Many Little Dimensions or One Big One?
Posted: Wed Mar 07, 2007 12:00 am
Adapted from two articles originally published in the newspaper
Tompkins Weekly (http://www.tompkinsweekly.com).
In the early months of 2007, the college town of Ithaca, New York was visited by two giants in the field of physics.
Dr. Lisa Randall, a Professor of Theoretical Physics at Harvard, went to Cornell University to talk about her theory concerning gravity, namely why is it that of the four fundamental forces of nature – strong, electromagnetic, weak, and gravity – the force of gravity is so weak compared to the other three sets of interactions between particles and the large-scale behavior of matter throughout the Universe?
Randall’s explanation for this conundrum was explained in two science papers she wrote in 1999 with Raman Sundrum, now a Professor in the Department of Physics and Astronomy at Johns Hopkins University in Baltimore, Maryland. Randall also explained her theory at a popular level in her book Warped Passages: Unraveling the Mysteries of the Universe’s Hidden Dimensions (HarperCollins Publishers, New York, 2005). The book’s official Web site is http://www.warpedpassages.com/.
Randall and Sundrum conceived of a theory that has our three-dimensional (four if you count time) Universe residing in an “infinite extra dimension that warps spacetime so much that gravity [in the form of particles called gravitons] is concentrated near another brane [a three dimensional hypersurface embedded in a higher dimensional bulk],” says Randall. “There are actual physical consequences because of this extreme warping of spacetime.”
In essence, certain parts of the Cosmos may have stronger concentrations of gravity than what we experience due to these higher dimensions, thus explaining why gravity is the weakest of the four forces of nature – at least for us in this Universe.
Randall and her colleagues may be able to prove their theory later this year when the Large Hadron Collider (LHC) becomes operational at CERN laboratory near Geneva, Switzerland.
The giant particle accelerator and collider may be powerful enough to produce and detect what are known as Kaluza-Klein particles that move through those extra dimensions. The physicists could then determine their properties and potentially prove that we do exist in a world of higher dimensions that obey different physical laws.
“If the theory is true, it will affect many other sciences such as cosmology and string theory,” says Randall. “The scientists in those fields will have to explain their theories and the phenomena they detect in relation to those extra dimensions that interact with our Universe.”
Several months later, Dr. Sylvester James Gates, Jr., the director of the University of Maryland Center for String and Particle Theory, came to Ithaca College to explain the concept of strings.
Imagine the smallest thing you can possibly imagine.
Now scrap that thought, because you cannot imagine just how small a string really is.
Not the kind of string you tie to a kite or around your finger, but a strand of vibrating energy that many physicists think is the fundamental building block of everything in the Cosmos, the thing that even atoms are ultimately made of.
How small is one of these strings? If an atom were expanded to the size of our Solar System, roughly ten billion miles across if you include the orbit of Pluto, a string inside that atom would be the size of your average tree.
On the real world scale, about 5 sextillion (a five followed by 22 zeroes) atoms are contained in a single drop of water. The strings inside the nucleus of all those atoms are 100 billion billion times smaller than the protons and neutrons that make up every atomic core.
Strings are seventeen orders of magnitude smaller than the smallest objects that current science can actually observe. Physicists estimate that in order to actually detect a string, they would need a particle accelerator the size of the Milky Way galaxy, 100,000 light years across, to create the energy buildup required to smash apart atoms enough to find the presumed strings within them. Such a device is just a bit beyond current science budget plans.
Yet diminutive as they are, if strings actually exist as scientists have predicted mathematically since the 1960s, they could be the basis for all that exists in the Cosmos.
Gates, the John S. Toll Professor of Physics at the College Park institution, explained to his listeners how the different ways strings oscillate “create” the particles that make up the atoms that are part of every object we know. Beyond this, the theory requires there to be extra dimensions beyond the ones we experience with our senses, perhaps as many as 11 in total.
Gates and others think that superstrings, a concept which combines all of the current separate theories on string particles into one unified whole, could also explain gravity, the only member of the four fundamental forces of nature whose existence and actions cannot be fully explained at the quantum level.
Gates was one of the physicists featured in the Nova science series on PBS television in a 2003 adaptation of the 2000 book The Elegant Universe, a popular exposition of superstring theory written by Columbia University physicist and mathematician Brian Greene. You can read Gates’ complete interview from that program here: http://www.pbs.org/wgbh/nova/elegant/view-gates.html.
Gates’ presentation on strings is a generalization of his college lectures on the subject, which can be purchased either as a DVD set or a transcript through this Web site: http://www.teach12.com/ttcx/coursedescl ... x?cid=1284
Strings of another sort accompanied and framed Randall’s lesson in physics, courtesy of musicians Stephen Andrew Taylor from the University of Illinois at Urbana-Champaign and Wendy Herbener Mehne and Pablo Cohen, both of Ithaca College.
Using a combination of flute, guitar, and live electronics, the trio performed Taylor’s piece titled seven microworlds, which premiered in 2000 in Toronto. The piece can be heard on Taylor’s Web site here: http://www.stephenandrewtaylor.net/
Taylor earned his Ph.D. in music composition from Cornell. Over the last two decades, he has composed a number of pieces honoring science, including one dedicated to Dr. Carl Sagan called Pale Blue Dot, after the late Cornell astronomer’s evocative description of our planet Earth as seen from the edge of the Solar System by the Voyager 1 space probe in 1990.
Taylor explains what brought him to create music based on particle physics.
“I was inspired to compose seven microworlds by learning about string theory, a recent branch of physics in which fundamental particles such as quarks and photons are thought to consist of unimaginably small, vibrating strings. By vibrating in different ways, these strings account for all currently known particles, just as you can play many different notes on a single guitar string.
“But nobody knows whether or not the theory is true, and in some ways it is quite bizarre. In addition to our three familiar spatial dimensions, strings inhabit several other ultra-microscopic dimensions curled into complex knots. We don't notice these microdimensions, even though the theory says we move through them constantly.
“In my piece, the electronics are intended to act as a bridge between the ‘real world’ of the flute and guitar and these hidden microworlds that permeate us all. Of the seven movements (played without pause), the first, fourth, and seventh for both flute and guitar loosely represent the three macrodimensions. The others are solo movements inspired by various twisting microdimensions. ‘Collision Focus’, the first movement, zooms into microscopic chaos; the fourth, ‘Verticality’ (the only movement without electronics), plays with ascents and wide leaps; ‘Flatland’ is a meditation on a plane curving into itself, just as the seemingly flat surface of Earth wraps into a sphere.”
Which theory is right about what lies beyond the reality we can see, or think we know? The answers may come sooner than we think, perhaps even in ways and with results we did not anticipate. But that is half the fun.
Tompkins Weekly (http://www.tompkinsweekly.com).
In the early months of 2007, the college town of Ithaca, New York was visited by two giants in the field of physics.
Dr. Lisa Randall, a Professor of Theoretical Physics at Harvard, went to Cornell University to talk about her theory concerning gravity, namely why is it that of the four fundamental forces of nature – strong, electromagnetic, weak, and gravity – the force of gravity is so weak compared to the other three sets of interactions between particles and the large-scale behavior of matter throughout the Universe?
Randall’s explanation for this conundrum was explained in two science papers she wrote in 1999 with Raman Sundrum, now a Professor in the Department of Physics and Astronomy at Johns Hopkins University in Baltimore, Maryland. Randall also explained her theory at a popular level in her book Warped Passages: Unraveling the Mysteries of the Universe’s Hidden Dimensions (HarperCollins Publishers, New York, 2005). The book’s official Web site is http://www.warpedpassages.com/.
Randall and Sundrum conceived of a theory that has our three-dimensional (four if you count time) Universe residing in an “infinite extra dimension that warps spacetime so much that gravity [in the form of particles called gravitons] is concentrated near another brane [a three dimensional hypersurface embedded in a higher dimensional bulk],” says Randall. “There are actual physical consequences because of this extreme warping of spacetime.”
In essence, certain parts of the Cosmos may have stronger concentrations of gravity than what we experience due to these higher dimensions, thus explaining why gravity is the weakest of the four forces of nature – at least for us in this Universe.
Randall and her colleagues may be able to prove their theory later this year when the Large Hadron Collider (LHC) becomes operational at CERN laboratory near Geneva, Switzerland.
The giant particle accelerator and collider may be powerful enough to produce and detect what are known as Kaluza-Klein particles that move through those extra dimensions. The physicists could then determine their properties and potentially prove that we do exist in a world of higher dimensions that obey different physical laws.
“If the theory is true, it will affect many other sciences such as cosmology and string theory,” says Randall. “The scientists in those fields will have to explain their theories and the phenomena they detect in relation to those extra dimensions that interact with our Universe.”
Several months later, Dr. Sylvester James Gates, Jr., the director of the University of Maryland Center for String and Particle Theory, came to Ithaca College to explain the concept of strings.
Imagine the smallest thing you can possibly imagine.
Now scrap that thought, because you cannot imagine just how small a string really is.
Not the kind of string you tie to a kite or around your finger, but a strand of vibrating energy that many physicists think is the fundamental building block of everything in the Cosmos, the thing that even atoms are ultimately made of.
How small is one of these strings? If an atom were expanded to the size of our Solar System, roughly ten billion miles across if you include the orbit of Pluto, a string inside that atom would be the size of your average tree.
On the real world scale, about 5 sextillion (a five followed by 22 zeroes) atoms are contained in a single drop of water. The strings inside the nucleus of all those atoms are 100 billion billion times smaller than the protons and neutrons that make up every atomic core.
Strings are seventeen orders of magnitude smaller than the smallest objects that current science can actually observe. Physicists estimate that in order to actually detect a string, they would need a particle accelerator the size of the Milky Way galaxy, 100,000 light years across, to create the energy buildup required to smash apart atoms enough to find the presumed strings within them. Such a device is just a bit beyond current science budget plans.
Yet diminutive as they are, if strings actually exist as scientists have predicted mathematically since the 1960s, they could be the basis for all that exists in the Cosmos.
Gates, the John S. Toll Professor of Physics at the College Park institution, explained to his listeners how the different ways strings oscillate “create” the particles that make up the atoms that are part of every object we know. Beyond this, the theory requires there to be extra dimensions beyond the ones we experience with our senses, perhaps as many as 11 in total.
Gates and others think that superstrings, a concept which combines all of the current separate theories on string particles into one unified whole, could also explain gravity, the only member of the four fundamental forces of nature whose existence and actions cannot be fully explained at the quantum level.
Gates was one of the physicists featured in the Nova science series on PBS television in a 2003 adaptation of the 2000 book The Elegant Universe, a popular exposition of superstring theory written by Columbia University physicist and mathematician Brian Greene. You can read Gates’ complete interview from that program here: http://www.pbs.org/wgbh/nova/elegant/view-gates.html.
Gates’ presentation on strings is a generalization of his college lectures on the subject, which can be purchased either as a DVD set or a transcript through this Web site: http://www.teach12.com/ttcx/coursedescl ... x?cid=1284
Strings of another sort accompanied and framed Randall’s lesson in physics, courtesy of musicians Stephen Andrew Taylor from the University of Illinois at Urbana-Champaign and Wendy Herbener Mehne and Pablo Cohen, both of Ithaca College.
Using a combination of flute, guitar, and live electronics, the trio performed Taylor’s piece titled seven microworlds, which premiered in 2000 in Toronto. The piece can be heard on Taylor’s Web site here: http://www.stephenandrewtaylor.net/
Taylor earned his Ph.D. in music composition from Cornell. Over the last two decades, he has composed a number of pieces honoring science, including one dedicated to Dr. Carl Sagan called Pale Blue Dot, after the late Cornell astronomer’s evocative description of our planet Earth as seen from the edge of the Solar System by the Voyager 1 space probe in 1990.
Taylor explains what brought him to create music based on particle physics.
“I was inspired to compose seven microworlds by learning about string theory, a recent branch of physics in which fundamental particles such as quarks and photons are thought to consist of unimaginably small, vibrating strings. By vibrating in different ways, these strings account for all currently known particles, just as you can play many different notes on a single guitar string.
“But nobody knows whether or not the theory is true, and in some ways it is quite bizarre. In addition to our three familiar spatial dimensions, strings inhabit several other ultra-microscopic dimensions curled into complex knots. We don't notice these microdimensions, even though the theory says we move through them constantly.
“In my piece, the electronics are intended to act as a bridge between the ‘real world’ of the flute and guitar and these hidden microworlds that permeate us all. Of the seven movements (played without pause), the first, fourth, and seventh for both flute and guitar loosely represent the three macrodimensions. The others are solo movements inspired by various twisting microdimensions. ‘Collision Focus’, the first movement, zooms into microscopic chaos; the fourth, ‘Verticality’ (the only movement without electronics), plays with ascents and wide leaps; ‘Flatland’ is a meditation on a plane curving into itself, just as the seemingly flat surface of Earth wraps into a sphere.”
Which theory is right about what lies beyond the reality we can see, or think we know? The answers may come sooner than we think, perhaps even in ways and with results we did not anticipate. But that is half the fun.
Actually, these books are heroic, but people--my mother, my neighbor--will often ask me about a particular popular science book, usually one by Hawking, and I have to explain that I haven't read it, and why I haven't read it.