ItemObserving the Interference Patterns of Light Passing through Two and More Slits Using a Charge-coupled Device(2023-06-16) Liu, Yuejun; Hare, HamishThomas Young's double-slit light interference experiment ranks among the few crucial experiments that eventually led to the confirmation of the essence of light as wave, which is one of the most revolutionary developments in the history of physics. In this project, we extend this experiment by using multiple slits and considering the widths of each slit. We conduct precise measurements of the interference patterns using a linear charge-coupled device and then compare the experimental measurements to predictions developed using electromagnetic theory to confirm the validity of treating light as an electromagnetic wave. However, our measurements did not match very well with theoretical model predictions, and we discuss possible reasons for that in this report. ItemBlackbody Radiation and the Ultraviolet Catastrophe - A Student Designed Undergraduate Physics Lab(2023-05-31) Powers-Luketic, Taylor; Moring, Mackenzie; Roper, Xander; Scholberg, Felix; Vanderwerff, LukeThe second-year physics curriculum at Queen’s University includes an introduction to quantum mechanics and highlights what classical mechanics fails to describe. This project aimed to design an appropriate second-year lab for Queen’s Physics, Engineering Physics and Astronomy Students accompanied by a complete lab manual, worksheet, python analysis code and a safety packet. Students will explore the classical theory of blackbody radiation and compare their results to their experimental data by measuring the intensity and wavelength of light emitted by an incandescent light bulb using a photodiode and Red Pitaya STEMLab. The project conducted the experiment and tested its feasibility and complexity. The results indicated that this project is a feasible and appropriate lab for second year students and highlights error analysis, instrument proficiency, as well as exploration of physical phenomena. The results yielded a clear relationship modelled by Planck’s law where intensity drops off with increasing wavelength, however, with an error of 150nm in wavelength, our peak wavelength of (340 ± 150) nm, predicts a temperature of (9000 ± 4000) K. A standard light bulb reaches approximately 2700K. Corrections will have to be made in order to account for the large error when being administered to second year students. ItemThe Effect of Optical Tweezers(2023-05-19) Mao, Jingjing; Enge, Daniel; Hong, Howie; Rajan, NeilIn this project, we create an optical trap for microscopic polystyrene spheres by constructing optical tweezers using a laser with a wavelength of 532nm. The potential well created by the optical trap is analogous to that of a harmonic oscillator. This allows us to define and measure the stiffness of the trap, which is dependent on the power of the laser. Using the position data obtained by a CCD camera, we can measure the stiffness of the trap using both the equipartition theorem and the mean squared distance method. We measured the trap stiffness for various laser power. Our result shows that the stiffness of the optical trap does not increase linearly with the power of the laser. ItemTesting Local Realism with Bell’s Inequality(2023-05-17) Robertson, Jake; Zheng, Han; Nedvidek, Brendan; Nish, Grant; Chen, ZoeIn this experiment, we constructed a single-channel Bell test to demonstrate the non-local nature of quantum mechanics. The apparatus was used to calculate Bell’s inequality(S) for entangled particles and show the violation of local realism. The experiment used a 405nm laser shun through a Beta-Barium Borate(BBO) crystal to create entangled photon pairs in a process called parametric down-conversion. Using interferometry techniques, the entangled photons were directed into two collimators both connected to a single-photon coincidence counter through fibre optic cables to detect entangled photon coincidences. The final part included the placement of linear polarizers in front of the collimators to take data for the calculation of S. The predicted result was that Bell’s inequality would be violated thus confirming the non-locality feature of entangled particles. Contrary to predictions, we found that Bell’s inequality was not violated for the measurement we took. This result is attributed to insufficient alignment as the non-locality in the quantum realm is a well-observed phenomenon. ItemInvestigating the speed of sound through different media(2023-05-16) Goodman, Ellie; Van Barr, Finley; Milchberg, Maxwell; Xiong, JiawenThe speed of sound was calculated through different materials by measuring the time taken for a vibrational signal to travel a known distance. The signal was detected at the starting and finishing points using piezoelectric transducers (PZTs). The media investigated include aluminium, acrylic, steel, glass and two samples of wood. The speeds found agreed with the recorded literature values, with the values for the speed through glass, (3300 ±180 ms⁻¹) and steel, (6000 ±370 ms⁻¹) being especially close and within the range of the calculated uncertainty. The young’s moduli of each material were also calculated, and it was determined that the wood sample was most likely balsa wood with values of 449 ±5.8 MPa and 790 ±13 MPa.