An interview with me by Betsy Mason has been published on Wired.com:
High Energy Particle Physics Demystified
Wednesday, September 9, 2009
Sunday, September 6, 2009
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
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
Wednesday, August 26, 2009
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.
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.
Wednesday, August 19, 2009
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
America's love affair with time travel endures
By Paul Halpern
Tuesday, August 18, 2009
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
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
Saturday, July 11, 2009
Thursday, July 9, 2009
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?
Whatever is the Matter?
Subscribe to:
Posts (Atom)
