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Statistics tell us that anything is most likely in the middle of its lifespan, and the human species is no exception.
For young scientists looking for targets in their own research, I recommend that they engage in a socially relevant research, such as mitigating climate change, accelerating vaccine development, meeting our energy or food needs, building long-term bases in space, or searching for technological remnants of extraterrestrial civilizations. Broadly speaking, society provides funding for scientific research, and scientists should also repay society by focusing on the public interest.
The most important social challenge is to prolong the existence of human civilization. In a recent speech to Harvard alumni, I was asked how long I thought human technological civilization would survive. Astrophysicist Richard Gott thinks we usually find ourselves in the middle of life, and my answer is based on this fact. The probability that a person is a newborn baby is tens of thousands of times smaller than the probability of being an adult. Similarly, if the fledgling age of technology continues for millions of years, it is impossible for humanity to perish after just one century. It's more like we're witnessing the adulthood of human technology, where humans may exist for centuries, but not for long. After making this statistical conclusion public, I realized how terrible this prediction was. But is such a fate really unavoidable?
In fact, there is a glimmer of hope behind this. There is also the possibility that because humans have free will, we will be able to plan the lives of our descendants centuries in advance in response to deteriorating circumstances. Technological catastrophes related to climate change and war pose a threat to humanity, but smart public policies can reduce these risks.
It is unclear whether our policymakers will respond to the challenges ahead and insulate us from the above statistical conclusions. Humans are not good at coping with unprecedented risks, as evidenced by the politics associated with climate change.
This brings us back to the fatalistic point of view. The Standard Model theory of physics assumes that we are all made up of elementary particles and have no other components. And because all particles and their interactions follow the laws of physics, as such a composite system, we are not inherently free. From this perspective, "free will" as we understand it encompasses only the uncertainties associated with human activity. These uncertainties can be quite large on an individual scale, but tend to be averaged in a large sample. On an individual level, humans and their complex interactions can free us from predictability, but perhaps the shaping of the fate of human civilization as a whole in the past has not escaped statistics.
To predict how much time our technological civilization has left, you can investigate the statistics of some civilizations similar to ours to understand their origins and ends. These civilizations were born before us and are bound by similar laws of physics. Most stars formed billions of years before the Sun, and may already have technological civilizations on their habitable planets, though these civilizations are now extinct. If we have historical data on the lifespan of civilizations, we can calculate the likelihood that our civilization will survive at different times. This approach is similar to calibrating the likelihood of decay of radioactive atoms based on a large record of the behavior of a large number of similar atoms. In principle, we can collect relevant data through space archaeology and searching the sky for the remains of a demise technological civilization. This provides the assumption that the fate of human civilization depends on physical constraints.
However, once faced with the problem of the distribution of survival probabilities, the will of the person may choose to ignore all possibilities and behave like a statistical outlier. For example, if some people choose to leave Earth, the chances of human civilization continuing increase. Currently, all the eggs are still in the same basket. Exploring space protects our civilization from ending up with the destruction of Earth. While Earth is a comfortable home for now, we will eventually be forced to relocate because the sun will burn all the liquid water on the Earth's surface in 1 billion years. The establishment of multiple human communities in other worlds, like Gutenberg's printing of the Bible around 1455, avoided the loss of precious content due to a catastrophe.
Of course, even a short trip from Earth to Mars can pose serious harms to human health, which can come from cosmic rays, high-energy solar particles, ultraviolet radiation, a lack of a breathable atmosphere, and a low-gravity environment. Overcoming the difficulty of settling on Mars will also improve our ability to identify habitable planets based on our own experience. Despite this assumption, know that the challenges on Earth are likely to prevent humanity from looking at space travel with a bolder eye. Some may feel that there are enough problems on Earth: "The cause of space doesn't meet our most pressing needs on Earth, so why waste precious time and money on it?"
Before accepting this premise, we should recognize that in the long run, a strict focus on worldly goals does not provide us with more of the necessary skills when circumstances are constantly changing. One may limit their attention to temporary issues. But history tells us that these troubles will eventually become irrelevant, such as "How do we remove the ever-increasing horse dung from city streets" before the invention of the automobile or "how to build a huge network of landline lines" before the invention of the mobile phone.
To be sure, it's imperative to focus on local issues, but we also need inspiration to take a bigger view of things in order to further broaden our horizons. Resting on our laurels can plunge us into conflict because it amplifies differences and problems of limited resources. A broader perspective facilitates collaborative approaches to global challenges. There is nothing better suited to this view than science, a "game of infinity" that can extend human lifespan. As Oscar Wilde (irish writer) put it, "We all live in the gutters, but there are still people looking up at the stars." "Hopefully more people will look up at the stars, because it will give us more inspiration, rather than pushing more people into the fatalistic camp like statistical predictions."
Written by | Abraham Loeb
Translated | Zhang Naixin
Reviewer | Wang Yu
About the Author: Abraham Lob is the former chair of the Department of Astronomy at Harvard University and director of the Institute for Theory and Computing at the Harvard and Smithsonian Center for Astrophysics.
Original link:
https://www.scientificamerican.com/article/how-much-time-does-humanity-have-left/