3 wonders of the universe, explained
Astronomer Michelle Thaller schools us on what atoms really look, the Big Bang theory, and the speed of light.
Dr. Michelle Thaller is an astronomer who studies binary stars and the life cycles of stars. She is Assistant Director of Science Communication at NASA. She went to college at Harvard University, completed a post-doctoral research fellowship at the California Institute of Technology (Caltech) in Pasadena, Calif. then started working for the Jet Propulsion Laboratory's (JPL) Spitzer Space Telescope. After a hugely successful mission, she moved on to NASA's Goddard Space Flight Center (GSFC), in the Washington D.C. area. In her off-hours often puts on about 30lbs of Elizabethan garb and performs intricate Renaissance dances. For more information, visit NASA.
1. This is NOT what an atom really looks like.
MICHELLE THALLER: Calling what an electron is and where it is around an atom an "orbit" is actually very misleading. In truth electrons don't move around a nucleus the same way that planets move around a star at all. It's very, very different and part of that has to do with what an electron really is. Elementary particles are not tiny, tiny little balls that are actually moving through space. They're more properly described as waves and an electron does not exist in only one location around an atom. It actually exists as a wave. And what that means is that there are volumes around the nucleus of an atom that an electron will fill in. A single electron can actually be an entire sphere around the nucleus of an atom, or these orbitals as we call them, but again I caution you nothing is actually moving around like a planet around a star. Some of these orbitals are shaped like dumbbells and a single electron actually fills out a volume that looks like a dumbbell, or sometimes they look like a disc. So these actually are mathematical solutions which show you where the probability of finding this electron is around an atom. We call these electron shells and it's not that a single electron is moving around inside the shell. It's in the whole shell all at once. The electron actually fills in that volume and all you're looking at is a probability area of where that electron may be. So despite our depictions of atoms with the nucleus in the middle and electrons going around the outside, reality is nothing like that. Electrons form these volumes and some of those volumes even go through the nucleus. Some of these dumbbells actually have electrons existing inside the nucleus as well. What an atom really is, is far more complicated than our artistic depictions of it, far more mysterious and I think really wonderful. One of the best things to study in quantum mechanics is how electrons form these volumes.
2. The Big Bang wasn't an explosion. Visualize it like this instead.
Now when you hear the term Big Bang that implies an explosion, and we all know how explosions work from our experience. Things actually fly out from a common center. And one of the things is that scientists really don't like describing the Big Bang as an explosion at all. That sort of sets you up in the wrong direction right away because you could imagine that there are galaxies all flying apart away from each other, away from a common center, and flying out into empty space. And the universe we observe is absolutely nothing like that. For example, the whole volume of the universe that we can see with the Hubble space telescope. We can see to a distance of nearly 13 billion lightyears. All of that volume is filled with galaxies. There is no empty center to the universe. And the other thing that we don't observe and we're pretty sure that nobody else ever could either is being on the edge of that. Being on a galaxy right on the edge of expansion and seeing all of the galaxies in one direction because you're looking inside and nothing but empty space on the outside. Space never looks like that. All around us we see galaxies. The universe is filled with them. So, what's really going on here? And this really gets at the crux of what the Big Bang was. The Big Bang wasn't an explosion of matter. It was an expansion of space itself. So that simply means that any amount of space in the universe is expanding and everything is getting farther away from everything else. I know that's very hard to visualize. Some people talk about blowing up a balloon and this always, to me, can put you in the wrong direction because they say aha, a balloon has an empty center and everything expands away from it. What they haven't told you is you need to pay attention just to the surface of the balloon. Pretend that there's no such thing as inside or outside the balloon. Just the two dimensional surface of the rubber. As you blow into it that expands in every direction. If you were to draw little points on the surface of the balloon every little point would start getting farther away from every other little point. But if you were a two dimensional creature that could only travel on the surface of the balloon, you could only shine a light. You couldn't possibly even know about what's up or what's down. If you were completely two dimensional you would see every point expanding away from every other point but there would be no empty center.
So the question is in our three dimension universe, do we need another dimension to expand into if this is the case? And the answer honestly is no. Space itself can simply get larger. We don't know the extent of the entire universe. If you want to think of the universe instead of the surface of a balloon as a big rubber sheet. You can just keep stretching that rubber sheet. Stretching it apart, everything's getting farther and farther away from each other but there's no empty center. There's still rubber everywhere you go and that rubber is just getting bigger. Now, we are pretty sure there's no edge to the universe. Is the universe infinite? We honestly don't know. Maybe the universe does have some larger shape that we're not aware of, but the thing to really remember is that there is no empty center. The Big Bang happened at every point in space. All of space began to expand at once. And so that means that we look out into the distant universe and we see pretty much all of the galaxies moving away from us. And if you point at any galaxy you want in the sky and put yourself there, you would see everything expanding away from you because space itself is expanding. There is no empty center to the universe.
3. The speed of light is more than a record-breaking speed.
You may have heard that nothing with mass can possibly go at the speed of light. The only things that travel at the speed of light are photons, pure energy light, the speed of light. Nothing with any mass at all can travel at the speed of light because as it gets closer and closer to the speed of light its mass increases. And if it were actually traveling at the speed of light it would have an infinite mass. So think about that. Even if you had a tiny little particle that was say billions of times less massive than an electron. Just a tiny, tiny little piece of mass. If for some reason that tiny thing accelerated to the speed of light it would have an infinite mass and that's a bit of a problem. So, let's talk about this. One of the things that you really have to realize is the speed of light is very, very special. It's not just simply a speed of something moving through space. As you go faster and faster and closer to the speed of light, time itself begins to slow down and space begins to contract. As you go close to the speed of light the entire universe becomes smaller and smaller until it basically just becomes a single point when you're going at the speed of light. And time as you go closer to the speed of light gets slower and slower until basically time is a single point at the speed of light. Light does not experience space or time. It's not just a speed going through something. All of the universe shifts around this constant, this speed of light. Time and space itself stop when you go that speed. So, the reason you can't accelerate to the speed of light and the reason we say you have an infinite mass gets a little complicated because the idea that mass actually is a measurement of energy. You may remember Einstein's famous equation E = mc2. Energy equals mass times the speed of light squared. Energy and mass are equivalent. Mass is basically a measurement of how much energy there is in an object.
When you're moving you have the energy of your motion, too. That's called kinetic energy. Energy of motion. So, E = mc2 now your mass has not just the stuff that's in you, but also the energy of your motion. And that's why mass seems to increase as you go faster and faster and closer to the speed of light. It's not that you're actually getting any heavier. The increase in mass is something that's only observed by people that are watching you go by. If you're on a spaceship going very fast at the speed of light you don't notice anything getting heavier. You are on your spaceship, you can jump up and down, you can skip rope. You can do whatever you want. You don't notice any change at all. But if people try to measure your mass as you go by they not only are measuring your rest mass, your mass when you were still, but this added energy of this huge speed that you have through space. And that's called a relativistic mass. It's a complex idea to think that mass itself is a measurement of energy so that changes depending on how fast you're going. If you were to slow down on your spaceship you would not keep that mass. You would go back to being the same mass you were before you started moving that quickly. So, as you can see it's a complicated answer depending on how you define mass because as you're going very close to the speed of light and you have a huge speed you need to take into account that energy because of the equation E = mc2.
- Most people have seen atoms illustrated in textbooks and know about the Big Bang and the speed of light, but there is a good chance what you think you know is not scientifically accurate.
- Michelle Thaller, an astronomer and Assistant Director for Science Communication at NASA, is here to clear up the misconceptions and explain why atoms don't actually look that way, why the Big Bang is a misnomer, and why the speed of light is more than just really fast.
- Is there an edge of space? Does light experience time? Watch this video for answers to those and other interesting questions.
- Is the universe a hologram? The strange physics of black holes. ›
- A universe in a nutshell: The physics of everything, with Michio Kaku ... ›
- Neil deGrasse Tyson: 3 mind-blowing space facts - Big Think ›
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Dr. Katie Mack explains what dark energy is and two ways it could one day destroy the universe.
- The universe is expanding faster and faster. Whether this acceleration will end in a Big Rip or will reverse and contract into a Big Crunch is not yet understood, and neither is the invisible force causing that expansion: dark energy.
- Physicist Dr. Katie Mack explains the difference between dark matter, dark energy, and phantom dark energy, and shares what scientists think the mysterious force is, its effect on space, and how, billions of years from now, it could cause peak cosmic destruction.
- The Big Rip seems more probable than a Big Crunch at this point in time, but scientists still have much to learn before they can determine the ultimate fate of the universe. "If we figure out what [dark energy is] doing, if we figure out what it's made of, how it's going to change in the future, then we will have a much better idea for how the universe will end," says Mack.
A unique exoplanet without clouds or haze was found by astrophysicists from Harvard and Smithsonian.
- Astronomers from Harvard and Smithsonian find a very rare "hot Jupiter" exoplanet without clouds or haze.
- Such planets were formed differently from others and offer unique research opportunities.
- Only one other such exoplanet was found previously.
Munazza Alam – a graduate student at the Center for Astrophysics | Harvard & Smithsonian.
Credit: Jackie Faherty
Jupiter's Colorful Cloud Bands Studied by Spacecraft<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="8a72dfe5b407b584cf867852c36211dc"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/GzUzCesfVuw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Astronomers find these five chapters to be a handy way of conceiving the universe's incredibly long lifespan.
- We're in the middle, or thereabouts, of the universe's Stelliferous era.
- If you think there's a lot going on out there now, the first era's drama makes things these days look pretty calm.
- Scientists attempt to understand the past and present by bringing together the last couple of centuries' major schools of thought.
The 5 eras of the universe<p>There are many ways to consider and discuss the past, present, and future of the universe, but one in particular has caught the fancy of many astronomers. First published in 1999 in their book <a href="https://amzn.to/2wFQLiL" target="_blank"><em>The Five Ages of the Universe: Inside the Physics of Eternity</em></a>, <a href="https://en.wikipedia.org/wiki/Fred_Adams" target="_blank">Fred Adams</a> and <a href="https://en.wikipedia.org/wiki/Gregory_P._Laughlin" target="_blank">Gregory Laughlin</a> divided the universe's life story into five eras:</p><ul><li>Primordial era</li><li>Stellferous era</li><li>Degenerate era</li><li>Black Hole Era</li><li>Dark era</li></ul><p>The book was last updated according to current scientific understandings in 2013.</p><p>It's worth noting that not everyone is a subscriber to the book's structure. Popular astrophysics writer <a href="https://www.forbes.com/sites/ethansiegel/#30921c93683e" target="_blank">Ethan C. Siegel</a>, for example, published an article on <a href="https://www.forbes.com/sites/startswithabang/2019/07/26/we-have-already-entered-the-sixth-and-final-era-of-our-universe/#7072d52d4e5d" target="_blank"><em>Medium</em></a> last June called "We Have Already Entered The Sixth And Final Era Of Our Universe." Nonetheless, many astronomers find the quintet a useful way of discuss such an extraordinarily vast amount of time.</p>
The Primordial era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTEyMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNjEzMjY1OX0.PRpvAoa99qwsDNprDme9tBWDim6mS7Mjx6IwF60fSN8/img.jpg?width=980" id="db4eb" class="rm-shortcode" data-rm-shortcode-id="0e568b0cc12ed624bb8d7e5ff45882bd" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="1049" />
Image source: Sagittarius Production/Shutterstock<p> This is where the universe begins, though what came before it and where it came from are certainly still up for discussion. It begins at the Big Bang about 13.8 billion years ago. </p><p> For the first little, and we mean <em>very</em> little, bit of time, spacetime and the laws of physics are thought not yet to have existed. That weird, unknowable interval is the <a href="https://www.universeadventure.org/eras/era1-plankepoch.htm" target="_blank">Planck Epoch</a> that lasted for 10<sup>-44</sup> seconds, or 10 million of a trillion of a trillion of a trillionth of a second. Much of what we currently believe about the Planck Epoch eras is theoretical, based largely on a hybrid of general-relativity and quantum theories called quantum gravity. And it's all subject to revision. </p><p> That having been said, within a second after the Big Bang finished Big Banging, inflation began, a sudden ballooning of the universe into 100 trillion trillion times its original size. </p><p> Within minutes, the plasma began cooling, and subatomic particles began to form and stick together. In the 20 minutes after the Big Bang, atoms started forming in the super-hot, fusion-fired universe. Cooling proceeded apace, leaving us with a universe containing mostly 75% hydrogen and 25% helium, similar to that we see in the Sun today. Electrons gobbled up photons, leaving the universe opaque. </p><p> About 380,000 years after the Big Bang, the universe had cooled enough that the first stable atoms capable of surviving began forming. With electrons thus occupied in atoms, photons were released as the background glow that astronomers detect today as cosmic background radiation. </p><p> Inflation is believed to have happened due to the remarkable overall consistency astronomers measure in cosmic background radiation. Astronomer <a href="https://www.youtube.com/watch?v=IGCVTSQw7WU" target="_blank">Phil Plait</a> suggests that inflation was like pulling on a bedsheet, suddenly pulling the universe's energy smooth. The smaller irregularities that survived eventually enlarged, pooling in denser areas of energy that served as seeds for star formation—their gravity pulled in dark matter and matter that eventually coalesced into the first stars. </p>
The Stelliferous era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTEzNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMjA0OTcwMn0.GVCCFbBSsPdA1kciHivFfWlegOfKfXUfEtFKEF3otQg/img.jpg?width=980" id="bc650" class="rm-shortcode" data-rm-shortcode-id="c8f86bf160ecdea6b330f818447393cd" data-rm-shortcode-name="rebelmouse-image" data-width="481" data-height="720" />
Image source: Casey Horner/unsplash<p>The era we know, the age of stars, in which most matter existing in the universe takes the form of stars and galaxies during this active period. </p><p>A star is formed when a gas pocket becomes denser and denser until it, and matter nearby, collapse in on itself, producing enough heat to trigger nuclear fusion in its core, the source of most of the universe's energy now. The first stars were immense, eventually exploding as supernovas, forming many more, smaller stars. These coalesced, thanks to gravity, into galaxies.</p><p>One axiom of the Stelliferous era is that the bigger the star, the more quickly it burns through its energy, and then dies, typically in just a couple of million years. Smaller stars that consume energy more slowly stay active longer. In any event, stars — and galaxies — are coming and going all the time in this era, burning out and colliding.</p><p>Scientists predict that our Milky Way galaxy, for example, will crash into and combine with the neighboring Andromeda galaxy in about 4 billion years to form a new one astronomers are calling the Milkomeda galaxy.</p><p>Our solar system may actually survive that merger, amazingly, but don't get too complacent. About a billion years later, the Sun will start running out of hydrogen and begin enlarging into its red giant phase, eventually subsuming Earth and its companions, before shrining down to a white dwarf star.</p>
The Degenerate era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTE1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNTk3NDQyN30.gy4__ALBQrdbdm-byW5gQoaGNvFTuxP5KLYxEMBImNc/img.jpg?width=980" id="77f72" class="rm-shortcode" data-rm-shortcode-id="08bb56ea9fde2cee02d63ed472d79ca3" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="810" />
Image source: Diego Barucco/Shutterstock/Big Think<p>Next up is the Degenerate era, which will begin about 1 quintillion years after the Big Bang, and last until 1 duodecillion after it. This is the period during which the remains of stars we see today will dominate the universe. Were we to look up — we'll assuredly be outta here long before then — we'd see a much darker sky with just a handful of dim pinpoints of light remaining: <a href="https://earthsky.org/space/evaporating-giant-exoplanet-white-dwarf-star" target="_blank">white dwarfs</a>, <a href="https://earthsky.org/space/new-observations-where-stars-end-and-brown-dwarfs-begin" target="_blank">brown dwarfs</a>, and <a href="https://earthsky.org/astronomy-essentials/definition-what-is-a-neutron-star" target="_blank">neutron stars</a>. These"degenerate stars" are much cooler and less light-emitting than what we see up there now. Occasionally, star corpses will pair off into orbital death spirals that result in a brief flash of energy as they collide, and their combined mass may become low-wattage stars that will last for a little while in cosmic-timescale terms. But mostly the skies will be be bereft of light in the visible spectrum.</p><p>During this era, small brown dwarfs will wind up holding most of the available hydrogen, and black holes will grow and grow and grow, fed on stellar remains. With so little hydrogen around for the formation of new stars, the universe will grow duller and duller, colder and colder.</p><p>And then the protons, having been around since the beginning of the universe will start dying off, dissolving matter, leaving behind a universe of subatomic particles, unclaimed radiation…and black holes.</p>
The Black Hole era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTE2MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMjE0OTQ2MX0.ifwOQJgU0uItiSRg9z8IxFD9jmfXlfrw6Jc1y-22FuQ/img.jpg?width=980" id="103ea" class="rm-shortcode" data-rm-shortcode-id="f0e6a71dacf95ee780dd7a1eadde288d" data-rm-shortcode-name="rebelmouse-image" data-width="1400" data-height="787" />
Image source: Vadim Sadovski/Shutterstock/Big Think<p> For a considerable length of time, black holes will dominate the universe, pulling in what mass and energy still remain. </p><p> Eventually, though, black holes evaporate, albeit super-slowly, leaking small bits of their contents as they do. Plait estimates that a small black hole 50 times the mass of the sun would take about 10<sup>68</sup> years to dissipate. A massive one? A 1 followed by 92 zeros. </p><p> When a black hole finally drips to its last drop, a small pop of light occurs letting out some of the only remaining energy in the universe. At that point, at 10<sup>92</sup>, the universe will be pretty much history, containing only low-energy, very weak subatomic particles and photons. </p>
The Dark Era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTE5NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0Mzg5OTEyMH0.AwiPRGJlGIcQjjSoRLi6V3g5klRYtxQJIpHFgZdZkuo/img.jpg?width=980" id="60c77" class="rm-shortcode" data-rm-shortcode-id="7a857fb7f0d85cf4a248dbb3350a6e1c" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="810" />
Image source: Big Think<p>We can sum this up pretty easily. Lights out. Forever.</p>
People often make a killing in stocks, but there are other ways to potentially turn major profits.
- Outside of stocks and bonds, some people make money investing in collectibles and make a fair amount on them.
- One stamp even sold for a billion times its face value.
- The extreme dependence on future collectability, however, limits the potential of most of these opportunities.