JHU Abstract 2014-The Cosmic Microwave Background
The Cosmic Microwave Background
Michael Mistretta (Hereford High School), Jeremy Smith (Hereford High School), Tyler Bradley (Towson High School), Dr. Morris Swartz (Johns Hopkins University)
My research was focused on learning more about the cosmic microwave background (CMB) and the information about the early stages of the universe which it contains. I read through various publications regarding the CMB including those from COBE, WMAP, PLANCK, and BICEP-2 to understand what kind of information that can be gained from analyzing the CMB and how these researchers are using these data to refine various theories about the behavior of our universe. The CMB is the afterglow of the Big Bang, it is essentially a snapshot of the universe as it was immediately following the Big Bang and can provide key insight into how the universe became what it is today. Its discovery alone was predicted in the early 60’s by the early Big Bang theories, and once it was discovered it became the smoking gun for the Big Bang theory. NASA’s COBE satellite later found that temperature of the light emitted from the CMB was, although astonishingly uniform, anisotropic to one part in one hundred thousand. COBE was then followed by more advanced telescopes such as WMAP and PLANCK which measured these anisotropies with much more precision. Researchers believe that these slight temperature variations could be a result of density perturbations in the early universe. Recent discovery of b-mode polarization in the radiation emitted by the CMB, as detected by BICEP-2, is believed to be evidence of gravitational waves in the very early stages of the universe, which could potentially provide insight for a refined theory of Cosmic Inflation. Research of the CMB is essential to understanding various aspects of our universe such as inflation, how galaxies and other celestial bodies were formed, and unlocking some of the mysteries of dark matter and energy.
JHU Abstract 2014-Measuring Average Muon Decay Time Using Cosmic Ray Detector
Measuring Average Muon Decay Time Using Cosmic Ray Detector
Luke Bender (Towson High School), Adam Der (Hereford High School), Shaina Furman (Towson High School), Michael Mistretta (Hereford High School), Jeremy Smith (Hereford High School), Tyler Bradley (Towson High School), Dr. Morris Swartz (Johns Hopkins University)
Our goal was to determine the lifetime of a muon. A muon decays into an electron and two neutrinos. When the muon is stopped in the cosmic ray muon detector the detector looks for two flashes the first being the muon being stopped and the second a pulse from the emission of an electron. The time for a muon to decay has been found to be about 2.2 microseconds. We attempted to get our data as close to this number as possible. We hoped that as the amount of data increased the closer our calculated lifetime would come to this number. We ran the detector for 5 weeks, running it for 24-hour periods starting at 9am. When our data was first collected we calculated the lifetime based on our results to be about 2.6 microseconds. Toward the end of our collection our calculated result had decreased to 2.4 microseconds. The more data we collected the more accurate our results were. If we were to continue collecting data our result could be calculated to be the same as the actual lifetime. Our research was successful and helped us to learn about the decay of muons. We could continue our research by testing if the decay rate changes at different temperatures or different angles from the sun.
JHU Abstract 2014-Searching for the Origins of Cosmic Rays
Searching for the Origins of Cosmic Rays
Anthony Fedorchak (Marriotts Ridge High School), Jeremy Smith (Hereford High School), Tyler Bradley (Towson High School), Dr. Morris Swartz (Johns Hopkins University)
The purpose of my research was to investigate the currently accepted source of cosmic rays, and then to branch out and make predictions as to other possible sources of cosmic rays based on the characteristics of the identified source. My research was primarily focused around a scientific journal published in early 2013 that pertained to data taken from the Fermi telescope, NASA’s telescope that is focused on analyzing high energy sources in space. This publication contained information about the processes used to identify Supernovae Remnants, namely IC 443 and W44, as sources of cosmic rays. After accessing this, I analyzed the energy levels of output of Pulsars, Active Galactic Nuclei, and the Sun, in order to try and hypothesize possible additional sources of cosmic rays, since all 3 of these bodies contain characteristics similar to Supernovae Remnants. Gamma ray energy levels were used to identify Supernovae Remnants as sources of cosmic rays through looking at the gamma rays born from a very specific type of neutral-pion decay, a type of decay specific to cosmic ray collisions. I then found interest in the effects that cosmic rays have here on Earth. I found information attributing 15% of the yearly exposure of radiation to cosmic rays, and also found that one end result of cosmic ray collisions within Earth’s atmosphere is the production of Carbon 14, which is central to the process of carbon dating. I continued my research, looking into the effects that cosmic rays can have on electrical equipment on, or in orbit around, Earth. I’ll continue looking into other effects that cosmic rays have here on Earth, and try to obtain a deeper understanding of the processes that generate these cosmic rays.
JHU Abstract 2014-Reconstructing Bosons and Mesons Using Data from CMS
Reconstructing Mass of W, Z Bosons and J/Psi Meson Using CMS Data
Adam Der (Hereford High School) Jeremy Smith (Hereford High School), Tyler Bradley (Towson high School), Dr. Morris Swartz (Johns Hopkins University)
The purpose of this research was to reconstruct the mass of the Z boson, W boson, and J/Psi meson by using data of the particles decay given to me by CMS. After reconstructing the mass these particles I also researched on how the CMS machine itself detects these particles and the particles they decay into. By reconstructing the mass of these particles I can better understand their movements along with the properties of the particles they decay into. Also I now better understand how these particles are detected through the CMS machine. When reconstructing the masses of these bosons and mesons I found that the Z boson has a mass of 91 GeV compared to its actual mass of 91.2 GeV, the W boson has a mass of 80 GeV compared to its actual mass of 80.4 GeV, and the J/Psi has a mass of approximately 3.1 GeV compared to its actual mass of 3.0969 GeV. An important relationship when reconstructing the mass of a W boson is the relationship between its transverse mass and its true mass. When looking at the transverse mass histogram of a boson you want to look for a drop off in the histogram. Right after the peak into the drop off is approximately the true mass of the boson. You must use this relationship for the W boson because this boson will decay in a lepton and a neutrino. The neutrino cannot be detected by the CMS machine so it is represented as missing transverse energy. Researching the mass and decays of Bosons and Mesons allows us to take a better look at high energy particles as well as anti particles that are produced during their decay.
JHU Abstract 2014-Gamma Ray Bursts
Gamma Ray Bursts
Luke Bender (Towson High School), Jeremy Smith (Hereford High School), Tyler Bradley (Towson high School), Dr. Morris Swartz (Johns Hopkins University)
The purpose of this research was to learn as much as possible about the history, cause,
and effects of gamma ray bursts as well as what they could tell us about our universe.
Gamma ray bursts are the brightest and most energetic events in the universe and occur
whenever a super massive star runs out of nuclear fuel or when 2 neutron stars orbiting
each other collide. When a super massive star explodes, the core will become a black hole
and expel energy as gamma rays in jets, and these bursts typically last from about 2
seconds to a few hundred seconds. With 2 neutron stars colliding, the burst is much
shorter, lasting a few hundred milliseconds to 2 seconds. The long gamma ray bursts are
far more common (~70%) in comparison to the short gamma ray bursts (~30%). There has
also been discovered neutron stars that have a much stronger magnetic field than normal.
These “magnetars” are hypothesized to be the cause of soft gamma ray repeaters, less
energetic gamma ray bursts are that repeatedly emitted. Gamma ray bursts typically occur
in galaxies billions of light years away, so these bursts help tell us about the early universe.
In fact, the oldest known thing in the universe was a star over 13 billion light years away that
caused a gamma ray burst. Additionally, if a super massive star were within a few
thousand light years away, then it could potentially destroy all life on Earth. In fact, it is
hypothesized that a gamma ray burst could have caused extinction before, but there is no
JHU Abstract 2014-The Physics of Medical Detection Devices, Specifically MRI
The Physics of Medical Detection Devices, Specifically MRI
Emily Larkin (Hereford High School), Jeremy Smith (Hereford High School), Tyler Bradley (Towson High School), Dr. Morris Swartz (Johns Hopkins University)
The study of medicine is applied physics. As doctors use medical devices to make diagnoses or to understand natural or manufactured biological compounds, they are fundamentally using laws and equations of physics through computer modules. One such detection device is MRI (Magnetic Resonance Imaging). I used an pNMR (pulsed Nuclear Magnetic Resonance) machine to understand how a natural and induced magnetic field can create a response in compounds that ultimately leads to an MRI scan, a three-dimensional soft-tissue image, differentiating between blood, bone, and viscera. With the pNMR and knowledge of physics, I concurred that chemical compounds with various structures react with different amplitudes of pulses to the applied field (created with an electromagnet) due to the accessibility of the nucleus given shielding created by electrons surrounding the molecules. Although the pNMR machine used lacked the computing technology of an MRI to quickly differentiate and calculate these pulses, I saw the importance of optimizing the signal. I also observed that as the delay time between the A and B pulses increases, the amplitude of the subsequent B pulse decreases in the pattern of an exponential decay. I believe this is because as the time increases, on the scale of tenths of milliseconds, the number of atoms that "spin out" of the electric field in the z axis increases, meaning that they are "relaxed" and therefore will not contribute to the amplitude of the B signal. In medicine, such technology is important as the basis of MRI scans to detect irregularities inside the body, but it also is used in the direct study of biological compounds. NMR is one of the leading devices being used to comprehend the structure of macromolecules such as proteins, oligonucleotides, and oligosaccharides. It can also be used in drug manufacture as a way to understand the structure of new drugs, and how this structure plays into their functionality in the body. Obviously, as medicine is approaching an age where diagnosis and description is based on the genome and proteome, further applications of NMR are needed to meet the demand.
JHU Abstract 2014-The Accelerated Expansion of the Universe
The Accelerated Expansion of the Universe
Derek Bierly (Hereford High School), Danny Mahoney (Hereford High School), Jeremy
Smith (Hereford High School), Tyler Bradley (Towson High School), Dr. Morris Swartz (Johns Hopkins University)
The purpose of our research was to provide evidence for the acceleration of the expansion
of the universe. We researched the work of 2011 Physics Nobel Prize recipients Dr. Adam
Riess, Dr. Saul Perlmutter, and Dr. Brian Schmidt, and attempted to replicate their
investigation of the accelerated expansion of the universe through the examination of
redshifted Type Ia supernovae. Evidence of a disconnect between the observed and
predicted distances to these supernovae supports the accelerating universe theory. We
looked up many supernovae on the Hubble Legacy Archive and attempted to get spectral
data for them. If we had more time we would have acquired these spectra, and solved for
the redshift and distance of each supernova. The theory of the accelerated expansion of
the universe necessitates the existence of dark energy, a hypothetical form of energy
believed to account for this negative vacuum pressure and make up roughly seventy
percent of the universe. The percentage of the universe that is dark energy will continue to
increase as the universe expands due to dark energy’s constant density. Researching the
accelerating expansion of the universe allows us to better understand the fate of the
universe, which could be an eventual “Freeze,” instead of The Big Crunch, which was