Leonard Susskind gives the first lecture of a three-quarter sequence of courses that will explore the new revolutions in particle physics. In this lecture he explores light, particles and quantum field theory.
Leonard Susskind gives the first lecture of a three-quarter sequence of courses that will explore the new revolutions in particle physics. In this lecture he explores light, particles and quantum field theory.
While the arts and science seem like opposite ends of the philosophical spectrum, they share a common purpose: discovery. Science is largely concerned with discovering the physical world around us. The arts are concerned with discovering ourselves, through which we discover each other. Discovery starts the process. It comes before. Discovering ourselves and discovering each other is the unifying force in the birth of community long before there are any discussions about budgets or programs or services. The community supports education and infrastructure, but it is the arts that foster community.
I am no scientist, but what little I know of quantum physics suggests that the interaction of the observer with the observed has a much greater influence than we had ever anticipated. It may even be that the observed does not exist until the observer is there to observe it. This is the essence of the arts, through which we confirm our own experience – our own existence. We observe each other the same way. Through the arts, we all enter the world – together.
Miss Hathaway, 27, who starred in The Princess Diaries and The Devil Wears Prada, spends her spare time reading physics textbooks rather than fashion pages.
She said: ‘I’m interested in elementary particles. What I like thinking about is how time and space exist in the universe and how we understand it.
‘Any spare time I have, I bury my head in a physics textbook.
The sensor head is made up of a series of coils that cancel out unwanted signals and amplifies the signals that are needed. So the tiny magnetic fields produced by a person's heart can be transmitted into the heavily shielded environment. What we've been able to do is combine existing technology from the areas of atomic physics and medical physics in a completely unique way.
3. Flying machine
"Abbas ibn Firnas was the first person to make a real attempt to construct a flying machine and fly," said Hassani. In the 9th century he designed a winged apparatus, roughly resembling a bird costume. In his most famous trial near Cordoba in Spain, Firnas flew upward for a few moments, before falling to the ground and partially breaking his back. His designs would undoubtedly have been an inspiration for famed Italian artist and inventor Leonardo da Vinci's hundreds of years later, said Hassani.
In 859 a young princess named Fatima al-Firhi founded the first degree-granting university in Fez, Morocco. Her sister Miriam founded an adjacent mosque and together the complex became the al-Qarawiyyin Mosque and University. Still operating almost 1,200 years later, Hassani says he hopes the center will remind people that learning is at the core of the Islamic tradition and that the story of the al-Firhi sisters will inspire young Muslim women around the world today.
The word algebra comes from the title of a Persian mathematician's famous 9th century treatise "Kitab al-Jabr Wa l-Mugabala" which translates roughly as "The Book of Reasoning and Balancing." Built on the roots of Greek and Hindu systems, the new algebraic order was a unifying system for rational numbers, irrational numbers and geometrical magnitudes. The same mathematician, Al-Khwarizmi, was also the first to introduce the concept of raising a number to a power.
"Many of the most important advances in the study of optics come from the Muslim world," says Hassani. Around the year 1000 Ibn al-Haitham proved that humans see objects by light reflecting off of them and entering the eye, dismissing Euclid and Ptolemy's theories that light was emitted from the eye itself. This great Muslim physicist also discovered the camera obscura phenomenon, which explains how the eye sees images upright due to the connection between the optic nerve and the brain.
Galactic electrons are thought to originate in the explosion of supernovae, and conventional models predict that they lose energy as they pass through the Milky Way's magnetic field. The annihilation of proposed dark-matter particles would also create electrons, and some theorists had interpreted the recent experimental detections of surplus high-energy electrons as evidence for this process.
But starlight also scatters the electrons. Petrosian says that starlight suppresses the energy of most electrons in a way that makes it seem as if there is an excess of certain high-energy electrons. The Stanford group's models show an excess that is similar to that reported by NASA's Fermi Gamma-ray Space Telescope; the High Energy Stereoscopic System (HESS), a ground-based detector in Namibia; and the Advanced Thin Ionization Calorimeter (ATIC), a balloon-borne detector that flew over Antarctica.
But by tweaking parameters in their model, the Stanford group can also mimic the PAMELA results. Like the electrons, the positrons are also thought to originate near supernovae — although through secondary collisions of protons. By increasing the density of gas and the number of photons near these supernovae — both possible scenarios given that supernovae occur in gas-rich star-forming regions near lots of stars — the model predicts high-energy positrons similar to those reported by PAMELA.
Reporting online January 10 in Nature Chemistry, the Harvard group, led by chemist Alán Aspuru-Guzik, developed the conceptual algorithm and schematic that defined the computer’s architecture. Aspuru-Guzik has been working on such things for years but didn’t have the hardware to test his ideas. At the University of Queensland, physicist Andrew G. White and his team, who have been working on such sophisticated gadgets, said they thought they could make one to the Harvard specs and, after some collaboration, did so. In principle the computer could have been rather small, “about the size of a fingernail,” White says. But his group spread its components across a square meter of lab space to make it easier to adjust and program.
Professor Donald, who is the Deputy Head of the Department of Physics, beat out such candidates as scientist Baroness Susan Greenfield and internet entrepreneur Martha Lane Fox to win the prize from the iconic women's lifestyle magazine.
In announcing the award in their latest edition, the magazine praised Professor Donald as a "great role model" who has "forged a real path for herself in the male-dominated world of physics."
But by the end of the year, the more anxious teachers were about their own math skills, the more likely their female students but not the boys were to agree that "boys are good at math and girls are good at reading."
In addition, the girls who answered that way scored lower on math tests than either the classes' boys or the girls who had not developed a belief in the stereotype, the researchers found.
Organized into “duels” of world views, round tables and “diatribes and polemics,” the conference was billed as a place where the physicists could let down their hair about what might come, avoid “groupthink” and “be daring (even at the expense of being wrong),” according to Dr. Spiropulu’s e-mailed instructions. “Tell us what is bugging you and what is inspiring you,” she added.
When two conducting plates are brought in close proximity to one another, vacuum fluctuations in the electromagnetic field between them create a pressure. This effective force, known as the Casimir effect, has a thermodynamic analog: the “critical Casimir effect.” In this case, thermal fluctuations of a local order parameter (such as density) near a continuous phase transition can attract or repel nearby objects when they are in confinement.
Successful regional sales of the Pluto Platter soon caught the attention of the then new Wham-O, Inc., a maker of slingshots. After introduction, and a period of discussion and negotiation, Wham-O purchased the rights to the Pluto Platter on January 23, 1957, which happened to be Morrison's 37th birthday. 1957 was an interesting and fortuitous year for Wham-O: The Hula Hoop craze was catching fire, causing the company to temporarily divert materials and production effort to keeping up with the insatiable demand. But by the following year, the disc was back on track, and had been given the Frisbee name we all fondly recognize today.
Now Choptuik and Frans Pretorius of Princeton University have simulated such collisions, including all the extremely complex mathematical details from general relativity. For simplicity and to make the simulations generic, they modeled the two particles as hypothetical objects known as boson stars, which are similar to models that describe stars as spheres of fluid. Using hundreds of computers, Choptuik and Pretorius calculated the gravitational interactions between the colliding particles and found that a black hole does form if the two particles collide with a total energy of about one-third of the Planck energy, slightly lower than the energy predicted by hoop conjecture, as they report in a paper in press at Physical Review Letters.
Does that mean the LHC will make black holes? Not necessarily, Choptuik says. The Planck energy is a quintillion times higher than the LHC's maximum. So the only way the LHC might make black holes is if, instead of being three dimensional, space actually has more dimensions that are curled into little loops too small to be detected except in a high-energy particle collision. Predicted by certain theories, those extra dimensions might effectively lower the Planck energy by a huge factor. "I would be extremely surprised if there were a positive detection of black-hole formation at the accelerator," Choptuik says. Physicists say that such black hole would harmlessly decay into ordinary particles.
By the mid-1950s, scientists had identified several excellent materials and had recognized that putting a mirror on each side of the laser medium would drastically increase the output, reflecting the photons back and forth, and producing more stimulus and more emissions on each transit. If one of the mirrors was partially transparent, a stream of photons would emerge from that end -- the now familiar laser beam. Finally in May 1960, Theodore Maiman, a physicist at Hughes Research Laboratories, constructed the first laser that emitted light in the visible range.
For instance, just 13 percent of the public now claims to follow science and technology news “very closely,” and this number has been on a downward trend for the past decade, ending with the current low. So while Americans may profess great admiration for science in the abstract, they hardly feel compelled to pay it much attention.
Now, what this means is that, while the public in general supports science, and scientific endeavors, they are doing it NOT because they are aware of what science is and what it does, but rather based on the PERCEIVED importance of science and technology. This is extremely important to keep in mind, because this implies that the support for science is built on an extremely shaky foundation. Such foundation can be easily eroded either via a mishap, or simply good "Public Relations" done by people against science.
Newton predicted in the 17th century that a beam of light reflected at a glass-vacuum surface should undergo a minuscule lateral shift. He was arguing that wavefronts, having reached the vacuum, should "slide" a short distance along the interface before re-emerging and reflecting back into the glass. Given the tiny scale of this effect, however, it was not until 1947 that it was first observed experimentally by the physicists F Goos and H Hänchen at the State Physical Institute in Hamburg, Germany.
Case closed? Well not quite because, as all physicists are taught in high school, the distinction between waves and particles is not as clear-cut as common sense might suggest. Due to the quantized nature of energy, light can sometimes behave as if it were composed of particles, and particles can behave as if they were waves. Now, a group of researchers led by Rob Dalgliesh and Sean Langridge at the ISIS facility and Victor de Haan from the Delft University of Technology (Netherlands) have finally completed the picture by demonstrating the so-called Goos-Hänchen effect with neutrons.
Some of the essays might come off as too abstract for readers who don't particularly care about a given topic; in particular, a lengthy review of mathematics expert Stephen Wolfram's 2002 book, A New Kind of Science, requires a deep and abiding interest in cellular automata. (For the rest of us, that's a kind of modeling that studies how individual cells evolve through time depending on what the cells next to them are doing.)
In other pieces, though, Weinberg can, within several eloquent pages, distill the essence of why science is important. His 2003 commencement speech at Montreal's McGill University points out that while it isn't so important to know who was prime minister of Canada a century earlier, in 1903 Ernest Rutherford and Frederick Soddy were at McGill figuring out how radioactivity worked – research that has profoundly shaped our knowledge of the natural world, including explaining why the Earth's core remains hot after billions of years.
Give us a glimpse into your writing routine. I do all my research and writing at home. If you see me on the UT campus, it’s because I’m giving a class or meeting with colleagues or students. But even when I’m at my desk at home, I often just spin my wheels, so I need something to keep me sitting there. My desk looks over Lake Austin, and I have a television set that I keep on while I’m working. Between watching old movies and enjoying the view of the lake, I generally manage to stay at my desk until I think of something worth doing.
Nickel particles float peacefully in a liquid medium until a giant snake seems to swim by and snatch several particles up, adding to its own mass. The self-assembled "snakes" act like biological systems, but they are not alive and are driven by a magnetic field. The research may someday offer some insight into the organization of life itself.
In the kitchen version of the experiment, the marble creates a crown-shaped splash and crater as it falls into the liquid. The crater deepens to the point at which the walls start to contract. This is due to both the weight of the water outside and possibly surface tension, both of which create pressure gradients that force the collapse. Air inside this collapsing neck must escape upward or downward as the neck approaches pinch-off. It is in this escaping air that Gekle et al. found supersonic velocities—the first jet in this simple experiment.
LBNE will use the Main Injector accelerator at Fermilab to produce protons that collide with a fixed target to generate a beam of muon neutrinos. This neutrino beam will strike a small detector on the Fermilab site and then travel more than 620 miles to strike an underground detector more than 10 times the size of the largest LHC detector.
NASA's Fermi Gamma-ray Space Telescope is identifying the locations of dozens of these galactic clocks, allowing radio astronomers to follow up and monitor them. Researchers can deduce whether a passing gravitational wave has jostled Earth by watching for slight variations in the arrival time of pulsar radio-wave bursts — just fractions of a second over the course of years. If these efforts succeed, researchers will have a new tool for exploring the cosmic cataclysms — colliding black holes, for example — that are thought to generate gravitational waves (see graphic).
The shoestring effort, involving groups in Australia, Europe and North America, could beat larger and better-funded groups that use laser interferometry to try to detect gravitational waves by their tiny effects on the movements of test masses. "People are finally taking notice," says Scott Ransom, an astronomer at the National Radio Astronomy Observatory in Charlottesville, Virginia, who last week announced the discovery of 17 millisecond pulsars at a meeting of the American Astronomical Society in Washington DC.
.. the tipping of the quantum rod can be understood as having been triggered by the uncertainty in angular momentum engendered by localization of the initial state...
Now, a new experiment by L. G. Herrmann in France, working with colleagues in France, Spain, and Germany, published in Physical Review Letters  demonstrates that electrons entangled in a superconducting Cooper pair can be spatially separated into different arms of a carbon nanotube, a material thought favorable for the efficient injection and transport of split, entangled pairs. This work may help pave the way for tests of nonlocal effects in solid-state systems, as well as applications such as quantum teleportation and ultrasecure communication.
Jenet's group thinks that anomalous dispersion should be added to this list. Using the Arecibo Observatory in Puerto Rico, they took radio data of the pulsar PSR B1937+21 at 1420.4 MHz with a 1.5 MHz bandwidth for three days. Oddly, those pulses close to the centre value arrived earlier than would be expected given the pulsar's normal timing, and therefore appeared to have travelled faster than the speed of light.
The cause of the anomalous dispersion for these pulses, according to the Brownsville astrophysicists, is the resonance of neutral hydrogen, which lies at 1420.4 MHz. But like anomalous dispersion seen in the lab, the pulsar's superluminal pulses do not violate causality or relativity because, technically, no information is carried in the pulse. Still, Jenet and colleagues believe that the phenomenon could be used to pick out the properties of clouds of neutral hydrogen in our galaxy.
And the late scientist is still springing new surprises on his biographer: "Genius is posthumous productivity. Last summer I found out that he had anticipated arguably the greatest discovery in theoretical physics of the 1990s so I had to redo that part of the book." Which means he's stuck with Dirac for the rest of his life? "Suits me," Farmelo says.
The most prominent scientists involved in this mainstream version of nanotechnology have admitted that Feynman's "Plenty of Room" talk had no influence on their work. Christopher Toumey, a University of South Carolina cultural anthropologist, interviewed several of nanotech's biggest names, including Nobel laureates; they uniformly told him that Feynman's lecture had no bearing on their research, and several said they had never even read it.
But there is another kind of nanotechnology, one associated with much more hype. First described in the 1980s by K. Eric Drexler, this vision involves building things "from the bottom up" through molecular manufacturing. It was Mr. Drexler who first brought the term "nanotechnology" to a wide audience, most prominently with his 1986 book "Engines of Creation." And it is Mr. Drexler's interpretation that has captured the public imagination, as witness the novels, movies and video games that name-drop nanotechnology with the same casual hopefulness that the comic books of the 1960s mentioned the mysteries of radiation.
Hoping to dissociate their nanotechnology work from dystopian scenarios and fringe futurists, some prominent mainstream researchers have taken to belittling Mr. Drexler and his theories. And that is where Feynman re-enters the story: Mr. Drexler regularly invokes the 1959 lecture, which broadly corresponds with his own thinking. As he told Mr. Regis, the science writer: "It's kind of useful to have a Richard Feynman to point to as someone who stated some of the core conclusions. You can say to skeptics, 'Hey, argue with him!'" It is thanks to Mr. Drexler that we remember Feynman's lecture as crucial to nanotechnology, since Mr. Drexler has long used Feynman's reputation as a shield for his own.
Some of Tilghman's talk to college presidents concerned the dismal state of science education in the United States, from elementary and secondary education through higher education. She recited various statistics and called for the creation of more courses that engage science students in "big questions" early in their careers. Too many college students are introduced to science through survey courses that consist of facts "often taught as a laundry list and from a historical perspective without much effort to explain their relevance to modern problems." Only science students with "the persistence of Sisyphus and the patience of Job" will reach the point where they can engage in the kind of science that excited them in the first place, she said.
All this may seem like impractical and esoteric knowledge. But modern society would be unrecognizable without discoveries in fundamental physics. Radio and TV, X-rays, CT scans, MRIs, PCs, iPhones, the GPS system, the Web and beyond -- much that we take for granted would not exist without this type of physics research and was not predicted when the first discoveries were made. Likewise, we cannot predict what future discoveries will lead to, whether new energy sources, means of space travel or communication, or amazing things entirely unimagined.
The cost of this research may appear high -- about $10 billion for the LHC -- but it amounts to less than a ten-thousandth of the gross domestic product of the U.S. or Europe over the approximately 10 years it has taken to build the collider. This is a tiny investment when one accounts for the continuing value of such research to society.
But beyond practical considerations, we should ponder what the value of the LHC could be to the human race. If it performs as anticipated, it will be the cutting edge for years to come in a quest that dates to the ancient Greeks and beyond -- to understand what our world is made of, how it came to be and what will become of it. This grand odyssey gives us a chance to rise above the mundane aspects of our lives, and our differences, conflicts and crises, and try to understand where we, as a species, fit in a wondrous universe that seems beyond comprehension, yet is remarkably comprehensible.
Brushing aside objections from his Lawrence Berkeley lab colleagues, who argued it would not portray the world's premiere research lab in the right light, he decided to appear in September on the Fox TV game show, "Are You Smarter Than a Fifth Grader?"
He appeared earlier in the year on the CBS sitcom, "The Big Bang Theory," playing himself as the keynote speaker at a conference attended by the main characters, ultra nerdy scientists. He said he agreed to go on the show because he likes that the scientists are portrayed as heroes.
But "Are You Smarter Than a Fifth Grader?" was different.
"It was kind of like rebelling," Smoot said. "It was risky because there was a big chance you wouldn't answer everything correctly. You are supposed to be this example to new generations, and to have to say you are not smarter than a fifth-grader would be embarrassing."
There are, of course, many people, among them prominent scientists, who have claimed and continue to claim that the scientific notions of evolution do indeed necessarily imply such a materialistic philosophy. Richard Dawkins is among the most vocal proponents of such a philosophy, arguing that "Darwin made it possible to be an intellectually fulfilled atheist". This strident atheism does not, however, help their scientific work in any way, and on the contrary, is the source of so much of the controversy that rages over it.
It is a fundamental mistake, however, to accept their bundling of the three scientific evolutionary ideas with what I have termed evolutionism. Rather, a more sophisticated response would be to show that the three scientific notions in any form are compatible with theistic philosophy.
In many cases, however, the reaction of religious believers to the materialistic claims of evolutionism is not to simply reject the assertion that evolutionism necessarily follows from scientific ideas. Rather, they tacitly or unconsciously accept the bundling of evolutionism with the science, and then see no option but to attack a part or all of the scientific ideas of evolution as a way of cutting the support for the philosophical claims of evolutionism.
In doing so, however, they find themselves in the awkward situation of attacking a solidly established science, ultimately motivated not by objections to the science per se, but by the illicit bundling of evolutionism with the science.