An Extraordinary Triumph for Science

    On July 4, two teams of researchers from CERN, Europe's center for particle physics research, made an extraordinary announcement, reporting the discovery of a new particle that appeared to match the profile of the long-sought Higgs boson.  One team, using the CMS detector, announced the discovery of a particle with a mass of 125 GeV (giga-electron volts), and the other, using the ATLAS detector, reported a mass of 126 GeV.  In tandem, they had found impressive evidence for a major find.

    The Higgs boson is the relic of the field that filled all of space during the nascent moments of time.  In those fleeting instants, as the Higgs field transformed, it lent mass to most of the other elementary particles and caused them to differentiate in their properties.  This process, called the Higgs mechanism, is a key ingredient of the Standard Model of particle physics, explaining why there are significant differences among particles.  For example photons, the particles that carry the electromagnetic force, are massless and act over a long range, while W and Z particles, carriers of the weak interaction, are heavy and act over a short range.

    One might use the analogy of water freezing into ice to think of how the Higgs mechanism works.  Imagine that the Higgs field in the hot early universe was a sea of liquid water.  Other particles moved through the sea like speed boats, each travelling at the speed of light and interacting with each other in the same way.  However, as the universe cooled, the Higgs "sea" began to freeze into tracks of slush.  Moving through these slush tracks in various directions, most of the particles were forced to slow down, becoming heavier.  The amount of mass, or heaviness acquired, depended on the angle that the particle was moving.  This led to profound differences in the properties of those particles.

    Additional work needs to be done to establish that the newly found particle truly is the Higgs boson.  However, the announcement was met with much optimism that the long road to finding the Higgs has almost reached its end.

    For more about the Large Hadron Collider and the Higgs boson, see my book Collider: A Search for the World's Smallest Particles

George Gamow's Grave

On a visit to Boulder, CO in June 2011 I visited George Gamow's grave in Green Mountain Cemetery.

Born in Odessa in 1904, then part of the Russian empire, Gamow escaped to the west and became professor at George Washington University. There, along with his student Ralph Alpher, he developed the concept of Big Bang nucleosynthesis. He later moved to Boulder where he was Professor of Physics at the University of Colorado. He wrote numerous popular books, and died in 1968.

Gamow's grave is somewhat hard to find as it is in a more isolated part of the cemetery. Nevertheless, I found it and snapped a few photos:

Smashing re-creation of Big Bang conditions at the Large Hadron Collider

Last month, the Large Hadron Collider switched gears. It ended its proton run, involving smashing those elementary particles together, and switched to lead nuclei. The goal is creating an ultra-high temperature substance, called quark-gluon plasma. This fiery liquid is believed to resemble the content of the universe shortly after the Big Bang. Quarks and gluons, the constituents of neutrons, protons and other particles, are normally confined to either triplets or pairs. However, at high energies, their confinement breaks and they are freer to move. The lead nuclei experiments at the LHC thus offer an exciting window to the dawn of time.

Guardian Review of Collider

I'm pleased to report that Collider has been reviewed in The Guardian:

Guardian Review of Collider

The Guardian calls it a "very readable history of our quest to understand the building-blocks of matter."

Collider - in paperback, with a new preface

I'm excited to see that Collider: The Search for the World's Smallest Particles is now available in paperback, with an all new preface about the suspenseful start-up of the Large Hadron Collider, the most powerful particle-smasher in the world. If you (or a friend or relative) are curious about the quest for supersymmetry, investigations into why there is so much more matter than antimatter in the universe, the search for higher dimensions, and the effort to understand the source of mass in the particle world, the book answers many of these intriguing questions and more.

As Publishers Weekly wrote about Collider:
"Halpern makes the search for mysterious particles pertinent and exciting by explaining clearly what we don't know about the universe, and offering a hopeful outlook for future research"

B. Tripp's Book Review of Collider

There is an excellent new review of Collider on Brendan Tripp's book review site. Here is a short excerpt:

"I thoroughly enjoyed reading Collider and would recommend it to anyone who has an interest in physics, or even science in general. Not only is is a wonderful survey of what has happened in the field, it provides personalizing backgrounds on many major players that I'd never encountered previously, as well information on folks who did significant pieces of research that I'd never heard of. "
-B. Tripp

Here is a link to the full review:
B. Tripp's Book Review of Collider

Interview with Marcus Chown on Bloggingheads.tv

I recently had the fantastic opportunity to interview science writer Marcus Chown on the blogging "talk show" Bloggingheads.tv. The topic was his new book "The Matchbox that Ate a Forty-Ton Truck."

As I am a long-time fan of his writings in New Scientist, and really enjoyed his book, it was a wonderful experience getting a chance to chat with him. He seems very down-to-earth, and has a gift for explaining difficult topics in a very visual, tangible manner.

Marcus's story about physicist Richard Feynman's letter to his mother is priceless. It is toward the end of the interview.

Here is a link to the video chat:

Interview with Marcus Chown on Bloggingheads.tv

Collider in Paperback

Collider is now available in paperback for pre-ordering. I'm very excited about the colorful new cover, including a photo of the CMS detector.



The paperback edition includes a brand new preface about the start-up of the Large Hadron Collider and the future of particle physics.

Collider Named in Library Journal's Best of 2009 Sci-Tech Books

I'm delighted to report that Collider: The Search for the World's Smallest Particles is the physics selection in Library Journal's Best of 2009 Sci-Tech Books

It is also the April selection of the TWIS (This Week in Science) Book Club.

Collisions with the Future

The Large Hadron Collider, the world's most powerful particle-smasher, is now up and running.  Here's a link to an opinion piece I wrote about it that has recently been published in the Philadelphia Inquirer:

Collisions with the Future

An Extraodinary New Era for Science

This weekend, the Large Hadron Collider, the world's most powerful particle-smashing machine, started up again. By all reports, everything is working brilliantly. Beams of protons entered the pipes and circulated around the 27-km (17 mile) ring in opposite directions, engaging in a graceful, ultra-rapid ballet. In coming weeks, the first collisions will begin and scientists will start analysing the data that may lead to the discovery of the Higgs boson, supersymmetric companions and other long-sought particles. Truly it is an extraordinary era for science!

For more about the Collider:

Collider: The Search for the World's Smallest Particles

Interview on Wired.com

An interview with me by Betsy Mason has been published on Wired.com:

High Energy Particle Physics Demystified

Galileo's Legacy

By Paul Halpern

Four hundred years ago last week, Italian astronomer Galileo Galilei announced the invention of what would be the world’s first astronomical telescope. Although the Dutch had pioneered the telescope, his instrument would be powerful enough to discover the mountains of the moon, four of the largest satellites of Jupiter, the phases of Venus, sunspots and other evidence of the magnificent diversity of the solar system. In short, it would prove most the most cutting-edge instrument of its era—as particle-smashers such as the Large Hadron Collider (LHC) in Europe are today. On August 25, 1609, Galileo presented one of his prototypes to the Venetian legislature, pointed out its military applications, and was promptly rewarded with a lifetime professorship and a substantial bonus.

After months of stargazing and taking careful notes about the features he observed, Galileo arrived at the astonishing conclusion that, contrary to age-old beliefs, there are other worlds in space besides Earth. If people could travel to the moon, he surmised, they could walk upon its surface too. He also verified the Copernican hypothesis that all planets in the solar system, including Earth, revolve around the Sun. By maintaining his belief in the non-uniqueness of Earth, and the capability of science to reveal new facts that supersede prior religious tenets, Galileo was eventually charged with heresy. History has vindicated Galileo, however, and established him as one of the founders of the modern scientific method. The Apollo mission of 1969, celebrated last month for its 40th anniversary, offered tangible proof that Galileo was amazingly prescient in his view of the universe.

The past century has revealed that the solar system and all the stars that speckle the sky are part of an incredibly vast spiral galaxy, itself but a minute part of an immense universe. As the noted American astronomer Edwin Hubble demonstrated in the 1920s with a huge optical instrument atop Mt. Wilson in California, the galaxies, by and large, are moving apart from each other. This discovery revealed the expansion of the universe. Further evidence gathered from the 1960s until the present day has indicated that the cosmos began in a hot, dense state known as the Big Bang. The wealth of cosmic knowledge gathered through variations of Galileo’s device is truly astounding.

Despite the amazing progress in astronomy our understanding of space is far from complete. In fact, observations made in the mid-to-late 20th century revealed that the visible content of the universe is but a small fraction of all that is out there. In the mid-1960s, astronomers Vera Rubin and Kent Ford engaged in a detailed study of the outermost stars in the Andromeda galaxy and found these to be moving much faster than expected. They arrived at the startling conclusion that invisible material, now known as “dark matter,” was exerting an extra gravitational tug on the stars—like hidden reigns pulling mechanical horses around a merry-go-round.

The situation became even trickier in the late 1990s, when two teams of astronomers, studying the energy profiles of exploding stars, or supernovae, in very distant galaxies, determined their distances and speeds, and discovered that the universe has been expanding at an increasingly rapid pace. Gravity alone could not explain such cosmic acceleration. Rather, some invisible dynamo, dubbed “dark energy” must be pushing all the galaxies away from each other at a faster and faster rate. Some models predict that the universe will eventually be torn apart, like a sheet stretched beyond its limits and ripped into tatters. Such a “Big Rip” would mean the complete fragmentation of space itself.

Dark matter and dark energy are mysteries that scientists cannot ignore. Around 72 percent of the known content of the universe is estimated to be dark energy, and another 23 percent dark matter. Only 5 percent is ordinary visible material, composed of the atoms that make up all things on Earth, the stars, planets and everything familiar.

Just as it took Galileo’s extraordinary new instrument to vanquish misconceptions about the solar system, it will take a fantastic new device to unravel the mysteries of dark matter and dark energy. One of the principal missions of the LHC, the largest particle collider ever completed, is to create massive particles that could potentially represent a component of the invisible substances in the cosmos. Although the LHC was shut down for repair soon after its opening in September 2008, it is scheduled to restart this November. By winter, if all goes well, physicists will begin collecting data that could further our understanding of the natural world in unprecedented ways. As we commemorate Galileo’s legacy, let’s hope that the LHC will revolutionize our vision of nature in the way the telescope did four centuries ago.


Paul Halpern is Professor of Physics at the University of the Sciences in Philadelphia
He is the author of Collider: The Search for the World’s Smallest Particles

Review of COLLIDER on the 'Keeper of the Snails" Blog

I am extraordinarily pleased that Clare Dudman, author of Wegener's Jigsaw and other works, has reviewed COLLIDER on her blog:

Keeper of the Snails

Dudman writes:
"I found Collider a compelling and invigorating read, and one that I am sure will change the way I think about the universe and my place within it."


If you scroll down a bit on her blog there is also a video review.

Our Deep Fascination with Time Travel

A piece I've written about our continued fascination with time travel appears in the Philadelphia Inquirer:

America's love affair with time travel endures
By Paul Halpern

The Strange Story of Atomism: From Blasphemy to Science

Atomism, the concept that things have smallest constituents, was introduced at the time of the ancient Greeks. To us moderns, it makes perfect sense. Yet for almost two millennia, mainstream European philosophers ignored or even shunned the idea. Why did it take so long to catch on?

The reason has perhaps more to do with who ended up trumpeting atomism than it has to do with the notion itself. In the battlefield of ideas, if a leading advocate is tremendously unpopular, opposing armies often see to it that all the notions he bears are equally trampled.

It is to atomism’s misfortune that its standard bearer for a time was Epicurus of Samos, founder of the much-maligned Epicurean school. He advocated atomism along with a set of widely scorned doctrines about the supremacy of pleasure over piety. Also he believed that the gods did not intervene in the lives of men. Thus he was widely condemned as a godless hedonist, discounting his atomist ideas.

Epicurus used atomism as a cleaver to divide the physical and spiritual realms. According to his theory, our bodies are composed of coarse atoms and our souls made of fine atoms. The gods consist of the most delicate atoms of all, floating in the spaces between physical worlds. Only in our thoughts and dreams do the mundane and godly come into contact. They do so in a way that the gods have no influence over people. Earth came into being through the random assembly of its own atoms and will pass away once they scatter into the void. The same with living beings; each must eventually perish due to material causes. Hence, Epicurus concluded, the gods have nothing to do with mortal existence and we need not fear or worship them.

In 56 B.C., a prominent Epicurean of the Roman era, Lucretius, wrote an epic Latin poem De Rerum Natura (On the Nature of Things) expounding upon atomism, materialism, and mortal life. Although his contemporaries seem to have valued his work, once the Roman Empire became Christian, his writings were denounced for their support of atheism and no longer published. Only a single copy survived the medieval period and was re-published in 1417.

Throughout the Middle Ages in Europe, the Church continued to treat Epicurean philosophy as blasphemous. As an indication of Europeans’ disdain toward Epicurean philosophy as late as the 14th century, note Italian poet Dante Alighieri’s description of the sixth circle of his fiery Inferno where Epicurean souls are forced to reside forever with their rotting corpses:

“The private cemetery on this side
serves Epicurus and his followers,
who make the soul die when the body dies.”

For those tormented spirits, it seems, their original sin was atoms not Adam’s. By contrast, according to Dante, non-atomist Aristotle has a relatively cushy spot in Limbo (non-Christians cannot enter Paradise), where he is sad but not tormented. Such was the attitude toward materialism in Dante’s times.

Atomism was resurrected in the 17th century, largely due to the writings of French philosopher Pierre Gassendi (1592-1655), an avid reader of Lucretius. Gassendi muted theological objections to the subject by speculating that God created atoms as the building blocks of nature. His work coincided with a growing recognition among Christian believers that scientific experimentation provided a way of understanding and appreciating creation. Along with the discoveries of German mathematician Johannes Kepler, Italian astronomer Galileo Galilei, and others of his day, Gassendi’s sharp observations prodded Europe away from blind belief in Aristotle’s theories and toward an empirical view of nature. Ultimately these trends led to the founding of the modern scientific concept of atoms.

More about the extraordinary quest for the most fundamental components of nature can be found in:

Collider: The Search for the World's Smallest Particles

New Webpage for Collider

I have recently revamped my website and added a new page for Collider:

Collider - Paul Halpern

LHC Physicist and Stand-Up Comic

Tom Whyntie is a physicist from the Large Hadron Collider who is moonlighting as a stand-up comic until the accelerator is restarted. Listen to his funny talk:
Whatever is the Matter?

Advanced Praise for COLLIDER

Advanced praise for Collider: The Search for the World's Smallest Particles

"Paul Halpern is a gifted writer who brings science and scientists alive. This is a wonderful introduction to the world of high-energy physics, where gigantic machines and tiny particles meet."
—Kenneth Ford, retired director of the American Institute of Physics and author of The Quantum World: Quantum Physics for Everyone

"Professor Paul Halpern takes the reader on a stimulating odyssey on topics ranging from particle physics and dark matter to unexplored dimensions of space. The masterful Halpern likens the physicist's quest to the excavation of archaeologists who seek to uncover 'new treasures' as they unearth wondrous gems that lay hidden all around us. Buy this book and feed your mind!"
—Dr. Cliff Pickover, author of Archimedes to Hawking and The Math Book

"With clarity and a Sagan-esque gift for explanation, Paul Halpern traces the story of how physicists use immensely powerful machines to probe the deepest mysteries of existence. Halpern also conclusively debunks the ludicrous claims that the Large Hadron Collider and other high-energy physics experiments threaten to destroy anything—except our residual ignorance about the nature and workings of our wondrous universe."
—Mark Wolverton, author of The Science of Superman and A Life in Twilight: The Final Years of J. Robert Oppenheimer

"A gem. The prose sparkles, the descriptions are exquisitely understandable, and the narrative is just plain fun. This book will charm experts, students, and anyone interested in scientific exploration."
—Catherine Westfall, Visiting Associate Professor of the History of Science at Lyman Briggs College, Michigan State University, and coauthor of Fermilab: Physics, the Frontier, and Megascience

"Paul Halpern has written a masterful account of particle accelerators and the theories they are constructed to investigate in a very accessible and engaging style. As the world's largest accelerator begins its search for the smallest particles, Halpern traces the human drive to find the ultimate building blocks of nature. "
—David C. Cassidy, professor at Hofstra University and the author of Beyond Uncertainty: Heisenberg, Quantum Physics, and the Bomb

"If you ever wondered about the Large Hadron Collider and what's brewing in high energy physics and cosmology, Paul Halpern is a wonderful guide. His lively and engaging writing deftly interweaves the historical background, the current frontiers, and the latest scientific instruments, now poised to address so many profound questions."
—Peter Pesic, author of Sky in a Bottle and Seeing Double: Shared Identities in Physics, Philosophy, and Literature

Happy 80th Birthday Prof. Peter Higgs!

Peter Higgs, the eminent British physicist who co-proposed a mechanism for how particles in the universe acquired mass, turns 80 today. The Higgs mechanism supposes that the very early cosmos went through a phase transition, similar to the freezing of water into ice. Just as ice freezes into particular patterns, Higgs posited that the universe "froze" into special values of mass. Consequently, the stuff of matter is weighty rather than ethereal.

If Higgs's theory is correct, a remnant of the agent that caused the transition should be around today, at an energy that may be detectable in the Large Hadron Collider (LHC). Thus, one of the LHC's goals is the quest for the long-sought Higgs particle (nicknamed the "God Particle").

Wishing Prof. Higgs many happy returns! Let's hope he will soon be able to unwrap a wonderful present -- news of the discovery of the particle that bears his name.

More information about the quest for the Higgs particle can be found in my new book: Collider: The Search for the World's Smallest Particles