Time Travel (Part 1) Back Through 4 Billion Years
The Fresh Perspective Podcast - Episode 8
How’s it going everyone? I’m Nick and you are listening to the Fresh Perspective Podcast.
When you were young, were you a fan of the magic school bus or Carl Sagan’s ship of the imagination? I’m still a fan, and today, we will be taking a journey on our own makeshift craft to explore the amazing discoveries of science.
This episode is the first part in a series where we will be looking back through the past a few billion years at a time. If you invented a time machine and began to travel backwards, what would you see? How far back could you go? In this episode, we will try to wrap our minds around some paleontology, biology, and geology as we rewind time at one billion years per minute, with the help of a little imagination.
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Picture, if you will, our time machine. It has taken years to design and construct with cutting-edge technology. If we sat inside and began to work the controls, what might we see?
I hope you packed a lunch because we may be gone for a while. I’m powering up the machine now. Many physicists such as Stephen Hawking have deduced that backward time-travel is impossible, given how easy it is to create paradoxes that would prevent your travel in the first place, but we will table a discussion on the physics, mechanisms, and logistics of time travel for some other day. Today, we are going back in time!
That is what you wanted to do today right? Go back as far as we can, maybe to the beginning of the universe? Let’s make it a quick ride, traveling at about 1 billion years a minute, or about 16 million years a second… I’ll program the computer to tell us once we hit each billion-year milestone. You know, at that speed, the techonomic plates below our feet will be moving at about 2,000 miles per hour. Usually, they only move at about 5 cm per year, but like I said, we are trying to make this trip quick. But to be on the safe side, let’s launch into the air to prevent whiplash. Alright, pull the lever to take us backwards. That one, there!
With a stunning spiral of sparks and light, we are flung into history. Quickly, look out the window! We are travelling so fast through time that we can’t distinguish between day and night.
If you blinked, then you just missed literally all of human history. I’m not just talking about World War II, the European Middle Ages, or even the construction of the Egyptian pyramids. Nope, in just one second we have gone back to before humans wrote anything down, before we settled down into farming villages, and even before our ancestors were walking on two legs.
Trees quickly dominate where farms and cities once stood. In just one second into our journey, all humanity has been reduced to a tree-dwelling ancestor in Africa. The Homo genus has not even branched off yet from the tree of life.
Lakes freeze back into massive glaciers and we careen past multiple ice-ages. We pass through the Neogene Period and the world is dominated by long-extinct mammals such as the early ancestors of woolly mammoths, giant sloths, and saber-tooth cats. Grassy fields disappear as the world grows more arid, mountainous, and desert-like.
Two seconds into our journey lands us in the middle of the Paleogene Period. Dense and hot jungles cover the land. The large mammals we saw are shrinking in size, back to their shrew-like ancestors, ruled over by large crocodiles and snakes, and then by large flightless birds. The dominant sharks and whales in the oceans are replaced by unrecognizable monsters.
Four seconds back and the earth is rocked by the K-T meteorite that killed the dinosaurs. For the next 11 seconds, we witness flowering plants vanish, and great herds of triceratops chased by the ancestors of modern birds, the theropods such as Tyrannosaurs, Allosaurus, and raptors. Duck-billed Hadrosaurs and the long-necked Sauropods take-over as the Earth’s continents continue to shift. The dinosaurs shrink in size, back into their reptilian ancestors and the continents of the world clump together into one landmass: Pangea.
About 15 seconds into our journey and the air becomes thick with coal smoke from Siberian volcanic eruptions during what scientists call “The Great Dying.” Less than 5% of all life on earth survived this, including our reptilian-like synapsid ancestor that descended from the lumbering Dimetrodon, with the sail on its back.
20 Seconds have passed and we are in the Carboniferous Period where the earth is a hot swamp planet with high levels of oxygen and massive insects! Dragon-flies the size of eagles and millipedes the size of alligators lurk below.
22 seconds and we can see that fish-like creatures are starting to live on land, such as Tiktaalik! In the Devonian and Silurian Periods, the real party is in the ocean as the massive varieties of fish and arthropods like scorpions coagulate back into just a handful of ancestral species. We see the first land plants and fungi recede.
Earth’s 2nd most devastating extinction event can be seen at 27 seconds, in which the earth enters a deep freeze. Before it, in the Ordovician Period, we see the first fish and cephalopods like squids evolve. We are now far enough back that Trilobites ruled the world!
One half minute into our journey back in time plants us in the Cambrian period, in which the oceans saw an explosion of the first large animals in astonishing variety, each looking more alien than the next! For another second, sponges, mollusks, choral, worms, sea snails, arthropods, all devolve back into simpler colonies of cells.
33 seconds back takes us into the Precambrian Neoproterozoic Era of the earth. Ediacarans are the first animals, swimming in a cooling and less oxygenated ocean as ice sheets spread over the earth. They were soft-bodied, and look more to me like a liver than an animal. The next few seconds take us to even earlier forms of life, but these have left almost no traces in our fossil record.
1 Billion Years Ago
In just over a minute and we have covered more than 100 million years of earth history! We have reached the Mesoproterozoic Era, a time in which our oldest rock layers formed that still exist today. Life is almost entirely single-celled organisms, now playing with something that gives them a new evolutionary advantage: sexual reproduction.
Now at 1 minute and 40 seconds, life has resorted back to asexual reproduction. In other words, if single-celled organisms want to reproduce, they just split and half to make two sister cells.
We now slip into the longest geological age of the earth: The Paleoproterozoic Era. The earliest forms of our planet’s continents stabilize. The days are only 20 hours long, and the first Eukaryotic Cells have emerged. These microbes are your direct ancestors. Can you see the family resemblance? They may be humble, but these cells are survivors.
2 Billion Years Ago
A massive increase in oxygen has killed off almost all life on earth. Only the single-celled organisms that can survive in this newly toxic atmosphere will be able to reproduce. Rolling time back allows us to see where all this oxygen came from. It was a byproduct of mostly cyanobacteria, capitalizing on a new invention: photosynthesis.
3 Billion Years Ago
Our journey has brought us to the Archean Eon. The earth begins to get warmer, and the rock of the earth’s surface is destabilizing into lava and magma. The entire planet was three times warmer than it is today, but many rock formations from this age have actually survived to present times.
At about three minutes and 45 seconds, we run into a humble cell floating in the ocean. She is something special compared to all of her doomed peers. We call her “LUCA” because she is the Last Universal Common Ancestor of all life on earth. You, your dog, the bacteria, bees, and flowers outside, all carry with them an evolved form of LUCA’s fortuitous collection of some 355 genes.
4 Billion Years Ago
It is a good thing we are in a time machine, because you can’t breathe out there. Almost no oxygen exists in earth’s atmosphere. It is a red and black wasteland of volcanoes, lightning storms, and oceans. We are now at about four minutes into our trip. We’ll pause here.
It’s time to take a closer look under that murky ocean. As we take a trip down into the archaic depths, we quickly find underwater volcanoes, spewing chemical rich gasses into the icy-cold depths. Our scanners are picking up something that just sent shivers down my back. Chemistry, just became biochemistry. The first forms of RNA have replicated themselves, which means that the electromagnetic interactions between atoms and molecules just handed the running of life over to the forces of natural selection.
In other words, life as we know it has been on the earth for about four billion years!
Deep in this dark ocean, this seems like a good place to take a break! Did you have a chance to grab a lunch? We’ll stop here between the Hadean Eon and the Archean Eon. In our next episode, we’ll see if we can go back a few more billion years, back to get beginning of the universe itself!
That is all I have for you today, but the conversation continues across social media and in the comment sections below. Do you agree with today’s message? Am I mistaken about some detail? How can I better elaborate on this topic in the future? Feel free to share your perspective!
Written By Nicholas Burk, Executive Board Member © 2019 Free Thought Initiative