3 mind-blowing space facts with Neil deGrasse Tyson
Tyson dives into the search for alien life, dark matter, and the physics of football.
Neil deGrasse Tyson was born and raised in New York City where he was educated in the public schools clear through his graduation from the Bronx High School of Science. Tyson went on to earn his BA in Physics from Harvard and his PhD in Astrophysics from Columbia. He is the first occupant of the Frederick P. Rose Directorship of the Hayden Planetarium. His professional research interests are broad, but include star formation, exploding stars, dwarf galaxies, and the structure of our Milky Way. Tyson obtains his data from the Hubble Space Telescope, as well as from telescopes in California, New Mexico, Arizona, and in the Andes Mountains of Chile.Tyson is the recipient of nine honorary doctorates and the NASA Distinguished Public Service Medal. His contributions to the public appreciation of the cosmos have been recognized by the International Astronomical Union in their official naming of asteroid "13123 Tyson".
Tyson's new book is Letters From an Astrophysicist (2019).
NEIL DEGRASSE TYSON: When we think of places you might find life we typically think of the Goldilocks Zone around the star where water would be liquid in its natural state. And if you get a little too close to the star, heat would evaporate the water and you don't have it anymore. It's gone. Too far away it would freeze and neither of those states of H2O are useful to life as we know it. We need liquid water. So you can establish this Green Zone, this habitable zone, this Goldilocks Zone, where if you find a planet orbiting there hey, good chance it could have liquid water. Let's look there first for life as we know it.
Now it turns out that this source of heat, of course is traceable to the sun and if you go farther out everything water should be frozen, all other things being equal. But Europa, a moon of Jupiter sitting well outside of the Goldilocks Zone is kept warm not from energy sources traceable to the Sun, but from what we call the tidal forces of Jupiter itself. So, Jupiter and surrounding moons are actually pumping energy into Europa. And how does it do that? As Europa orbits Jupiter its shape changes. It's not fundamentally different from tides rising and falling on Earth. The shape of the water system of the Earth is responding to tidal forces of the moon. And when you do that to a solid object, the solid object is stressing. And because of this, a consequence of this is that you are pumping energy into the object. It is no different from when you say to anyone who's familiar with racquet sports, indoor racquet sports. It could be racquetball or squash. You say let's arm up the ball before we start playing.
You want to hit it around a few times. You are literally warming up the ball. It's not just simply let's get loose. You are literally warming up the ball. How? You are distorting it every time you smack it and then the resilience of the ball pops it back into shape and every time you do that, every smack, you're pumping energy into the ball. It's not fundamentally different from what's going on in orbit around Jupiter. So, you have this frozen world, Europa, completely frozen on its surface but you look at the surface and there are cracks in the ice. There are ridges in the ice where there's a crack and it shifted and then refroze. So this ridge has a discontinuity in the crack and it continues in another place. So what this tells you is that Europe cannot be completely frozen because if it were nothing would be moving. You look at the surface of Europa, the frozen surface, there are like ice chunks that are shifted and refrozen and shifted again. It looks just like if you fly over the Arctic Ocean.
Fly over the Arctic Ocean in the winter these are ice sheets that are breaking and refreezing all the time. It's the same signature as that. So all of us are convinced that beneath this icy surface is an ocean of liquid water. And there's no reason to think it wouldn't have been liquid for billions of years. On Earth where we find liquid water we find life. So what this means not only do we have a source of heat outside of the Goldilocks Zone, we have conditions under which life could be thriving. And knowing that this is possible has completely broadened the net that we are casting in search for life in the universe. No longer is it the limit, let's find a 72 degree tidal pond and see life forming there. No, life is pretty hardy. And by the way Europa is not the only one of these moons in the outer solar system that's kept warm by these sort of tidal stress forces. There are other moons that feel the same influx of energy. So, for example, Io, that's the innermost moon of Jupiter. That suffers from this phenomenon even more. And that moon is so hot there are volcanoes erupting from within. It is rendered molten, whatever solid parts of that moon there are. And so, in fact, the most volcanically active place in the solar system is Io, one of the moons of Jupiter. And we don't know how to sustain life under temperatures that hot so, but it's a reminder that if you're looking for sources of energy we no longer need to be anchored to a host star in our search for life in the universe.
2. Dark Matter. Dark matter = Dark gravity?
NEIL DEGRASSE TYSON: The question isn't about whether dark matter exists or not. What's going on is when we measure gravity in the universe the collective gravity of the stars, the planets, the moons, the gas clouds, the black holes, the whole galaxies. When we do this 85 percent has no known origin. So it's not a matter of whether dark matter exists or not. It's a measurement, period. Now, dark matter is not even what we should be calling it because that implies that it's matter. It implies we know something about it that we actually don't. So a more precise labeling for it would be dark gravity. Now, if I called it dark gravity are you going to say does dark gravity really exist? I'd say yeah because 85 percent of the gravity has no known origin. There it is. Let's figure out what's causing it. The fact that the word matter got into that word is forcing people to say I have another idea. I bet it's not matter. It could be something else. We're overreacting to a label that overstates our actual insights or knowledge into what it is we're describing. Then I just joke we should just call it Fred. Fred or Wilma, something where there is no reference to what we think it is because, in fact, we have no idea.
So here's how you actually measure the stuff. In a galaxy which is the smallest aggregation of matter where dark matter manifests, so you look how fast it's rotating and we know from laws of gravity first laid down by Johannes Kepler and then enhanced and given further detail and deeper understanding by Isaac Newton. You write down these equations and say oh, look how fast it's rotating. You invoke that rotation rate in the equation and out the other side says how much gravity. How much mass should be there attracting you. And the more mass that's there the faster we expect you to be orbiting. That kind of makes sense. So when you do this calculation on a galactic scale we get vastly more mass attracting you than we actually can detect. I'm adding up stars, gas clouds, moons, planets, black holes. Add it all up. It's a fraction of what we know is attracting you in this orbit. And we cannot detect the rest. And so we hand it this title dark matter.
Understandably I suppose but it implies that we know that it's matter, but we don't. We know we can't detect it in any known way and we know it has gravity. So it really should be called dark gravity. I think the over/under on what dark matter might be today I think we're all kind of leaning towards a family of particles, subatomic particles that have hardly any ability to interact with the particles we have come to know and love, "ordinary matter." And that would make it matter. Dark matter as we've all been describing it. And it's not a weird thing that you could have a particle that doesn't interact with our particles. Within our own family of particles there are examples where the interaction is very weak or nonexistent. You might have heard of neutrinos. This is a ghost-like particle that permeates the universe and hardly interacts with familiar matter at all.
Yet it is part of our family of particles that we know exist and that we can detect and interact with. So if we can have an illusive particle that's part of our own familiar family of particles it's not much of a stretch to think of a whole other category of particles where none of them give a rat's ass about the rest of us and they just pass right through us as though we're not even there. Now here's what's interesting about dark matter. We know it doesn't interact with us except gravitationally. By the way what do I mean by interact? Does it bind and make atoms and molecules and solid objects? No, it does not interact with us in any important known way. But it also doesn't interact with itself. That's what's interesting. So, if it interacted with itself you can imagine finding dark matter planets, dark matter galaxies because to interact with yourself is what allows you to accumulate and have a concentration of matter in one place versus another.
These are the atomic bonds and the molecular bonds that create solid objects and if particles do not interact with one another they just pass through, you just have this zone of mass not really doing anything interesting. So, dark matter not only doesn't interact with us, it doesn't interact with itself. And that's why when we find dark matter across the universe it's very diffusely spread out. It's like over here. It's not in this one spot and look at this concentration. No, that's not how that works.
3. Football physics. Earth's rotation can make or break the season.
NEIL DEGRASSE TYSON: Just as a quick example, I was channel surfing, came across a football game that had just ended in a tie. They went into overtime. I had 15 minutes to kill before my movie came on. I said I'll sit there and watch this overtime period. And I'm watching it and there's the requisite exchange of possession before you go into sudden death overtime. So, they get it to within 50 yards of the goalpost and so they decide to kick a field goal for the win. And so I'm watching this and it's exciting, right. So then the ball gets hiked, they kick, the ball tumbles and it heads toward the left upright, careens off the left post and in for the win. And I said wait a minute. Oh, we have a round ball and a cylindrical thing so fractions of an inch matter which way this will bounce off of a post.
So I said let me check this out. So I check the orientation of the stadium, the latitude of the city and I did a calculation and then I tweeted and I said, "The winning field goal by the Cincinnati Bengals in overtime was likely enabled by a third of an inch drift to the right, enabled by Earth's rotation." And people say oh, my god. Blow my mind. And the local news got it and everybody got it. Of course you want to know that the rotation of the Earth helped that field goal kick. Because a kick going due north or due south will be deflected to the right in the northern hemisphere. And that's exactly what happened to that kick. And I use that as an excuse to send out a second tweet saying, "By the way, we call this the Coriolis force and that's what creates the circulation of all storms. Hurricanes, tornadoes." What do they call them in the Pacific? Cyclones.
- Astrophysicist Neil deGrasse Tyson joins us to talk about one of our favorite subjects: space.
- In the three-chaptered video, Tyson speaks about the search for alien life inside and outside of the Goldilocks Zone, why the term "dark matter" should really be called "dark gravity," and how the rotation of the Earth may have been the deciding factor in a football game.
- These fascinating space facts, as well as others shared in Tyson's books, make it easier for everyone to grasp complex ideas that are literally out of this world.
- How Neil deGrasse Tyson shuts down flat Earthers - Big Think ›
- Neil deGrasse Tyson Explains the Strange Paradoxes of Time Travel ›
- Neil deGrasse Tyson Says This Is His Most Important Message Ever ... ›
- Six solar system oddities and why we learn about them - Big Think ›
But most city dwellers weren't seeing the science — they were seeing something out of Blade Runner.
On Sept. 9, many West Coast residents looked out their windows and witnessed a post-apocalyptic landscape: silhouetted cars, buildings and people bathed in an overpowering orange light that looked like a jacked-up sunset.
India finishes last of 60 countries in environment and sustainability, as ranked by the expats who work there.
- How 'green' is life in your work country?
- That's the question InterNations asked its network of expats.
- The United States ended 30th out of 60 countries.
Nordics on top<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2NjgyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NTczNzkyOX0.VgfqyjAa9avw6gFOE0qlgSgKuBN7DJmzOc5lzFGLm8g/img.jpg?width=980" id="1f0dc" class="rm-shortcode" data-rm-shortcode-id="b27458cf472d26cf1f87cb91623a0621" data-rm-shortcode-name="rebelmouse-image" alt="Evo Hiking Area, H\u00e4meenlinna, Finland." />
Evo Hiking Area in Hämeenlinna, Finland. Great nature, clean air, clean water? Check, check and check.
Credit: Kanta-Hämeen kuvapankki on Flickr/ Public Domain.<p><br><strong>1. Finland</strong></p><p>The Nordic country scores at or near the top in all categories surveyed, including the quality of the natural environment (say 96 percent of expats in Finland), water and sanitation (96 percent) and air (95 percent). <br></p><p><strong>2. Sweden</strong></p><p>Swedes lead the world in environmental awareness (84 percent versus just 48 percent globally). Perhaps not surprising, for the homeland of <a href="https://bigthink.com/politics-current-affairs/greta-effect" target="_blank">Greta Thunberg</a>. This is reflected by government policy. Sweden currently gets more than 50 percent of its power from renewable sources and wants to go 100% renewable before 2040. "I've been here for over 20 years and I clearly see the benefits of my taxes paid coming back to me and the rest of society," says one American expat.<br></p><p><strong>3. Norway</strong></p><p>"The beautiful nature, the clean air and tap water, and the focus on the environment," are what one Ukrainian expat enjoys most about Norway. With 76 percent of expats happy with the availability of green goods and services, Norway's 'weakest' category is still 13 percentage points above the global average. <br></p><p><strong>4. Austria</strong></p><p>The first non-Nordic in the global ranking, Austria places in the Top 10 for each category and comes in first for the availability of green goods and services (90 percent). <br></p><p><strong>5. Switzerland</strong></p><p>Swiss nature is the most appreciated in the world (98 percent versus 83 percent on average). Switzerland also gets stellar results for air and water quality and the availability of green energy and green goods and services. </p><p><strong>6. Denmark</strong></p><p>Danes are very much into green causes, as is their government, say 83 percent resp. 84 percent of expats. "Organic food is readily available, and they are good with recycling," observes a South African expat. And they love cycling: 9 out of 10 Danes own a bike.</p><p><strong>7. New Zealand</strong></p><p>85 percent of expats agree that the New Zealand government takes green issues seriously. In fact, New Zealand plans to use 90 percent electricity from renewables by 2025. The country also scores high on the quality of its natural environment and all other categories – albeit slightly less on the quality of its water and sanitation.</p><p><strong>8. Germany</strong></p><p>"I enjoy the rising awareness about environmental issues and the alternatives the government and society are developing," says one Colombian expat. Indeed, 80 percent of expats agree the German government is pro-environment (versus 55 percent globally). <br></p><p><strong>9. Canada</strong></p><p>The only North American destination in the Top 10, thanks especially to expat appreciation of Canada's natural environment (96 percent), but also the quality of its water and sanitation (90 percet) and the availability of green goods and services (80 percent). <br></p><p><strong>10. Luxembourg</strong></p><p>"Access to nature for hiking and bicycling" is a definite boon for one American expat. In fact, the country's natural environment, although ranking 13th out of 60, is its lowest-rated subcategory. Luxembourg does even better when it comes to green energy, waste management, and the quality of its air and water.</p>
Taiwan, most sustainable destination in Asia<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njg1Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NzkxMDAxNH0.Roy7h_Od1cmaqBmamk-DP4rKMpLjTM-qIajG96alZAg/img.jpg?width=980" id="00799" class="rm-shortcode" data-rm-shortcode-id="dab52370e1edb5da5ebb0f5631027b1c" data-rm-shortcode-name="rebelmouse-image" alt="\u200bEternal Spring Shrine in the Taroko Gorge, Hualien County, Taiwan." />
Eternal Spring Shrine in the Taroko Gorge, Hualien County. Outside of Taipei, Taiwan can be surprisingly green and beautiful.
Credit: Zairon, CC BY-SA 4.0<p><strong>11. Taiwan</strong></p><p>The highest-scoring expat destination in Asia, Taiwan boasts 92 percent approval of its waste management and recycling, and 80 percent of the availability of green goods and services. But "the air pollution (in Taipei) is getting worse because it is too crowded," one expat complains.</p><p><strong>12. Netherlands</strong></p><p>Green goods and services are widely available, agree 82 percen of expats, as is green energy. However, 13 percent rate the Dutch environment negatively, 4 percet above the global average. <br></p><p><strong>13. Portugal</strong></p><p>Well ahead of its neighbor Spain (#20), the country scores high for air quality (91 percent) and natural environment (95 percent). "I like the opportunity for gardening and growing our own food," says one expat. <br></p><p><strong>14. Estonia</strong></p><p><strong></strong>Estonia scores in the Top 20 for every category and gets its highest marks for its natural environment. "A beautiful country with excellent air quality and open spaces," praises an Indian expat.<br></p><p><strong>15. Costa Rica</strong></p><p><strong></strong>Both the government and the people are very supportive of green policies, find 82 percent, resp. 67 percent of expats. "It's easy to live a healthy lifestyle with regard to the food, climate, clean air and water," says one. Costa Rica won the 2019 UN Champion of the Earth award and has pledged to go carbon neutral by 2050.<br></p><p><strong>16. Czechia</strong></p><p><strong></strong>"The beauty of the environment" is one of the best things about living in Czechia, says a Russian expat. No less than 97 percent of expats agree.<br></p><p><strong>17. France</strong></p><p><strong></strong>77 percent of expats are happy about the availability of green goods and services in France, which is 14 percentage points above average. The country also scores well for waste management and recycling. In short, France has a "good, green and clean environment," one Iranian expat finds. <strong><br></strong></p><p><strong>18. Australia</strong></p><p><strong></strong>While ranking high on the quality of its nature, water and air, Australia scores low when it comes to government support for green issues (51 percent). Fortunately, expats see more interest among the general population (68 percent). </p><p><strong>19. Singapore</strong></p><p><strong></strong>Expats rate the government's interest in green issues higher than globally average (77 percent versus 55 percent), but the Singaporean public's engagement for the same less than average (40 percent versus 48 percent). Of course, in a small, crowded place like Singapore, "(nature) spots are limited."<br></p><p><strong>20. Spain</strong></p><p>Spain's "scenery, diversity of places to visit and healthier environment" are what rate highly with one British expat. Its weak point is governmental and public support for green issues – but still slightly above the global average. <br></p>
London is "polluted and noisy"<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njg4Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NDg3NjkyOH0.3ySSD7jFBfAWA07u-EN-oL9x9cq9FZn06iz5aV0hEOw/img.jpg?width=980" id="f5630" class="rm-shortcode" data-rm-shortcode-id="80c9fa119e7ff3acc91e027b7529bfed" data-rm-shortcode-name="rebelmouse-image" alt="\u200bEven at 2:30pm, London gets clogged." />
Afternoon traffic jam in London.
World map for the 'sustainable expat'<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njg5MC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzMzAyNjQ2MH0.hjRiMDmOSnn9EvKJtx_tlzql3Gf7ph8lt8bL6dPCft4/img.png?width=980" id="def5d" class="rm-shortcode" data-rm-shortcode-id="149be2f5a19cc625cb555d8078f62ce2" data-rm-shortcode-name="rebelmouse-image" alt="The best & worst destiations for the sustainable expat" />
Sixty expat destinations ranked for sustainability, from best (orange) to worst (light blue). In between: fairly okay (brown), middling (grey) and not that great (dark blue).
South Korea's "rather horrible" air<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2NjkxNS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MTY1MjIwNn0.2e6eBIc38sAZLFQGKw4UL3-SY3hA9NthX0Uj9L4ibZA/img.jpg?width=980" id="c10db" class="rm-shortcode" data-rm-shortcode-id="cba918e6e5455c2e5ff4f9d5caf54775" data-rm-shortcode-name="rebelmouse-image" alt="\u200bSmoggy Seoul" />
Seoul's air quality is so bad you can picture it. Only India's air is perceived as worse than South Korea's, according to the expat survey.
Bad, worse, India<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2Njk0MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NTcyMTczMH0.Pt2bGDrpSKSwVjimMK_iK0Jejpu8ILn77VEzHTdzQQ4/img.jpg?width=980" id="28411" class="rm-shortcode" data-rm-shortcode-id="8b8b602261a168a46b05c53e09ab1b02" data-rm-shortcode-name="rebelmouse-image" alt="man standing surrounded by garbage" />
India scores worst in all three categories, but to be fair – some of its problems were imported from more developed countries.
Famous physicists like Richard Feynman think 137 holds the answers to the Universe.
- The fine structure constant has mystified scientists since the 1800s.
- The number 1/137 might hold the clues to the Grand Unified Theory.
- Relativity, electromagnetism and quantum mechanics are unified by the number.
A study finds 1.8 billion trees and shrubs in the Sahara desert.
- AI analysis of satellite images sees trees and shrubs where human eyes can't.
- At the western edge of the Sahara is more significant vegetation than previously suspected.
- Machine learning trained to recognize trees completed the detailed study in hours.
Why this matters<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2MDQ1OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzOTkyODg5NX0.O3S2DRTyAxh-JZqxGKj9KkC6ndZAloEh4hKhpcyeFDQ/img.jpg?width=980" id="3770d" class="rm-shortcode" data-rm-shortcode-id="3c27b79d4c0600fb6ebb82e650cabec0" data-rm-shortcode-name="rebelmouse-image" />
Area in which trees were located
Credit: University of Copenhagen<p>As important as trees are in fighting climate change, scientists need to know what trees there are, and where, and the study's finding represents a significant addition to the global tree inventory.</p><p>The vegetation Brandt and his colleagues have identified is in the Western Sahara, a region of about 1.3 million square kilometers that includes the desert, <a href="https://en.wikipedia.org/wiki/Sahel" target="_blank">the Sahel</a>, and the <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/subhumid-zones" target="_blank" rel="noopener noreferrer">sub-humid zones</a> of West Africa.</p><p>These trees and shrubs have been left out of previous tabulations of carbon-processing worldwide forests. Says Brandt, "Trees outside of forested areas are usually not included in climate models, and we know very little about their carbon stocks. They are basically a white spot on maps and an unknown component in the global carbon cycle."</p><p>In addition to being valuable climate-change information, the research can help facilitate strategic development of the region in which the vegetation grows due to a greater understanding of local ecosystems.</p>
Trained for trees<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2MDQ3MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNTk5NTI3NH0.fR-n1I2DHBIRPLvXv4g0PVM8ciZwSLWorBUUw2wc-Vk/img.jpg?width=980" id="e02c0" class="rm-shortcode" data-rm-shortcode-id="79955b13661dca8b6e19007935129af1" data-rm-shortcode-name="rebelmouse-image" />
Credit: Martin Brandt/University of Copenhagen<p>There's been an assumption that there's hardly enough vegetation outside of forested areas to be worth counting in areas such as this one. As a result the study represents the first time a significant number of trees — likely in the hundreds of millions when shrubs are subtracted from the overall figure — have been catalogued in the drylands region.</p><p>Members of the university's Department of Computer Science trained a machine-learning module to recognize trees by feeding it thousands of pictures of them. This training left the AI be capable of spotting trees in the tiny details of satellite images supplied by NASA. The task took the AI just hours — it would take a human years to perform an equivalent analysis.</p><p>"This technology has enormous potential when it comes to documenting changes on a global scale and ultimately, in contributing towards global climate goals," says co-author Christian Igel. "It is a motivation for us to develop this type of beneficial artificial intelligence."</p><p>"Indeed," says Brandt says, "I think it marks the beginning of a new scientific era."</p>