Category Archives: Quantum Physics
U-M forms collaboration to advance quantum science and technology – University of Michigan News
The University of Michigan has formed a collaboration with Michigan State University and Purdue University to study quantum science and technology, drawing together expertise and resources to advance the field.
The three universities are partnering to form the Midwest Quantum Collaboratory, or MQC, to find grand new challenges we can work on jointly, based on the increased breadth and diversity of scientists in the collaboration, said Mack Kira, professor of electrical engineering and computer science at Michigan Engineering and inaugural director of the collaboration.
U-M researchers call quantum effects the DNA of so many phenomena people encounter in their everyday lives, ranging from electronics to chemical reactions to the study of light wavesand everything they collectively produce.
We scientists are now in a position to start combining these quantum building blocks to quantum applications that have never existed, said Kira, also a professor of physics at U-Ms College of Literature, Science, and the Arts. It is absolutely clear that any such breakthrough will happen only through a broad, diverse and interdisciplinary research effort. MQC has been formed also to build scientific diversity and critical mass needed to address the next steps in quantum science and technology.
Collaborators at U-M include Steven Cundiff, professor of physics and of electrical engineering and computer science. Cundiffs research group uses ultrafast optics to study semiconductors, semiconductor nanostructures and atomic vapors.
The main goal of the MQC is to create synergy between the research programs at these three universities, to foster interactions and collaborations between researchers in quantum science, he said.
Each university will bring unique expertise in quantum science to the collaboration. Researchers at U-M will lead research about the quantum efforts of complex quantum systems, such as photonics, or the study of light, in different semiconductors. This kind of study could inform how to make semiconductor-based computing, lighting, radar or communications millions of times faster and billions of times more energy efficient, Kira says.
Similar breakthrough potential resides in developing algorithms, chemical reactions, solar-power, magnetism, conductivity or atomic metrology to run on emergent quantum phenomena, he said.
The MQC will be a virtual institute, with in-person activities such as seminars and workshops split equally between the three universities, according to Cundiff. In the first year, MQC will launch a seminar series, virtual mini-workshops focused on specific research topics, and will hold a larger in-person workshop. The collaboration hopes fostering connections between scientists will lead to new capabilities, positioning the MQC to be competitive for large center-level funding opportunities.
We know collaboration is key to driving innovation, especially for quantum, said David Stewart, managing director of the Purdue Quantum Science and Engineering Institute. The MQC will not only provide students with scientific training, but also develop their interpersonal skills so they will be ready to contribute to a currently shorthanded quantum workforce.
The MQC will also promote development of the quantum workforce by starting a seminar series and/or journal club for only students and postdocs, and encouraging research interaction across the three universities.
MQC also provides companies with interest in quantum computing with great opportunities for collaboration with faculty and students across broad spectrums of quantum computing with the collaborative expertise spanning the three institutions, said Angela Wilson, director of the MSU Center for Quantum Computing, Science and Engineering.
Additionally, bringing together three of our nations largest universities and three of the largest quantum computing efforts provides potential employers with a great source of interns and potential employees encompassing a broad range of quantum computing.
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U-M forms collaboration to advance quantum science and technology - University of Michigan News
Emotion Isn’t the Enemy of Reason – The Atlantic
Paul Dirac was one of the greatest physicists of the 20th century. A pioneer in quantum theory, which shaped our modern world, Dirac was a genius when it came to analytical thinking. But when his colleagues asked him for advice, his secret to success had nothing to do with the traditional scientific method: Be guided, Dirac told them, by your emotions.
Why would the cold logic of theoretical physics benefit from emotion? Physics theories are expressed in mathematics, which is governed by a set of rules. But physicists dont just study existing theoriesthey invent new ones. In order to make discoveries, they have to pursue roads that feel exciting and avoid those that they fear will lead nowhere. They have to be brave enough to question assumptions and confident enough to present their conclusions to their skeptical colleagues. Dirac recognized that the best physicists are comfortable letting emotion guide their decisions.
Diracs advicelike his physicsran against the common assumption of psychology in his day: that rational thought primarily drives our behavior, and that when emotions play a role, they are likely to deflect us from our best judgment.
Today researchers have gained a deeper understanding of emotion and how it can positively influence logical choices. Consider a study led by Mark Fenton-OCreevy, a professor at the Open University Business School, in England. Fenton-OCreevy and his colleagues conducted interviews with 118 professional traders and 10 senior managers at four investment banks. The experimenters found that even among the most-experienced traders, the lower-performing ones seemed less likely to effectively engage with the emotions guiding their choiceswhether to buy or sell a set of securities, for example, with millions of dollars at stake. The most-successful traders, however, were particularly likely to acknowledge their emotions, and followed their intuitive feelings about stock options when they had limited information to draw on. They also understood that when emotions become too intense, toning them down can be necessary. The issue for the successful traders was not how to avoid emotion but how to harness it.
One way emotions aid decision making is by steering attention to both threats and opportunities. Consider the role that disgust plays in encoding your experience of foods that could sicken you. If youre about to slurp down an oyster and you notice worms crawling all over it, you dont stop and consciously analyze the details of that situation; you just gag and throw it down. The traders, similarly, have to know what to prioritize and when to actand they have to do it quickly. People think if you have a Ph.D. you will be very good, because you have an understanding of options theory, but this is not always the case, said one of the investment-bank managers the researchers interviewed. You have to also have good gut instincts, and those gut instincts are largely rooted in emotion.
Read: The best headspace for making decisions
In the past decade, scientists have begun to understand precisely how emotions and rationality act together. The key insight is that before your rational mind processes any information, the information must be selected and evaluated. Thats where emotion plays a dominant role. Each emotionfear, disgust, angercauses certain sensory data, memories, knowledge, and beliefs to be emphasized, and others downplayed, in your thought processes.
Imagine youre walking up a dark street in a relaxed state, looking forward to dinner and a concert later that evening. You may be aware of being hungry and may not register small movements in the shadows ahead, or the sound of footsteps behind you. Most of the time, ignoring those things is fine; the footsteps behind you are probably other pedestrians traveling to their own evening plans, and the movements in the shadows could just be leaves blowing in the wind. But if something triggers your fear, those sights and sounds will dominate your thinking; your sense of hunger will vanish, and the concert will suddenly seem unimportant. Thats because when you are in a fear mode of processing, you focus on sensory input; your planning shifts to the present, and your goals and priorities change. You might adjust your route to one that takes longer but is better lit, sacrificing time for safety.
In one illustrative study, researchers induced fear in their subjects by sharing a grisly account of a fatal stabbing. They then asked these participants to estimate the probability of various calamities, including other violent acts and natural disasters. Compared with subjects whose fear had not been activated, these subjects had an inflated sense of the probability of those misfortunesnot only related incidents, such as murder, but also the unrelated, such as tornadoes and floods. The gruesome stories affected the subjects mental calculus on a fundamental level, making them generally warier of environmental threats. In the world outside the laboratory, that wariness pushes you to avoid dangerous situations.
The ways in which our emotions influence our judgment arent always clear to us. In a study on disgust, for instance, scientists showed volunteers either a neutral film clip or a scene from Trainspotting in which a character reaches into the bowl of a filthy toilet. One of the characteristics of disgust is a tendency toward disposal, whether of food or other items. After playing the clips, the researchers gave the subjects the opportunity to trade away one box of unidentified office supplies for anotherand found that 51 percent of those who had seen the Trainspotting clip exchanged their box, compared with 32 percent of participants whod watched the neutral clip. But when quizzed about their decision afterward, the disgusted participants tended to justify their actions with rational reasons.
Welcoming emotion into the decision-making process can help us be more clear-eyed about where our choices come from. Dirac knew that emotion helped him look beyond the beliefs of his contemporaries. Again and again, his controversial ideas proved correct. He invented a mathematical function that seemed to violate the basic rules of the subjectbut that was eventually embraced and developed by later mathematicians. He predicted a new type of matter, called antimatteranother idea that was revolutionary at the time but is widely embraced today. And his appreciation for the role of emotion was prescient in itself. Dirac died in 1984, a couple of decades before the revolution in emotion theory began, but hed no doubt have been happy to see that hed been right again.
This article was adapted from Leonard Mlodinows forthcoming book, Emotional: How Feelings Shape Our Thinking.
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Superdeterminism and Free Will – Discovery Institute
Photo credit: Vladislav Babienko via Unsplash.
The conventional view of nature held by materialists, who deny free will, is that all acts of nature, including our human acts and beliefs, are wholly determined by the laws of nature, understood as the laws of physics. We cannot be free, they assert, because all aspects of human nature are matter, and the behavior of matter is wholly determined by physical laws. There is no room for free will
Its noteworthy that physicists who have studied determinism in nature (specifically, in quantum mechanics) have for the most part rejected this deterministic view of free will and implicitly (if not explicitly) endorsed the reality of free will. There are two reasons for this.
First, experiments that have followed from the research done by Irish physicistJohn Bell(19281990) in the 1970s have shown that determinism on a local level is not true. The theory and the experiments are subtle, but suffice to say, detailed and quite rigorous experiments have shown that the outcomes of quantum processes are not determined locally. That is, theres nothing baked in inanimate matter that determines the outcome of the quantum measurement. Nature is not locally deterministic.
The second reason that physicists have rejected determinism relates to the theory ofSuperdeterminism.Superdeterminism posits that, while inanimate matter is not locally determined, the entire universe including the thoughts and actions of the experimenters who are investigating nature is determined as a whole. The experiments based on Bells theorem have disproven local determinism but they do not disprove Superdeterminism.
The problem with Superdeterminism from the perspective of most physicists is that it seems to invalidate the process of science itself. That is, if the scientists own thoughts, ideas, and judgments are just as determined as the behavior of inanimate matter, then science itself has no claim to seek or find the truth. In other words, the laws of physics are not propositions and they have no truth value. If all of nature is an enormous robot, then it makes no sense to claim that tiny parts of the robot are seeking or have found the truth. Because Superdeterminism seems to obviate the very scientific method used to investigate it, physicists have generally rejected Superdeterminism.
Recently, however, several physicists have suggested that Superdeterminism is a quite plausible way of solving the measurement problem in quantum physics so it seems to be having a bit of a resurgence. PhysicistSabine Hossenfelderoffers aninteresting videoon the topic:
A detailed discussion of her views is beyond this post, but I note a few things:
1) I think Hossenfelder is right that Superdeterminism has been inappropriately dismissed by the physics community. It offers a rigorous and elegant way of understanding quantum mechanics and of beginning a path toward uniting quantum theory with general relativity.
2) Hossenfelder is wrong to deny the reality of free will. I think her critique of physicists who deny Superdeterminism because it denies free will has salience, but the denial of free will is self-refuting regardless of the issues in theoretical physics. Free will is a precondition for all science, all reasoning, and all claims to know the truth. As noted above, if free will is not real and all of our actions, including our investigations of reality, are determined by the laws of nature which in themselves are not propositions and have no truth value. Thus, if free will is not real, human thought has no access to truth. To deny free will is to assert it, and any denial of free will on any basis whatsoever is nonsensical. If we lack free will, we have no justification whatsoever to believe that we lack free will.
3) I do believe, however, that Superdeterminism is a viable and even attractive way of understanding nature, and that genuine free will is true and is quite compatible with Superdeterminism.
How so? Superdeterminism is the view that the outcomes of all possibilities both inanimate nature and the human mind are baked in to nature itself. There are two ways of understanding what that means. The first way is to see nature as a mindless machine running like clockwork without free will. As Ive said, such a view is incompatible with human reason.
However there is another way to understand how the outcomes of all possibilities in nature are baked into nature itself. This involves the concept of a block universe and the Augustinian understanding of nature as a thought in Gods mind.
Read the rest at Mind Matters News, published by Discovery Institutes Bradley Center for Natural and Artificial Intelligence.
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Space mission hopes to solve the riddle of ‘missing’ matter – The Irish Times
The stuff astronomers can see when they look out at the universe stars, planets, and galaxies, makes up a paltry 4 per cent of whats actually out there. The rest, a staggering 96 per cent, is made of something invisible, the nature of which scientists can only guess at.
The Euclid mission of the European Space Agency (ESA) will set out to search for the universes elusive missing matter.
Scientists have known that most of the universes mass was missing since the 1930s. That was when Fritz Zwicky, a Swiss-American astronomer, made the startling discovery that the observed mass of all the stars in a cluster of galaxies called Coma made up only 1 per cent of the mass that he calculated was required to generate enough gravitational pull to hold the cluster together.
The missing mass question simmered for decades until its presence was further confirmed in a similar fashion in the 1970s when Vera Rubin and W Kent Ford, two American astronomers, observed the mass of the stars that were visible within a typical galaxy was only about 10 per cent of what was needed to keep these stars orbiting around the galaxys centre. The missing matter was nowhere to be seen, so it was called dark matter.
Theoretical astrophysicist at Maynooth University Prof Peter Coles, who has worked as a cosmologist since 1985, says the idea of what constituted dark matter formulated back then, remains largely in place. It was a kind of neutral particle that didnt do anything fancy like interacting with other matter. It just assisted the process of gravitational instability. For that reason, it was called cold dark matter, he adds.
The 1990s saw the discovery of the cosmic microwave background (CMB) the radiation left over from the Big Bang which permeates the universe. Then, in 1998, a cosmological bombshell landed when American astrophysicist Saul Perlmutter, who set out to find by how much the expansion of the universe was slowing since the Big Bang, found this expansion was accelerating.
The accelerated expansion of the universe appeared counterintuitive: a bit like asking scientists to accept the speed of a tennis ball would endlessly accelerate after being hit by a racquet. To deal with it, scientists theorised that an invisible energy was driving this process. They called it dark energy.
The new need to accommodate dark energy meant that estimates for the amount of dark matter had to be revised downwards significantly. The new estimate, which still holds, is that the universe is made of 70 per cent dark energy, 25 per cent dark matter, and about 5 per cent normal baryonic matter that we can see.
The ESAs Euclid mission has the ambitious goal of better understanding dark energy and dark matter. It is a colossal scientific effort, involving a consortium of some 1,000 people based mainly in Europe but also worldwide. There have been delays due to Covid-19; it is now set to launch in 2023.
Euclid will use its telescope to look back through the last 10 billion years of the universes history, beginning when dark energy is thought to have started pushing the universes expansion. The light from distant, ancient galaxies takes several billion years to reach our Solar System, which means astronomers see these galaxies as they were billions of years ago.
Coles is the only Ireland-based researcher in Euclid. He is interested in why galaxies cluster in groups rather than spread randomly in space and how some kind of cosmic glue referred to as dark energy holds the clusters together. He admits no-one has any idea what this glue is, or how to find it. If you ask, what is dark energy, the correct scientific answer is that nobody knows, he says.
Euclid, at its most basic, is a satellite with a space telescope with a diameter of 1.2 metres. Thats not particularly big given the Hubble Space Telescope, has a width of 2.4 metres while the James Web Telescope launched on Christmas Day is even bigger.
Yet what Euclid does have is an impressive camera attached to its telescope, which can take high resolution images across a big field of sky.
These images will enable scientists to look back in time, deep into the early universe, to trace the evolution and formation of galaxies, galaxy clusters and much else. There is a lot that Euclid can discover, says Coles, but the big-ticket item, the one driving the mission, is the hunt for dark energy, and whether that energy, once found, is determined to be constant, or varying.
If dark energy is found to be constant, that will fit in with existing ideas of the universe, as described by Einstein. This result would disappoint all those astrophysicists hoping that dark energy, once its discovered and measured, will represent something new, exciting, and outside of existing physical laws.
The dark forces of the universe remain hidden, but physicists infer their presence from how visible matter behaves. Invisible gravitational effects are thought, for example, to hold solar systems, galaxies, galaxy clusters, even superclusters of galaxies together that would otherwise fall apart.
Invisible forces of gravity are also thought to bend light around visible matter, in a process called weak lensing. This results in the distortion, stretching or magnification of the shape of galaxies, and the resulting patterns can be used to calculate the distribution of dark matter.
Measuring redshift can provide further clues. This term dates back to 1929 when Edwin Hubble discovered that the universe is expanding, and that galaxies are mostly moving away from us. Hubble found that the wavelengths of light emitted from galaxies shifts from shorter wavelengths to longer wavelengths as galaxies move away from us. The light, Hubble said, was redshifted from shorter UV wavelengths to the longer red wavelengths.
Calculating the redshift of galaxies today enables scientists to produce a 3D map of the universe. Scientists use redshift to measure the distance each galaxy is from us, the rate of accelerated expansion of the Universe, and how galaxies have moved with respect to one another. The nature of dark energy, which is thought to drive all of this, can, be inferred as a result.
Scientists get excited when they think about what exactly dark energy might be. There are some that believe dark energy represents a completely new physics, outside of the known physical laws, but until such theories can be tested with data from Euclid, it will remain nothing more than a name given to something that scientists dont understand. Any new theory of how the universe works will have to fit with observational data from Euclid.
If Euclid finds, measures and quantify dark energy and dark matter, it will be one of historys greatest scientific achievements. It will open the door for something Einstein tried but failed to achieve: a theory of everything that explains and links the physics of big stuff like stars, planets, and galaxies with the weird quantum physics of tiny atoms and sub-atomic particles.
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Space mission hopes to solve the riddle of 'missing' matter - The Irish Times
Ben Stokes injury adds to England woes on wicketless second morning in Sydney – newsconcerns
Englands hopes of forging ahead in the fourth Ashes Test fell foul of a wicketless second morning in Sydney with a dropped catch and an injury to Ben Stokes adding to their woes.
The tourists have already surrendered the urn after sustaining an irretrievable 3-0 deficit in the series but were in a promising position after restricting their opponents to 126 for three on a rain-affected first day.
But they were unable to add to their tally as 51 not out from Steve Smith and an unbeaten 39 from the returning Usman Khawaja took the score to 209 for three at lunch.
Jack Leach, right, was let down by the catching efforts of Jos Buttler and captain Joe Root (Jason OBrien/PA)
(PA Wire)
Spinner Jack Leach should have dismissed Khawaja for 29, but wicketkeeper Jos Buttler and slip Joe Root were both guilty of sloppy handiwork as they combined to fluff the chance. As if that was not bad enough, England had to endure the sight of all-rounder Stokes leaving the field in pain during the very next over.
He had been bowling a barrage of bouncers in a bid to unsettle the fourth-wicket pair but the effort took its toll as he clasped his side in his follow through and immediately left the field seeking treatment.
With hopes high after a late double strike the previous evening, England walked off the field looking browbeaten once again.
After just 46.5 overs were possible on day one, play was brought forward half-an-hour to try and make up lost time. But instead, the New South Wales weather continued to frustrate as there were three separate rain breaks for passing showers.
Steve Smith celebrated a half-century just before lunch (Jason OBrien/PA)
(PA Wire)
The first short passage of play saw England use all four of their specialist bowlers inside eight overs as the Australia duo settled in. The second saw the batting pair move on to the front foot, Smith pumping James Andersons first ball back down the ground as he over-pitched and Khawaja striking Leach through the infield.
Smith appeared keener than most to get off when the weather changed again, despite looking perfectly settled, and his eagerness to indulge the interruptions appeared to irk England, who declined to even leave the field during the third, and shortest, delay.
Australia were making steady progress, Khawaja cutting Leach aerially for four to bring up the 50 partnership and Smith always able to manipulate a scoring shot.
When Leach finally coaxed out an error, Buttler was not sharp enough to take the outside edge and Root spilled the ricochet as it arrived at gentle speed and perfect height. England has faced told a story of abject frustration, but that turned to anxiety as Stokes short-ball stint saw him injure his left side trying in vain to force the issue.
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Ben Stokes injury adds to England woes on wicketless second morning in Sydney - newsconcerns
2022 will boost quantum physics and space exploration – Central Valley Business Journal
01/02/2022
Act. At 10:52 CET
Drafting T21
The year 2022 will be important for quantum physics, with the restart of activities of the Large Hadron Collider at CERN, as well as for space exploration, which will not only bring us closer to the Moon and Mars, but will also crash a suicide probe against a distant asteroid.
The journal Nature advances that the year that now begins promises significant advances in the field of Physics and space exploration.
It notes that after a multi-year shutdown and extensive maintenance work, the Large Hadron Collider (LHC) is scheduled to restart operations at CERN, the European particle physics laboratory outside Geneva, in June, Swiss.
The main LHC experiments, ATLAS and CMS, were updated and expanded with additional layers of detector components. This will allow them to collect more data from the 40 million proton collisions that each of them produces every second, the magazine notes.
The Large Hadron Collider returns in 2022. | CNRS
And after their own updates, the worlds four gravitational wave detectors one in Japan, one in Italy and two in the United States will also begin a new series of observations in December 2022.
Additionally, the magazine adds, at Michigan State University in East Lansing, the rare isotope beam facility is expected to begin operations early in the new year.
The multistage accelerator aims to synthesize thousands of new isotopes of known elements, and will investigate the nuclear structure and physics of neutron stars and supernova explosions.
The magazine stands out as the second relevant scientific field in the new year will be space.
Remember that a veritable armada of orbiters and landers from space agencies and private companies is scheduled to leave for the Moon this year.
NASA will launch the Artemis I orbiter in the long-awaited first launch system test that will eventually carry astronauts back to the Moons surface.
Likewise, the US agencys CAPSTONE orbiter will carry out experiments in preparation for Gateway, the first space station to orbit the Moon.
Indias third lunar mission, Chandrayaan-3, aims to be the first to make a soft landing (one that does not damage the spacecraft) and will carry its own rover.
Japan will also attempt its first soft landing on the Moon, with the SLIM mission, as well as put a transformable robot on its surface, in order to prepare for the deployment of a future manned rover, which would arrive at our satellite in 2029.
For its part, Russia aims to revive the glory of the Soviet lunar program with the Luna 25 lander. The Korea Pathfinder Lunar Orbiter will inaugurate South Koreas own lunar exploration.
In 2022 we will also advance in the knowledge and terraforming of Mars, with an eye to sending the first human expeditions later.
An epic space trip will be the joint Russian-European ExoMars mission, which is scheduled to take off in September and will take the European Space Agencys Rosalind Franklin rover to Mars, where it will look for signs of past life.
The launch was originally scheduled for 2020, but was delayed in part due to problems with the parachutes required to land safely.
China, which hopes to send people to Mars in 2033, plans this year to complete its space station, Tiangong, and has prepared more than 1,000 experiments to do so, ranging from astronomical and Earth observation to the effects of microgravity and gravity. cosmic radiation in bacterial growth.
NASAs DART suicide probe. | NASA / JHUAPL / Steve Gribben
Asteroids wont be without news this 2022: NASAs Psyche mission will launch in August to explore a strange metal-dominated asteroid that may once have been part of the core of a long-dead planet.
NASAs Suicide Probe (DART) is also expected to hit its asteroid target this new year, hoping to crash into it and discover what it would take to launch a dangerous space rock off a trajectory that would lead to it colliding. with the Earth.
New developments are expected this year from NASAs James Webb Space Telescope, Hubbles successor, finally launched into space on December 25.
JWST is tasked with reconstructing the early history of the universe using its powerful and sensitive instrumentation to see the light from some of the universes earliest galaxies and cut through the dust to view newborn stars.
The space telescope is also expected to analyze the atmospheres of distant alien planets.
Astronomers and planetary scientists have made it a priority for this decade to find a potential Earth twin orbiting a star like the Sun. We are on our way to that, and 2022 may reveal something about it.
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2022 will boost quantum physics and space exploration - Central Valley Business Journal
This is why physicists suspect the Multiverse very likely exists – Big Think
When we look out at the Universe today, it simultaneously tells us two stories about itself. One of those stories is written on the face of what the Universe looks like today, and includes the stars and galaxies we have, how theyre clustered and how they move, and what ingredients theyre made of. This is a relatively straightforward story, and one that weve learned simply by observing the Universe we see.
But the other story is how the Universe came to be the way it is today, and thats a story that requires a little more work to uncover. Sure, we can look at objects at great distances, and that tells us what the Universe was like in the distant past: when the light thats arriving today was first emitted. But we need to combine that with our theories of the Universe the laws of physics within the framework of the Big Bang to interpret what occurred in the past. When we do that, we see extraordinary evidence that our hot Big Bang was preceded and set up by a prior phase: cosmic inflation. But in order for inflation to give us a Universe consistent with what we observe, theres an unsettling appendage that comes along for the ride: a multiverse. Heres why physicists overwhelmingly claim that a multiverse must exist.
Back in the 1920s, the evidence became overwhelming that not only were the copious spirals and ellipticals in the sky actually entire galaxies unto themselves, but that the farther away such a galaxy was determined to be, the greater the amount its light was shifted to systematically longer wavelengths. While a variety of interpretations were initially suggested, they all fell away with more abundant evidence until only one remained: the Universe itself was undergoing cosmological expansion, like a loaf of leavening raisin bread, where bound objects like galaxies (e.g., raisins) were embedded in an expanding Universe (e.g., the dough).
If the Universe was expanding today, and the radiation within it was being shifted towards longer wavelengths and lower energies, then in the past, the Universe must have been smaller, denser, more uniform, and hotter. As long as any amount of matter and radiation are a part of this expanding Universe, the idea of the Big Bang yields three explicit and generic predictions:
All three of these predictions have been observationally borne out, and thats why the Big Bang reigns supreme as our leading theory of the origin of our Universe, as well as why all its other competitors have fallen away. However, the Big Bang only describes what our Universe was like in its very early stages; it doesnt explain why it had those properties. In physics, if you know the initial conditions of your system and what the rules that it obeys are, you can predict extremely accurately to the limits of your computational power and the uncertainty inherent in your system how it will evolve arbitrarily far into the future.
But what initial conditions did the Big Bang need to have at its beginning to give us the Universe we have? Its a bit of a surprise, but what we find is that:
Whenever we come up against a question of initial conditions basically, why did our system start off this way? we only have two options. We can appeal to the unknowable, saying that it is this way because its the only way it couldve been and we cant know anything further, or we can try to find a mechanism for setting up and creating the conditions that we know we needed to have. That second pathway is what physicists call appealing to dynamics, where we attempt to devise a mechanism that does three important things.
The only idea weve had that met these three criteria was the theory of cosmic inflation, which has achieved unprecedented successes on all three fronts.
What inflation basically says is that the Universe, before it was hot, dense, and filled with matter-and-radiation everywhere, was in a state where it was dominated by a very large amount of energy that was inherent to space itself: some sort of field or vacuum energy. Only, unlike todays dark energy, which has a very small energy density (the equivalent of about one proton per cubic meter of space), the energy density during inflation was tremendous: some 1025times greater than dark energy is today!
The way the Universe expands during inflation is different from what were familiar with. In an expanding Universe with matter and radiation, the volume increases while the number of particles stays the same, and hence the density drops. Since the energy density is related to the expansion rate, the expansion slows over time. But if the energy is intrinsic to space itself, then the energy density remains constant, and so does the expansion rate. The result is what we know as exponential expansion, where after a very small period of time, the Universe doubles in size, and after that time passes again, it doubles again, and so on. In very short order a tiny fraction of a second a region that was initially smaller than the smallest subatomic particle can get stretched to be larger than the entire visible Universe today.
During inflation, the Universe gets stretched to enormous sizes. This accomplishes a tremendous number of things in the process, among them:
This reproduces the successes of the non-inflationary hot Big Bang, provides a mechanism for explaining the Big Bangs initial conditions, and makes a slew of novel predictions that differ from a non-inflationary beginning. Beginning in the 1990s and through the present day, the inflationary scenarios predictions agree with observations, distinct from the non-inflationary hot Big Bang.
The thing is, theres a minimum amount of inflation that must occur in order to reproduce the Universe we see, and that means there are certain conditions that inflation has to satisfy in order to be successful. We can model inflation as a hill, where as long as you stay on top of the hill, you inflate, but as soon as you roll down into the valley below, inflation comes to an end and transfers its energy into matter and radiation.
If you do this, youll find that there are certain hill-shapes, or what physicists call potentials, that work, and others that dont. The key to making it work is that the top of the hill need to be flat enough in shape. In simple terms, if you think of the inflationary field as a ball atop that hill, it needs to roll slowly for the majority of inflations duration, only picking up speed and rolling quickly when it enters the valley, bringing inflation to an end. Weve quantified how slowly inflation needs to roll, which tells us something about the shape of this potential. As long as the top is sufficiently flat, inflation can work as a viable solution to the beginning of our Universe.
But now, heres where things get interesting. Inflation, like all the fields we know of, has to be a quantum field by its very nature. That means that many of its properties arent exactly determined, but rather have a probability distribution to them. The more time you allow to pass, the greater the amount that distribution spreads out. Instead of rolling a point-like ball down a hill, were actually rolling a quantum probability wavefunction down a hill.
Simultaneously, the Universe is inflating, which means its expanding exponentially in all three dimensions. If we were to take a 1-by-1-by-1 cube and call that our Universe, then we could watch that cube expand during inflation. If it takes some tiny amount of time for the size of that cube to double, then it becomes a 2-by-2-by-2 cube, which requires 8 of the original cubes to fill. Allow that same amount of time to elapse, and it becomes a 4-by-4-by-4 cube, needing 64 original cubes to fill. Let that time elapse again, and its an 8-by-8-by-8 cube, with a volume of 512. After only about ~100 doubling times, well have a Universe with approximately 1090original cubes in it.
So far, so good. Now, lets say we have a region where that inflationary, quantum ball rolls down into the valley. Inflation ends there, that field energy gets converted to matter-and-radiation, and something that we know as a hot Big Bang occurs. This region might be irregularly shaped, but its required that enough inflation occurred to reproduce the observational successes we see in our Universe.
The question becomes, then, what happensoutsideof that region?
Heres the problem: if you mandate that you get enough inflation that our Universe can exist with the properties we see, then outside of the region where inflation ends, inflation will continue. If you ask, what is the relative size of those regions, you find that if you want the regions where inflation ends to be big enough to be consistent with observations, then the regions where it doesnt end are exponentially larger, and the disparity gets worse as time goes on. Even if there are an infinite number of regions where inflation ends, there will be a larger infinity of regions where it persists. Moreover, the various regions where it ends where hot Big Bangs occur will all be causally disconnected, separated by more regions of inflating space.
Put simply, if each hot Big Bang occurs in a bubble Universe, then the bubbles simply dont collide. What we wind up with is a larger and larger number of disconnected bubbles as time goes on, all separated by an eternally inflating space.
Thats what the multiverse is, and why scientists accept its existence as the default position. We have overwhelming evidence for the hot Big Bang, and also that the Big Bang began with a set of conditions that dont come with a de facto explanation. If we add in an explanation for it cosmic inflation then that inflating spacetime that set up and gave rise to the Big Bang makes its own set of novel predictions. Many of those predictions are borne out by observation, but other predictions also arise as consequences of inflation.
One of them is the existence of a myriad of Universes, of disconnected regions each with their own hot Big Bang, that comprise what we know as a multiverse when you take them all together. This doesnt mean that different Universes have different rules or laws or fundamental constants, or that all the possible quantum outcomes you can imagine occur in some other pocket of the multiverse. It doesnt even mean that the multiverse is real, as this is a prediction we cannot verify, validate, or falsify. But if the theory of inflation is a good one, and the data says it is, a multiverse is all but inevitable.
You may not like it, and you really may not like how some physicists abuse the idea, but until a better, viable alternative to inflation comes around, the multiverse is very much here to stay. Now, at least, you understand why.
(This article is re-run from earlier in 2021 as part of a best of 2021 series that will run from Christmas Eve until the New Year. Happy holidays, everyone.)
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This is why physicists suspect the Multiverse very likely exists - Big Think
The US government needs a commercialization strategy for quantum – TechCrunch
Laura E. ThomasContributor
Laura E. Thomas is the senior director of National Security Solutions at quantum sensing and computing company ColdQuanta. She is a former Central Intelligence Agency case officer and Chief of Base who built and led sensitive programs at CIA headquarters and abroad in multiple international assignments.
TheTechCrunch Global Affairs Projectexamines the increasingly intertwined relationship between the tech sector and global politics.
Quantum computers, sensors and communications networks have the potential to bring about enormous societal and market opportunities along with an equal amount of disruption. Unfortunately for most of us it takes a Ph.D. in physics to truly understand how quantum technologies work, and luminaries in the field of physics will be the first to admit that even their understanding of quantum mechanics remains incomplete.
Fortunately you dont need an advanced degree in physics to grasp the magnitude of potential change: computers that can help us design new materials that fight the climate crisis, more accurate sensors without a reliance on GPS that enable truly autonomous vehicles and more secure communications networks are just a few of the many technologies that may emerge from quantum technology.
The challenge of the quantum industry isnt ambition; its scale. Physicists know how to design useful quantum devices. The challenge is building larger devices that scale along with innovative business models. The confluence of talented physicists, engineers and business leaders tackling the problem is reason for much confidence. More private investors are placing bets on the technology. They cant afford not to we may look back on the commercialization of quantum and compare it to the steam engine, electricity, and the internet all of which represented fundamental platform shifts in how society tackled problems and created value.
More difficult than quantum physics, however, is getting the U.S. governments regulatory and funding strategy right toward the technology. Aligning various government entities to push forward an industry while navigating landmines of regulation, Byzantine government contracting processes and the geopolitical realities of both the threats and disruptions that quantum technology portends will be a challenge much greater than building a million-qubit quantum computer.
While this claim may be slight hyperbole, Ive now worked in both worlds and seen it up close and personal. As a former CIA case officer, even at the tip of the spear, Ive seen how slowly the government moves if left to its own devices. However, Ive also seen the value it can bring if the right influencers in the right positions decide to make hard decisions.
The government can help pave the pathway for commercialization or cut the industry off at its knees before it has a chance to run. The U.S. government needs a quantum commercialization strategy in addition to its quantum R&D strategy. We need to get out of the lab and into the world. To push the industry forward, the government should:
The U.S. government must inject more money more quickly into the commercial sector for these emerging technologies. This new technological era demands that we compete at a pace and scale that the government budgeting process currently is not built to handle. Smaller companies can move fast and we are in an era where speed, not efficiency, matters most in the beginning because we have to scale up before our geopolitical competition, which is directly pouring tens of billions of dollars into the sector.
When I was at the CIA, I often heard the words Acta non verba or deeds not words. In this case, the deeds are putting money on the table in the right ways, as well as not regulating the industry too early. Not everyone in senior U.S. government positions has to believe in quantums potential. I wouldnt blame them if they have some doubts this is truly beyond rocket science. But the smart move is to hedge. The U.S. government should make such a bet by pushing a commercialization strategy now. At the least it shouldnt stand in the way of it.
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The US government needs a commercialization strategy for quantum - TechCrunch
How We Make Sense of Time – The New York Times
Time is a mystery humans have grappled with across cultures and centuries, often with ritual as our guide. January traces to Janus, the Roman god of doorways and beginnings. The ancient Babylonians charted the course of Venus, dating the dynasties of kings. The Greeks had Chronos, the god of time, and for many Hindus time was associated with Kali, who doubled as the goddess of death.
Calendars are flexible things, shaped by and for the communities that make them. The Gregorian calendar, the solar dating system commonly used today, was created by Pope Gregory XIII in the late 16th century, as a revision of the Julian calendar, established by Julius Caesar. Rosh Hashana, the Jewish New Year, arrived this year in September with the sounding of the shofar. The coming Lunar New Year will begin on Feb. 1, when the Year of the Ox, representing fortitude and strength, will give way to the Year of the Tiger, which some hope is a sign of roaring back.
I like to think of a new year being possible at any moment, as every moment is a kind of doorway, said Joy Harjo, the United States poet laureate. You can go any direction, although directions can be impeded.
This year, directions everywhere seemed blocked. Plans were made and then canceled. The ritual of the New Years party is not the same on Zoom.
Vijay Iyer, a pianist and composer, lost his father over the summer. Everyone, he said, is carrying some bit of grief.
The Great Read
Here are more fascinating talesyou cant help but read all the way to the end.
Theres what we call a lifetime, and theres the way that someones afterlife continues to matter, and the way they become part of other people, he said. Time becomes a very fluid, almost reversible thing.
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Waves in science, technology The National – The National
By MICHAEL JOHN UGLOWELCOME again to this lecture (No 14) in the Science in Action series.Our topic is on Waves as taught in science, particularly physics in this country. There is immense application of this scientific study as the world is currently living in technology and science.In pertinence, as so much of a blessing as its use of its applications in technology for the good of the society, there is a counter-productive and evil use as people are using waves in the sense of science and physics to the detriment of moral values nourishment and prosperity. That is prostitution, adultery and corruption (deeds to derail from justice) is on the rise.Control of a persons mindset and fear of doing bad with its adverse consequences to uphold dignity of a persons life is paramount and should take priority over greed, fame and selfishness.
WavesThe text messages and mobile phone communications you have every day come to you in the form of a wave. Waves are studied in physics. Waves can also be calculated in physics as well as mathematics as a signal. Waves come in many forms, includinh tidal waves, sound waves, seismic waves, gravity waves, electromagnetic waves, gravitational waves, plasma waves and terahertz waves.Waves are a travelling disturbance in space from an equilibrium point. Therefore, a wave can be travelling. Also, a wave can be static known as a static wave. Waves as studied in physics today are based on mechanical waves and electromagnetic waves and also wave probabilities from quantum mechanics. The travelling waves generate energy, momentum and information.The two most important parts to be studied about waves are the time or the period of the wave propagation and the next is the frequency at which this propagation occurs. Mechanical waves are generated as a result of strain or deformation happening in a medium of particles. As a result, it creates stresses in the nearby particles which create further stress and so on.This sends a wave of particles in motion. The mechanical waves can generate any of the two forms of waves known as longitudinal and transverse waves. Whether mechanical or electromagnetic, the magnitude of the wave can be calculated if it is in a linear wave form.A linear waveform can be a harmonic wave which is sinusoidal or simply a sine wave or a complex waveform called a superimposed wave form from which a method called Fourier analysis can be used to find the waves components of sinusoids, frequencies and wavelengths to be analysed. If a wave form is non-linear, then a Fourier analysis cannot be used because it will be very complex to work out. All wave forms travel in a form of a sinusoidal wave form and have nodes at the standing points. The standing points maintain the equilibrium points of wave at a constant amplitude and also at a constant wavelength.Sinusoidal waveform or Sine wave. Picture from electronics-tutorials.wsMechanical waves can produce transverse waves on a linear medium such as the vibrations on a string. The direction of travel together with the direction of the wave propagation are perpendicular to each other. Perpendicular means that they are at right angles to each other. Another mechanical wave that produces longitudinal wave is a sound wave. Variations in the local pressures of particles that propagating through space creates the sounds of different tones. These particles actually travel in the direction of the wave motion and are therefore said to be longitudinal.The electromagnetic waves are all transverse waves meaning they propagate in space with the constituent particles acting at right angles or perpendicular to each other. The two parts to an electromagnetic wave are the electric fields and the magnetic fields. There are many electromagnetic waves and namely the radio waves, microwaves, the terahertz wave, the infrared wave, the visible light, ultraviolet wave, the X-ray and the gamma ray waves.The change in electric fields creates a magnetic current and a change in magnetic field creates an electric current. They propagate in that mode and travel at the speed of approximately 3108 meters per second. They can travel in a vacuum and do not require a medium to travel in like the other waves.The waves can change their speed when they travel from air which is one medium of one density to another medium say a transparent glass of another medium.Air is less dense than a glass so its speed will be slower. That means with the incident light and the normal point to the glass will be the points where the light passing through will bend. It will bend towards the normal because the glass is more, dense than air. The bending of light as described here is called refraction. When we reverse the scene, as light now is made to come out from the glass into the air, that is light travelling from a more, dense medium (glass) to a less dense medium (air) then, light will bend away from the normal.In refraction, it is relevant to find the refractive index of the medium it is coming into contact with to see how much of a refraction can be measured. Snells law of refraction is normally used here. The formula is, n1/n2 = sin 2/sin 1 where n1 is the first medium and n2 is the second medium. Sin a1 and sin a2 are the sines of the angle of the first and the second medium respectively. The following is a diagrammatic representation:Snells law is defined as The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for the light of a given colour and for the given pair of media. Snells law formula is expressed as:Sin i sin r = constant = In diffraction, light is made to spread at the corners where the wavelength of the travelling wave encounters an obstacle or either an opening called an aperture that allows the wave to bend around the corner or the edge. The aperture and the obstacle become the secondary source of generation of the propagating wave.Waves get reflected as well. When they fall on or incident on a surface that does not absorb any light, they reflect all the light back.This is called reflection of light. They take the form of the perfect mirror to reflect all light rays and waves back. The three laws of reflection are 1. The angle between the incident ray and the normal is equal to the angle between the reflected ray and the normal. 2. The incident ray, the normal and the reflected ray are all in the same plane. 3. Incident ray and refracted ray are on different sides of thenormal. These laws are applied to all flat, curved, concave and all convex mirrors.In mathematics a wave can be calculated using the function F(x,t). The F takes the function form while x is a particular point when the particle is taken at a rest position. The t takes the form of a particular time at which the particle is resonating. Normally the highest amplitudes of a group wave is considered for this calculation. In the instance where you have to have several a total amount say a total of a echo of radar from an air plane is measured, then you will include the mediums or families of waves in the equation such as F(A,B; x,t) to include those families.Gravity wavesA water wave is an example of a standing wave travelling to derive the equilibrium. Such waves come under gravity waves whereby two mediums are generating waves to maintain equilibrium. Gravitational waves are rather different because, they are a disturbance in the space time in the universe as is contained in the Relativity theory.My prayer for PNG today is; Awake from your slumber. Arise from your sleep. A new day is dawning, for all those who weep. Let us build the city of God. May our tears be turned into dancing. The One who has loved us, has brightened our way
Next week: The sciences of Communication and technology
Michael Uglo is the author of the science textbook Science in PNG, Pacific, Asia & Caribbean and a lecturer in Avionics, Auto- Piloting and Aircraft Engineering. Please send comments to: [emailprotected]
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