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Life Is Short and the World Will End, Can It Have Meaning?

Life is rendered all the more urgent and purposeful by its evanescence.

 Peera | AdobeStock
Fireflies in the forest.
Source: Peera | AdobeStock

As we hurtle toward a cold and barren cosmos, we must accept that there is no grand design. Particles are not endowed with purpose. There is no final answer hovering in the depths of space awaiting discovery. Instead, certain special collections of particles can think and feel and reflect, and within these subjective worlds, they can create purpose.

—Brian Greene, Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe1

In his sweeping survey of the universe’s origin and ultimate fate, and of humans’ fleeting moment within it, physicist Brian Greene reminds us that any notion that the universe is designed for us, or designed for any purpose at all, is pure human fantasy. Science tells us that self-aware, purposeful collections of particles such as us could in fact have evolved unguided in a fundamentally purposeless universe.

A universe that can only transiently support life

Greene explains why the conditions that are conducive to life emerging and evolving anywhere in the universe are limited to a transient phase in the universe’s existence. Life, and therefore consciousness, is headed for inevitable extinction, due to conditions in the universe eventually progressing to the point where it will simply become physically impossible anywhere to sustain complex matter. Even protons will eventually decay. This will occur trillions of trillions of years from now. But life on Earth will become extinct comparatively soon in cosmic terms when the sun burns out a "mere" five billion years from now. And Homo sapiens is likely to have a still much shorter shelf-life.

Transient complexity in a universe headed toward increasing disorder

Greene talks about the tension between entropy and evolution. The universe tends toward an increasing state of disorder or entropy (dictated by the second law of thermodynamics). So how could complex things form spontaneously, and how could life evolve? The answer is that while the net entropy of the universe as a whole increases, entropy in small local areas of the universe can temporarily decrease, so long as there is a compensatory increase in entropy elsewhere. To drive down entropy in a localized area requires a concentrated source of energy. Concentrated sources of energy exist in the form of stars, which are made possible by gravity.

The concentrated source of energy that is our sun enables entropy on planet Earth to be driven down by biological evolution, which creates order, sculpting highly-organized collections of particles—but only temporarily (for a few billion years). As the Earth’s biosphere takes in high-quality energy from the sun, the planet radiates low-quality energy (dissipated energy—think of it as “used” energy) into space, thereby increasing entropy around it. Entropy can decrease here as long as it increases there. Greene refers to this dance as the “entropic two-step,” which is ultimately made possible in the universe thanks to gravity having concentrated the energy into stars.2, 3

Individual living organisms dance this entropic two-step on a still more localized level, consuming high-quality energy from the sun (via plants and photosynthesis, the energy making its way up the food chain) while expelling waste. This state of affairs can only continue temporarily: living organisms die, and the sun will eventually burn out.


Complexity, life, and consciousness are indeed fleeting, relative to the exceedingly long duration of the existence of the universe. As Greene puts it: “We are ephemeral. We are evanescent.” For those who would despair in our finitude, he adds:

Yet our moment is rare and extraordinary, a recognition that allows us to make life’s impermanence and the scarcity of self-reflective awareness the basis for value and a foundation for gratitude. […] That very same clarity underscores how utterly wondrous it is that a small collection of the universe’s particles can rise up, examine themselves and the reality they inhabit, determine just how transitory they are, and with a flitting burst of activity create beauty, establish connection, and illuminate mystery.4

I’ve discussed elsewhere in this blog series and in more depth in my book many of the ways in which people find purpose and meaning in life and adversity5—especially through connecting with and caring for others. Our human sense of purpose and meaning (and morality) are neither derived from nor dependent on the universe having a purpose, nor on the universe and life continuing to exist indefinitely.

Be careful what you wish for6

Do you really wish for immortality and eternity? Think carefully.

Douglas Adams had a talent for capturing profound philosophical wisdom in witty sci-fi stories. He played with the idea of how our sense of purpose in life might actually be lost if we were immortal. In his novel Life, the Universe and Everything,7 an alien named Wowbagger the Infinitely Prolonged accidentally becomes immortal. As a way of dealing with his boredom and irritation, Wowbagger conceives his purpose thus: to visit everyone in the universe and insult them, one by one, in alphabetical order—just to kill some time!

A universe designed for us

Adams also had this to say about the dangers of our human tendency to think that the universe is designed for us:

Imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact, it fits me staggeringly well, may have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it's still frantically hanging on to the notion that everything's going to be alright because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.8

Death is the price paid to have human consciousness

From a biological point of view, death seems to be a prerequisite for complexity to evolve. The somatic cells of multicellular organisms could probably only have evolved to become as complex and specialized as they are because they are mortal. Somatic cells are the “body” cells—distinct from germ cells (sperm and ova). Whereas germ cells achieve a kind of immortality by propagating the genetic code through sexual reproduction, the body (soma) that carries them and performs the mating can flourish, but then must die. As the biologist Ursula Goodenough explains:

It is because these [somatic] cells [such as neurons] were not committed to the future that they could specialize and cooperate in the construction of this most extraordinary, and most here-and-now, center of my perception and feelings. So our brains, and hence our minds, are destined to die with the rest of the soma. And it is here that we arrive at one of the central ironies of human existence. Which is that our sentient brains are uniquely capable of experiencing deep regret at the prospect of our own death, yet it was the invention of death, the invention of the gene/soma dichotomy, that made possible the existence of our brains […]

Sex without death gets you single-celled algae and fungi; sex with a mortal soma [body] gets you the rest of the eukaryote [complex-celled] creatures. Death is the price paid to have trees and clams and birds and grasshoppers, and death is the price paid to have human consciousness, to be aware of all that shimmering awareness and all that love.9

We are the lucky ones

Each of us is the somatic product of a collection of individual genes that combined in unique ways when one particular ovum was fertilized by one particular sperm.

We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia. Certainly, those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here.

—Richard Dawkins, Unweaving the Rainbow: Science, Delusion and the Appetite for Wonder10

Adams, whose life was sadly so much shorter than his many devoted readers wish it had been, left us with these words:11

The world is a thing of utter inordinate complexity and richness and strangeness that is absolutely awesome. I mean the idea that such complexity can arise not only out of such simplicity but probably absolutely out of nothing, is the most fabulous extraordinary idea. And once you get some kind of inkling of how that might have happened, it’s just wonderful. And . . . the opportunity to spend 70 or 80 years of your life in such a universe is time well spent as far as I am concerned.

Live your life with a sense of feverish urgency.


1. Brian Greene, Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe (New York: Knopf, 2020), p. 325.

2. As the universe expanded over billions of years, uneven patches of higher density of energy/matter coalesced under the influence of gravity to form galaxies, and within these, stars. Energy is highly concentrated in stars because their matter is highly concentrated, and anything in their vicinity, such as planets, is therefore in the presence of an energy gradient (higher energy closer to the star, lower energy further from the star). Wherever such an energy gradient exists, there is the potential for “work” to be done; this is the basic principle of the steam engine, on which the whole field of thermodynamics was established. In the presence of an energy gradient, interesting things can happen spontaneously. Complex things can form and complexity can increase until the energy gradient is finally dissipated when the star burns out, at which time everything will revert to a smooth, sterile state of equilibrium. The earth is currently in a state far from equilibrium, with complexity continuing to grow at an intense pace under the influence of the energy gradient, thanks to the sun. Stars can therefore drive local isolated islands of increasing complexity—transiently, for billions of years. Note that solar systems are temporarily riding a wave of locally reduced entropy (reduced disorder), while the universe as a whole is proceeding toward a state of increasing entropy (increasing disorder).

3. Physicist Sean M. Carroll describes the relationship between entropy and complexity using a different analogy, in his book The Big Picture: On the Origins of Life, Meaning, and the Universe Itself (New York: Dutton, 2016). Carroll compares the transient phase of locally increasing complexity in the increasingly disordered universe to a cup of coffee in which cream has been added. Initially, there is a state of both low entropy and low complexity, as the cream and coffee are still separated with a high concentration gradient between them. Then, as the cream begins to mix in, entropy increases and so does complexity, with interesting complex patterns forming spontaneously in local areas as tendrils of cream reach into the coffee. Entropy continues to increase until the cream eventually mixes smoothly into the coffee, and the complexity of the system then decreases. Within our solar system, we are currently in a local state of transiently increasing complexity, while the universe as a whole is progressing steadily toward increasing entropy. Eventually, this transient complexity will be lost, and all of our universe will end up in a smooth state of high entropy, with all particles dispersed, as a result of the endless expansion of the universe.

4. Until the End of Time, pp. 322-3

5. See also, and

6. Parts of this article are taken from: Ralph Lewis, Finding Purpose in a Godless World: Why We Care Even If The Universe Doesn’t (Amherst, NY: Prometheus Books, 2018).

7. Douglas Adams, Life, the Universe and Everything, 1st UK ed. (London: Pan Books, 1982), chap. 1.

8. Douglas Adams' speech at Digital Biota 2, Cambridge U.K., September 1998

9. Ursula Goodenough, The Sacred Depths of Nature (New York: Oxford University Press, 1998), pp. 149, 151.

10. Richard Dawkins, Unweaving the Rainbow: Science, Delusion and the Appetite for Wonder (Boston: Houghton Mifflin, 1998), chap. 1.

11. From an interview in the documentary Break the Science Barrier, written and presented by Richard Dawkins, aired October 30, 1996, on Channel 4 (UK).