Jay D. Tasson

Physics and Astronomy Department

Carleton College

Contact Information

Office: Olin Hall 337

Office Hours: Monday 2:00-3:00 pm, by appointment, or any time you find me. Just stop by!

Email: jtasson[at]carleton.edu

Current Teaching (Winter '13)

PHYS 151 Relativity and Particles (2nd 5 weeks)

Olin 02
M,W: 12:30-1:40 pm; F: 1:10-2:10 pm

PHYS 151L Relativity and Particles Lab (2nd 5 weeks)

Olin 301
T: 1:00 pm-5:00 pm

PHYS 229/230 Analytical/Computational Mechanics

Olin 02
M,W: 8:30-9:40 am; F: 8:30-9:30 am

Special Projects

A diverse set of opportunities exist for students to work with me on projects related to relativity testing (testing Lorentz symmetry). The opportunities could involve a variety of activities ranging from data analysis to paper and pencil theory and span a variety of areas of physics. There are also projects suited to a variety of backgrounds and skill levels. Also see the department special projects page. For more information about relativity testing, see FAQ about CPT and Lorentz violation or the publications and animations of recent results below.

Recent Teaching

Carleton College Fall '12 - PHYS 355 Topics in Advanced Classical Mechanics (Now a full-term version of PHYS 350)

Carleton College Fall '12 - PHYS 131 Newtonian Mechanics

Carleton College Spring '12 - PHYS 152 Environmental Physics

Carleton College Spring '12 - PHYS 131 Newtonian Mechanics

Carleton College Winter '12 - PHYS 120 Revolutions In Physics

Carleton College Winter '12 - PHYS 230 Computational Mechanics

2012 siege engine pictures

Carleton College Winter '12 - PHYS 229 Analytical Mechanics

Carleton College Fall '11 - PHYS 350 Advanced Mechanics

Carleton College Fall '11 - PHYS 142 Matter and Interactions

Whitman College Spring '11 - PHYS 156 General Physics II

Whitman College Spring '11 - PHYS 452 General Relativity

LIGO tour pictures

Whitman College Fall '10 - PHYS 155 General Physics I

Whitman College Fall '10 - PHYS 370 Thermal and Statistical Physics

Publications

Lorentz Violation, Gravitomagnetism, and Intrinsic Spin,
Jay D. Tasson,
To appear in Phys. Rev. D,
arXiv preprint available.

Antimatter, the SME, and Gravity,
Jay D. Tasson,
Hyperfine Interact. 213, 137 (2012),
arXiv preprint available.

Lorentz Symmetry, the SME, and Gravitational Experiments,
Jay D. Tasson,
in The proceedings of the 46th Rencontres de Moriond and GPhyS Colloquium ,
E. Augé, J. Dumarchez, and J. Trân Thanh Vân, ed., Thế Giới, Vietnam, 2011,
arXiv preprint available.

Lorentz Symmetry and Matter-Gravity Couplings,
Jay D. Tasson,
in CPT and Lorentz Symmetry V, V.A. Kostelecky, ed., World Scientific, Singapore, 2011,
arXiv preprint available.

Matter-Gravity Couplings and Lorentz Violation,
V. Alan Kostelecky and Jay D. Tasson,
Phys. Rev. D 83, 016013 (2011),
arXiv preprint available.

Gravitational Physics with Antimatter,
Jay D. Tasson,
Hyperfine Interact. 193, 291 (2009),
arXiv preprint available.

Prospects for Large Relativity Violations in Matter-Gravity Couplings,
V. Alan Kostelecky and Jay D. Tasson,
Phys. Rev. Lett. 102, 010402 (2009),
arXiv preprint available.

Constraints on Torsion from Bounds on Lorentz Violation,
V. Alan Kostelecky, Neil Russell, and Jay D. Tasson,
Phys. Rev. Lett. 100, 111102 (2008),
arXiv preprint available.

Probing Lorentz Symmetry with Gravitationally Coupled Matter,
Jay D. Tasson,
in CPT and Lorentz Symmetry IV, V.A. Kostelecky, ed., World Scientific, Singapore, 2008,
arXiv preprint available.

A Current-Mode Detector Array for Gamma Asymmetry Measurements,
the NPDGamma collaboration,
Nucl. Instrum. Meth. A, 540, 328 (2004).

Animations of Recent Results

Download Animation

The potential relativity violations considered in Phys. Rev. Lett. 102, 010402 (2009) change the gravitational properties of an object according to its motion. One striking effect results from the revolution of the Earth around the Sun. For example, the rate at which objects fall to the Earth can depend on the season. This is illustrated in the animation at left. The Earth is shown moving around the Sun in a background of red arrows representing the relativity violations. The motion of the Earth and objects like an apple aligns differently with the arrows in the summer and winter, which causes identical apples to fall at different rates in the two seasons. There is also a similar but smaller day-night effect due to the rotation of the Earth. The cover story for the April 15, 2009 issue of New Scientist provides additional lay discussion of these effects.

Download Animation

Einstein's theory of General Relativity is based on the idea that space and time are curved. An additional warping of space and time that is popular in some alternative theories of gravity is known as Torsion. The work published in Phys. Rev. Lett. 100, 111102 (2008) provides the first measurement of potential effects arising from 15 of the 24 quantities that describe torsion and provides improved sensitivity to the effects of 4 more.

The paper develops an analogy between the effects of spacetime torsion and the effects of tiny deviations from the laws of Special Relativity. Such motions have been excluded at an astounding level in experiments at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts and the University of Washington in Seattle

The University of Washington group uses a pendulum containing a large number of aligned electron spins to magnify these effects. The apparatus can measure changes in the rotation of the pendulum smaller than 0.000001 degrees. A simplified illustration of the motion of such a device is provided by the animation at left.

The complementary approach used in the Harvard-Smithsonian experiment involves precision studies of microwaves emitted from a helium-xenon maser. This permits measurements of changes in the spin orientation of neutrons at levels comparable to the measurements made on the electron by the Washington group.