D. Lincoln

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Don Lincoln; Erratum: “Where Is Half of the Universe?” Phys. Teach. 61, 646–650 (2023). Phys. Teach. 1 January 2024; 62 (1): 3. https://doi.org/10.1119/5.0190806 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAmerican Association of Physics TeachersThe Physics Teacher Search Advanced Search |Citation Search

A theoretical physicist offers an intuitive primer on the nature of matter and energy.

Abstract The physical properties of a plastic scintillating strip with axial wavelength shifting fiber and VLPC readout have been extensively investigated. Different construction techniques were tried and 18 variations on the basic detector were studied in a cosmic ray test stand. Over 15 000 cosmic rays were recorded per scintillating strip. The high event statistics and the greatly improved photostatistics provided by the VLPC readout allowed us to study the system in much more detail than has been done previously. Results on light yields, signal uniformity, attenuation length, edge effects, and crosstalk are presented. Typical light yields were 18 photons per mm of scintillator traversed for minimum ionizing particles. The detectors had very uniform response at different positions along the strip.

The upgraded DØ detector at the Tevatron collider will use about 100 000 pixels of Visible Light Photon Counters (VLPCs) readout for its scintillating fiber tracker and preshower detectors. VLPCs are solid state photodetectors that are operated at the temperature of a few degrees Kelvin, capable of detecting single photons. All VLPC chips were characterized in the presence of a 20 MHz background of photoelectrons. The acceptance rate was 87%. The operating bias ranges from 5.8 to 8.0 V, the gain from 20 000 to 60 000, and the threshold from 5 to 15 fC. All 8 pixels belonging to one chip have very similar efficiencies, thresholds and gains.

We present a measurement of the A dependence of ${\mathit{k}}_{\mathit{T}\mathrm{\ensuremath{\varphi}}}$, the out-of-plane component of the dijet transverse momentum, in dijet events produced with a real photon beam. We also present the same measurement for dijets produced from pion-nucleus collisions in our detector. Both data sets are taken at a mean \ensuremath{\surd}s of 21 GeV in the ${\mathit{p}}_{\mathit{T}}$ range 3--7 GeV/c. A clear A dependence of comparable magnitude is seen in both processes. The energy dependence of the nuclear behavior is also extracted.

We have measured the polarization P, the analyzing power A, and the polarization transfer D of ${\ensuremath{\Sigma}}^{0}$'s produced inclusively by a polarized proton beam at 18.5 GeV/c. Our data cover a region of moderate ${p}_{T}$ (average 1 GeV/c) and Feynman x up to 0.75. We find agreement with a previous measurement of the ${\ensuremath{\Sigma}}^{0}$ polarization P. We observe nonzero values for A and D, but they are significantly smaller than predictions based on a simple parton-recombination model. We have extended this model to include finite transversity spin flips, which improves agreement with the data considerably.

Jets have been used to verify the theory of quantum chromodynamics (QCD), measure the structure of the proton, and search for physics beyond the Standard Model. In this article, we review the current status of jet physics at the Tevatron, a [Formula: see text] TeV [Formula: see text] collider at the Fermi National Accelerator Laboratory. We report on recent measurements of the inclusive jet production cross section, dijet production measurements, and the results of searches for physics beyond the Standard Model using jets.

Through a century of work, physicists have refined a model to describe all fundamental particles, the forces they share, and their interactions on a microscopic scale. This masterpiece of science is called the Standard Model. While this theory is incredibly powerful, we know of at least one particle that exhibits behaviors that are outside of its scope and remain unexplained. These particles are called neutrinos and they are the enigmatic ghosts of the quantum world. Interacting only via the weak nuclear force, literally billions of them pass through you undetected every second. While we understand that particular spooky behavior, we do not understand in any fundamental way how it is that neutrinos can literally change their identity, much as if a house cat could turn into a lion and then a tiger before transitioning back into a house cat again.

It's a dark, dark universe out there, and I don't mean because the night sky is black. After all, once you leave the shadow of the Earth and get out into space, you're surrounded by countless lights glittering everywhere you look. But for all of Sagan's billions and billions of stars and galaxies, it's a jaw-dropping fact that the ordinary kind of matter like that which makes up you and me is but 5% of the energy budget of the universe. The glittering spectacle of the heavens is a rather thin icing on a very large and dark cake.

In a deep and dark corner of space, a cataclysm loomed. Two cosmic nemeses circled one another, locked in a macabre dance of death. Unfolding over millennia, the deadly waltz began leisurely enough. But with the dance came radiation and the energy loss that it implies. Orbit after orbit, the distance between the two protagonists shrank as their grip on each other tightened. Radiation carried away energy, but not angular momentum, so the orbital velocity grew to incomprehensible levels—well into the realm where Einstein’s theory of special relativity reigns supreme. With the closing distances, the inevitable occurred as the two twisted knots of spacetime approached each other and merged in a spasm that shook the universe so violently that the energy output briefly outshone the electromagnetic energy output of the entire universe. The two adversaries become one, finally merged together for all eternity. The traces of their ordeal died away, leaving only a fading death scream that spread throughout the cosmos, growing ever fainter. That is, until they passed through Earth. That was the moment that changed everything.

Abstract Light yield and spatial uniformity for a large variety of configurations of scintillator tiles were studied. The light from each scintillator was collected by a Silicon Photomultiplier (SiPM) directly viewing the produced scintillation light (SiPM-on-tile technique). The varied parameters included tile transverse size, tile thickness, tile wrapping material, scintillator composition, and SiPM model. These studies were performed using 120 GeV protons at the Fermilab Test Beam Facility. External tracking allowed the position of each proton penetrating a tile to be measured. The results were compared to a GEANT4 simulation of each configuration of scinitillator, wrapping, and SiPM.

As is true of a far more famous story, it all began a long time ago, in a galaxy far, far away. It even involved a binary star system. A small star, called a white dwarf, had become a burned out husk of its former self and it turned to gorging on hydrogen and helium from its bloated red giant neighbor. The transferred gas reignited the fires of the white dwarf until the temperature from the fusion reaction proved too much for the gravity that struggled to contain it. In the blink of an eye, the star detonated in a supernova, a cosmic maelstrom seen perhaps only once per century in a typical galaxy.

Early History The Path to Knowledge (History of Particle Physics) Quarks and Leptons Forces: What Holds It All Together Hunting for the Higgs Accelerators and Detectors: Tools of the Trade Near Term Mysteries Exotic Physics (The Next Frontier) Recreating the Universe 10,000,000 Times a Second Epilogue: Why Do We Do It?.

In this paper, the D∅ collaboration reports on the test results of 142 880 VLPC pixels. We have explored the space of operating conditions and found good performance at a temperature of 9 K and an average bias voltage of 7 V. Preliminary tests have shown an average quantum efficiency of 80% and a gain of 20 000–60 000. Tests have shown that the devices can be made to work at very high rates. The pixel-to-pixel variation within a chip is manageable, allowing one to assemble like-performing VLPC chips into cassettes containing 1024 pixels each.

This summer, perhaps while you were lounging around the pool in the blistering heat, the blogosphere was buzzing about data taken at the Large Hadron Collider1 at CERN. The buzz reached a crescendo in the first week of July when both Fermilab and CERN announced the results of their searches for the Higgs boson. Hard data confronted a theory nearly half a century old and the theory survived.

Physics can be a weighty subject, full of substance and gravitas. It is therefore perhaps entirely reasonable that a central topic of the discipline is mass. But what is mass, really? What is the origin and nature of this most essential feature of the world around us? And are there any surprises to be had as we dig deeper into that question? In this article, I hope to surprise every reader at least once.

When the sun rose over America on July 4, 2012, the world of science had radically changed. The Higgs boson had been discovered. Mind you, the press releases were more cautious than that, with “a new particle consistent with being the Higgs boson” being the carefully constructed phrase of the day. But, make no mistake, champagne corks were popped and backs were slapped. The data had spoken and a party was in order. Even if the observation turned out to be something other than the Higgs boson, the first big discovery from data taken at the Large Hadron Collider had been made.

Two well-regarded measurements for the expansion rate of the universe disagree, leaving cosmologists very puzzled. It may be that something large has been overlooked in our theory of the Big Bang. This discrepancy is called the Hubble tension and it has led to a very interesting conversation within the cosmology community.

The highest-energy particle accelerator ever built, the Large Hadron Collider runs under the border between France and Switzerland. It leapt into action on September 10, 2008, amid unprecedented global press coverage and widespread fears that its energy would create tiny black holes that could destroy the earth. By smashing together particles smaller than atoms, the LHC recreates the conditions hypothesized to have existed just moments after the big bang. Physicists expect it to aid our understanding of how the universe came into being and to show us much about the standard model of particle physics-even possibly proving the existence of the mysterious Higgs boson. In exploring what the collider does and what it might find, Don Lincoln explains what the LHC is likely to teach us about particle physics, including uncovering the nature of dark matter, finding micro black holes and supersymmetric particles, identifying extra dimensions, and revealing the origin of mass in the universe. Thousands of physicists from around the globe will have access to the LHC, none of whom really knows what outcomes will be produced by the 7.7 billion project. Whatever it reveals, the results arising from the Large Hadron Collider will profoundly alter our understanding of the cosmos and the atom and stimulate amateur and professional scientists for years to come.

Winston Churchill once said of Russia that it was a riddle wrapped in mystery inside an enigma. Were the British Bulldog a physicist, he might have been talking of something other than our Slavic comrades. He might have been talking about an electron.

They say that there is no such thing as a stupid question. In a pedagogically pure sense, that's probably true. But some questions do seem to flirt dangerously close to being really quite ridiculous. One such question might well be, “How many dimensions of space are there?” I mean, it's pretty obvious that there are three: left/right, up/down, and forward/backward. No matter how you express an object's coordinate, be it Cartesian, spherical, cylindrical, or something exotic, it's eminently clear that we live in a three-dimensional universe.

Abstract Creating a theory of everything is an ambitious goal and one that is unlikely to proceed without data and experiment to guide thinkers. The energy scale at which a theory of everything is thought to be possible is a quadrillion times higher than the highest energies achievable today, and it will be centuries before we could conceivably build equipment to test a theory of everything. This points out the need for researchers to develop new technology. When one considers the theoretical effort that is needed to develop a theory of everything, it is important to remember that even the science heroes of the past didn’t work alone. They benefited from working with others, thinking through good ideas and killing bad ones. We must remember the final goal, which is a theory of everything, and be satisfied that we continue to progress toward it.

Abstract Einstein’s equation E = mc2 says that energy can convert to matter and vice versa; however, that’s not the full story. When energy makes matter, it makes antimatter in equal quantities. When one combines this fact with the idea of the Big Bang, which says that the early universe was full of energy, this suggests that the current universe should consist equally of matter and antimatter; yet it isn’t. We see only matter. While we don’t understand why this is true, Andrei Sakharov worked out the minimum conditions for there to be an imbalance in the amount of matter and antimatter. This chapter explores those conditions and tells us how much imbalance had to exist between matter and antimatter to evolve into the universe we see today. It turns out for every 2,000,000,000 antimatter particles that once existed, 2,000,000,001 matter particles had to exist. The 2,000,000,000s cancelled each other out, leaving the trace amount of matter to make up the cosmos.

Abstract The standard model and general relativity explain many experiments and observations, but they don’t explain everything. Because of this, scientists try to figure out additional connections between seemingly unrelated phenomena. The goal of this is to find a single theory which explains everything. Over the last century, scientists have used patterns they’ve observed to help work out unappreciated laws. These patterns led to the creation of the standard model in the 1960s. Similar approaches have been followed in the last half-century, hoping to extend the theory, but these attempts have failed. In addition, researchers have proposed the theories of superstrings and quantum gravity as candidate future theories. No theory proposed so far has succeeded in explaining everything, but this chapter explains the effort. It concludes with a metaphor that shows why hopes of a quick development of a theory of everything are likely to fail.

Abstract Esther Polianowski once had a conversation with Albert Einstein in which he told her what interested him. He wasn’t interested in the details of science; he was interested in the big picture, what he called “God’s thoughts.” He was interested in why the universe was the way it is. To answer that properly requires that scientists identify the building blocks of nature and the law or laws that govern them. This chapter illustrates how very disparate things often have common origins; for instance, the laws of physics explain how the sun burns, galaxies rotate, sodas fizz, and why kittens are fuzzy. While Einstein wasn’t interested in each of those things individually, he was interested in the connections between them.

Abstract The ultimate goal of physics is grand—it is to develop a theory that explains all physical phenomena. The name for this is “a theory of everything.” While many theories have been proposed, none have fit the bill. In Einstein’s Unfinished Dream, Don Lincoln takes us on a journey through earlier attempts, culminating in the standard model of particle physics and Einstein’s general theory of relativity. He then explains the obstacles that lay between where we are now and that final goal. In quick fashion, he dispenses with some popular theories that vie for the title of final theory, and then he lays out the actual path being followed by modern scientists. Rather than guessing at the final answer, scientists study data, trying to understand phenomena that aren’t yet explained. These are the clues that will lead the field forward. Lincoln introduces dark matter and dark energy, two substances that make up 95% of the matter and energy in the universe. He digs through the historical list of the building blocks of matter, hoping to find a smaller particle still. He points to the imbalance of matter and antimatter, a fact that modern science simply can’t explain. In short, the book brings the reader into the world of modern physics research, allowing people to understand what scientists are actually doing to help us answer the grandest question of all, “Why is there something, rather than nothing?”

Abstract Over the centuries, scientists have devised several ideas to explain the origins of the laws of nature. As we better understood the individual theories, researchers realized that a lot of phenomena can be explained as arising from a deeper cause, like how electricity, magnetism, chemistry, and light all can arise from electromagnetism. In the modern day, we know of two theories that describe nearly all experiments. The theory that describes the subatomic world is called the standard model of particle physics, while the theory that describes the cosmos is called general relativity. This chapter describes how these theories came to be devised and the range of phenomena they successfully describe.

Abstract While Einstein’s theory of general relativity does a good job of describing the motion of many astronomical objects, mysteries remain. Galaxies rotate faster than their visible mass and the laws of physics allow. Clusters of galaxies remain bound together despite moving faster than gravity can contain. The explanation of these mysteries is unknown, with possible solutions ranging from invisible matter, called dark matter, to needing to rewrite the laws of either motion or gravity. This chapter explains the myriad of possible explanations, rules out many, and leaves a few. Given that dark matter is five times more prevalent than ordinary atomic matter, it is imperative that these mysteries be explained.

Abstract Over 2,500 years ago, the Greek philosopher Democritus postulated that the nature of matter consisted of ultimate building blocks that he called atomos. Over the ensuing millennia, we have realized that he was broadly correct. We know of molecules, atoms, protons, neutrons, and electrons, and now we even know of quarks, which are found inside protons and neutrons, and leptons, of which the electron is the most familiar example. However, there was a time when we didn’t know of the constituents of atoms; we simply knew of the patterns of the chemical periodic table of elements. We’re in a similar point today, where we see patterns in the quarks and leptons and ask if they could be built of even smaller particles. In this chapter, we explore that idea and get a sense of how tricky figuring that out will be.

Abstract With the realization that the universe began in a colossal explosion called the Big Bang and that the cosmos is expanding, scientists asked what the ultimate fate of the universe would be. Would it expand forever, never stopping? Would it expand, ever slowing, and stopping in the infinite future? Or would the expansion reverse, and the universe collapse together in a “Big Crunch?” In 1998, scientists looked to the sky to answer the question and found, to their surprise, that the expansion of the universe is speeding up. The proposed explanation is that the universe is filled with an energy field that is a repulsive form of gravity. This field is called “dark energy.” This chapter discusses the discovery of dark matter and what it might be. Given that dark energy is about 70% of the matter and energy of the universe, understanding it is crucially important to understanding the cosmos.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Don Lincoln; Using Cosmic Rays to See the Unseeable. Phys. Teach. 1 April 2023; 61 (4): 249–252. https://doi.org/10.1119/5.0143816 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAmerican Association of Physics TeachersThe Physics Teacher Search Advanced Search |Citation Search

We present the results of studies of multiparton interactions done by the DØ collaboration using the Fermilab Tevatron at a center of mass energy of 1.96 TeV. Three analyses are presented, involving three distinct final signatures: (a) a photon with at least 3 jets (γ + 3jets), (b) a photon with a bottom or charm quark tagged jet and at least 2 other jets (γ + b/c + 2jets), and (c) two J/ψ mesons. The fraction of photon + jet events initiated by double parton scattering is about 20%, while the fraction for events in which two J/ψ mesons were produced is 30 ± 10. While the two measurements are statistically compatible, the difference might indicate differences in the quark and gluon distribution within a nucleon. This speculation originates from the fact that photon + jet events are created by collisions with quarks in the initial states, while J/ψ events are produced preferentially by a gluonic initial state.

Neutrinos are perhaps the least understood of the known denizens of the subatomic world. They have nearly no mass, interact only via the weak nuclear force and gravity, and, perhaps most surprising, the three known species of neutrinos can transform from one variant into another. This transformation, called neutrino oscillation, has been demonstrated only relatively recently and has led to speculation that there might be another, even more mysterious, neutrino variant, called the sterile neutrino. While the sterile neutrino remains a hypothetical particle, it is an interesting one and searches for it are a key research focus of the world’s neutrino scientist community.

This article summarizes recommendations made by the Community Engagement Frontier conveners as part of the 2022 Snowmass process. It suggests that institutions involved in high energy physics (e.g., universities, national laboratories, funding agencies, etc.) add education and outreach as a valuable effort and one that should be considered in hiring and promotion decisions.

The Large Hadron Collider (or LHC) is the world’s most powerful particle accelerator. In 2012, scientists used data taken by it to discover the Higgs boson, before pausing operations for upgrades and improvements. In the spring of 2015, the LHC will return to operations with 163% the energy it had before and with three times as many collisions per second. It’s essentially a new and improved version of itself. In this video, Fermilab’s Dr. Don Lincoln explains both some of the absolutely amazing scientific and engineering properties of this modern scientific wonder.

One of the most non-intuitive physics theories ever devised is Einstein’s Theory of Special Relativity, which claim such crazy-sounding things as two people disagreeing on such familiar concepts as length and time. In this video, Fermilab’s Dr. Don Lincoln shows that every single day particle physicists prove that moving clocks tick more slowly than stationary ones. He uses an easy to understand example of particles that move for far longer distances than you would expect from combining their velocity and stationary lifetime.

In this paper, a common calorimeter calibration scheme is explored and a hidden bias found. Since this bias mimics a non-linearity in response in the calorimeter, it must be understood and removed from the calibration before true non-linearities are investigated. The effect and its removal are explored and understood through straightforward calculus and algebra.

Interactions of high energy photons on a hyrogen target have been studied using a large acceptance segmented calorimeter. The event topology clearly shows the production of dijet final states as predicted by perturbative QCD. The energy flow in the photon (forward) direction is compared both to Monte Carlo expectations and to that produced in \ensuremath{\pi}p interactions.

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In 1922, Einstein was speaking to young Esther Salaman during a long walk; she was talking of her dreams and goals and he was sharing some of his thoughts. Among thoughts of travel, he described his core guiding intellectual principle when he said, “I want to know how God created this world [wie sich Gott die Welt beschaffen]. I’m not interested in this or that phenomenon, in the spectrum of this or that element. I want to know His thoughts; the rest are just details.”

Abstract In this paper, the DO collaboration reports on the test results of over 60 000 VLPC pixels. We have explored the space of operating conditions and find good performance at a temperature of 9 K and a bias voltage of 7 V. Preliminary tests have shown an average quantum efficiency of 80% and a gain of 25,000–50,000. Tests have shown that the devices can be made to work at very high rates. The pixel-to-pixel variation within a chip is manageable, allowing one to assemble like-performing VLPC chips into cassettes containing 1024 pixels each.

The Victorian era mathematician, Augustus de Morgan wrote, “Great fleas have little fleas upon their backs to bite ‘em,And little fleas have lesser fleas, and so ad infinitum.”

The idea of a liberal arts education is deeply rooted in our academic history. Originally based in the goal of learning about the classical literature of Greece and Rome, the approach has morphed over the years into a broad course of study, including mathematics, literature, history, languages, philosophy, art, and the sciences. It is those last two subjects that caused the two of us to come to meet one another.

The DØ experiment at the Fermilab pp¯ Tevatron collider (Batavia, IL, USA) has undergone significant upgrades in anticipation of high luminosity running conditions. As part of the upgrade, the capabilities of the Central Track Trigger (CTT) to make trigger decisions based on hit patterns in the Central Fiber Tracker (CFT) have been much improved. We report on the implementation, commissioning and operation of the upgraded CTT system.

While the majority of students that pursue a physics education learn mostly in a classroom setting, hands-on experiences can take their appreciation of physics to the next level. Summer internships offer just that, hands-on learning experiences and a taste of what a career in physics is really like. Many research-oriented institutions offer summer internship experiences for students at all levels, from high school through graduate school. The experience and connections made during these summer programs can be transformative to a student’s career and science identity.

The Big Bang is the name of the most respected theory of the creation of the universe. Basically, the theory says that the universe was once smaller and denser and has been expending for eons. One common misconception is that the Big Bang theory says something about the instant that set the expansion into motion, however this isn’t true. In this video, Fermilab’s Dr. Don Lincoln tells about the Big Bang theory and sketches some speculative ideas about what caused the universe to come into existence.

The Large Hadron Collider or LHC is the world’s biggest particle accelerator, but it can only get particles moving very quickly. To make measurements, scientists must employ particle detectors. There are four big detectors at the LHC: ALICE, ATLAS, CMS, and LHCb. In this video, Fermilab’s Dr. Don Lincoln introduces us to these detectors and gives us an idea of each one’s capabilities.

1 Irradiation test of the HCAL Forward and Endcap upgrade electronics at the CHARM facility at CERN Francesco Costanza, Tugba Karakaya, Ozgur Sahin, (DESY, Germany) Tullio Grassi (Univ. of MD, USA), James F Hirschauer, Don Lincoln, Nadja Strobbe (Fermilab, USA), Alexander Kaminskiy (M.V. Lomonosov Moscow State University), Danila Tlisov (Russian Academy of Sciences), Yanchu Wang (Univ. ov VA, USA)

After a century of study, scientists have come to the realization that the ordinary matter made of atoms is a minority in the universe. In order to explain observations, it appears that there exists a new and undiscovered kind of matter, called dark matter, that is five times more prevalent than ordinary matter. The evidence for this new matter’s existence is very strong, but scientists know only a little about its nature. In today’s video, Fermilab’s Dr. Don Lincoln talks about an exciting and unconventional idea, specifically that dark matter might have a very complex set of structures and interactions. While this idea is entirely speculative, it is an interesting hypothesis and one that scientists are investigating.

With the discovery of what looks to be the Higgs boson, LHC researchers are turning their attention to the next big question, which is the predicted mass of the newly discovered particles. When the effects of quantum mechanics is taken into account, the mass of the Higgs boson should be incredibly high...perhaps upwards of a quadrillion times higher than what was observed. In this video, Fermilab's Dr. Don Lincoln explains how it is that the theory predicts that the mass is so large and gives at least one possible theoretical idea that might solve the problem. Whether the proposed idea is the answer or not, this question must be answered by experiments at the LHC or today's entire theoretical paradigm could be in jeopardy.

Scientists were shocked in 1998 when the expansion of the universe wasn't slowing down as expected by our best understanding of gravity at the time; the expansion was speeding up! That observation is just mind blowing, and yet it is true. In order to explain the data, physicists had to resurrect an abandoned idea of Einstein's now called dark energy. In this video, Fermilab's Dr. Don Lincoln tells us a little about the observations that led to the hypothesis of dark energy and what is the status of current research on the subject.

The manner in which particle physicists investigate collisions in particle accelerators is a puzzling process. Using vaguely-defined “detectors,” scientists are able to somehow reconstruct the collisions and convert that information into physics measurements. In this video, Fermilab’s Dr. Don Lincoln sheds light on this mysterious technique. In a surprising analogy, he draws a parallel between experimental particle physics and bomb squad investigators and uses an explosive example to illustrate his points. Be sure to watch this video… it’s totally the bomb.

The weakness of gravity compared to the other subatomic forces is a real mystery. While nobody knows the answer, one credible solution is that gravity has access to more spatial dimensions than the other three known forces. In this video, Fermilab's Dr. Don Lincoln describes this idea, with the help of some very urbane characters.

Albert Einstein said that what he wanted to know was “God’s thoughts,” which is a metaphor for the ultimate and most basic rules of the universe. Once known, all other phenomena would then be a consequence of these simple rules. While modern science is far from that goal, we have some thoughts on how this inquiry might unfold. In this video, Fermilab’s Dr. Don Lincoln tells what we know about GUTs (grand unified theories) and TOEs (theories of everything).

The Higgs boson was discovered in July of 2012 and is generally understood to be the origin of mass. While those statements are true, they are incomplete. It turns out that the Higgs boson is responsible for only about 2% of the mass of ordinary matter. In this dramatic new video, Dr. Don Lincoln of Fermilab tells us the rest of the story.

Matter is malleable and can change its properties with temperature. This is most familiar when comparing ice, liquid water and steam, which are all different forms of the same thing. However beyond the usual states of matter, physicists can explore other states, both much colder and hotter. In this video, Fermilab’s Dr. Don Lincoln explains the hottest known state of matter – a state that is so hot that protons and neutrons from the center of atoms can literally melt. This form of matter is called a quark gluon plasma and it is an important research topic being pursued at the LHC.

Scientists are aware of four fundamental forces- gravity, electromagnetism, and the strong and weak nuclear forces. Most people have at least some familiarity with gravity and electromagnetism, but not the other two. How is it that scientists are so certain that two additional forces exist? In this video, Fermilab’s Dr. Don Lincoln explains why scientists are so certain that the strong force exists.

U.S. scientists at Fermilab celebrate the official start of LHC Run II and discuss what they hope to find at a higher energy and increased intensity.

The Standard Model of particle physics is composed of several theories that are added together. The most precise component theory is the theory of quantum electrodynamics or QED. In this video, Fermilab’s Dr. Don Lincoln explains how theoretical QED calculations can be done. This video links to other videos, giving the viewer a deep understanding of the process.

The theory of quantum electrodynamics (QED) is perhaps the most precisely tested physics theory ever conceived. It describes the interaction of charged particles by emitting photons. The most precise prediction of this very precise theory is the magnetic strength of the electron, what physicists call the magnetic moment. Prediction and measurement agree to 12 digits of precision. In this video, Fermilab’s Dr. Don Lincoln talks about this amazing measurement.

At any time in history, a few scientific measurements disagreed with the best theoretical predictions of the time. Currently, one such discrepancy involves the measurement of the strength of the magnetic field of a subatomic particle called a muon. In this video, Fermilab’s Dr. Don Lincoln explains this mystery and sketches ongoing efforts to determine if this disagreement signifies a discovery. If it does, this measurement will mean that we will have to rewrite the textbooks.

In the world of high energy physics there are several parameters that are important when one constructs a particle accelerator. Two crucial ones are the energy of the beam and the luminosity, which is another word for the number of particles in the beam. In this video, Fermilab’s Dr. Don Lincoln explains the differences and the pros and cons. He even works in an unexpected sporting event.

The Particle at the End of the Universe: How the Hunt for the Higgs Boson Leads Us to the Edge of a New World, Sean Carroll, Dutton, New York, 2012. $27.95 (341 pp.). ISBN 978-0-525-95359-3 Buy at Amazon

In this video, Fermilab's Dr. Don Lincoln describes the principle of supersymmetry in an easy-to-understand way. A theory is supersymmetric if it treats forces and matter on an equal footing. While supersymmetry is an unproven idea, it is popular with particle physics researchers as a possible next step in particle physics.

Dr. Don Lincoln introduces one of the most fascinating inhabitants of the subatomic realm: the neutrino. Neutrinos are ghosts of the microworld, almost not interacting at all. In this video, he describes some of their properties and how they were discovered. Studies of neutrinos are expected to be performed at many laboratories across the world and to form one of the cornerstones of the Fermilab research program for the next decade or more.

Updated: http://youtu.be/ktEpSvzPROc Fermilab scientist Don Lincoln describes the concept of how the search for the Higgs boson is accomplished. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.

The Standard Model of particle physics treats quarks and leptons as having no size at all. Quarks are found inside protons and neutrons and the most familiar lepton is the electron. While the best measurements to date support that idea, there is circumstantial evidence that suggests that perhaps the these tiny particles might be composed of even smaller building blocks. This video explains this circumstantial evidence and introduces some very basic ideas of what those building blocks might be.

The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.

Einstein's equation E = mc2 is often said to mean that energy can be converted into matter. More accurately, energy can be converted to matter and antimatter. During the first moments of the Big Bang, the universe was smaller, hotter and energy was everywhere. As the universe expanded and cooled, the energy converted into matter and antimatter. According to our best understanding, these two substances should have been created in equal quantities. However when we look out into the cosmos we see only matter and no antimatter. The absence of antimatter is one of the Big Mysteries of modern physics. In this video, Fermilab's Dr. Don Lincoln explains the problem, although doesn't answer it. The answer, as in all Big Mysteries, is still unknown and one of the leading research topics of contemporary science.

Carl Sagan's oft-quoted statement that there are and billions of stars in the cosmos gives an idea of just how much stuff is in the universe. However scientists now think that in addition to the type of with which we are familiar, there is another kind of out there. This new kind of is called matter and there seems to be five times as much as ordinary matter. Dark interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.

Fermilab scientist Don Lincoln describes antimatter and its properties. He also explains why antimatter, though a reality, doesn't pose any current threat to our existence!