Ronald Mallett
Encyclopedia
Ronald Lawrence Mallett is an American theoretical physicist
, academic, and author. He has taught physics at the University of Connecticut
since 1975. He is best known for his scientific position on the possibility of time travel
.
, on March 30, 1945 and grew up in The Bronx
in New York City, New York. When he was 10 years old, his father died at age 33 of a heart attack. Inspired by a Classics Illustrated comic book version of H.G. Wells' The Time Machine
, Mallett resolved to travel back in time to save his father. This idea became a lifelong obsession.
His brother is artist Keith Mallett
.
from Penn State University. Also that year, he received the Graduate Assistant Award for Excellence in Teaching.
, where he continues to work today. His research interests include general relativity
, quantum gravity
, and time travel
.
In 1980, Mallett was promoted to Associate Professor, and since 1987, he has been a full Professor
. He has received two grants and many other distinctions.
In 2007, Mallett's life story of pursuing a time machine
was told on This American Life
, episode #324.
Mallett is a member of both the American Physical Society
and the National Society of Black Physicists
.
's properties within the context of Einstein's Theory of Relativity
. Mallett first argued that the ring laser would produce a limited amount of frame-dragging
which might be measured experimentally, saying:
s (CTC), allowing time travel into the past:
He also wrote a book entitled, Time Traveler: A Scientist's Personal Mission to Make Time Travel a Reality, co-written with New York Times best-selling
author Bruce B. Henderson
, that was first published in 2006. In June 2008, motion picture director Spike Lee
's production company announced it had acquired the film rights to Mallett's book. Lee is co-writing the movie script and directing the picture.
In 2006 Mallett declared that time travel into the past would be possible within the 21st century and possibly within less than a decade. Mallett uses Albert Einstein
's General Theory of Relativity to attempt to substantiate his claims.
which Mallett used in his analysis contains a singularity
even when the power to the laser is off and is not the spacetime that would be expected to arise naturally if the circulating laser were activated in previously empty space. Mallett has not offered a published response to Olum and Everett, but in his book Time Traveler he mentions that he was unable to directly model the optical fiber
or photonic crystal
which bends the light's path as it travels through it, so the light circulates around rather than moving in a straight line; as a substitute he chose to include a "line source" (a type of one-dimensional singularity) which would act as a "geometric constraint", bending spacetime in such a way that the light would circulate around on a helix
-shaped path in a vacuum (for an older solution involving an infinite cylinder which creates CTCs, in this case due to the cylinder's own rotation rather than light circulating around it, see the Tipler cylinder
). He notes that closed timelike curves are present in a spacetime containing both the line source and the circulating light, while they are not present in a spacetime containing only the line source, so that "the closed loops in time had been produced by the circulating flow of light, and not by the non-moving line source." However, he does not provide any additional argument as to why we should expect to see closed timelike curves in a different spacetime where there is no line source, and where the light is caused to circulate due to passing through a physical substance like a photonic crystal rather than circulating in a vacuum due to the curved spacetime around the line source.
Another objection by Olum and Everett is that even if Mallett's choice of spacetime were correct, the energy required to twist spacetime sufficiently would be huge, and that with lasers of the type in use today the ring would have to be much larger in circumference than the observable universe. At one point Mallett agreed that in a vacuum the energy requirements would be impractical but noted that the energy required goes down as the speed of light goes down. He then argued that if the light is slowed down significantly by passing it through a medium
(as in the experiments of Lene Hau
where light was passed through a superfluid
and slowed to about 17 metres per second) the needed energy would be attainable. However, the physicist J. Richard Gott
argues that slowing down light by passing it through a medium cannot be treated as equivalent to lowering the constant c (the speed of light
in a vacuum) in the equations of General Relativity, saying:
Finally, Olum and Everett note a theorem proven by Stephen Hawking
in a 1992 paper on the Chronology Protection Conjecture
, which demonstrated that according to General Relativity it should be impossible to create closed timelike curves in any finite region that satisfies the weak energy condition, meaning that the region contains no exotic matter
with negative energy. Mallett's original solution involved a spacetime containing a line source of infinite length, so it did not violate this theorem despite the absence of exotic matter, but Olum and Everett point out that the theorem "would, however, rule out the creation of CTC's in any finite-sized approximation to this spacetime."
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
, academic, and author. He has taught physics at the University of Connecticut
University of Connecticut
The admission rate to the University of Connecticut is about 50% and has been steadily decreasing, with about 28,000 prospective students applying for admission to the freshman class in recent years. Approximately 40,000 prospective students tour the main campus in Storrs annually...
since 1975. He is best known for his scientific position on the possibility of time travel
Time travel
Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space. Time travel could hypothetically involve moving backward in time to a moment earlier than the starting point, or forward to the future of that point without the...
.
Early life
Mallett was born in Roaring Spring, PennsylvaniaRoaring Spring, Pennsylvania
Roaring Spring in Morrisons Cove, is a borough Blair County, Pennsylvania, United States. The population was 2,418 at the 2000 census. It is part of the Altoona, PA Metropolitan Statistical Area-History:...
, on March 30, 1945 and grew up in The Bronx
The Bronx
The Bronx is the northernmost of the five boroughs of New York City. It is also known as Bronx County, the last of the 62 counties of New York State to be incorporated...
in New York City, New York. When he was 10 years old, his father died at age 33 of a heart attack. Inspired by a Classics Illustrated comic book version of H.G. Wells' The Time Machine
The Time Machine
The Time Machine is a science fiction novella by H. G. Wells, published in 1895 for the first time and later adapted into at least two feature films of the same name, as well as two television versions, and a large number of comic book adaptations. It indirectly inspired many more works of fiction...
, Mallett resolved to travel back in time to save his father. This idea became a lifelong obsession.
His brother is artist Keith Mallett
Keith Mallett
-Early life:Mallett was born in Roaring Spring, Pennsylvania. His father Boyd Mallett was a veteran of World War II and was an engineer and electrician who died of a heart attack at the age of 33. Mallett was six at the time of his father's death. His mother, Dorothy Williams raised Keith, his two...
.
Education
In 1973 when he was 28 years old, Mallett received a Ph.D.Doctor of Philosophy
Doctor of Philosophy, abbreviated as Ph.D., PhD, D.Phil., or DPhil , in English-speaking countries, is a postgraduate academic degree awarded by universities...
from Penn State University. Also that year, he received the Graduate Assistant Award for Excellence in Teaching.
Career
In 1975, Mallett was appointed a job as Assistant Professor at the University of ConnecticutUniversity of Connecticut
The admission rate to the University of Connecticut is about 50% and has been steadily decreasing, with about 28,000 prospective students applying for admission to the freshman class in recent years. Approximately 40,000 prospective students tour the main campus in Storrs annually...
, where he continues to work today. His research interests include general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
, quantum gravity
Quantum gravity
Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...
, and time travel
Time travel
Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space. Time travel could hypothetically involve moving backward in time to a moment earlier than the starting point, or forward to the future of that point without the...
.
In 1980, Mallett was promoted to Associate Professor, and since 1987, he has been a full Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
. He has received two grants and many other distinctions.
In 2007, Mallett's life story of pursuing a time machine
Time travel
Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space. Time travel could hypothetically involve moving backward in time to a moment earlier than the starting point, or forward to the future of that point without the...
was told on This American Life
This American Life
This American Life is a weekly hour-long radio program produced by WBEZ and hosted by Ira Glass. It is distributed by Public Radio International on PRI affiliate stations and is also available as a free weekly podcast. Primarily a journalistic non-fiction program, it has also featured essays,...
, episode #324.
Mallett is a member of both the American Physical Society
American Physical Society
The American Physical Society is the world's second largest organization of physicists, behind the Deutsche Physikalische Gesellschaft. The Society publishes more than a dozen scientific journals, including the world renowned Physical Review and Physical Review Letters, and organizes more than 20...
and the National Society of Black Physicists
National Society of Black Physicists
The National Society of Black Physicists was established in 1977 to promote the professional well-being of African Diaspora physicists and physics students within the international scientific community and the world community at large.-Brief history:...
.
Time machine project
For quite some time, Ronald Mallett has been working on plans for a time machine. This technology would be based upon a ring laserRing laser
A ring laser is a laser in which the laser cavity has the shape of a ring. Light in ring lasers has two possible directions of propagation: clockwise and counter-clockwise....
's properties within the context of Einstein's Theory of Relativity
Theory of relativity
The theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity. However, the word relativity is sometimes used in reference to Galilean invariance....
. Mallett first argued that the ring laser would produce a limited amount of frame-dragging
Frame-dragging
Einstein's general theory of relativity predicts that non-static, stationary mass-energy distributions affect spacetime in a peculiar way giving rise to a phenomenon usually known as frame-dragging...
which might be measured experimentally, saying:
In a later paper, he argued that at sufficient energies, the circulating laser might produce not just frame-dragging but also closed timelike curve
"In Einstein's General Theory of Relativity, both matter and energy can create a gravitational field. This means that the energy of a light beam can produce a gravitational field. My current research considers both the weak and strong gravitational fields produced by a single continuously circulating unidirectional beam of light. In the weak gravitational field of an unidirectional ring laser, it is predicted that a spinning neutral particle, when placed in the ring, is dragged around by the resulting gravitational field."
Closed timelike curve
In mathematical physics, a closed timelike curve is a worldline in a Lorentzian manifold, of a material particle in spacetime that is "closed," returning to its starting point...
s (CTC), allowing time travel into the past:
Funding for his program, now known as The Space-time Twisting by Light (STL) project, is progressing. Full details on the project, Mallett's theories, a list of upcoming public lectures and links to popular articles on his work can be found at the Professor's UConn web page, and an illustration showing the concept on which Mallett has designed the time machine can be seen here.
For the strong gravitational field of a circulating cylinder of light, I have found new exact solutions of the Einstein field equations for the exterior and interior gravitational fields of the light cylinder. The exterior gravitational field is shown to contain closed timelike lines.
The presence of closed timelike lines indicates the possibility of time travel into the past. This creates the foundation for a time machine based on a circulating cylinder of light.
He also wrote a book entitled, Time Traveler: A Scientist's Personal Mission to Make Time Travel a Reality, co-written with New York Times best-selling
New York Times Best Seller list
The New York Times Best Seller list is widely considered the preeminent list of best-selling books in the United States. It is published weekly in The New York Times Book Review magazine, which is published in the Sunday edition of The New York Times and as a stand-alone publication...
author Bruce B. Henderson
Bruce B. Henderson
Bruce Henderson , also known as Bruce B. Henderson, is an American writer and the author of more than 20 nonfiction books. He is a member of the Authors Guild and American Society of Journalists and Authors, and has taught writing courses at USC School of Journalism and Stanford University...
, that was first published in 2006. In June 2008, motion picture director Spike Lee
Spike Lee
Shelton Jackson "Spike" Lee is an American film director, producer, writer, and actor. His production company, 40 Acres & A Mule Filmworks, has produced over 35 films since 1983....
's production company announced it had acquired the film rights to Mallett's book. Lee is co-writing the movie script and directing the picture.
In 2006 Mallett declared that time travel into the past would be possible within the 21st century and possibly within less than a decade. Mallett uses Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
's General Theory of Relativity to attempt to substantiate his claims.
Objections
In a recent paper by Ken Olum and Allen Everett the authors claimed to have found problems with Mallett's analysis. One of their objections is that the spacetimeSpacetime
In physics, spacetime is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space as being three-dimensional and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions...
which Mallett used in his analysis contains a singularity
Gravitational singularity
A gravitational singularity or spacetime singularity is a location where the quantities that are used to measure the gravitational field become infinite in a way that does not depend on the coordinate system...
even when the power to the laser is off and is not the spacetime that would be expected to arise naturally if the circulating laser were activated in previously empty space. Mallett has not offered a published response to Olum and Everett, but in his book Time Traveler he mentions that he was unable to directly model the optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
or photonic crystal
Photonic crystal
Photonic crystals are periodic optical nanostructures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductor crystal affects the motion of electrons...
which bends the light's path as it travels through it, so the light circulates around rather than moving in a straight line; as a substitute he chose to include a "line source" (a type of one-dimensional singularity) which would act as a "geometric constraint", bending spacetime in such a way that the light would circulate around on a helix
Helix
A helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...
-shaped path in a vacuum (for an older solution involving an infinite cylinder which creates CTCs, in this case due to the cylinder's own rotation rather than light circulating around it, see the Tipler cylinder
Tipler Cylinder
A Tipler cylinder is a cylinder of dense matter of infinite length, rotating about its longitudinal axis. This hypothetical object is theorized to allow time travel and is also called a Tipler time machine....
). He notes that closed timelike curves are present in a spacetime containing both the line source and the circulating light, while they are not present in a spacetime containing only the line source, so that "the closed loops in time had been produced by the circulating flow of light, and not by the non-moving line source." However, he does not provide any additional argument as to why we should expect to see closed timelike curves in a different spacetime where there is no line source, and where the light is caused to circulate due to passing through a physical substance like a photonic crystal rather than circulating in a vacuum due to the curved spacetime around the line source.
Another objection by Olum and Everett is that even if Mallett's choice of spacetime were correct, the energy required to twist spacetime sufficiently would be huge, and that with lasers of the type in use today the ring would have to be much larger in circumference than the observable universe. At one point Mallett agreed that in a vacuum the energy requirements would be impractical but noted that the energy required goes down as the speed of light goes down. He then argued that if the light is slowed down significantly by passing it through a medium
Transmission medium
A transmission medium is a material substance that can propagate energy waves...
(as in the experiments of Lene Hau
Lene Hau
Lene Vestergaard Hau is a Danish physicist. In 1999, she led a Harvard University team who, by use of a superfluid, succeeded in slowing a beam of light to about 17 metres per second, and, in 2001, was able to momentarily stop a beam.In 1989, Hau accepted a two-year appointment as a postdoctoral...
where light was passed through a superfluid
Superfluid
Superfluidity is a state of matter in which the matter behaves like a fluid without viscosity and with extremely high thermal conductivity. The substance, which appears to be a normal liquid, will flow without friction past any surface, which allows it to continue to circulate over obstructions and...
and slowed to about 17 metres per second) the needed energy would be attainable. However, the physicist J. Richard Gott
J. Richard Gott
John Richard Gott III is a professor of astrophysical sciences at Princeton University. He is known for developing and advocating two cosmological theories with the flavor of science fiction: Time travel and the Doomsday argument.- Exotic matter time travel theories :Paul Davies's bestseller How...
argues that slowing down light by passing it through a medium cannot be treated as equivalent to lowering the constant c (the speed of light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
in a vacuum) in the equations of General Relativity, saying:
Later, Mallett abandoned the idea of using slowed light to reduce the energy, writing that, "For a time, I considered the possibility that slowing down light might increase the gravitational frame dragging effect of the ring laser ... Slow light, however, turned out not to be helpful for my research."
One has to distinguish between the speed of light in a vacuum, which is a constant, and through any other medium, which can vary enormously. Light travels more slowly through water than through empty space, for example, but this does not mean that you age more slowly while scuba diving or that it is easier to twist space-time underwater.
The experiments done so far don't lower the speed of light in empty space; they just lower the speed of light in a medium and should not make it easier to twist space-time. Thus, it should not take any less mass-energy to form a black hole or a time machine of a given size in such a medium.
Finally, Olum and Everett note a theorem proven by Stephen Hawking
Stephen Hawking
Stephen William Hawking, CH, CBE, FRS, FRSA is an English theoretical physicist and cosmologist, whose scientific books and public appearances have made him an academic celebrity...
in a 1992 paper on the Chronology Protection Conjecture
Chronology protection conjecture
The chronology protection conjecture is a conjecture by the physicist Professor Stephen Hawking that the laws of physics are such as to prevent time travel on all but sub-microscopic scales. Mathematically, the permissibility of time travel is represented by the existence of closed timelike curves...
, which demonstrated that according to General Relativity it should be impossible to create closed timelike curves in any finite region that satisfies the weak energy condition, meaning that the region contains no exotic matter
Exotic matter
In physics, exotic matter is a term which refers to matter which would somehow deviate from the norm and have "exotic" properties. There are several uses of the term....
with negative energy. Mallett's original solution involved a spacetime containing a line source of infinite length, so it did not violate this theorem despite the absence of exotic matter, but Olum and Everett point out that the theorem "would, however, rule out the creation of CTC's in any finite-sized approximation to this spacetime."
External links
- Mallett's UConn Homepage
- R. L. Mallett, "Weak gravitational field of the electromagnetic radiation in a ring laser"
- R.L. Mallett "The gravitational field of a circulating light beam"
- Ron Mallett interviewed on Conversations from Penn State
- My Brilliant Plan - This American LifeThis American LifeThis American Life is a weekly hour-long radio program produced by WBEZ and hosted by Ira Glass. It is distributed by Public Radio International on PRI affiliate stations and is also available as a free weekly podcast. Primarily a journalistic non-fiction program, it has also featured essays,...
The episode contains a story about Ron Mallett's life goal of creating a time machineTime travelTime travel is the concept of moving between different points in time in a manner analogous to moving between different points in space. Time travel could hypothetically involve moving backward in time to a moment earlier than the starting point, or forward to the future of that point without the...
. - A list of documentaries Mallett has been featured in
- Ron Mallett Penn State African American Chronicles profile and interview