## Big numbers 13.8 billion years have passed, but the universe is probably just getting started. The first stars formed 13.2 billion years ago, and most of the heavier elements—those that make up your body and most of what surrounds you—were formed in huge explosions as these stars burned out. Planet Earth is quite big. But you could fit 1.3 million Earth-size volumes inside the Sun. The Sun is one of 250 billion stars in the Milky Way galaxy. The Milky Way is one of at least 200 billion galaxies in the observable universe. The observable universe may be just a small part of what is out there.  When you look at the night sky, the stars you can see are just a tiny fraction of those in the Milky Way.  The Earth has been around 4.5 billion years. Life on Earth has been going for at least 3.77 billion years. Multicellular life emerged about a billion years ago, and our [tetrapod ancestor](https://www.reddit.com/r/HistoryMemes/comments/bgta7s/thanks_land/) crawled out of the sea about 500 million years ago. (Want to get a better sense of how big these numbers are? See [here](https://waitbutwhy.com/2014/11/from-1-to-1000000.html).) The Agricultural Revolution took place about 10,000 years ago, we began writing 5000 years ago, and the major world religions emerged some 60-90 human generations ago. About 200 years ago, Darwin developed the theory of natural selection. With that, we learnt that we are survival machines—robot vehicles blindly programmed by the forces of nature to preserve the self-replicating molecules known as genes (c.f. [[Richard Dawkin]). <!-- Around the same time, [[Non-religious ethics]] began in earnest. [[Friedrich Nietzsche]]: > At last the horizon appears free to us again, even granted that it is not bright; at last our ships may venture out again, venture out to face any danger; all the daring of the lover of knowledge is permitted again; the sea, our sea, lies open again; perhaps there has never yet been such an ‘open sea’. --> About [108 billion](https://www.prb.org/howmanypeoplehaveeverlivedonearth/) humans have lived so far. People alive today have enjoyed and endured [15%](https://www.lesswrong.com/posts/SwBEJapZNzWFifLN6/the-funnel-of-human-experience) of all the human experience there has ever been. In terms of material wealth, we are among the most fortunate people to have lived. Our access to knowledge and information is without precedent, so too is our access to food, shelter, comfort. I am writing this from a small village in England. Hmm. ## Things are changing If you look at world population and GDP over the last 12,000 years, you’ll see that the rate of change was slow, then modest, and then...     The rapid recent growth was caused by the [Industrial Revolution](https://en.wikipedia.org/wiki/Industrial_Revolution), a period where a lot of hand production methods were replaced with machines. David Roodman [notes](https://www.openphilanthropy.org/blog/modeling-human-trajectory): > The human economy has grown super-exponentially. The bigger it has gotten, the faster it has doubled, on average. The global economy churned out $74 trillion in goods and services in 2019, twice as much as in 2000. Such a quick doubling was unthinkable in the Middle Ages and ancient times. Perhaps our earliest doublings took millennia. Hmm. ## What’s next? Well, a typical species lasts for about a million years. Humans are not a typical species. [We might destroy ourselves](https://nickbostrom.com/papers/vulnerable.pdf) sometime soon. If we avoid that and spread into space, the "earth-originating life" party could continue for millions or perhaps billions of years. [Digital minds are coming soon](https://arxiv.org/abs/2303.12712). We may be just at the start of something very, very, very big.  <!-- Roodman again: > Any system whose rate of growth rises with its size is inherently unstable. The human future might be one of explosion, perhaps an economic upwelling that eclipses the industrial revolution as thoroughly as it eclipsed the agricultural revolution. Or the future could be one of implosion, in which environmental thresholds are crossed or the creative process that drives growth runs amok, as in an AI dystopia. > > […] > > The range of possible futures is wide. So it is our task as citizens and funders, at this moment of potential leverage, to lower the odds of bad paths and raise the odds of good ones. Hmm. ## What’s after that? [Brian Cox](https://www.youtube.com/watch?v=uD4izuDMUQA): > Life as we know it is only possible for 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000001% of the lifespan of the Universe (as measured from the Big Bang until the evaporation of the last black hole). Hmm.  -->