Measuring the Black Body Spectrum Emitted from a Tungsten Filament
Peer-review ID: E501
Measuring the black body spectrum emitted from a tungsten filament as a function of the filament’s temperature
John Greavu
Partner: Nicholas Souhleris
School of Physics and Astronomy,
University of Minnesota, Minneapolis, Minnesota 55455
9 May 2014
The black body spectrum emitted from a standard incandescent lamp was measured as a function of its temperature. Using a miniature spectrometer set, we have experimentally verified the Stefan-Boltzmann law to 2 in addition to getting an experimental value for k/hc. Our average value for k/hc was (66.59 3.9) m-1-K-1, or .8 of the accepted value.
I. INTRODUCTION
I-i. History
In 1874, a 17-year old Max Planck enrolled at the University of Munich under the supervision of physics professor Phillip von Jolly. Professor von Jolly initially advised Planck against going into physics, warning that, “almost everything is already discovered, and all that remains is to fill a few holes.” A young Planck claimed he did not desire to discover new things, rather, that it would be sufficient for him to understand the fundamentals. At Munich, he conducted the only experiments of his career (observing the diffusion of hydrogen through heated platinum) before quickly venturing off to Berlin and into theory where, contrary to the notions of his advisor, he’d eventually kick off a revolution in physics unlike any before: quantum mechanics.
At the turn of the 20th century, electric companies were met with the task of maximizing the intensity of light bulbs as energy efficiently as possible. This was a newly emerging sector and no one at the time could fully explain the complete dependence of the intensity of black body radiation on its frequency/wavelength and body temperature. A black body is simply any physical body that absorbs all incident electromagnetic radiation (light). If at a constant temperature (thermal equilibrium) the black body will emit a characteristic continuous
Measuring the black body spectrum emitted from a tungsten filament as a function of the filament’s temperature
John Greavu
Partner: Nicholas Souhleris
School of Physics and Astronomy,
University of Minnesota, Minneapolis, Minnesota 55455
9 May 2014
The black body spectrum emitted from a standard incandescent lamp was measured as a function of its temperature. Using a miniature spectrometer set, we have experimentally verified the Stefan-Boltzmann law to 2 in addition to getting an experimental value for k/hc. Our average value for k/hc was (66.59 3.9) m-1-K-1, or .8 of the accepted value.
I. INTRODUCTION
I-i. History
In 1874, a 17-year old Max Planck enrolled at the University of Munich under the supervision of physics professor Phillip von Jolly. Professor von Jolly initially advised Planck against going into physics, warning that, “almost everything is already discovered, and all that remains is to fill a few holes.” A young Planck claimed he did not desire to discover new things, rather, that it would be sufficient for him to understand the fundamentals. At Munich, he conducted the only experiments of his career (observing the diffusion of hydrogen through heated platinum) before quickly venturing off to Berlin and into theory where, contrary to the notions of his advisor, he’d eventually kick off a revolution in physics unlike any before: quantum mechanics.
At the turn of the 20th century, electric companies were met with the task of maximizing the intensity of light bulbs as energy efficiently as possible. This was a newly emerging sector and no one at the time could fully explain the complete dependence of the intensity of black body radiation on its frequency/wavelength and body temperature. A black body is simply any physical body that absorbs all incident electromagnetic radiation (light). If at a constant temperature (thermal equilibrium) the black body will emit a characteristic continuous