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Here's some high value physics.
Vacuum QED effects detected around Neutron Stars?
Just over a week ago I received an interesting call from a science magazine reporter. He asked me what do I think about the recent discovery of the Quantum Electrodynamic (QED) produced vacuum birefringence around neutron stars. It was an interesting surprise as my colleague Jeremey Heyl at the University of British Columbia and I had what seemed to be a bizarre prediction back in around 1998, a prediction which seems to have been verified almost 2 decades later. So, what is the effect and what was measured?
[FONT="]Just over a week ago I received an interesting call from a reporter from science magazine. He asked me what do I think about the recent discovery of the Quantum Electrodynamic (QED) produced vacuum birefringence around neutron stars. It was an interesting surprise as my colleague Jeremey Heyl at the University of British Columbia and I had what seemed to be a bizarre prediction back in around 1998, a prediction which seems to have been verified almost 2 decades later. So, what is the effect and what was measured? [/FONT][FONT="]In 1936, Heisenberg, Euler and separately Weisskopf realized that light rays can interact with the virtual electrons in the vacuum if there is a very strong magnetic field. This interaction causes the electrons to oscillate and produce an electromagnetic wave such that the sum is an electromagnetic wave appearing to move slower than the speed of light. This is very similar to what happens with real electrons in everyday media (e.g., in your glasses where light moves slower than the speed of light), except that in everyday situations the interaction is not with the vacuum's virtual electrons. [/FONT][FONT="]As a consequence of this interaction, the index of refraction is different from unity. However, the cool thing is that the two indices of refraction of the two polarization states (in the direction perpendicular to the magnetic field and perpendicular to the latter) are different. This is because electrons oscillating in the direction of the magnetic field are not affected by it (well, almost), while electrons oscillation perpendicular to the magnetic field are. Thus, not only is the index of refraction different from unity, it is different for the two polarization models of the light, namely, depending on how the light ray's electric field is oriented with respect to the magnetic field. This effect is called birefringence (and it is wavelength independent for the vacuum birefringence). . . . [/FONT]
Vacuum QED effects detected around Neutron Stars?
Just over a week ago I received an interesting call from a science magazine reporter. He asked me what do I think about the recent discovery of the Quantum Electrodynamic (QED) produced vacuum birefringence around neutron stars. It was an interesting surprise as my colleague Jeremey Heyl at the University of British Columbia and I had what seemed to be a bizarre prediction back in around 1998, a prediction which seems to have been verified almost 2 decades later. So, what is the effect and what was measured?
[FONT="]Just over a week ago I received an interesting call from a reporter from science magazine. He asked me what do I think about the recent discovery of the Quantum Electrodynamic (QED) produced vacuum birefringence around neutron stars. It was an interesting surprise as my colleague Jeremey Heyl at the University of British Columbia and I had what seemed to be a bizarre prediction back in around 1998, a prediction which seems to have been verified almost 2 decades later. So, what is the effect and what was measured? [/FONT][FONT="]In 1936, Heisenberg, Euler and separately Weisskopf realized that light rays can interact with the virtual electrons in the vacuum if there is a very strong magnetic field. This interaction causes the electrons to oscillate and produce an electromagnetic wave such that the sum is an electromagnetic wave appearing to move slower than the speed of light. This is very similar to what happens with real electrons in everyday media (e.g., in your glasses where light moves slower than the speed of light), except that in everyday situations the interaction is not with the vacuum's virtual electrons. [/FONT][FONT="]As a consequence of this interaction, the index of refraction is different from unity. However, the cool thing is that the two indices of refraction of the two polarization states (in the direction perpendicular to the magnetic field and perpendicular to the latter) are different. This is because electrons oscillating in the direction of the magnetic field are not affected by it (well, almost), while electrons oscillation perpendicular to the magnetic field are. Thus, not only is the index of refraction different from unity, it is different for the two polarization models of the light, namely, depending on how the light ray's electric field is oriented with respect to the magnetic field. This effect is called birefringence (and it is wavelength independent for the vacuum birefringence). . . . [/FONT]
