Time Travel (Part 2) Back Through 13 Billion Years
The Fresh Perspective Podcast - Episode 9
How’s it going everyone? I’m Nick and you are listening to the Fresh Perspective Podcast.
Did you get a chance to listen to our last episode about our journey back through 4 Billion years of earth’s history? If not, pause this episode and go check it out. I’ll be sure to leave a link below.
This episode is the second 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 planetary science, astrophysics, and cosmology, as we rewind time at one billion years per minute, with the help of a little imagination.
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Mmmhmm, now that was a good lunch! I noticed you were looking out the window. Are you hoping to see something swimming out there? It’s unlikely, we have already traveled over 4 billion years into the past. As far as we know, our planet is now completely barren. True, there are organic molecules all over the earth, but they’re not quite yet alive.
Did you hear that? It could be an earthquake or volcano. Most likely, the earth has been hit. You see, this far back in time, the space between the planets of the solar system wasn’t quite as empty like it is in our time. There is an awful lot of space junk up there being collected by gravity into anything big close by, like us.
Our time machine is about to surface, and then we can continue our trip back to the beginning of time. To tell you the truth, we aren’t even half way there! Are you ready? Alright, I’ll re-set our speed to travel at about one billion years per minute, or at about 16 million years per second. Our computer will also let us know when we reach each billion-year milestone. Go ahead and pull that lever back!
Our vehicle glows and twists space-time, hurdling us back into the past. We are in the Hadean Eon, looking down, as much of our oceans boil and rumble into clouds of steam. The clouds are reabsorbed into balls of rocky ice, comets, which fly off in all directions, leaving massive craters in the hellish landscape of our infant planet.
We pass through the late heavy bombardment in which the Earth and moon is pelted, non-stop, by asteroids, meteorites, and all kinds of space debris. The moon flies past us, dangerously close to the surface of the earth, spiraling in until it dissolves into countless rocks and globs of earth. For a few seconds, our lava planet has no moon, but has at least a partial set of rings.
At 30 seconds into our journey, the planet shakes and is almost broken in half! Its rings and vaporized-rock atmosphere re-form into its surface and a protoplanet, about the size of mars, which struck the earth! This protoplanet, named “Theia,” flies back into space, re-assuming its doomed spiral toward us.
More evaporated water is pulled back onto the infant world, a red-hot ember of molten rock and radioactive elements. From here, you can almost see the light rocky elements of the crust falling and the heavy metal elements rising, mixing the world up into a liquefied mess as rocks from space continued to bombard it.
We pull back to keep our distance in just enough time to see our world spin faster and faster, flinging its rock, metal, and water out into space. In no time at all, it’s gone. The earth is nothing but a massive cloud of light elements, a dust pile around a new star.
I was so focused on our planet that I missed the formation of Mercury, Venus, Mars, or Jupiter. All the planets, moons, and objects in our solar system have now dissolved into a scattered and dusty gas cloud.
Once we pass 40 seconds back, the light goes out. 99% of the mass of our solar system is no longer condensed by gravity enough for nuclear fusion. The matter around us is no longer compact enough to form a star. In a few more seconds, we drift in the darkness of space, unable to tell that we were once in a system of majestic planets.
If you look down there, you can see the constellation Libra. Below that you can see the stars of the Southern Cross. Between those two is the Centaurus constellation. Do you see the brightest star in the centaur? That is where you can find the Alpha Centauri system of three stars and a planet. Proxima Centauri is the closest star to us, but at about 50 seconds we see it fly further away from us, and then shrink back into its own stellar nursery of gas clouds.
Surrounded mostly by invisible hydrogen and helium in a molecular cloud, we see the stellar siblings of our sun grow closer to us, only to also be snuffed out in the rewinding of time.
5 Billion Years Ago
At this speed you can see some of the constellations slowly contort and become unrecognizable. Some stars in other constellations go out while other remain unchanged. The expansion of the universe is stretching the space between the galaxies, but we are seeing this in reverse. In fact, distant stars and galaxies seem to be rushing closer. Don’t worry, we have plenty of time before they collide with us. They appear to be moving quickly now because we are in the Dark Energy Dominated Era. Pretty soon, the mysterious dark energy that accelerated this expansion will, for some reason, have a weaker effect.
6 Billion Years Ago
From here, you can see the bright center of our galaxy. There is an ancient black hole there, and it usually takes our sun about 225 million years to circle it. At our speed of one-billion-years per minute, we will rotate around the center of the galaxy about every 14 seconds. Our Milky Way has about 100 billion stars, and there are about 125 billion galaxies in the universe, but that number is slowly dropping as we fly through history.
As far as we know, we are the only living things that can see this view out the window. What is so special about the stars and galaxies out there? To be fair, it still looks a lot like something you’d see from the Hubble telescope. Well, we’ve made it half way. We have traveled through half of the age of the universe. In other words, we are half way to the Big Bang!
7 Billion Years Ago
After seven minutes of travel, our milky way is starting to change its size and shape. Many of its stars, including our sun, have gone out, but long dead stars have reignited. Smaller galaxies slowly pull away from it and the Milky Way has begun to shrink. Some parts of our home galaxy house some of the oldest stars in the universe, so we shouldn’t expect it to vanish any time soon.
8 Billion Years Ago
Superclusters begin to break apart into clusters, clusters into groups, and groups into lone galaxies. Neighboring galaxies in our local group are spinning and dissolving into smaller clusters of stars. For the next 6 minutes, you are going to see a lot of that. The universe is expanding in reverse for us, so as it slowly closes in, it is getting easier to spot other galaxies shrinking, splitting apart, and growing dimmer as fewer stars set them apart from the inky black cosmos.
9 Billion Years Ago
The universe is only 4.8 billion years old now, and many of the elemental clouds that would give birth to future stars are collapsing into supernovae, blinding explosions that flash for the briefest instant, only to swell back into super massive stars where most of the heavy elements of the cosmos are cooked.
10 Billion Years Ago
The edges of the universe have again begun to speed up toward us. The universe is only 3.8 billion years old now, and it is getting warmer. Gravity hasn’t had much time to clump all of the galaxies together, so the stars we see are far more spread out compared to what we are used to seeing. To us, our own Milky Way has become unrecognizable, but I am sure there are some experts that could point out some notable features even this far back.
11 Billion Years Ago
Wait, have you been touching any of the controls to the time machine? I haven’t. It seems like we are getting faster. Does time itself warp more dramatically, the closer we get to the big bang? I don’t know, but it is a fascinating thing to consider.
12 Billion Years Ago
It is really dark out there! There are a few stars near us, and there must be countless other stars, but most of them are just too far away for us to see. It was nice when there were bright galaxies, but I can’t even see any of them anymore.
There are plenty of black holes out there. The truth is we could fall into one of the smaller ones at any moment, and we would never see it coming.
Look! Even the oldest stars, quasars, and dwarf galaxies are going out! In a few seconds, we won’t see a thing…
I don’t think I have ever seen anything so dark.
13 Billion Years Ago
Our sensors are picking up a great deal of ultraviolet light. The space around us is quickly heating up into a kind of plasma. Blasts of light come from blinding hyper novae, the death of the very first stars. They were super massive Hydrogen giants. Now that they have reformed we have crossed into a universe ruled by energy, not matter.
The Hydrogen giants weren’t formed by gravity collecting hydrogen gas alone. No, most of the stuff out our window is dark matter, as has always been the case, accelerating the collection of molecules together.
At 13 minutes and 50 seconds into our voyage, even the first black holes are evaporating back into their stellar forms. Matter is spread fairly evenly across the cosmos. We are plunged in darkness yet again. This is fitting, because we have crossed into the Cosmic Dark Age.
At our current speed, it’s not going to stay dark for long.
White light floods our windows, like a searchlight, right into our eyes! No, that isn’t some explosion or star. That is a wave of photons released from the Recombination & Decoupling stage of our universe. The first neutral atoms had just formed, allowing tremendous amounts of energy to fly free in the now transparent cosmos. We can even see this energy back in our own time, as the cosmic microwave background radiation! Just as suddenly as the light arrived, it vanishes.
This is the end of the line for us. I know we wanted to go further, but I have to insist. The universe is only 47,000 years old, but this is as far as we can go. It is getting so hot outside our time machine that atoms are no longer able to hold onto their electrons. In other words, our time machine will soon dissolve into a plasma itself! The universe is now dark and opaque, a dense foggy soup of plasma, like the inside of a star. If we travel much further, we will be ripped apart by antimatter and crushed by the pressure of the universe closing in around us.
There is no time for a debate! Our craft can’t take this heat! Push that button to reverse our course – hurry!
Now that was an adventure.
Now that we are safe back home, I really can’t wait to get my feet back on the ground. I hope you aren’t too disappointed that we couldn’t see the big bang. I suppose that no time-machine, probe, robot, or space craft can really go much further back in time than we did. However, if you would like to perform a thought experiment to see if we can go back to the big bang, and even before it, I do have an episode of this podcast called, “What Happened before the Big Bang?” Why don’t you give it a listen? I bet you’d get a kick out of it.
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