Why are so many objects in space shaped like discs?
It's one of the most consistent patterns in the unviverse. What causes it?
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.
MICHELLE THALLER: Rick, you have noticed one of the most wonderful and consistent patterns in the whole universe. The universe is very good at making spinning discs. Our solar system is a disc, and all the planets go around in basically the same plane, and they all go around in the same direction. Why should that be?
There are discs all over the place. I mean, think about the rings of Saturn. The rings of Saturn are also very, very thin, and they all go around in the same direction. Galaxies, spiral galaxies are one big disc with everything moving around a common center. Discs seem to be something that the universe likes to make. And, in fact, that really is true. And it has to do with a number of things. It has to do with the force of gravity and something called the conservation of angular momentum.
Now, gravity is very good at bringing stuff together and bringing it together so it becomes denser and denser and begins to fall into the center. Our solar system formed out of a giant cloud of dust and gas about 4 and 1/2 billion years ago. It was actually many trillions of miles across at first, but it had to get much smaller in order for the densities to get high enough and the temperatures also to get warm enough inside to give birth to the Sun, actually ignite a star. So you have this collapsing cloud of dust.
OK, well, you can sort of understand that gravity wants to bring all that together, but why does it start to spin up? There's something called the conservation of angular momentum. And that basically says that if anything has any spin at all, even just a little bit of motion, as gravity brings it together and makes it smaller, that spin is accelerated; it's sped up. And probably the example most people know best of all – you can actually feel this if you want to do this – but an ice skater. If you've seen an ice skater do a spin, usually what they do is that they have their arms outstretched, and they're spinning around relatively slowly. And then they bring their arms in, and they spin faster and faster. It's kind of amazing that any person can keep their balance when they do that. That is an application of the conservation of angular momentum. You have an extended body, your arms are out, and you're spinning slowly. In order to conserve the energy in that spin, as that body becomes smaller, the spin goes faster and faster. And so what happens in these clouds is that a cloud usually has just a tiny little bit of a drift velocity. It's going around the galaxy or maybe a nearby star exploded, and it's kind of all moving in one direction. The cloud itself has a little bit of velocity as a cloud, as a whole. Particles inside that cloud could be going any which way.
But as the cloud begins to come together under gravity, any little bit of spin gets accelerated, actually becomes faster. And so as the cloud collapses, any little directional drift becomes a spin, and the cloud itself begins to spin around. OK, so that gets you a spinning cloud. Why does it collapse down into a disc? And this is an interesting bit of physics that has to do with things like collisions. In the case of a very large cloud that's forming a star, it might not even be that things are colliding directly, but gravitationally they're influencing them as you go by. As you go by different parts of mass, they tug on each other with their gravity. So this whole cloud is spinning, and things begin to interact gravitationally. They begin to collide with each other. The particles have motion in every direction. Some are going up, and some are going down. And as they start to hit each other, that's kind of balanced out; that up and down is sort of canceled out, but everything has the same motion as the cloud is spinning. So that's basically the only thing that's left over at the end. Everything gets canceled out as all these things collide and interact, but the spin of the cloud is still there. And so over time, you collapse down into a disc. So the only reason you make discs is because of this law of conservation of angular momentum, and the idea of gravity brings things together. Have those two things working side-by-side, and you get a disc. And that's why our solar system formed that way. The planets then formed out of that spinning disc of gas. So it makes sense that they're all going in the same direction. They all formed out of the gas going around the Sun in that way.
- Spinning discs are everywhere – just look at our solar system, the rings of Saturn, and all the spiral galaxies in the universe.
- Spinning discs are the result of two things: The force of gravity and a phenomenon in physics called the conservation of angular momentum.
- Gravity brings matter together; the closer the matter gets, the more it accelerates – much like an ice skater who spins faster and faster the closer their arms get to their body. Then, this spinning cloud collapses due to up and down and diagonal collisions that cancel each other out until the only motion they have in common is the spin – and voila: A flat disc.
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While not the first such minister, the loneliness epidemic in Japan will make this one the hardest working.
- The Japanese government has appointed a Minister of Loneliness to implement policies designed to fight isolation and lower suicide rates.
- They are the second country, after the U.K., to dedicate a cabinet member to the task.
- While Japan is famous for how its loneliness epidemic manifests, it isn't alone in having one.
The Ministry of Loneliness<iframe width="730" height="430" src="https://www.youtube.com/embed/I5FIohjZT8o" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p><a href="https://www.jimin.jp/english/profile/members/114749.html" target="_blank" rel="noopener noreferrer">Tetsushi Sakamoto</a>, already in the government as the minister in charge of raising Japan's low birthrate and revitalizing regional economies, was appointed this <a href="https://www.japantimes.co.jp/news/2021/02/21/national/japan-tackles-loneliness/" target="_blank" rel="noopener noreferrer">month</a> to the additional role. He has already announced plans for an emergency national forum to discuss the issue and share the testimony of lonely <a href="https://www.japantimes.co.jp/news/2021/02/12/national/loneliness-isolation-minister/" target="_blank" rel="noopener noreferrer">individuals</a>.</p><p>Given the complexity of the problem, the minister will primarily oversee the coordination of efforts between different <a href="https://www.insider.com/japan-minister-of-loneliness-suicides-rise-pandemic-2021-2" target="_blank" rel="noopener noreferrer">ministries</a> that hope to address the issue alongside a task <a href="https://www.japantimes.co.jp/news/2021/02/21/national/japan-tackles-loneliness/" target="_blank" rel="noopener noreferrer">force</a>. He steps into his role not a moment too soon. The loneliness epidemic in Japan is uniquely well known around the world.</p><p><a href="https://en.wikipedia.org/wiki/Hikikomori" target="_blank" rel="noopener noreferrer"><em>Hikikomori</em></a><em>,</em> often translated as "acute social withdrawal," is the phenomenon of people completely withdrawing from society for months or years at a time and living as modern-day hermits. While cases exist in many <a href="https://www.frontiersin.org/articles/10.3389/fpsyt.2019.00247/full" target="_blank" rel="noopener noreferrer">countries</a>, the problem is better known and more prevalent in Japan. Estimates vary, but some suggest that one million Japanese live like this and that 1.5 million more are at <a href="https://www.nationalgeographic.com/photography/article/japan-hikikomori-isolation-society" target="_blank" rel="noopener noreferrer">risk</a> of developing the condition. Individuals practicing this hermitage often express contentment with their isolation at first before encountering severe symptoms of loneliness and <a href="https://www.sciencedaily.com/releases/2020/01/200110155241.htm" target="_blank" rel="noopener noreferrer">distress</a>.</p><p><a href="https://en.wikipedia.org/wiki/Kodokushi" target="_blank" rel="noopener noreferrer"><em>Kodokushi</em></a>, the phenomenon of the elderly dying alone and remaining undiscovered for some time due to their isolation, is also a widespread issue in Japan that has attracted national attention for decades.</p><p>These are just the most shocking elements of the loneliness crisis. As we've discussed before, loneliness can cause health issues akin to <a href="https://www.inc.com/amy-morin/americas-loneliness-epidemic-is-more-lethal-than-smoking-heres-what-you-can-do-to-combat-isolation.html" target="_blank" rel="noopener noreferrer">smoking</a>. A lack of interaction within a community can cause social <a href="https://bigthink.com/in-their-own-words/how-religious-neighbors-are-better-neighbors" target="_self">problems</a>. It is even associated with changes in the <a href="https://bigthink.com/mind-brain/loneliness-brain" target="_self">brain</a>. While there is nothing wrong with wanting a little time to yourself, the inability to get the socialization that many people need is a real problem with real <a href="https://bigthink.com/mind-brain/brain-loneliness-hunger" target="_self">consequences</a>.</p>
The virus that broke the camel's back<iframe width="730" height="430" src="https://www.youtube.com/embed/Hp-L844-5k8" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p> A global loneliness pandemic existed before COVID-19, and the two working in tandem has been catastrophic. </p><p>Japanese society has always placed a value on solitude, often associating it with self-reliance, which makes dealing with the problem of excessive solitude more difficult. Before the pandemic, 16.1 percent of Japanese seniors reported having nobody to turn to in a time of need, the highest rate of any nation <a href="https://www.japantimes.co.jp/news/2021/02/21/national/japan-tackles-loneliness/" target="_blank" rel="noopener noreferrer">considered</a>. Seventeen percent of Japanese men surveyed in 2005 said that they "rarely or never spend time with friends, colleagues, or others in social groups." This was three times the average rate of other <a href="http://www.oecd.org/sdd/37964677.pdf" target="_blank" rel="noopener noreferrer">countries</a>. </p><p>American individualism also creates a fertile environment for isolation to grow. About a month before the pandemic started, nearly<a href="https://www.npr.org/sections/health-shots/2020/01/23/798676465/most-americans-are-lonely-and-our-workplace-culture-may-not-be-helping" target="_blank" rel="noopener noreferrer"> 3 in 5</a> Americans reported being lonely in a <a href="https://www.cigna.com/about-us/newsroom/studies-and-reports/combatting-loneliness/" target="_blank" rel="noopener noreferrer">report</a> issued by Cigna. This is a slight increase over previous studies, which had been pointing in the same direction for years. </p><p>In the United Kingdom, the problem prompted the creation of the Jo Cox Commission on Loneliness. The commission's <a href="https://www.ageuk.org.uk/globalassets/age-uk/documents/reports-and-publications/reports-and-briefings/active-communities/rb_dec17_jocox_commission_finalreport.pdf" target="_blank" rel="noopener noreferrer">final report </a>paints a stark picture of the U.K.'s situation in 2017, with millions of people from all parts of British society reporting feeling regular loneliness at a tremendous cost to personal health, society, and the economy.</p><p>The report called for a lead minister to address the problem at the national level, incorporating government action with the insights provided by volunteer organizations, businesses, the NHS, and other organizations on the crisis's front lines. Her Majesty's Government acted on the report and appointed the first Minister for Loneliness in <a href="https://time.com/5248016/tracey-crouch-uk-loneliness-minister/" target="_blank" rel="noopener noreferrer">2018</a>, <a href="https://en.wikipedia.org/wiki/Tracey_Crouch" target="_blank" rel="noopener noreferrer">Tracey Crouch</a>, and dedicated millions of pounds to battling the problem. </p><p>The distancing procedures necessitated by the COVID-19 epidemic saved many lives but exacerbated an existing problem of loneliness in many parts of the world. While the issue had received attention before, Japan's steps to address the situation suggest that people are now willing to treat it with the seriousness it deserves.</p><p>--</p><p><em>If you or a loved one are having suicidal thoughts, help is available. The suicide prevention hotline can be reached at 1-800-273-8255.</em></p>
MIT professor Azra Akšamija creates works of cultural resilience in the face of social conflict.
Scientists use new methods to discover what's inside drug containers used by ancient Mayan people.
- Archaeologists used new methods to identify contents of Mayan drug containers.
- They were able to discover a non-tobacco plant that was mixed in by the smoking Mayans.
- The approach promises to open up new frontiers in the knowledge of substances ancient people consumed.
PARME staff archaeologists excavating a burial site at the Tamanache site, Mérida, Yucatan.
Do they really need the human touch?
- In Pinduoduo's Smart Agriculture Competition, four technology teams competed with traditional farmers over four months to grow strawberries.
- Data analysis, intelligent sensors and greenhouse automation helped the scientists win.
- Fourth Industrial Revolution technologies such as AI are forecast to deliver huge productivity gains – but need the right governance, according to the Global Technology Governance Report 2021.
Pinduoduo<h3>Growing potential</h3><p>Numerous studies show the potential for Fourth Industrial Revolution technologies like AI to boost economic growth and productivity.</p><p>By 2035, labour productivity in developed countries could rise by 40% due to the influence of AI, according to<a href="https://www.weforum.org/agenda/2020/12/ai-productivity-automation-artificial-intelligence-countries/" target="_blank" rel="noopener noreferrer"> analysis from Accenture and Frontier Economics</a>.</p><p>Sweden, the US and Japan are expected to see the highest productivity increases.</p>