The Milky Way Is Gaining New Stars From A Collision That Hasn’t Even Occurred Yet
“This is the first direct evidence of new stars forming from any galactic stream associated with the Magellanic Clouds, and it appears to have occurred from a stream of gas that’s already passed through the galactic plane. It’s eminently conceivable that it was that very event – when this gas ejected from the Magellanic Clouds passed through the Milky Way’s disk – was what triggered the formation of the new stars we’re seeing today.
When you take all of this information together, it leads to a remarkable conclusion that changes the way we think our local galactic neighborhood is evolving. New gas is already being funneled into the Milky way from satellite galaxies that are still nearly 200,000 light-years away. This gas, low in heavy element abundance but cool in temperature, provides about 95% of the cold gas suitable for the formation of new Milky Way stars. These nearby galaxies haven’t even encountered us yet, and we’re already forming new stars because of them.”
In another few hundred million years, the two Magellanic Clouds, located a little less than 200,000 light-years away, will collide with and begin merging with our Milky Way. But already, over 100 million years ago, a fraction of the gas from these clouds came into our galaxy and formed stars! 94,000 light-years away, in the halo of the Milky Way, these stars are unlike anything else seen in our galaxy before.
Here’s how the Milky Way has gained stars from a collision that hasn’t even occurred yet, and what it means for our galaxy’s future!
This Is How The Universe Changes With Every New Year That Passes
“With an 13.8 billion year lifetime so far, the Universe has certainly been around for some time. While it may seem to change only imperceptibly on human timescales, the fact remains that these changes are real, important, and cumulative. If we look closely and precisely enough, we can observe these changes on timescales as small as a single year.
These changes affect not only our home world, but our Solar System, galaxy, and even the entire Universe. We are only in the beginning stages of exploring how the Universe changes over time and what it looks like at the greatest distances and faintest extremes. May the 2020s mark the decade, at long last, where we pool our efforts as a species into the endeavor to uncover the greatest cosmic secrets of all.”
With every year that goes by, tiny, imperceptible changes occur in our physical Universe that really add up over time. The Earth’s rotation is slowing, the Moon is spiraling outwards, the Sun is heating up and new stars are forming. On a cosmic scale, the Universe is expanding and getting cooler, and more galaxies are becoming visible while fewer stars are capable of being visited.
This is how the Universe changes with each new year that passes, and we can quantify the effects today!
Ask Ethan: Did God Create The Universe?
“I am very interested in space and with who made us and what made us… what do you have to say about people who say that “God” made us?”
In some ways, it’s the ultimate cosmic question. Before the Big Bang, before the final few moments of cosmic inflation, our knowledge ends. Not only does it end in the sense that we don’t know what came before that instant, but any information that ever existed is now definitively no longer present within our observable Universe. There is nothing we could ever look at, measure, observe, or experiment with, to the best of our knowledge and understanding, to reveal information about that epoch.
It might run contrary to science to appeal to the divine to explain the physical phenomena that have already been scientifically explained and understood, but it’s definitively true that science cannot and will not provide the answer to any and every question we can conceivably ask. For some questions, all science can do is remain agnostic, with every opinion on the matter remaining a matter of faith.
Regardless of what you believe, there’s a lesson for us all in how we treat one another, particularly if they believe differently from ourselves. It’s the last Ask Ethan of the 2010s, and if you’re only going to read one, this should be it!
These 5 Accomplishments Prove That Santa Claus Is The World’s Greatest Scientist
“With 500 million households to hit in just 42 hours, there is so much that Santa needs to accomplish at each one. At a bare minimum, he has to:
- travel from the previous house to the next one without wasting too much time,
- park and depart his sleigh, entering the household undetected,
- deliver each and every one of the necessary presents to that house,
- eat any snacks that were left for him,
- and then exit the house undetected, re-entering the sleigh, and beginning the process all over again.
If we allot him the entirety of the 42 hours available to accomplish this task, he can only spend a maximum of 300 microseconds (or 0.0003 seconds) on the sum total of these tasks for each and every household. It might seem an impossibility, at least for a normal human with conventional technology.
But if Santa truly is the world’s greatest scientist, it could all feasibly fall into place. Here are each the five challenges he’s clearly conquered, with speculation as to how.”
Have you ever wondered how Santa Claus delivers toys all over the world in just one night to so many households? The answer is easy: with science!
Here’s how Santa must have gone about conquering his greatest obstacles to bring about another year of unparalleled success in making children happy all over the world.
No, Scientists Will Never Be Able To Remove The Empty Space From Atoms
“It might be a delightful science fiction dream to remove the empty space from atoms, decreasing the volume that matter occupies by factors of millions, trillions or even more. However, it isn’t that the electrons orbiting the nucleus inherently occupy an extremely large volume of space, but rather that the quantum properties inherent to particles — masses, charges, interaction strength, and quantum uncertainty — all combine to create the atoms that exist in our Universe.
Even if we had a stable, heavier counterpart of the electron, or the ability to compress matter to arbitrarily dense states, we’d run into a quantum threshold where the atomic nuclei at the centers of atoms would spontaneously fuse, preventing stable configurations of multiple atoms from existing at all. The fact that our atoms are mostly empty space permits the existence of molecules, chemistry, and life.
Removing the empty space from atoms might be a fun thought experiment, but atoms are the size they are because of the rules of the Universe. Our existence is dependent on that empty space being present, but with the constants of nature having the values they do, don’t worry. It cannot be any other way.”
What you’ve heard is true: atoms really are mostly empty space. Ever since that discovery more than a century ago, people have imagined what it might be like if it were possible to remove the empty space from these atoms, and what sort of interesting things we’d be able to create if we could do so. As it turns out, though, there are good fundamental reasons why the empty space can’t be removed, and dire consequences we face when we try the only two things we can think of.
Come learn the science of why we’ll never be able to remove the empty space from atoms.
This Is Why Scientists Will Never Exactly Solve General Relativity
“One of the most valuable lessons I ever got in my life came during the first day of my first college math class on differential equations. The professor told us, “Most of the differential equations that exist cannot be solved. And most of the differential equations that can be solved cannot be solved by you.” This is exactly what General Relativity is — a series of coupled differential equations — and the difficulty that it presents to all those who study it.
We cannot even write down the Einstein field equations that describe most spacetimes or most Universes we can imagine. Most of the ones we can write down cannot be solved. And most of the ones that can be solved cannot be solved by me, you, or anyone. But still, we can make approximations that allow us to extract some meaningful predictions and descriptions. In the grand scheme of the cosmos, that’s as close as anyone’s ever gotten to figuring it all out, but there’s still much farther to go. May we never give up until we get there.”
In our best theory of gravity, General Relativity, we can compute to arbitrary accuracy the effects on matter of any spacetime that we can write down. Unfortunately, most of the spacetimes that we can dream up in our head aren’t ones that we can write down, and most of the ones that we can write down can only be solved approximately, not exactly.
This is not a flaw nor a benefit: it is simply a property of the theory that we have. Is it the final answer? Perhaps not. But it’s the best one we’ve got so far. Here’s what it means.
Your 2019 Holiday Gift Guide For Space, Astronomy, And Science Lovers
“At The Edge Of Time, by Dan Hooper. This new book, out just a few weeks ago, is my favorite new science book of 2019. As a theoretical cosmologist, Dan is all the things I appreciate in a scientist who writes about his own research: he’s knowledgeable, comprehensive, and careful to get the details right. He has clear opinions and preferences, but is willing and able to push them aside in service of teaching the reader about the strengths and weaknesses of a variety of perspectives on a myriad of issues at the frontiers of physics.
If you’re mystified and curious about the mysteries of the Universe, including dark matter, dark energy, and cosmic inflation, and want a unique take on all of these puzzles with a peek behind how science-in-action works, you won’t want to miss this book. (I liked it so much that Dan is going to be my next upcoming guest on the Starts With A Bang podcast!)”
Do you love space, science, astronomy, physics, the Moon, and learning about the frontiers of what we know? Well, the holidays are coming up (today is Black Friday), and if that describes you or someone close to you in your life, here is a complete gift guide for the science enthusiast in your life.
With a total of 11 recommended books, a wall calendar, hats, accessories, and even a unique puzzle, you won’t want to miss this holiday gift guide!
This Is Why ‘Multi-Messenger Astronomy’ Is The Future Of Astrophysics
“The three types of signals we know how to collect from the Universe — light, particles, and gravitational waves — all deliver fundamentally different types of information right to our front door. By combining the most precise observations we can take with each of these, we can learn more about our cosmic history than any one of these signal types, or “messengers,” can provide in isolation.
We’ve already learned how neutrinos are produced in supernova, and how their travel path is less impeded by matter than light’s is. We’ve already linked merging neutron stars with kilonovae and the production of the heaviest elements in the Universe. With multi-messenger astronomy still in its infancy, we can expect a deluge of new events and new discoveries as this science progresses throughout the 21st century.
Just as you can learn more about a tiger by hearing its growl, smelling its scent, and watching it hunt than you can from a still image alone, you can learn more about the Universe by detecting these fundamentally different types of messengers all at once. Our bodies might be limited in terms of the senses we can use in any given scenario, but our knowledge of the Universe is limited only by the fundamental physics governing it. In the quest to learn it all, we owe it to humanity to use every resource we can muster.”
In 2017, three different gravitational wave observatories from across the world, LIGO Livingston, LIGO Hanford, and the Virgo detector all witnessed the arrival of gravitational waves from a neutron star collision some 130,000,000 light-years away. Two seconds after the wave signal ceased, the first light from the merger arrived. A new term that was previously reserved for professional astronomers, “multi-messenger astronomy,” suddenly entered the public arena.
But what is multi-messenger astronomy? What makes something a “messenger” and why is it important? As it turns out, it’s going to revolutionize how we understand our Universe in the 21st century. Come find out how today.
6 Steps Everyone Can Take To Become An Ally In White, Male-Dominated Workplaces
“Step 1: Listen to (women/people of color/URMs) when they discuss the problems they face. This is the first real step towards being an ally, and all it requires you do to is pay attention to the many voices out there — especially the voices of people whose experiences are vastly different from your own — and pay attention to them.
You’ll find lots of challenges that they talk about, and a myriad of ways that people are given the message that they are inadequate. This is a problem that practically everyone faces, but the degree of severity of this problem varies drastically among people of different races, genders, sexual orientations, religions, and ages. Many things that we think of as minor offenses if they only happen once or twice become unbearable, like death-by-a-thousand-papercuts, when they happen continually.”
So, you’ve chosen the field you want to go into, and it’s a field where your talents and interest both lie. You know you’re good enough to do it, but you know there are going to be formidable obstacles and challenges to overcome. If that field happens to be dominated by white men (the dominant culture in many STEM fields), and you yourself aren’t a white man, you’re no doubt going to encounter obstacles and challenges that go above and beyond what you’d face if you were a white man.
You have a choice as far as how you behave in this environment, particularly if you yourself are a white man. If you’re interested in being an ally, you might find this essential reading.
What Came First: Inflation Or The Big Bang?
“In fact, our entire observable Universe contains no signatures at all from almost all of its pre-hot-Big-Bang history; only the final 10^-32 seconds (or so) of inflation even leave observably imprinted signatures on our Universe. We do not know where the inflationary state came from, however. It might arise from a pre-existing state that does have a singularity, it might have existed in its inflationary form forever, or the Universe itself might even be cyclical in nature.
There are a lot of people who mean “the initial singularity” when they say “the Big Bang,” and to those people, I say it’s long past due for you to get with the times. The hot Big Bang cannot be extrapolated back to a singularity, but only to the end of an inflationary state that preceded it. We cannot state with any confidence, because there are no signatures of it even in principle, what preceded the very end-stages of inflation. Was there a singularity? Maybe, but even if so, it doesn’t have anything to do with the Big Bang.”
Have you heard that our Universe began some 13.8 billion years ago with the start of the Big Bang? There’s a good chance that some version of that story has made it to you, but it unfortunately has probably gotten to you the same way it got to me: with an error that’s many decades out of date.
What if I told you that you couldn’t extrapolate the Universe back to a singularity, where all the matter and energy was consolidated into a space so tiny that the laws of physics break down?
What if I told you that we have a verified, validated theory of what happened before the Big Bang, and it has (for decades, now) superseded and replaced the idea of an initial singularity as the earliest stages of the Universe?
Meet cosmic inflation, the pre-origin of our Universe that set up and gave rise to the Big Bang, and learn why the naysayers are out of legs to stand on.