
	Where results make sense

Topic: Lamb shift

Related Topics

Hydrogen atom

Casimir effect

Uncertainty principle

Battle fatigue

Dramatic portrayals of Jesus

Negative energy

Arnold Schwarzenegger

Henry Hill

Jesus christ

Stone Pine

Null

Jon Voight

Joe Louis

Muhammad Ali

Universal Waite tarot deck

	The Lamb Shift
		In 1951, Willis Lamb discovered that this was not so - that the 2p(1/2) state is slightly lower than the 2s(1/2) state resulting in a slight shift of the corresponding spectral line (the Lamb shift).
		While the Lamb shift is extremely small and difficult to measure as a splitting in the optical or uv spectral lines, it is possible to make use of transitions directly between the sublevels by going to other regions of the electromagnetic spectrum.
		When the Lamb shift was experimentally determined, it provided a high precision verification of theoretical calculations made with the quantum theory of electrodynamics.
	hyperphysics.phy-astr.gsu.edu /hbase/quantum/lamb.html (709 words)

	Willis Lamb
		In 1955 Lamb won the Nobel Prize for physics "for discoveries concerning the fine structure of the hydrogen spectrum" that led to refinements of the quantum theories of electromagnetic phenomena.
		Lamb received his B.S. in Chemistry in 1934 at the University of California at Berkeley then went on to earn a Ph.D. in physics in 1938, having carried out his doctoral research on the electromagnetic properties of nuclear systems, working under the direction of Robert Oppenheimer.
		Lamb spent the next twelve years teaching physics at Yale, and then, in 1974 he accepted a position as professor of physics and optical sciences at the University of Arizona.
	www.nndb.com /people/936/000035831 (320 words)

	The Lamb Shift in hydrogen (Site not responding. Last check: 2007-11-05)
		In 1947 Lamb and Retherford measured the energy difference between the lowest n=2 states predicted to be degenerate by the Dirac theory.
		In addition to measuring the fine structure splittings and the Lamb shift, one can use the recorded linewidths to estimate the lifetimes of the various excited states.
		Lamb, W. E., and R. Retherford, "Fine structure of the hydrogen atom by a microwave method," Phys.
	courses.washington.edu /phys432/lamb_shift.html (310 words)

	The Lamb Shift by Saturation Spectroscopy (Site not responding. Last check: 2007-11-05)
		When you try to obtain very high resolution to examine small splittings in spectral lines, such as the hydrogen fine structure and the Lamb shift, those details are obscured by the sources of line broadening.
		In a low pressure gas, the main source of broadening is Doppler broadening from the thermal motion of the atoms or molecules of the gas.
		The spectrum shown was obtained by tuning the dye laser slowly through the frequency range of the transition and measuring the change in intensity of the probe beam at the modulation or "chopping" frequency.
	hyperphysics.phy-astr.gsu.edu /hbase/quantum/lamb2.html (405 words)

	Physics Today January 2002
		Lamb used this history to point out the perils of the temptation to treat evidence from a particularly reliable source with diminished weight because it deviates inconveniently from a well-established prevailing model.
		I conclude that Houston is a half-forgotten hero of this story, the grandfather of the Lamb shift measurement (and a great uncle, maybe, of the QED revolution after Shelter Island).
		Lamb must have had confidence from the beginning in just about what the result would be, and that confidence would have helped enormously in supporting the continuing determination needed for such a tour de force experiment.
	www.physicstoday.org /pt/vol-55/iss-1/p77a.html (724 words)

	UA Physicist Chosen for Highest U.S. Award
		Lamb, 87, was one of 12 U.S. scientists and engineers named to receive the medal at a Dec. 1 awards dinner in Washington.
		Lamb was born July 12, 1913, in Los Angeles, and graduated from public schools there, then attended the University of California at Berkeley.
		Lamb determined that there is a small but significant difference in the energy levels existing between two states of excitation of the hydrogen atom.
	www.physics.arizona.edu /physics/public/lamb-star.html (673 words)

	Lamb Shift -- from Eric Weisstein's World of Physics
		Quantum electrodynamics requires an absence of vacuum polarization near the nucleus of a hydrogen atom.
		This is in good agreement with quantum electrodynamics using the larger of the two current proton radius measurements of 0.862 ± 0.012 fm (Berkeland et al.
		Griffiths, D. "The Lamb Shift." §5.4 in Introduction to Elementary Particles.
	scienceworld.wolfram.com /physics/LambShift.html (183 words)

	Lamb shift - Wikipedia, the free encyclopedia
		In physics, the Lamb shift, named after Willis Lamb, is a small difference in energy between two energy levels 2s
		By using lower frequencies than for optical transitions the Doppler broadening could be neglected (Doppler broadening is proportional to the frequency).
		This particular difference is a one-loop effect of quantum electrodynamics, and can be interpreted as the influence of virtual photons that have been emitted and re-absorbed by the atom.
	en.wikipedia.org /wiki/Lamb_shift (257 words)

	Lamb shift Summary
		The Lamb shift describes a small but measurable difference in electron energy levels within the hydrogen atom that is accounted for by quantum electrodynamic theory.
		This self-energy leads to an energy level shift for atomic wavefunctions that are nonzero at the center of the atom; this explains why the 2s and 2p states are split, because the s-state wavefunctions are nonzero at the center of the atom while the p-state wavefunctions are zero there.
		The accuracy of the theoretical prediction of the Lamb shift verifies that renormalization theory is a valid way to treat infinities in quantum theory.
	www.bookrags.com /Lamb_shift (574 words)

	Willis Lamb, Jr., the Hydrogen Atom, and the Lamb Shift
		Willis E. Lamb, Jr., was awarded the 2000 National Medal of Science for "his towering contributions to classical and quantum theories of laser radiation and quantum optics, and to the proper interpretation of non-relativistic quantum mechanics.
		Lamb's discovery of the quantum effect that became known as the "Lamb shift" led physicists to rethink the basic concepts behind the application of quantum theory to electromagnetism.
		Lamb continued working in the general area of atomic spectroscopy and theoretical laser physics as a member of the Stanford University faculty (1951-56) and as professor and Fellow of New College at the University of Oxford, England (1956-62).
	www.osti.gov /accomplishments/lamb.html (605 words)

	Nobel Prize in Physics 1955 - Presentation Speech
		Lamb's discovery refers to the hydrogen atom, where one single electron moves around the nucleus in one of a series of orbits, each having a definite energy.
		Lamb reported on his results at a physics meeting which was held in the neighbourhood of New York in the early summer of 1947.
		During the discussion it was made probable that the Lamb shift could be explained using certain general ideas of Kramers, the purpose of which was to improve the theories just mentioned.
	nobelprize.org /physics/laureates/1955/press.html (1038 words)

	Nobel Prize in Physics 1965 - Presentation Speech
		For the hydrogen atom, which has only one electron and consequently is the simplest atom to investigate theoretically, the calculation of the motion of the electron in the electric field of the nucleus led to results of such accuracy that 20 years elapsed until any error of the theory could be found experimentally.
		Lamb and his collaborator Retherford discovered that some energy levels of hydrogen which should coincide theoretically were in fact somewhat shifted relative to each other.
		As soon as Tomonaga knew about the Lamb experiment and Bethe's paper he realized that an essential step to be taken was to substitute the experimental mass for the fictive mechanical mass which appeared in the equations of quantum electrodynamics and to perform a similar renormalization of the electric charge.
	nobelprize.org /nobel_prizes/physics/laureates/1965/press.html (1096 words)

	Willis Lamb - Wikipedia, the free encyclopedia
		Lamb and Polykarp Kusch were able to precisely determine certain electromagnetic properties of the electron.
		Lamb is a professor at the University of Arizona.
		Lamb was born in Los Angeles, California, United States.
	en.wikipedia.org /wiki/Willis_Lamb (151 words)

	Przesunięcie Jagnięcia (Site not responding. Last check: 2007-11-05)
		The Lamb's shift*, a minimal difference in lowest energetic level of the excited hydrogen atom can’t be explained in any way without introduction of the absolutely new concept in Physics: Quantum Electrodynamics.
		mb's shift: a subtle structure of the n=2 level in hydrogen according to Bohr's, Dirac's and QED with assumption Lamb's shift.
		The song on Mary's lamb was the first "phonograf" record, made by Edison, but this is a different story. .
	www.science.unitn.it /~karwasz/lamba-en.html (176 words)

	Laser Spectroscopy@EBIT
		Interestingly, 2s Lamb shift measurements in the range Z=15-18 are all a little lower than the theoretical predictions, with the most precise measurement, for P
		The accuracy of most such experiments is inherently limited by the Doppler effect, and uncertainties associated with the high velocity of the ions in a fast beam form a significant source of error in all measurements performed to date.
		However, in practice, a direct determination of the 2s Lamb shift is much more difficult, since the large natural width of the 2p state requires the laser to be tuned over a large fraction of its frequency.
	www.physics.ox.ac.uk /ebit/laser1.asp (619 words)

	HISTORY OF PHYSICS: ON RENORMALIZATION IN QED
		Lamb and Retherford measured a quantity that became known as the "Lamb shift" -- the frequency of a microwave field that induced transitions between the lowest two excited states of the hydrogen atom.
		Lamb measured it to be 1000 megahertz, with an uncertainty of a few percent.
		On the one hand, the Lamb experiment gave clear evidence that the effects of electromagnetic quantum fluctuations were real and finite.
	scienceweek.com /2005/sw051104-2.htm (1820 words)

	The Lamb Shift (Site not responding. Last check: 2007-11-05)
		Some of the effects of this theory which cause the Lamb shift are shown in the Feynman diagrams of figure 5.
		Figure 5: Feynman loop diagrams showing some effects that contribute to the Lamb shift.
		Notice that the Lamb shift is very small except for l=0.
	www.pha.jhu.edu /~rt19/hydro/node8.html (248 words)

	Re: how were the lamb shift experiments done?
		Since the Lamb shift is so small (~1057 MHz), it is necessary to use very long wavelengths to observe this energy.
		To measure the shift, he first had to excite atoms in the 2s(1/2) state hydrogen up to 2p(1/2) state because the atoms cannot directly transition from 2s(1/2) to 1s(1/2) due to
		From the 2p(1/2) level, Lamb exposed the atoms to microwave radiation at 2395 MHz, then varied the magnetic field until it produced transitions from the 2p(1/2) to 2p(3/2) levels.
	www.madsci.org /posts/archives/nov2000/975611177.Ph.r.html (178 words)

	Lamb shift and mass
		Lamb shift proved that within an atom the energy level of electrons changes with changes in orbital position.
		This shift occurs at both fine structure levels by the same amount and so doesn't affect the splitting.
		Lamb shift on the other hand is attributable to what is called a 'radiative correction' or the self energy of the electron.
	www.physicsforums.com /showthread.php?p=499922 (692 words)

	M.I.T. Junior Lab 8.13/ 8.14
		A high resolution monochromator with a wavelength range from 2500 to 15,000 angstroms in first and second order is used to study the Balmer lines of hydrogen and the more complex hydrogenic spectrum of sodium, using the mercury spectrum as the wavelength calibrator.
		The transitions responsible for the sodium spectrum are identified, and the regularities in the fine structure and adherence to the selection rules are observed.
		A research grade monochromator is used to measure the isotope shift between the Balmer lines of hydrogen and deuterium, and the ratio of the deuteron mass to the proton mass is derived from the data.
	web.mit.edu /8.13/www/17.shtml (381 words)

	Sir Run Run Shaw Lecture: Willis E. Lamb, Jr. (Site not responding. Last check: 2007-11-05)
		The Lamb shift, announced at the historic conference held at Shelter Island in 1947, established the range of applicability of the Dirac theory of the electron, served as a key inspiration in the development of quantum field theory, and helped issue in an era that continues to this day.
		A native of California, Dr. Lamb received his Ph.D from the University of California at Berkeley in 1938, for nuclear studies, with the supervision of J. Robert Oppenheimer.
		Dr. Lamb held professorships at Columbia and Stanford, and was Wykeham Professor of Physics at Oxford and J. Willard Gibbs Professor of Physics at Yale.
	insti.physics.sunysb.edu /ITP/runrunshaw/w-lamb.html (257 words)

	Rinton Press - Publisher in Science and Technology
		Lamb has taught physics throughout his entire career: at Columbia University; Stanford University; Harvard University; Oxford University; Yale University; and the University of Arizona.
		Lamb's contributions to physics are highly honored and justly celebrated: it was his measurement of the Lamb shift that led to the renormalized quantum electrodynamical theories of Schwinger, Feynman, Tomonaga, and Dyson.
		The editor, Jagdish Mehra, was trained as a theoretical physicist in the research schools of Werner Heisenberg and Wolfgan Pauli, and later came under the strong influence of P.A.M. Dirac.
	www.rintonpress.com /books/wlamb.html (352 words)

	Princeton University Senior Theses brief display (Site not responding. Last check: 2007-11-05)
		Friedman, Daniel (1982): Measurement of the Lamb Shift in 4 He +: Determination of the Zeeman Splitting Field With alpha-Beta Resonance and NMR.
		Friedman, Daniel (1982): Measurement of the Lamb Shift in 4 He+: Determination of the Zeeman Splitting Field with Alpha-Beta Resonances and NMR.
		Shukan, David Scott (1986): Towards a 30ppm Measurement of the Lamb Shift in Singly Ionized He(3).
	libweb5.princeton.edu /theses/thesesvw.asp?Lname=&Fname=&Submit=Search&Title1=measurement&Title2=lamb&Title3=shift&department=&Class=&Adviser= (120 words)

	NRC Research Press: Canadian Journal of Physics
		The resonance frequency, and, hence, the Lamb shift and the proton radius, is determined by measuring the intensity of these X-rays as a function of the laser wavelength.
		A broad range of laser frequencies was scanned in 2003 and the analysis is currently under way.
		La fréquence de résonance, donnant le déplacement Lamb et le rayon du proton, est déterminée en mesurant l'intensité de ces rayons X en fonction de la longueur d'onde laser.
	pubs.nrc-cnrc.gc.ca /cgi-bin/rp/rp2_abst_e?cjp_p05-016_83_ns_nf_cjp4-05 (480 words)

	Optical frequency standards and metrology: measurements of the 1S Lamb shift in highly charged hydrogenic ions
		Measurements of the 1S Lamb shift in highly charged hydrogenic ions have been reported over a wide range of Z, most experiments having been performed using fast ion beams at accelerator facilities.
		Satellite contamination was minimal, whilst Doppler shift uncertanties were controlled by accurate measurements of the beam velocity using a time-of-flight technique.
		Although this is some way short of the precision required to test the calculations of the two-loop binding corrections, the result is far from being limited by the statistical quality of the data.
	www.npl.co.uk /optical_frequency_standards/introduction/hydrogenic_systems/1s_lamb_shift_measurements.html (417 words)

	Physics News Update Number 159 - NEW LAMB SHIFT MEASUREMENTS DISAGREE WITH QED (Site not responding. Last check: 2007-11-05)
		Ironically, QED was devised in the 1950s to explain the Lamb shift (named after Willis Lamb), the slight shift in the energy of an electron bound to a nucleus due to energy fluctuations in the vacuum, which can create electron-positron pairs or virtual photons seemingly out of nothing.
		In what they have called "the most stringent test of QED for a bound atom to date," the researchers employed the latest advances in laser and optical spectroscopy to make the measurements of the 1S Lamb shift, which can be measured to greater precision than the 2S and 2P Lamb shifts traditionally studied.
		However, the researchers do not particularly suspect that any "new physics" is at work here; they believe that a new, unpublished theoretical calculation taking into account previously ignored effects in QED should bring the results into agreement with theory.
	www.aip.org /pnu/1994/split/pnu159-1.htm (170 words)

	Class minutes---week 14
		He noted that the shift of the energy of a FREE electron would also be infinite, so he subtracted
		The spin-orbit shift is therefore proportional to m_s m_l.
		# In hw#12.8 you evaluate the weak, strong, and intermediate Zeeman shift for a p-orbital.
	www.glue.umd.edu /~tajac/622c/622minutes15.html (805 words)

	Giant Lamb shift of atoms near lossy multimode optical micro-waveguides \| Optoelectronics Research Centre \| University ... (Site not responding. Last check: 2007-11-05)
		Atoms coupled to optical fields strongly confined in two spatial dimensions, as in solid state microstructures, can experience very large Lamb shifts due to a spectrally strongly asymmetric mode density.
		We analytically find strong shifts of the atomic resonance frequency due to the modified vacuum, which can be an order of magnitude larger than the atomic linewidth.
		At the same time one gets significantly enhanced scattering of the guided light by the atom, which could be used as a tool to investigate these effects or to build non-destructive single atom detectors.
	www.orc.soton.ac.uk /viewpublication.html?pid=2491 (169 words)

Try your search on: Qwika (all wikis)