889 posts tagged Science
What Is the Universe? Real Physics Has Some Mind-Bending Answers
Science says the universe could be a hologram, a computer program, a black hole or a bubble—and there are ways to check
The questions are as big as the universe and (almost) as old as time: Where did I come from, and why am I here? That may sound like a query for a philosopher, but if you crave a more scientific response, try asking a cosmologist. This branch of physics is hard at work trying to decode the nature of reality by matching mathematical theories with a bevy of evidence. Today most cosmologists think that the universe was created during the big bang about 13.8 billion years ago, and it is expanding at an ever-increasing rate. The cosmos is woven into a fabric we call space-time, which is embroidered with a cosmic web of brilliant galaxies and invisible dark matter. It sounds a little strange, but piles of pictures, experimental data and models compiled over decades can back up this description. And as new information gets added to the picture, cosmologists are considering even wilder ways to describe the universe—including some outlandish proposals that are nevertheless rooted in solid science:
The universe is a hologram
Look at a standard hologram, printed on a 2D surface, and you’ll see a 3D projection of the image. Decrease the size of the individual dots that make up the image, and the hologram gets sharper. In the 1990s, physicists realized that something like this could be happening with our universe.
Classical physics describes the fabric of space-time as a four-dimensional structure, with three dimensions of space and one of time. Einstein’s theory of general relativity says that, at its most basic level, this fabric should be smooth and continuous. But that was before quantum mechanics leapt onto the scene. While relativity is great at describing the universe on visible scales, quantum physics tells us all about the way things work on the level of atoms and subatomic particles. According to quantum theories, if you examine the fabric of space-time close enough, it should be made of teeny-tiny grains of information, each a hundred billion billion times smaller than a proton.
Stanford physicist Leonard Susskind and Nobel prize winner Gerard ‘t Hooft have each presented calculations showing what happens when you try to combine quantum and relativistic descriptions of space-time. They found that, mathematically speaking, the fabric should be a 2D surface, and the grains should act like the dots in a vast cosmic image, defining the “resolution” of our 3D universe. Quantum mechanics also tells us that these grains should experience random jitters that might occasionally blur the projection and thus be detectable. Last month, physicists at the U.S. Department of Energy’s Fermi National Accelerator Laboratory started collecting data with a highly sensitive arrangement of lasers and mirrors called the Holometer. This instrument is finely tuned to pick up miniscule motion in space-time and reveal whether it is in fact grainy at the smallest scale. The experiment should gather data for at least a year, so we may know soon enough if we’re living in a hologram.
The universe is a computer simulation
Just like the plot of the Matrix, you may be living in a highly advanced computer program and not even know it. Some version of this thinking has been debated since long before Keanu uttered his first “whoa”. Plato wondered if the world as we perceive it is an illusion, and modern mathematicians grapple with the reason math is universal—why is it that no matter when or where you look, 2 + 2 must always equal 4? Maybe because that is a fundamental part of the way the universe was coded.
In 2012, physicists at the University of Washington in Seattle said that if we do live in a digital simulation, there might be a way to find out. Standard computer models are based on a 3D grid, and sometimes the grid itself generates specific anomalies in the data. If the universe is a vast grid, the motions and distributions of high-energy particles called cosmic rays may reveal similar anomalies—a glitch in the Matrix—and give us a peek at the grid’s structure. A 2013 paper by MIT engineer Seth Lloyd builds the case for an intriguing spin on the concept: If space-time is made of quantum bits, the universe must be one giant quantum computer. Of course, both notions raise a troubling quandary: If the universe is a computer program, who or what wrote the code?
Being around people who are different from us makes us more creative, more diligent and harder-working
The first thing to acknowledge about diversity is that it can be difficult. In the U.S., where the dialogue of inclusion is relatively advanced, even the mention of the word “diversity” can lead to anxiety and conflict. Supreme Court justices disagree on the virtues of diversity and the means for achieving it. Corporations spend billions of dollars to attract and manage diversity both internally and externally, yet they still face discrimination lawsuits, and the leadership ranks of the business world remain predominantly white and male.It is reasonable to ask what good diversity does us. Diversity of expertise confers benefits that are obvious—you would not think of building a new car without engineers, designers and quality-control experts—but what about social diversity? What good comes from diversity of race, ethnicity, gender and sexual orientation? Research has shown that social diversity in a group can cause discomfort, rougher interactions, a lack of trust, greater perceived interpersonal conflict, lower communication, less cohesion, more concern about disrespect, and other problems. So what is the upside?The fact is that if you want to build teams or organizations capable of innovating, you need diversity. Diversity enhances creativity. It encourages the search for novel information and perspectives, leading to better decision making and problem solving. Diversity can improve the bottom line of companies and lead to unfettered discoveries and breakthrough innovations. Even simply being exposed to diversity can change the way you think. This is not just wishful thinking: it is the conclusion I draw from decades of research from organizational scientists, psychologists, sociologists, economists and demographers.
Neuroscientists identify key role of language gene
Neuroscientists have found that a gene mutation that arose more than half a million years ago may be key to humans’ unique ability to produce and understand speech. Researchers from MIT and several European universities have shown that the human version of a gene called Foxp2 makes it easier to transform new experiences into routine procedures. When they engineered mice to express humanized Foxp2, the mice learned to run a maze much more quickly than normal mice. The findings suggest that Foxp2 may help humans with a key component of learning language — transforming experiences, such as hearing the word “glass” when we are shown a glass of water, into a nearly automatic association of that word with objects that look and function like glasses, says Ann Graybiel, an MIT Institute Professor, member of MIT’s McGovern Institute for Brain Research, and a senior author of the study. “This really is an important brick in the wall saying that the form of the gene that allowed us to speak may have something to do with a special kind of learning, which takes us from having to make conscious associations in order to act to a nearly automatic-pilot way of acting based on the cues around us,” Graybiel says. Wolfgang Enard, a professor of anthropology and human genetics at Ludwig-Maximilians University in Germany, is also a senior author of the study, which appears in the Proceedings of the National Academy of Sciences this week. The paper’s lead authors are Christiane Schreiweis, a former visiting graduate student at MIT, and Ulrich Bornschein of the Max Planck Institute for Evolutionary Anthropology in Germany. All animal species communicate with each other, but humans have a unique ability to generate and comprehend language. Foxp2 is one of several genes that scientists believe may have contributed to the development of these linguistic skills. The gene was first identified in a group of family members who had severe difficulties in speaking and understanding speech, and who were found to carry a mutated version of the Foxp2 gene. In 2009, Svante Pääbo, director of the Max Planck Institute for Evolutionary Anthropology, and his team engineered mice to express the human form of the Foxp2 gene, which encodes a protein that differs from the mouse version by only two amino acids. His team found that these mice had longer dendrites — the slender extensions that neurons use to communicate with each other — in the striatum, a part of the brain implicated in habit formation. They were also better at forming new synapses, or connections between neurons. (via Neuroscientists identify key role of language gene — ScienceDaily)
John Wilkins - Philosophy of Evolutionary Biology
The philosophy of biology is a subfield of philosophy of science, which deals with epistemological, metaphysical, and ethical issues in the biological and biomedical sciences. Although philosophers of science and philosophers generally have long been interested in biology (e.g., Aristotle, Descartes, and even Kant), philosophy of biology only emerged as an independent field of philosophy in the 1960s and 1970s. Philosophers of science then began paying increasing attention to biology, from the rise of Neodarwinism in the 1930s and 1940s to the discovery of the structure of DNA in 1953 to more recent advances in genetic engineering. Other key ideas include the reduction of all life processes to biochemical reactions, and the incorporation of psychology into a broader neuroscien
Evolution’s Random Paths Lead to One Place
A massive statistical study suggests that the final evolutionary outcome — fitness — is predictable.
In his fourth-floor lab at Harvard University, Michael Desai has created hundreds of identical worlds in order to watch evolution at work. Each of his meticulously controlled environments is home to a separate strain of baker’s yeast. Every 12 hours, Desai’s robot assistants pluck out the fastest-growing yeast in each world — selecting the fittest to live on — and discard the rest. Desai then monitors the strains as they evolve over the course of 500 generations. His experiment, which other scientists say is unprecedented in scale, seeks to gain insight into a question that has long bedeviled biologists: If we could start the world over again, would life evolve the same way? Many biologists argue that it would not, that chance mutations early in the evolutionary journey of a species will profoundly influence its fate. “If you replay the tape of life, you might have one initial mutation that takes you in a totally different direction,” Desai said, paraphrasing an idea first put forth by the biologist Stephen Jay Gould in the 1980s. Desai’s yeast cells call this belief into question. According to results published in Science in June, all of Desai’s yeast varieties arrived at roughly the same evolutionary endpoint (as measured by their ability to grow under specific lab conditions) regardless of which precise genetic path each strain took. It’s as if 100 New York City taxis agreed to take separate highways in a race to the Pacific Ocean, and 50 hours later they all converged at the Santa Monica pier. The findings also suggest a disconnect between evolution at the genetic level and at the level of the whole organism. Genetic mutations occur mostly at random, yet the sum of these aimless changes somehow creates a predictable pattern. The distinction could prove valuable, as much genetics research has focused on the impact of mutations in individual genes. For example, researchers often ask how a single mutation might affect a microbe’s tolerance for toxins, or a human’s risk for a disease. But if Desai’s findings hold true in other organisms, they could suggest that it’s equally important to examine how large numbers of individual genetic changes work in concert over time. “There’s a kind of tension in evolutionary biology between thinking about individual genes and the potential for evolution to change the whole organism,” said Michael Travisano, a biologist at the University of Minnesota. “All of biology has been focused on the importance of individual genes for the last 30 years, but the big take-home message of this study is that’s not necessarily important.” (via Yeast Study Suggests Genetics Are Random but Evolution Is Not | Simons Foundation)
Could ‘solid’ light compute previously unsolvable problems?
An “artificial atom” makes photons behave like exotic matter
Researchers at Princeton University have “crystallized” light. They are not shining light through crystal — they are actually transforming light into crystal, as part of an effort to develop exotic materials such as room-temperature superconductors. The researchers locked together photons so that they became fixed in place. “It’s something that we have never seen before,” said Andrew Houck, an associate professor of electrical engineering and one of the researchers. “This is a new behavior for light.” The results raise intriguing possibilities for a variety of future materials, and also address questions in condensed matter physics — the fundamental study of matter. “We are interested in exploring — and ultimately controlling and directing — the flow of energy at the atomic level,” said Hakan Türeci, an assistant professor of electrical engineering and a member of the research team. “The goal is to better understand current materials and processes and to evaluate materials that we cannot yet create.” The team’s findings, reported online Sept. 8 in the journal Physical Review X (open access), are part of an effort to answer fundamental questions about atomic behavior by creating a device that can simulate the behavior of subatomic particles. Special-purpose quantum computers Such a tool could be an invaluable method for answering questions about atoms and molecules that are not answerable even with today’s most advanced computers. In part, that’s because current computers operate under the rules of classical mechanics, while the world of atoms and photons obeys the rules of quantum mechanics, which include a number of strange and very counterintuitive features. One of these odd properties is called “entanglement,” in which multiple particles become linked and can affect each other over long distances. A computer based on the rules of quantum mechanics could help crack problems that are currently unsolvable. But building a general-purpose quantum computer has proven to be incredibly difficult. Another approach, which the Princeton team is taking, is to build a system that directly simulates the desired quantum behavior. Although each machine is limited to a single task, it would allow researchers to answer important questions without having to solve some of the more difficult problems involved in creating a general-purpose quantum computer. The device could also allow physicists to explore fundamental questions about the behavior of matter by mimicking materials that only exist in physicists’ imaginations. (via Could ‘solid’ light compute previously unsolvable problems? | KurzweilAI)