By the beginning of the 20th century, humanity was on the verge of many new discoveries that would completely alter our perception of the Universe.
Host | Matthew S Williams
On ITSPmagazine 👉 https://itspmagazine.com/itspmagazine-podcast-radio-hosts/matthew-s-williams
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Episode Description
By the beginning of the 20th century, humanity was on the verge of many new discoveries that would completely alter our perception of the Universe.
Between Relativity, Quantum Physics, Dark Matter, Dark Energy, Black Holes, and new revelations on the size and age of the Universe, our models of the Universe have been revised repeatedly!
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For more podcast Stories from Space with Matthew S Williams, visit: https://itspmagazine.com/stories-from-space-podcast
The History of Cosmology (Part II)
The authors acknowledge that this podcast was recorded on the traditional unseeded lands of the Lekwungen Peoples.
Welcome back to stories from space. I'm your host, Matt Williams. Today we're going to pick up where we left off last time with the history of cosmology.
So to recap what we covered last time, we saw how from the ancient world through classical antiquity in the Middle Ages, right on up to the scientific revolution, our concept of the universe - it grew by several orders of magnitude, it changed immensely.
We went from believing that the world was a flat surface or something held up by pillars, ziggurats, a box-shaped object, depending upon the cosmological tradition you're referring to, to a sphere adrift in space orbited by other spheres, in one great big system governed by universal laws.
And by the time of Copernicus, we had come to learn at last that the Earth was not the center of it all that the sun was. And from there, we then learned that our Sun was merely one of millions and then billions of suns that were adrift in our galaxy.
And where we left off, in the 19th century, humanity was now on the verge of realizing that our galaxy was one of countless galaxies in the Universe.
And thanks to Einstein, we're on the verge of another major breakthrough where he, like his predecessors, Copernicus, Newton, and Galileo, synthesized so much knowledge that had been accumulated up until that point to show how it all fit together.
And this would come in the form of his theories of Relativity, which represented a significant challenge to Newtonian mechanics, which had remained Canon for about 200 years, but by the 19th and early 20th centuries, we're running into a lot of problems.
Now to break it down, Classical Newtonian mechanics essentially stated that the laws of physics were the same in all inertial reference frames, that time and space were both absolute and separate.
And it described gravity as an action at a distance, where two objects with mass will feel a gravitational attraction to each other, the strength of which is determined by the mass and the distance. But it is felt instantaneously between the two regardless of distance.
Another key factor in Newton's model of the universe was the idea of Relativity. And contrary to what many suspect, or have been led to believe, it was Galileo who originally proposed this term, and it was his way of explaining how motion and velocity were actually relative to the observer based on their own moving reference frame.
And this explains how an observer on Earth, being unaware that they are moving, will think that other objects that appear to be moving around them, that they alone are moving, and they (the observer) and the planet they're standing on is standing still.
But as Copernicus and Galileo further demonstrated, Earth is moving its rotation is why the stars are passing through the night sky. And our motion relative to the other planets is why they have the appearance of retrograde motion, or they appear to be speeding up and slowing down during certain times of the year.
And Galileo liked to illustrate this with his ship at sea metaphor. If you're on the deck of a ship, and it's moving along at a consistent speed, you won't be aware that you are moving. If you drop a ball on the deck, it falls straight down relative to you. If you drop the ball off the side of the deck, though, from a person who's standing on the shore, it will look like the ball is falling in an arc or a parabola - meaning that it's still traveling forward as it's falling down.
And if the person on the ship or on the shore, if it were pitch-black, and they could only see each other because they're both holding a lantern, and the person on the ship didn't even know they're on the ship. As far as they could tell, the person on the shore holding the light would be the one that was moving and they were the one standing still.
But by the 20th century, problems began to emerge in this as astronomers were looking farther and farther beyond the Solar System and learning the true extent of the Milky Way and the fact that there are other galaxies. And even within the solar system itself, Newton's theories of gravity began to encounter problems.
Similarly, Newton's theories could not explain electromagnetic behavior. Scientists had learned at this point by measuring electric current that electricity and magnetism were a single phenomenon - hence the term electromagnetism.
They also learned that light was an electromagnetic phenomenon and that light itself may not be a wave, but it may be composed of particles. Particles that behaved in packets of energy rather than a consistent stream. And this gave rise to the term quanta.
And they’d even measured the speed of light and determined that it was the same as electromagnetic phenomenon, roughly 300 million meters per second, so extremely fast. They'd also learned at this point that this was an absolute. Nothing in nature moved fast as light did.
However, all evidence still suggested that when measuring light, measuring its propagation through space, it behaved like a wave.
And one thing that did not make sense as far as their experiments were concerned was its speed was constant. It didn't matter if the light source you were looking at was moving toward you, or moving away from you, the speed remained the same as measured by the observer.
Now this contradicted Relativity because Relativity essentially stated that if a distant object is moving, the time that it takes for the light to reach you your whole perception of their velocity, it should be affected.
If the object is getting closer, the light appears to be moving faster. If it's getting farther away, it appears to be moving slower. And why? Because it's taking longer to reach you.
And yet all the experiments said this does not apply. light reaches the observer, regardless of the motion of the source, regardless of the motion of the observer, no matter what. So scientists were hard-pressed to explain this, and they began looking for explanations in the form of space itself. They said:
“If light is, in fact, a wave - and that's certainly how it seems to behave most of the time - and it's traveling through space, then it needs a medium to propagate through. Maybe that medium, the aether of space (or the “luminiferous aether,” as they called it) maybe it is speeding light up or slowing it down. And we need to measure that influence if we can figure out how the ether works. And we can explain all this in our physical cosmological models, they'll all make sense.”
Unfortunately, all the experiments failed to find any influence of an aether. And in 1905, Einstein would come along and offer an explanation. He managed to synthesize a lot of other theories, a lot of other experimental results, and basically said:
“The experiments are correct, the data is accurate. What we're looking at here is not an effect of space, but perhaps time.”
And this was based in part on Lorentz transformations or the work of Dutch physicist Henrik Lorentz. Curiously, Lorentz was also looking at something that Galileo had done pioneering work in, which was the concept of Galilean Transformation.
Basically, this transformation, it describes how objects moving through space are also moving through time. But it has within it this presumption that the experience of the passage of time is the same for every observer everywhere. And that motion is what is relative. That, whereas two objects can be moving in different directions and therefore perceive each other's motion as different than how would look if one of them were in a resting frame, their experience of time is identical.
However, Lorentz transformations began to consider how in an accelerating reference frame, two objects can have different perceptions of time. And that how, in that accelerating reference frame, things get sort of compacted along the line of travel or in the direction of travel.
And this specifically applied in his Lorentz transformations to the behavior of lights. Einstein was able to resolve and synthesize all this with his field equations. And as always, his use of very helpful, clear metaphors. Much like Galileo had done with his ship, Einstein use the example of a train.
Now if a person on a train is holding a series of mirrors, and light is bouncing up and down, say in a vertical direction for this person. If they could slow the passage of time to the point where they could see the photons themselves moving, they would see these photons bouncing up and down at a consistent speed of 300 million meters per second.
Now, to an observer who's watching this train go by, they would see the light bouncing up and down, yes. But the forward motion would mean that the light looked like it was moving in a zigzag pattern. But this is not possible from the point of view of the person on the train, the light is bouncing back and forth instantaneously.
So if the mirrors are moving and the light has to zigzag to keep up with them, something has to give. There has to be something that allows the light to catch up for both of these observers to both obtain the same results.
And this, Einstein explained, “Well, if they could check their watches, the observer on the train would notice that his watch was running just a little bit slower than the person observing from the field beside the tracks.
In short, the speed of light as Einstein would then say, is the same in all inertial reference frames. Regardless of the observer and their relative motion, the speed of light does not change our perception of time does.
If you put it another way, let's use two spaceships. If they're both in space, traveling towards the same star, but one of them is moving at a very slow velocity consistently, while the other is accelerating towards the speed of light. And they get up to say, a fraction of the speed of light.
Now, they will both record the exact same speed from that oncoming light, there'll be no difference. But the spacecraft that's accelerating, they're going to notice that the amount of time that has passed for them relative to the other ship was shorter.
But because energy is never lost in the system, Einstein began looking at this in its equation form. And he thought, “Well, if time is lost in this accelerating reference frame, then that seems like a loss of energy too.”
So if we plot E energy, and using the same Newtonian formula for calculating force: mass times acceleration - he said E equals mass times acceleration towards the speed of light. So E=mc2.
And there were a number of consequences to this, because it showed that for objects approaching the speed of light, their mass, their feeling of mass, their inertial mass, will get heavier as they approach it. And so it takes more and more energy to accelerate them further.
And the speed of light cannot be reached or passed, because it would take infinite energy to do that. And by the time they reached it, the object would have achieved infinite mass. And this is physically impossible. So it all seemed to balance out.
But another very cool consequence of this was scientists were looking at it and they said, “Now hold on, if you just swap around some of these parameters, it all works out the same. So energy and mass here are interchangeable in this equation, which means that there is equivalency between energy and mass.”
And it's there in argued this in the form of the Mass-Energy Equivalence. Basically, mass is just stable energy. Another very interesting consequence was he was also basically asserting that time and space were equivalent, there were separate expressions of the same thing.
So whereas in Newtonian physics, time and space were absolutes and separate, Einstein demonstrated that they are, in fact, part of the same reality. They are not absolute, they are relative to the observer.
So instead of space coming down to three dimensions (X, Y, and Z), and time as a separate dimension (T), spacetime; it can be described as four-dimensional. So physicists immediately were drawn to this theory, which Einstein called his Special Theory of Relativity.
Because it not only meant that their observations and the experimental results they got were correct, there was no strange mystery or missing aether in order to explain their observations. It also resolved classical Newtonian mechanics with Maxwell's equations of electrodynamics.
And so for the next 10 years, Einstein would expand on this, and he would put the finishing touches on it by about 1915/1916, because he wanted to account for gravity as well. Which, as I said, scientists were beginning to have some troubles with.
So from his Special Relativity paper, he drew a lesson that maybe Newton was wrong. He described gravity as an action at a distance and an instantaneous one. But special relativity demonstrated that nothing in the universe is instantaneous. It travels at a limited speed, the speed of light. Still extremely fast, but over cosmic distances. It takes his time.
And so he began rethinking gravity. First of all, Enstein took a page from all the recent developments in the field of electromagnetism, and he considered whether or not gravity was in fact a field. There wasn't a direct pull by objects, but rather something that was generated locally by objects with mass.
Second, he began looking into how gravity and acceleration were likely related. Because as scientists had come to realize, at this point, there really is no distinction between gravity and acceleration.
So for an accelerating object, anybody inside that object, they're going to feel a push, the moment you accelerate, you get pushed back in the opposite direction of travel. And for this, Einstein used a really brilliant metaphor, the elevator.
So if you're standing in an elevator, and it's perfectly still, you feel no sense of motion. When it starts to move, you'll feel a bit of a jolt depending on the direction you're going. But as the elevator achieves a consistent speed, you'll no longer be aware that you're moving, you'll feel
just comfortable, and you'll see the numbers changing. But if they weren't there, you'd have no way of knowing.
On the other hand, if someone were to cut the cable of that elevator, you'd begin to fall very quickly, and you'd feel weightless because gravity is now pulling you down very, very fast. And for the person inside the elevator, that cancels out the sensation of gravity, you're now basically in freefall as this elevator is hurtling to the ground.
And as Einstein demonstrated with Special Relativity, acceleration alters the perception of time. So Einstein began to wonder if gravity was not an action at a distance, but a local action, something that is imparted by massive objects on spacetime around them.
And so if we were to visualize it, if we were to look at spacetime as a two-dimensional plane or a flat sheet, then wherever there's a massive object, like a planet, or a moon or star, you then have a sort of dimple effect in the surrounding spacetime.
So the curvature of space-time is altered by the presence of a large gravitational field caused by massive objects. And for objects that fall into this field, their perception of time is altered because gravity is imparting acceleration on them, it's causing them to speed up.
And furthermore, that in and around this bent spacetime, anything that is falling towards it, it will be tracing the curvature of that spacetime. And so when he applied this and the necessary mathematics to the Universe, suddenly all the observations that didn't match with Newtonian physics made sense.
In particular, Mercury's orbit around the sun, scientists noted that Newtonian mechanics don't account for its long-term orbit. But if we apply Einstein's theory, which was now known as General Relativity, then it does, it works out.
It comes down to the fact that gravity is pretty much as Newton described it there. It's a force, it's calculable, it's dependent upon mass. But it is not instantaneous. And it's not just two objects pulling at each other. It's objects altering the very fabric of spacetime around them.
And Einstein summarize this by saying that “matter tells spacetime how to curve, curved space, time tells matter how to behave. And since 1915, General Relativity has been tested nine ways from Sunday, and it was always verified.
Astronomers have noticed that if you observe large, massive objects in space, then objects that are behind them that should be obscured by them, you can actually see the light coming from them because it traces the curvature of that spacetime, and appears as if it's next to these massive objects.
In fact, there's several terms for this depending upon how the light appears. It can be known as an Einstein Ring, an Einstein Cross, which are all different types of gravitational lenses. Another key test that proved that Einstein was correct was the use of atomic clocks and space.
These clocks would be perfectly synchronized and coordinated with clocks down on Earth. They'd then be sent to orbits, to varying degrees of orbit, greater and greater distances from the planet. And then their operators would compare what time they had, and they noted that clocks on Earth run faster than clocks in space. And the further away they are from Earth, the faster they will run.
However, General Relativity when ended up having some very serious implications, which Einstein wasn't too fond of. Beginning in 1917, there was what was known as the Great Debate between astronomers, cosmologists, and astrophysicists about the structure of the universe.
This coincided with the fact that astronomers were once again looking at what were thought to be nebulas within our Milky Way, and we're suggesting that they were in fact galaxies beyond it, and that the Milky Way was merely one of several galaxies in the Universe.
And improved telescopes allowed for astronomers to confirm this for the first time. Between 1923 in 1924, famed astronomer Edwin Hubble, he used Cepheid variables, which are stars that change in brightness over time, and this characteristic has allowed astronomers to use them to measure cosmic distances.
Now Hubble identified several of these types of stars in the Andromeda Galaxy and the distance measurements he got confirmed that they were positioned far beyond the edge of the Milky Way. Therefore, they couldn't be nebulous within our galaxy, they were other galaxies beyond it.
Another important aspect of the Great Debate was if Einstein's theories were to be believed, then the Universe would need to be in a state of recession. All this gravity of all these massive objects would be pulling everything closer and closer together until it eventually went crunch.
\And the fact that there was no indication that that was happening meant that there must be something else at work. And Einstein proposed a theory, which was the Cosmological Constant. And this was the idea that there was a force in the universe that acted against gravity, and kept everything in a static stable state.
And whereas some physicists, including Einstein himself, argued for this Steady State model of the cosmos, others speculated that depending on the value of the Cosmological Constant, the Universe could in fact be expanding.
And between 1927 and 1929, both Edward Lemaitre and Edwin Hubble made a key discovery that settled that debate. Using spectrometers, they were able to measure the wavelengths of light coming from distant galaxies.
And what they noticed was that those closest to us, the light coming from them was shifted towards the blue end of the spectrum, whereas with all other galaxies beyond a certain distance, any galaxy that was not closest to our own, the light coming from them was redshifted.
And in accordance with Special Relativity, light does not speed up or slow down, depending upon the motion of the source. But if the space between the source and the observer is expanding, then the wavelength of light itself will expand.
And this is what happens with redshift. Red light, it has a longer wavelength than blue light, and so objects moving away will be redshifted. Those moving closer to us will be blue shifted.
And this gave rise to what's known as Hubble's Law or the Hubble-Lemaitre Law, which states that the Universe is in a state of expansion. Einstein initially didn't like this idea. But when Hubble invited him to his observatory and showed him firsthand that the redshift measurements didn't lie, Einstein dropped the Cosmological Constant and said, “biggest mistake of my career.”
However, the important takeaway was, the Universe is in fact expanding. And from that, Lemaitre proposed that, “Well, if the universe is expanding outwards, at some point, it had to have been in a much smaller volume of space. And if we traced that backwards, it would mean that the universe began from a single point.”
And this is where the camps really began to form. Because now you had people on one side, arguing that the universe began from a single point in space and time, where all matter and energy were compressed down to a single point and then from there, began expanding outwards; and those who believed that the Universe was in a Steady State, with new galaxies and stars being created all the time.
And the former theory was derisively named The Big Bang Theory. And even though it was meant to be a joke, the name stuck. And Lemaitre himself was accused of letting his own religious feelings because he was. in fact, a priest as well as a physicist. He was accused of letting these intrude on his scientific theories.
But by the 1960s, the discovery of the Cosmic Microwave Background ended that debate. And the reason for that is because scientists knew that if the universe began from an initial point in space that was really tiny and dense, and then exploded outwards and began expanding, there would be some kind of relic radiation, primordial light somewhere out there.
And its distance from us, the observers, would correspond to the age of the universe because it's traveling at the speed of light. If the universe has been around for umpteen billion years, we would see this relic radiation umpteen billion light-years away. And that's precisely what happened with the cosmic microwave background.
By the 1960s, microwave telescopes, they detected a faint persistent background hum. Which once they were able to resolve it, they noted that yes, there is microwave energy at a distance of roughly 14 billion years in all directions from us. And the reason it appears in the microwave spectrum is because that light, it's been so redshifted, over time, because of the expansion of the Universe, is no longer visible to us.
This not only settled the debate largely between the Steady State Hypothesis in the Big Bang Theory, but it also led to increasingly accurate ages of the Universe. Today, astronomers have constrained it to 13 point 8 billion years, plus or minus a few 100 eons. And that's based on increasingly accurate resolutions of the cosmic microwave background.
So another thing that was taking place during the 1960s, it was known as the “Golden Age of General Relativity.” At this point, astronomers had instruments sophisticated enough to see countless galaxies, and not just in optical telescopes, but in non-visible wavelengths, like the radio spectrum, the microwave spectrum, the ultraviolet and X-ray spectrum. And they were able to test General Relativity at this point at the largest of scales.
And this is when problems began because astronomers noted when they were observing the rotational curves of other galaxies. Basically, they said these galaxies are moving too fast, and the effect they have on light that is bending around them, around their massive bodies, it's greater than anything suggested by what we can see. There's not enough visible matter there to account for their behavior.
And so this led to General Relativity being seriously questioned. And given that General Relativity has to this day been confirmed nine ways from Sunday, astronomers began to speculate that, in addition to visible matter that we see - which is either emitting light or reflecting it, absorbing it, radiating it - that there must be some mysterious invisible mass out there as well.
And this gave rise to the term Dark Matter. And according to their calculations, astrophysicists estimated that dark matter must account for 85% of the matter in the known Universe. So once again, the predominantly held cosmological models of the Universe, they shed their skin and they began to incorporate new theories, new ideas.
In this particular case, it was that if Dark Matter exists today, well, it must have always been there. Because it's a key part of gravitation, it must have played a role in galactic evolution. Today, scientists believe that, in fact, Dark Matter was there from the very beginning.
And it played a key role in the formation of the earliest galaxies. And it's gone on to do so ever since it forms the halo which caused all the neutral hydrogen in the early Universe to fall in, collapse, and form the first stars that gathered together to form the first galaxies. And over time, this is held galaxies together.
And another very interesting discovery that happened about a decade later. It was the realization that the massive radio source that was coming from the center of our galaxy, which was known as Sagittarius A with a little star affixed to it, that this massive radio source could actually be a supermassive black hole.
This was another benefit of the “Golden Age of General Relativity,” scientists were able to confirm the presence of black holes, which had been proposed in the early 20th century as an interpretation of Einstein's field equations.
Basically, scientists speculated that there could be an object so massive that the effect it had on spacetime, that would alter the curvature of space-time to the point of infinity, at which point this pocket of spacetime, time would stop.
And this would be the result of massive stars undergoing gravitational collapse at the end of their lives. But instead of going supernova, shedding off their outer layers and becoming a white dwarf, they instead would collapse to form a black hole.
And now by the 1970s and thereafter, astronomers and astrophysicists now had evidence that at the center of all major galaxies, there are supermassive black holes. Which also would have been there during the early Universe, gradually growing over time. And this, too, would have had an effect on galactic evolution.
Well, as if that wasn't confusing and challenging enough. By the 1990s, Hubble took to space and began taking the deepest images of the universe yet. And part of its mission was to investigate the mystery of Dark Matter, of General Relativity, on the largest of scales, and to really discern how the Universe evolved ever since the Big Bang.
Prior to Hubble, astronomers had been limited in what they could see, they could only really see a few billion years back in time, but with Hubble and the Deep Fields, and then the Ultra-Deep Fields, we not only got a much better idea of just how many galaxies there are out there, which at the time was estimated to 200 billion.
But scientists also noted another curious phenomenon that indicated that perhaps our notions of gravity were wrong. And that is the fact that during the past 4 billion years, the Universe has been expanding at an accelerating rate.
And pushing the boundaries of astrophysics, looking back as early as we possibly can, scientists noted that immediately after the Big Bang, there was an expansion, which seemed to slow and then began to pick up speed again. And from that point onward, it seemed relatively consistent, the universe was expanding at a relatively consistent rate. Faster than the speed of light, yes, but it didn't appear to be picking up speed.
Whereas roughly 10 billion years after the Big Bang, suddenly it started moving faster. And so this led to speculation that in addition to there being a mysterious form of mass out there that we couldn't account for, there was also a mysterious energy.
This gave rise to the notion of Dark Energy. And according to current theories and calculations, it's estimated that roughly 72% of the total mass-energy density of the Universe is made up of Dark Energy. That's opposed to mass alone.
In the same scheme, Dark Matter makes up 23%, whereas visible or normal matter, makes up only 4.6. And so this has led to yet another debate in which General Relativity is either wrong, giving rise to alternative forms of gravity - such as modified Newtonian dynamics (or MOND) - or that Einstein was actually correct with his theory of the Cosmological Constant.
And those who speculated that depending upon the value of it, that the Universe would in fact be expanding, it seems that they were more right than they knew. Not only is there a force that is pushing against gravity and overpowering it.
But as the galaxies get farther and farther apart, as the large-scale structure of the Universe continues to get spaced apart, gravity has less than less of a pull. And so that expansionary force is making everything move farther and farther away from themselves. And that has incredible implications for the future of our Universe.
Based on Einstein's theories, astronomers believed that sooner or later, gravity would slow the expansion of the Universe down, and it would start to recede, eventually resulting in a Big Crunch. But at this point, we're really not sure the Universe could end: in a Big Rip or the Heat Death, where it just keeps expanding ad infinitum until all stars, all galaxies die out.
Now, several other revolutionary changes have happened since the 1990s. Thanks to Hubble, the age of space telescopes began, which began observing the Universe in multiple wavelengths, infrared, ultraviolet, gamma rays, X-rays, microwaves, radio waves. And this has allowed the census of galaxies to jump from 200 billion, a full order of magnitude higher, to 2 trillion.
On top of that, astronomers have noted several curious phenomena, such as gamma-ray bursts and fast radio bursts, that have become mysteries in their own right. What is causing these phenomena?
And by the late 2000s, the Kepler Space Telescope led to a boom in the number of confirmed exoplanets. As we addressed in a previous episode, whereas only a few dozen planets had been confirmed beyond our Solar System right on up into the first decade of the 21st century, today, that number has jumped to well over 5000 confirmed planets, with another 10,000 or so awaiting confirmation.
And then, in 2015, astrophysicists confirmed for the very first time the detection of Gravitational Waves. This was another phenomenon predicted by Einstein's theory of General Relativity, that stated that when massive objects merge together, they created ripples in the fabric of spacetime, which could be detected hundreds, thousands, even millions or billions of light-years away.
And here, too, since the first confirmed detection, countless events have been picked up and studied and even traced back to their sources in some cases. And today, astrophysicists are looking forward to space laser interferometers, or Gravitational Wave observatories, which will detect thousands of more events and use these to probe the interiors of stars and many other interesting forms of scientific research.
But we'll also be looking for primordial gravitational waves that were caused by the Big Bang, if the Big Bang did, in fact, leave behind relic radiation - and we know it did, the Cosmic Microwave Background - then it will also have left Gravitational Waves which would have
traveled the same amount of distance, because as we know gravitational waves move at the speed of light, much like gravity itself.
So as you can clearly tell just from this relatively brief and topical treatment of the history of cosmology, it's gone through several, several phases. Much like all of our astronomical and astrological systems, many emerged all across the planet, every single culture that ever existed had its own version.
Over time, these merged and influenced each other. And as the era of modern astronomy began to dawn, certain conventions and knowledge became relatively universal. And as our instruments improved and our methods improved, we began to make more and more startling and fascinating discoveries.
And at every single interval, these really shook up our previously held notions, the Universe as we knew it got bigger and bigger and bigger. And it's gotten to the point now where we live in a universe that may very well be infinite, we have no way of knowing we can only see so far.
And thanks to the James Webb Space Telescope and future observatories such as Euclid, Nancy Grace, Roman, LUVOIR, and others. We are finally at a point where we can see back to the very beginnings of time, where we can see galaxies that are within the so-called Cosmic Dark Ages, a period of the Universe that is completely invisible in optical light and which also happens to be the period where the first stars and galaxies were born.
And what these next-generation telescopes are going to do in the coming years is measure and chart how the Universe has evolved over time, how its expanded and changed from those first galaxies, all created shortly after the Big Bang, to form the large-scale structure of the Universe we've come familiar with, and how that has changed itself over time, what its ultimate fate may be.
And part of the goal here in conducting these in-depth, but also very, very broad observations is to determine the roles of dark matter and Dark Energy, and confirm at last if they do actually exist, or if our physics models are in need of adjustment.
So much like the field of Quantum Mechanics and the study of subatomic particles and how matter behaves on the tiniest of tiny levels. We are looking at how matter behaves on the largest of scales on the cosmological scale in the hopes of better understanding how everything works and how it all fits together.
And one thing that is especially exciting about that is we really have no idea what we're going to find. But to quote Arthur C. Clarke, “The truth, as always, will be stranger than fiction.”
And like all previous revolutionary discoveries that we've made, they are likely to significantly shake up all of our previously held notions, everything that we thought we knew is going to be challenged and changed.
Or not! Only time will tell. Personally, I can't wait to find out. In the meantime, thank you for listening.
I'm Matt Williams, and this has been Stories from Space