Why 'Change without Change' Is One of the Fundamental Principles of the Universe
Symmetry is about way more than splitting circles: It's change without change, and it has applications throughout mathematics, physics, and nature.
Frank Wilczek is an American theoretical physicist, mathematician and a Nobel laureate. He is currently the Herman Feshbach Professor of Physics at the Massachusetts Institute of Technology (MIT). Wilczek, along with David Gross and H. David Politzer, was awarded the Nobel Prize in Physics in 2004 for their discovery of asymptotic freedom in the theory of the strong interaction. He is on the Scientific Advisory Board for the Future of Life Institute. His new book is titled A Beautiful Question: Finding Nature's Deep Design.
Frank Wilczek: Symmetry in common usage is a kind of vague term like most terms in common usage. We use it flexibly. The idea of symmetry that has turned out to be extremely fruitful in mathematics and physics and in the fundamental description of nature is a precise distillation of some aspects of the common usage. So it’s not unnatural to call it symmetry, but it’s something very precise that we can describe.
When I say what it is it’ll sound kind of mystical, but it’s actually — I’ll spell it out and you’ll see what I mean. So symmetry in the sense that’s turned out to be fruitful in mathematics and physics and fundamental investigations is change without change. Now you might be puzzled. What does that have to do with symmetry? Well consider a circle. A circle is a very symmetric object. You can rotate it around its center by any angle and although every point on the circle may move, the circle as a whole doesn’t change. And that’s what makes it symmetric in the intuitive sense. You can change it. You can make changes on it which might have changed it, but although they transformed each part of it, don’t transform the thing as a whole. So that’s what makes a circle a symmetric object.
An equilateral triangle, for instance, you can’t rotate through any angle and get the same thing. It’ll change. If you rotate it one-third of the way around though by 120 degrees, it goes over into itself. If you rotate around the center by 120 degrees, it’s the same equilateral triangle. Whereas if you take some lopsided triangle, it’ll never go back to itself until you come all the way back to a trivial transformation. That doesn’t change anything. So change — so a triangle has less symmetry than a circle according to this concept, but some symmetry.
And so you start to see how this concept of change without change matches the intuitive notion of symmetry. The great advantage of that definition is that you can apply it in very broad context not only to describing the symmetry of objects, but to describing the symmetry of physical laws or the symmetry of equations. So, for instance, the theory of relativity is a statement of symmetry that if you change the way the world looks by moving past it at a constant velocity, you change the appearance of everything that’s happening. But the underlying laws are still valid. That’s the assumption of the theory of relativity that drives it and makes it powerful.
The idea that the laws of physics don’t change as a function of time is also a symmetry because it means you can change when you start your clocks and although the time stamps you’ll give to each event look different, the underlying equations will be the same. That’s the way of staying, that the laws of physics don’t change. And similarly with that the fact that the same physical laws apply at different places is a symmetry because you can change your position without changing the way the laws work. So symmetry is a very powerful constraint on our description of the world that nature seems to respect in many ways. Now the kind of symmetry that leads to quantum chromodynamics or general relativity or quantum electrodynamics is, mathematically, considerably more complex but it’s the same idea.
So there are transformations of the equations that change the different terms in them. So they might change an electric field into a magnetic field or a magnetic field into a combination of electric and magnetic that change the way the equations look, but don’t change their consequences. So the equations look quite different — some parts have moved over to the left and some parts have moved over to the right and some things have been multiplied in funny ways. But their consequences, their content is exactly the same. That’s the kind of equations that are like the circles among equations — are ones that have this symmetry property and those are the kinds of equations that turn out to be the ones that appear most prominently in our fundamental description of nature. It’s an extraordinary thing — but that’s not only true, but that’s how we got to the equations in the first place.
In his new book A Beautiful Question, theoretical physicist and Nobel laureate Frank Wilczek marries the age-old human quest for beauty and the age-old human quest for truth into a thrilling synthesis: The universe wants to be beautiful. In this video interview, Wilczek delves deep into the fundamental idea of symmetry. Did you know symmetry is much more complex than what we were taught in school? The possible and plausible abstractions of symmetry throughout physics and nature are plenty. The world is full of instances of change without changing.
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How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.
- A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
- It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
- While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Tribalism and discrimination<p>One question the "Genetic Pressure" series explores: What would tribalism and discrimination look like in a world with designer babies? As designer babies grow up, they could be noticeably different from other people, potentially being smarter, more attractive and healthier. This could breed resentment between the groups—as it does in the series.</p><p>"[Designer babies] slowly find that 'everyone else,' and even their own parents, becomes less and less tolerable," author Eugene Clark told Big Think. "Meanwhile, everyone else slowly feels threatened by the designer babies."</p><p>For example, one character in the series who was born a designer baby faces discrimination and harassment from "normal people"—they call her "soulless" and say she was "made in a factory," a "consumer product." </p><p>Would such divisions emerge in the real world? The answer may depend on who's able to afford designer baby services. If it's only the ultra-wealthy, then it's easy to imagine how being a designer baby could be seen by society as a kind of hyper-privilege, which designer babies would have to reckon with. </p><p>Even if people from all socioeconomic backgrounds can someday afford designer babies, people born designer babies may struggle with tough existential questions: Can they ever take full credit for things they achieve, or were they born with an unfair advantage? To what extent should they spend their lives helping the less fortunate? </p>
Sexuality dilemmas<p>Sexuality presents another set of thorny questions. If a designer baby industry someday allows people to optimize humans for attractiveness, designer babies could grow up to find themselves surrounded by ultra-attractive people. That may not sound like a big problem.</p><p>But consider that, if designer babies someday become the standard way to have children, there'd necessarily be a years-long gap in which only some people are having designer babies. Meanwhile, the rest of society would be having children the old-fashioned way. So, in terms of attractiveness, society could see increasingly apparent disparities in physical appearances between the two groups. "Normal people" could begin to seem increasingly ugly.</p><p>But ultra-attractive people who were born designer babies could face problems, too. One could be the loss of body image. </p><p>When designer babies grow up in the "Genetic Pressure" series, men look like all the other men, and women look like all the other women. This homogeneity of physical appearance occurs because parents of designer babies start following trends, all choosing similar traits for their children: tall, athletic build, olive skin, etc. </p><p>Sure, facial traits remain relatively unique, but everyone's more or less equally attractive. And this causes strange changes to sexual preferences.</p><p>"In a society of sexual equals, they start looking for other differentiators," he said, noting that violet-colored eyes become a rare trait that genetically engineered humans find especially attractive in the series.</p><p>But what about sexual relationships between genetically engineered humans and "normal" people? In the "Genetic Pressure" series, many "normal" people want to have kids with (or at least have sex with) genetically engineered humans. But a minority of engineered humans oppose breeding with "normal" people, and this leads to an ideology that considers engineered humans to be racially supreme. </p>
Regulating designer babies<p>On a policy level, there are many open questions about how governments might legislate a world with designer babies. But it's not totally new territory, considering the West's dark history of eugenics experiments.</p><p>In the 20th century, the U.S. conducted multiple eugenics programs, including immigration restrictions based on genetic inferiority and forced sterilizations. In 1927, for example, the Supreme Court ruled that forcibly sterilizing the mentally handicapped didn't violate the Constitution. Supreme Court Justice Oliver Wendall Holmes wrote, "… three generations of imbeciles are enough." </p><p>After the Holocaust, eugenics programs became increasingly taboo and regulated in the U.S. (though some states continued forced sterilizations <a href="https://www.uvm.edu/~lkaelber/eugenics/" target="_blank">into the 1970s</a>). In recent years, some policymakers and scientists have expressed concerns about how gene-editing technologies could reanimate the eugenics nightmares of the 20th century. </p><p>Currently, the U.S. doesn't explicitly ban human germline genetic editing on the federal level, but a combination of laws effectively render it <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">illegal to implant a genetically modified embryo</a>. Part of the reason is that scientists still aren't sure of the unintended consequences of new gene-editing technologies. </p><p>But there are also concerns that these technologies could usher in a new era of eugenics. After all, the function of a designer baby industry, like the one in the "Genetic Pressure" series, wouldn't necessarily be limited to eliminating genetic diseases; it could also work to increase the occurrence of "desirable" traits. </p><p>If the industry did that, it'd effectively signal that the <em>opposites of those traits are undesirable. </em>As the International Bioethics Committee <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">wrote</a>, this would "jeopardize the inherent and therefore equal dignity of all human beings and renew eugenics, disguised as the fulfillment of the wish for a better, improved life."</p><p><em>"Genetic Pressure Volume I: Baby Steps"</em><em> by Eugene Clark is <a href="http://bigth.ink/38VhJn3" target="_blank">available now.</a></em></p>
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A new study explains how a chaotic region just outside a black hole's event horizon might provide a virtually endless supply of energy.
- In 1969, the physicist Roger Penrose first proposed a way in which it might be possible to extract energy from a black hole.
- A new study builds upon similar ideas to describe how chaotic magnetic activity in the ergosphere of a black hole may produce vast amounts of energy, which could potentially be harvested.
- The findings suggest that, in the very distant future, it may be possible for a civilization to survive by harnessing the energy of a black hole rather than a star.
The ergosphere<p>The ergosphere is a region just outside a black hole's event horizon, the boundary of a black hole beyond which nothing, not even light, can escape. But light and matter just outside the event horizon, in the ergosphere, would also be affected by the immense gravity of the black hole. Objects in this zone would spin in the same direction as the black hole at incredibly fast speeds, similar to objects floating around the center of a whirlpool.</p><p>The Penrose process states, in simple terms, that an object could enter the ergosphere and break into two pieces. One piece would head toward the event horizon, swallowed by the black hole. But if the other piece managed to escape the ergosphere, it could emerge with more energy than it entered with.</p><p>The movie "Interstellar" provides an example of the Penrose process. Facing a fuel shortage on a deep-space mission, the crew makes a last-ditch effort to return home by entering the ergosphere of a blackhole, ditching part of their spacecraft, and "slingshotting" away from the black hole with vast amounts of energy.</p><p>In a recent study published in the American Physical Society's <a href="https://journals.aps.org/prd/abstract/10.1103/PhysRevD.103.023014" target="_blank" style="">Physical Review D</a><em>, </em>physicists Luca Comisso and Felipe A. Asenjo used similar ideas to describe another way energy could be extracted from a black hole. The idea centers on the magnetic fields of black holes.</p><p style="margin-left: 20px;">"Black holes are commonly surrounded by a hot 'soup' of plasma particles that carry a magnetic field," Comisso, a research scientist at Columbia University and lead study author, told <a href="https://news.columbia.edu/energy-particles-magnetic-fields-black-holes" target="_blank" rel="noopener noreferrer">Columbia News</a>.</p>
Event Horizon Telescope Collaboration<p>While there might not be immediate applications for the theory, it could help scientists better understand and observe black holes. On an abstract level, the findings may expand the limits of what scientists imagine is possible in deep space.</p><p style="margin-left: 20px;">"Thousands or millions of years from now, humanity might be able to survive around a black hole without harnessing energy from stars," Comisso said. "It is essentially a technological problem. If we look at the physics, there is nothing that prevents it."</p>
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PARME staff archaeologists excavating a burial site at the Tamanache site, Mérida, Yucatan.
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