach the planet Iscandar in a single warp. There is a limit to the distance you can fly in one warp. Also, it seems that once you warp, you can’t warp again for a while. In the story, he says that they warp twice a day. Under these restrictions, how will Yamato travel 296,000 light years?
Since continuous warping is not possible, the only way to proceed is to alternate between warp and normal navigation. Since a warp is over in an instant, almost the entire year will be spent in normal navigation.
In early materials, the speed of Yamato‘s normal flight was estimated to be 99% of the speed of light. This means that even if the spacecraft were to travel at this speed almost the entire year, the distance it could travel would be only 0.99 light years (footnote 6)!
This means that the remaining 295,999.01 light years can only be traversed by warp. In other words, Yamato‘s journey is entirely dependent on warping. In fact, it is this steady progress that will determine the success or failure of Yamato‘s journey.
As I mentioned earlier, when you are moving at close to the speed of light, time slows down for you. When traveling at 99% of the speed of light, time moves at one-seventh the pace of the outside world. So even if Yamato thinks she’s only traveling for one normal day, seven days will pass on Earth.
In other words, in order to come back within a year in Earth time, Yamato would have to complete the trip in 52 days! That’s a busy time.
Looking at all 26 episodes of the TV series, there are many different incidents happening. They fight the Gamilas fleet, forage for food, get stranded in a space storm for three weeks, Captain Okita’s surgery is performed, they search for Aihara who runs off into space, Yabu stages a coup d’etat, Analyzer falls in love…! How can there be time to do so many things in just 52 days?
It’s tempting to rush, but the opposite is true. The absurd truth is that the more you hurry, the more time you lose (footnote 7). Space travel is really tricky.
What if Yamato travels at a speed of about 51 km/h (footnote 8), the same as the maximum speed of the Battleship Yamato? In that case, it would only be able to travel 447,000 km in a year. But we can use the whole year as we do on Earth, since we can only go a little farther in normal navigation. There is no need to panic.
The more you hurry, the more room you have in your heart. It’s a lesson that might be useful in life as well.
“Hohohoho, come quickly!”
1: Large Magellanic Cloud[Translator’s note: the literal word in the Japanese text here is “nebula.”]
In this article, the name “Large Magellanic Nebula” is used in accordance with the name in Space Battleship Yamato. However, it is now usually referred to as the “Large Magellanic Galaxy.” A nebula is a collection of stars and gas in a galaxy, while a galaxy is a collection of stars at the same level as the galaxy. The “Large Magellanic Galaxy” is the more scientifically correct name.
So how did the terms “nebula” and “galaxy” get mixed up? When Astronomer Charles Messier of France catalogued non-stellar objects in 1771, there was no way to distinguish between nebulae and galaxies, and both were called nebulae.
In 1918, Astronomer Harlow Shapley in America measured the distance to a “nebula” and found it to be very far away. Since then, many galaxies have been discovered. The term “galaxy” was coined to distinguish them from nebulae. Naturally, it took some time for the term to catch on, and the year 1974 when Yamato was broadcast, seems to have been a period of transition.
However, the memory of the phrase “the Planet Iscandar in the Large Magellanic Cloud” remains strong, and it can be said that the transition period is still continuing.
2: Time is now moving at a rate of 1/296,000th of a second.
This is the way of thinking when Yamato‘s movement is observed from its surroundings. The idea from Yamato‘s point of view is as follows:
One of the conclusions of special relativity is that an object approaching the speed of light appears to have a shorter length in the direction of travel. From Yamato‘s point of view, the surrounding universe is blown backward at the same speed, so the distance between Earth and Iscandar becomes 1/296,000 for Yamato.
This would allow Yamato to make the round trip in one year.
3: Space Battleship Yamato 2199
Yamato 2199 is a remake of the 1974 version. Although the setting and the main plot of the story remain the same, many inconsistencies were corrected.
For example, in the 1974 version, the skin color of the enemy Gamilas aliens was beige until Episode 9, but changed to blue in Episode 10. There was no explanation for this, so I imagined that they changed it because the blue color looked more evil.
However, in 2199, it is explained that “the skin color of Gamilas aliens is blue, but other aliens who were invaded by Gamilas and became allies have beige skin.” Isn’t that more impressive?
The whole story started out almost the same as the 1974 version, gradually developed in its own way, and came to the same ending again. The sequels after 1974 had a “hmmmm” feeling to them.
4: How to use a wormhole
In Yamato 21299, Shiro Sanada, the head of the science division, explains it as follows: “We artificially create a wormhole and leap from point A to point B. The vast amount of energy to form and maintain the wormhole is pumped up from vacuum energy.” (summary)
Wormholes and vacuum energy are both believed to exist in reality. A “wormhole” is like a tunnel connecting two distant points. When you enter from point A, you exit at point B in zero time, like a door to anywhere in the universe.
“Vacuum energy” is the energy that is accelerating the expansion of the universe. It is also called “dark energy.” The universe has been expanding since it was born, and the rate is getting faster and faster.
Neither of these have been confirmed. However, since phenomenae have been found that would be inexplicable without them, we posit that they do exist.
However, the diameter of a wormhole is only 10 trillionth by 1 trillionth of the diameter of an atom. It is constantly being created and destroyed. It is thought that a huge amount of energy is needed to grow and maintain it. However, the Wave Engine can pump it out of the vacuum energy.
That’s what Sanada says. I see, this may allow us to reach Iscandar without worrying about the speed-of-light problem.
5: dark energy
This is a name that somehow implies “evil energy.” Let me explain how it came about.
In 1934, Astronomer Fritz Zwicky of America measured the motions of galaxies belonging to a cluster of galaxies The mass of the galaxies was found to be much heavier than the theoretical value obtained from the intensity of the light emitted. From this, we know that there is a mysterious matter in the universe that has only mass. It is called “dark matter>”
This also sounds “bad,” but the first thing that was recognized about dark matter was that it did not emit light, so it could not be helped.
In 1998, Cosmologist Michael S. Turner of America proposed a hypothetical energy to explain the expansion of the universe and called it dark energy. Considering the history, this was natural.
The existence of dark energy has been confirmed by subsequent observations. If a mysterious force is revealed to be at work in the universe in the future, it will be called the “dark force.” This is seriously bad naming.
6: 0.99 light years
This is the scale of the inner solar system.
The Oort cloud, the home of long-period comets, is about one light year away from the Sun. Yamato will not even be able to leave the solar system using normal navigation.
7: The more you hurry, the less time you have
For example, if we travel at 99.9% of the speed of light, the time on board Yamato will be 1/32 that on Earth. We would have to make the round trip in 12 days!
8: 51 km/h
The maximum speed of the Battleship Yamato was 27.46 knots. A knot is a unit of speed, which is 1 nautical mile (1.852 km) per hour, so Yamato‘s speed was 51 kilometers per hour.
You may be thinking, “Was it really that slow?” The fastest destroyer in the current Maritime Self-Defense Force does 40 knots. The resistance of water is that great.