What Was It Like When Human Civilization Reached Its Pinnacle?
“Over the past 70 years, a slew of developments have occurred that have fundamentally transformed our world. Our population passed 5 billion in 1986, and sits at 7.4 billion today. The structure of DNA was found in the 1950s, and since then the human genome has been sequenced, leading to a revolution in our understanding of genetics and biology. We have cloned advanced, living mammals.
We have entered space, landed astronauts on the Moon, and have sent spacecraft out of the Solar System. We have changed our planet’s climate, and continue to do so, but have become aware of our impacts on the planet.
As of today, 13.8 billion years after it all began, we are the most intelligent known creatures ever to grace this Universe. We have figured out the cosmic history of us, bringing us to a crucial point in human history. The next steps for humanity are all up to us. Will this be the beginning of the end for humanity? Or will we rise to the challenges of the modern world? Human civilization and the future of planet Earth hangs in the balance.”
If you ask an astrophysicist, “where did all this come from?” you just might get a 31-part answer that covers all of cosmic history. This is the final part in our what-was-it-like-when series, going all the way from the first modern humans, 300,000 years ago, up through our present day.
Links to all 30 of the previous parts can be found at the end of the article, and you, too, can follow our entire story as best as we know it. It’s your story, too.
This Is Why We Will Never Know Everything About Our Universe
“The total amount of information accessible to us in the Universe is finite, and hence, so is the amount of knowledge we can gain about it. There’s a limit to the amount of energy we can access, the particles we can observe and the measurements we can make. That doesn’t mean we’re done, or that we shouldn’t strive to learn everything we absolutely can. Only we can push the frontiers of knowledge back as far as they can go.
There’s a whole lot left to learn and a whole lot that science has yet to reveal. If we continue to look, many of the present unknowns will likely fall in the near future. But what is knowable is finite, and this implies that there are necessarily some things we may never know. The Universe may yet be infinite, but our knowledge of it never will be.”
The Universe is enormous, the speed of light is incredibly fast, and the Big Bang happened a very long time ago. But even if you could somehow know all the properties of every particle that could possibly be connected to us via the laws of physics, we still wouldn’t know everything. The total amount of information contained within the Universe is finite, as is the total amount of energy. With those constraints, even if we knew everything that was knowable, we would still have questions that would be unanswerable in principle.
Sounds disconcerting? Well, maybe you need a little bit of unease. Science, no matter how good it gets, will never know everything about the Universe. Find out why.
This Is How Amateur Astronomers Can Image What Professionals Cannot
“The Universe is full of astronomical wonders, but it’s up to humanity to observe and analyze them. The key factors determining what we can reveal are resolution, light-gathering power, and the wavelengths filters we choose. Professionals have larger, more powerful telescopes with superior instruments, but amateurs have the advantage of time.”
Have you ever looked at a spectacular image of a distant object in the sky and thought there was no way you could ever construct something like that? That it would simply be impossible to take such a large, high-quality image without the benefit of a professional telescope, observatory, or setup? Well, Ciel Austral, a team of five amateur astronomers, spent 10 months over 2018 and 2019 photographing the nearest large galaxy to our own: the Large Magellanic Cloud. They recorded a total of 1060 hours of observations over that time, stitching a total of 620 GB of data together into a single mosaic.
The results are in, and it’s a spectacular view of the LMC that severely outstrips anything professionals have done. Come get the story and some amazing views here today!
This Is Why Earth’s Oceans And Skies Are Blue
“The sky and ocean aren’t blue because of reflections at all; they’re both blue, but each of their own volition. If you took our oceans away entirely, a human on the surface would still see blue skies, and if you managed to take our skies away (but still somehow gave us liquid water on the surface), our planet would still appear blue.
For the skies, the blue sunlight scatters more easily, and comes to us indirectly from where sunlight strikes the atmosphere as a result. For the oceans, longer-wavelength visible light gets absorbed more easily, so the deeper they go, the darker bluer the remaining light appears. Blue atmospheres may be common for planets, as Uranus and Neptune both possess them, too, but we’re the only one we know of with a blue surface. Perhaps when we find another world with liquid water on its surface, we won’t be so alone in more ways than one!”
The sky is blue. The oceans are blue. Earth, as seen from space, is blue. But have you ever stopped to think about why? Many popular but incorrect explanations abound, such as the idea that sunlight is blue, that oxygen is blue, or that one reflects the other. Of course, none of these are correct! The sky really is blue, and it’s blue because of the physics that governs how light passes through the atmosphere. The ocean is really blue, too; it’s why our planet appears blue from space. But the physics of why the ocean is blue is completely independent of why the skies are blue!
Want to get the real reason why Earth’s oceans and also our skies are blue? Come get the science you crave today.
Your Glorified Ignorance Wasn’t Cool Then, And Your Scientific Illiteracy Isn’t Cool Now
“You are not right about everything. Many of the opinions that you hold — and some of the facts that you believe to be true — will turn out to be falsely-held beliefs. Some of them, most likely, have already had their falsehood demonstrated beyond a reasonable scientific doubt. Unless you yourself are a huckster, trying to profit off of the willful deception of others, you must be open to changing your mind and deferring to the genuine experts who know more than you.
Glorified underachieving, proclaiming falsehoods as truths, and the derision of actual knowledge are banes on our society. The world is made objectively worse by every anti-science element present within it. Nobody likes to hear that sometimes, they’re the problem. But sometimes, it really is on each of us to do better. The next time you find yourself on the opposite side of an issue from the consensus of experts in a particular field, remember to be humble. Remember to listen and be open to learning. The future of our civilization may hang in the balance.”
Did you ever have an experience in school where you knew the answer, but didn’t raise your hand because it wasn’t cool to do so? Did you ever get a report card full of good grades, but were afraid to be proud of your achievement? Did you ever hear people proudly proclaiming falsehoods so outrageous that it seemed like people were flouting their ignorance, as though they were proud of it?
The seeds of a scientifically illiterate society get planted when we’re young, and it’s up to all of us to work together to overcome them. Here’s the antidote.
What Was It Like When The First Humans Arose On Earth?
“Approximately 300,000 years ago, the first Homo sapiens — anatomically modern humans — arose alongside our other hominid relatives. It is unknown whether we descended directly from Homo erectus, heidelbergensis, or antecessor, although neanderthals, which came slightly later at 240,000 years ago, most certainly came from Homo heidelbergensis. Modern speech is thought to have arisen almost as soon as Homo sapiens did.
It took 13.8 billion years of cosmic history for the first human beings to arise, and we did so relatively recently: just 300,000 years ago. 99.998% of the time that passed since the Big Bang had no human beings at all; our entire species has only existed for the most recent 0.002% of the Universe. Yet, in that short time, we’ve managed to figure out the entire cosmic story that led to our existence. Fortunately, the story won’t end with us, as it’s still being written.”
For those of you who haven’t been following, this is now part 30 of my series on “what was it like when…” where I’ve been chronicling our natural history, from before the Big Bang up through the present day. Next week’s will be the final installment of that series, as we’ll arrive at the present!
This edition takes us from 65 million years ago to just 300,000 years ago: the development of modern humans. Come take a read; it’s the story of us all.
This Is Why Mars Is Red And Dead While Earth Is Blue And Alive
“Both Mars and Earth had early atmospheres that were heavy, massive, and extraordinarily rich in CO2. While Earth’s carbon dioxide got absorbed into the oceans and locked up into carbonate rocks, Mars was unable to do the same, as its oceans were too acidified. The presence of sulfur dioxide led to Martian oceans that were rich in sulfuric acid. This led to geology of Mars we’ve discovered with rovers and landers, and pointed to a different cause — the solar wind — as the culprit in the mystery of the missing Martian atmosphere.
Thanks to NASA’s MAVEN mission, we’ve confirmed that this story is, in fact, the way it happened. Some four billion years ago, the core of Mars became inactive, its magnetic field disappeared, and the solar wind stripped the atmosphere away. With our magnetic field intact, our planet will remain blue and alive for the foreseeable future. But for a smaller world like Mars, its time ran out long ago. At last, we finally know why.”
For most of the 20th century, we knew that Earth had a carbon dioxide-rich past for its atmosphere, but that those atmospheric molecules were deposited into the ocean and precipitated or fossilized out as carbonate rocks like limestone and dolomite. We assumed that Mars, which once had a thick atmosphere and a water-rich surface, lost its atmosphere the same way. But landers and rovers changed all of that, discovering very little in the way of carbonate rocks, meaning that there must have been a different process at play to strip the Martian atmosphere away.
It wasn’t until NASA’s MAVEN mission that we knew for sure! Come learn why Mars is red and dead while Earth is blue and alive today.
Scientists Solve The Mystery Of STEVE, And Find It’s So Much More Than An Aurora
“Normally, aurorae are produced by the Sun’s charged particles striking the atoms in Earth’s upper atmosphere. The solar wind particles get bent by Earth’s magnetic field, exciting and ionizing oxygen, nitrogen, and hydrogen. When electrons recombine with ions, they cascade back down to lower energies, creating aurorae from their emission lines. STEVE is distinct from this for multiple reasons.”
It isn’t often that a naked-eye skywatcher gets a chance to observe an entirely new optical phenomenon that’s never been seen or recorded before. Yet earlier this century, that’s exactly what’s happened with a purple/green/mauve ribbon of light that sometimes appears in the sky. Known as STEVE, for strong thermal emission velocity enhancement, this ribbon includes colors never seen in an aurora, appears at lower latitudes than those where aurorae are typically found, and most importantly, isn’t created coincident with the precipitation of charged particles. In other words, it’s an entirely new phenomenon!
The mystery of what creates STEVE has now been solved, and it’s not only a great scientific story, it’s also beautiful to behold. Come see the full story (and some great photos and videos) today!
Ask Ethan: How Well Has Cosmic Inflation Been Verified?
“To what margin of error or what level of statistical significance would you say you say inflation has been verified?”
So, you’ve got an alternative theory to our best mainstream scientific ideas? Well, guess what: those are the same shoes that every scientific idea we accept today were wearing at one point in the distant past. The thing that separates them from the ideas that fell by the wayside were three remarkable feats:
1. They reproduced all the earlier successes of the previous prevailing model.
2. They resolved or explained puzzles or problems that the previous model had no sufficient answer for.
3. And, perhaps most importantly, they made new predictions that we could go out and test about the Universe, and those predictions were proven correct by the appropriate experimental or observational test.
Although most people don’t appreciate it, inflation has hurdled all three bars, and has no fewer than four spectacular predictions that have since been confirmed. Come learn how well cosmic inflation has been verified today!
When Did The Universe Become Transparent To Light?
“The Universe became transparent to the light left over from the Big Bang when it was roughly 380,000 years old, and remained transparent to long-wavelength light thereafter. But it was only when the Universe reached about half a billion years of age that it became fully transparent to starlight, with some locations experiencing transparency earlier and others experiencing it later.
To probe beyond these limits requires a telescope that goes to longer and longer wavelengths. With any luck, the James Webb Space Telescope will finally open our eyes to the Universe as it was during this in-between era, where it’s transparent to the Big Bang’s glow but not to starlight. When it opens its eyes on the Universe, we may finally learn just how the Universe grew up during these poorly-understood dark ages.”
There are two ways that astrophysicists talk about the Universe becoming transparent. The first is when the particles from the Big Bang finally form neutral atoms, becoming “transparent” to the leftover photons from that era. The second is hundreds of millions of years later, when those same neutral atoms are reionized, and starlight can travel freely through intergalactic space. Which one is right? When did the Universe become transparent to light?
The truth is we need them both, as they make the Universe transparent to different types of light. Come get the full story today.