The year 2021 was full of triumphs in humanity’s venture to space. The Mars Rover Perseverance (cost: $2.75B), which I have been proudly working on for seven years, landed on the red planet in February to search for the sign of ancient extraterrestrial life. To the relief of many anxious scientists and engineers who are involved, an Ariane 5 rocket successfully launched the James Webb Space Telescope (cost: ~$10B) on Christmas morning, which will search for the light from the first stars and galaxies of the universe. The International Space Station (cost: >$100B) expanded its floor space with the addition of Russia’s Nauka module (with a pulse-pounding event after the docking), hosted numerous scientific research, and welcomed 17 visitors from five countries including a Russian actress and a Japanese billionaire tourist. Speaking of billionaires, Jeff Bezos and Richard Brandson went up to the edge of space on suborbital spaceships built by their own companies after investing billions of dollars from their wealth. Jared Isaacman paid an undisclosed amount (likely ~$200M) to SpaceX and made a historical 3-day orbital flight on Inspiration4 (which also raised $200M donation for St. Jude Children’s Research Hospital, augmented by Issacman’s $100M and Elon Musk’s $50M donations.)

Now, with all the glories in space, let’s look back and see how humans are doing on our own planet. According to World Bank, 9.1-9.4% of the world’s population (~700 million) live in extreme poverty on less than $1.90 per day in 2020, and potentially ~150 million more in 2021 due to the continuing pandemic. A similar number of people (663 million) are undernourished, according to the Food and Agriculture Organization of the United Nations. These problems could be made even worse by the ongoing global climate change, to which the global leaders could only find incomplete and highly compromised solutions in COP 21. And here in LA, more than 60,000 people are living on the streets.

How can we justify spending billions for finding microbes on Mars or catching photons from the beginning of the universe while millions of kids are starving on Earth? Why do we dare to unlock the secrets of heaven while there is no shortage of important problems on the ground?

As a person who is engaged in space missions and paid a salary from tax payer’s money, I think I have a moral obligation to face this question. I don’t think I can offer a solution right away. My intent in writing this article is not to convince everyone, which I don’t think I can. But at least I should explain why I think my job is still important to humanity, and be open to conversation with those who have different opinions, rather than shutting my eyes from what I don’t want to see.

So let me try.

Unsatisfactory Answers

A typical response to this question goes like this: space is humanity’s future, our dream, and you cannot underestimate the value of inspiring our next generation. I found this answer unsatisfactory. Don’t get me wrong, perhaps I am one of the persons who appreciate the value of dreams the most because my entire life has been driven by a dream to space. But if I meet a mother of starving children in Afghanistan or somewhere, what she would ask from me? Would she ask me to share my experiences on Mars rovers and encourage her kids to pursue their dreams? Of course, not. She will surely ask for $100.

Those who advocate the “colonization” of Mars claim that it could save humanity from potential extinction because we will have a “backup” just in case. Some even suggest to “nuke Mars” to accelerate terraforming. I humbly disagree. There is no backup for a kid dying now. Besides, how many mistakes have we made under the name of colonization in our past? (FWIW, Mars might be inhabited.) And if homo sapiens is fool enough to destroy its home planet, I think it should rather extinct before messing up the second one.

Then, what would be a reason, if any, that we should still explore the space?

This question is deeply personal to me because I once decided to give up my dream for it. My decision at that time was probably affected by my experiences from backpacking trips to more than 30 countries during my college and graduate school years. I wandered every inhabited continent, including sub-Saharan Africa, South America, and South Asia, without hotel reservations or tour guides. To me, it was my personal space exploration – adventures into the unknown. I just didn’t want to be ignorant. I was born and grew up in one of the most fortunate corners of this planet and I thought I must learn about other corners, not just through books but with first-hand experiences.

I met a boy in Banjul, Gambia, a refugee from Guinea-Bissau, who didn’t know his own birthday. Tens of street seller kids near Datong, China (it was in 2002 and China was poor at that time) fought each other in front of me over who to sell a little souvenir to me. On a stinky unpaved street in Varanasi, India, I had to coldly ignore the groan of numerous beggars, some were deformed or without a limb or two, because otherwise I cannot walk even a hundred feet. I saw a woman in a church in Thessaloniki, Greece, who was kissing an icon of Jesus and sobbing sadly.

I felt helpless. My dream, my PhD research, or any effort to unlock the mystery of the universe, was completely irrelevant at these corners of this planet. So I thought I should make a big trajectory correction maneuver of my career in the middle of my PhD. But I did not know which direction I should go to. I lost my dream.

In the end, I came back to where I started, and I am now working for NASA’s Jet Propulsion Laboratory. It was a long story and I will write about it in another opportunity (there is one in Japanese if you can read it). It was a detour in my career and it probably cost a year or two. But it was a meaningful detour because I found an answer to the question. It is likely not a satisfying answer for everyone. Perhaps I should call it my faith rather than an answer. But it is what I believe in from the bottom of my heart.

Memento Mori

To explain my “answer” I have to start from a principle of mine – and perhaps of many others. I said in this article that my entire life is driven by my dream, but actually that was only half true. It is driven by a dream and fear – a dream for space and fear of death.

I got my dream when I was six after seeing Voyager 2’s spectacular encounter with Neptune. About the same age, I started wondering what would happen to me when I die. I think initially it was started out of my curiosity. With the same mental power to imagine the end of the Solar System, I imagined the end of me. My first thought was that I would no longer be able to watch TV. My family was secular so no one gave me an immediate answer. At funerals, people were saying that s/he went to heaven but I was not sure if I would believe it. And as I grow up, I started realizing that a logical conclusion, at least for a science-inclined non-religious teenage boy, is that death is simply the end of subjective experiences. What I call I will vanish away just like a morning dew on a leaf.

That is a terrifying thought. I wished the fear of death will somehow disappear when I am older, but it didn’t. There are moments in the night – not every night but once or twice a month – when I am suddenly haunted by the thought that my consciousness, my memory, and my feeling will someday disappear into nothing. It was often triggered after I drink alcohol. More than once I screamed in front of a mirror and scratched all over my body in a desperate hope to escape from fate.

The only way to reclaim peace in my mind is to think about how to make my life meaningful before it disappears. How to make sure that I feel happy and satisfied when I close my eyes for the last time.

At the bare minimum, I have to provide for my family and myself. I want us to be always safe and healthy. But with these, will I be satisfied at the end of my life? Surely not. I want more.

So, I would work hard and buy us a cozy house with multiple bathrooms, and a car or two of the latest models. We would go on vacations every summer to a tropical island, or maybe own a vacation home near a beautiful lake in a mountain. I would buy a new iPhone every two years with an ever-increasing number of pixels in its cameras and subscribe to Amazon Music Unlimited so that I can listen to my favorite songs anytime, anywhere. Will that be a satisfying life? Sure, it is certainly much better than living on the poverty line, but I doubt materialistic wealth can help me much in the last moment of life.

So what do I want? What would give a meaning to my temporary existence in this universe?

There could be a wide range of answers. My mother once said my sister and I are the meaning of her life. Steve Jobs famously asked John Sculley, the then-president of Pepsi, “Do you want to sell sugar water for the rest of your life or come with me and change the world?”

I want to leave my mark – even just a tiny mark is OK – on humanity’s Great Journey to space. If I am fortunate enough to achieve that, on top of happy family life, I would be able to close my eyes on the last day of my life with a peaceful state of mind.

Memento Mori. That is my guiding principle. When I am unsure about what to do, I remind myself of my death. That often helps me to find the right way.

Memento Mori for Civilization

Now, I propose to use memento mori as a guiding principle for our civilization, too.

I think it is reasonable to assume that, just like ourselves, civilization is mortal. Even a person with the healthiest possible lifestyle cannot escape from the eventual death. Even the most prosperous empires in history did not last forever. I don’t know when or how. I hope it is not in the next few hundred years. But at some point in the future, maybe thousands or millions of years later, there will be the last day of human civilization.

Will a civilization get eternal life in heaven after its death? I don’t think so. The death of civilization simply means the end of everything we created – technologies, cultures, history, art, poems, and songs.

Then, what does this civilization stand for?

The primary role of civilization is to provide for its “family,” by which I mean the entire human race. As I wrote above, it has not fulfiled this responsibility because there are still ~700 million people living in extreme poverty. However, as opposed to the common perception, we have actually made substantial progress in this regard. In 1820, 75-80% of the global population lived under extreme poverty (Source: Clio-Inra). It improved to ~60% in 1920 and ~9% in 2020. And now the world produces more than sufficient food and wealth for everyone. It is just a matter of distribution. It is certainly possible, for the first time in history, to completely remove poverty and hunger from this planet in the next tens of years if, and only if, we have a will to do so.

But if we keep everyone safe from poverty, hunger, or any physical danger, are we done? I don’t think so. It is known that the average self-reported life satisfaction by country is highly correlated to GDP. Improving people’s material well-being is indeed an important function of civilization. It is not wrong at all to wish for air-conditioned housings for everyone, and maybe with a TV set for entertainment and a music player to enjoy nights. It would be a great idea to make the Internet available to everyone. Every hardworking man and woman deserves a relaxed vacation time. And every single kid on Earth deserves a present from Santa Clause.

But is that all? Does this civilization exist just to materialistically satisfy its inhabitants through the exploitation of the planetary deposit of resources and energy? How do we want to be evaluated by another civilization in the distant future that would excavate and study our remains? In Hitchhiker’s Guide to the Galaxy, it was just two words: “mostly harmless.” Or it might go like this: “The relatively short-lived Civilization 2BiL!u7987 originated from the third planet of the Solar System was thought to be rich enough to supply almost every inhabitant with a personal transportation vehicle, a portable communication device with a characteristically big LCD screen, and access to the global communication network for mainly exchanging their self-promoting images or praising/condemning others.” Is that all that our civilization is meant for?

I hope not. Like every one of us, I think there must be a meaning that this civilization was born on the Pale Blue Dot in the barren vastness of the Cosmos.

The Meaning of Civilization

Then, what would be the meaning of the life of civilization? How can it leave its mark – even just a tiny mark – on the immense time-space of the universe?

It is not an easy question and the answer is certainly not singular. There is a saying that “the wise learn from history” – so let’s look back our history and see if we can get some hints.

In the 10,000 year history of our civilization, there were countless chiefdoms, kingdoms, or empires that rose and fell on the Earth. Like we don’t have a name for every star, most of them are forgotten or even undiscovered. What we have in our history books is a highly sparse and biased sample of fortunate ones. But interestingly, the member states of the prestigious club are not limited to those that are the most prosperous or expansive.

Take, for example, the Nasrid dynasty. It was one of many small Muslim dynasties in the Middle Ages barely survived between the dominant empires of the time, which only claimed a small portion of the Mediterranean coast of Spain from the 13th to 15th centuries. What made this rather insignificant kingdom remembered by history is Alhambra, majestically standing on a hill of the city of Granada. When I visited Alhambra in 2003, I was completely overwhelmed by its beauty. Its inner walls and ceilings are filled with delicately crafted geometric patterns out of marbles, while its courtyard exhibits a harmony of stones, water, and flowers placed in perfect symmetry.

Art, including music, is not merely a consumable entertainment for the contemporaries. It is a tangible representation of philosophies, beliefs, and technologies accumulated and matured through a long span of time in civilization. I think that’s worth it for this civilization to leave behind.

No history book of the world can ignore Ancient Greece. But it was a collection of many competing city-states, or poleis, that usually had insignificant territorial extent, with an exception of the very short-lived empire by Alexander the Great. It was economically highly prosperous, but it is not their material wealth, which was supported by slave labor, that reserved the prestigious position in history for them. It was their philosophy, science, literature, and art. And since many other ancient civilizations also left great philosophies, literature, and art, I think what made Ancient Greece (Athens in particular) truly outstanding was science.

Science is more than a collection of knowledge. It represents the humble recognition of our own ignorance, we well as our desire to learn more. If it is not among the purposes of the species that call itself homo sapience, what else could be?

Among the rich ethnical diversity of humanity, Polynesians are a unique group of people with outsized recognition compared to its relatively small population (2 million or 0.025% of the global population). It is not just because they are the people who welcome rich tourists on tropical islands. It is their amazing voyage. Without a compass or a steam engine, they sailed away from Taiwan about 5000 years ago and traveled tens of thousands of leagues to spread all over the Pacific islands, from Indonesia and Micronesia to Hawaii, Tahiti, Samoa, and eventually to New Zealand. They also sailed across the Indian ocean and reached Madagascar. The difficulty of such voyages would be comparable to modern interplanetary flights. It is simply marvelous.

Voyage is not just a result of expansionist desire or Manifest Destiny. It is also driven by the same curiosity behind science to learn more about the unknown worlds. A milestone of the physical achievements of civilization. I think it is another meaningful item to be remembered.

Art. Science. Voyage. I submit that the meaning of civilization can be found among these uniquely humanistic activities. Of course, there could be more. What do you think the meaning of our civilization is?

How much did we achieve?

How much did we achieve regarding the three items I identified above?

I cannot speak much about art because I am not an expert. Or perhaps no one can because it is simply not possible to estimate how much artistic expressions are not explored yet.

I can say a bit more about science because there are many known unknowns. For example, we don’t know yet how life emerged from the primordial soup, or why and how consciousness arises from a neural network of our physical brain. We haven’t characterized 95% of the energy of the universe. Since we don’t know what it is, we simply call it dark matter and dark energy. And we don’t know yet if we are alone in the universe. We have not found any evidence of extraterrestrial life or intelligence. But as Carl Sagan famously said, the absence of evidence is not the evidence of absence.

What about voyage? Imagine that the Solar System is the size of a baseball stadium (if you are not living in a baseball-loving country, a soccer stadium has a comparable size). On this scale, Earth is just 0.1 mm (0.004 inches) in diameter. And the furthest place that we traveled, the Moon, is only 2 mm (0.08 inches) away. There are a number of uncrewed spacecraft flying across the stadium. But there are only two so far – Voyager 1 and 2 – that went outside.

In terms of science and voyage, our civilization is still Athens before Socrates or Polynesians before setting off from Taiwan.

And I humbly think space exploration is a quest for the meaning of civilization. We fly probes to planets, satellites, and asteroids in the Solar System and beyond to understand how we came into being and search for the sign of life. We launch space telescopes to understand how this universe was born, find out what the remaining 95% is made of, and look for the signature of life or even civilization in the atmosphere of distant exoplanets. We send men and women beyond the Moon to push the boundary of our voyage. I’m sure that is what Archimedes or Hipparchus would do had they lived now. Space exploration is not anything new. It is as old as our civilization because it is merely a continuation of the Great Journey that we started when our ancestors left Africa.

The Final Golden Record

Having said all that I wrote above, there are priorities. The vast majority of GDP must be used for providing the basic needs of people including food, housing, education, health care, and physical security, and for further improving their material life. But at the same time, I think we should use a few percent of our effort to continue the never-ending pursuit of the existential value of ourselves, like art, science, and voyage. (FWIW, NASA’s budget accounts for ~0.1 % of the GDP of the US.)

Of course, some may think there is no such thing as the meaning of life. Likewise, some may argue that it is pointless to even think about the meaning of civilization. I cannot say such an argument is wrong.

But as I ask myself memento mori and struggle for finding the meaning of my life, I think this civilization should also ask itself memento mori.

Imagine what humans would do in the last days of civilization. I think they would build a physical memory device with zettabytes or yottabytes of storage space, write all the art and knowledge humans produced in history, and launch it to the interstellar space with symbolic instruction about how to decode the data, hoping that someday an alien civilization will find it and inherit what we’ve done. Basically the extreme version of Voyager’s Golden Record. What do we want our descendants to write about us? That’s the question that we have to ask.

And going back to my personal goal, I hope my work of lifetime will contribute to a byte or two of the Final Golden Record.