The conventional approach to teaching blackbody radiation in introductory modern physics courses relies on an oversimplified explanation of Wien's displacement law, which does not uphold students' conceptual understanding of Planck's law and can lead to well-known misconceptions. Thus, there is a need to clarify the pedagogical role of this…

The concept of black body is of primary importance in studying the energy transfer of thermal electromagnetic radiation at all wavelengths. Several physical bodies like incandescent lamps, electric heaters, stoves, the sun and the other stars, microwave background radiation, etc., are considered to be black bodies as their radiation spectra fits…

In 1974, Stephen Hawking theoretically discovered that black holes emit thermal radiation and have a characteristic temperature, known as the "Hawking temperature." The aim of this paper is to present a simple heuristic derivation of the Hawking temperature, based on the Heisenberg uncertainty principle. The result obtained coincides…

The peak position of the spectral density for blackbody radiation is given by the Wien displacement law. Within introductory physics materials it is often stated, or implied through example, that the color of the light emitted from a blackbody, such as the Sun, can be ascertained from knowledge of the position of that peak in the spectral density.…

As introductory chemistry courses expose students to many distinctive properties of matter, it is helpful to systematically evaluate and relate different measures such as mass, moles, and molarity, or specific heat capacity and heat capacity. Intensive and extensive designations help distinguish intrinsic and component properties of a system and…

An experiment was carried out to investigate the changes in ionizing cosmic radiation as a function of altitude. This was carried out using a Geiger-Müller tube on-board a high altitude balloon, which rose to an altitude of 31 685 m. The gathered data show that the Geiger-Müller tube count readings increased to a maximum at an altitude of about 24…

This article describes a lesson on the greenhouse effect in which students explore blackbody radiation and Wien's law. The lesson, which has been tested in a variety of high school physics classrooms, uses probeware and online simulations and combines two well-established instructional strategies: the 5E Learning Cycle (Bybee et al. 2006) and the…

We repeated the historical infra-red radiation experiments performed by Melloni, to investigate why, at the end of his life, he came to the conclusion that radiation from light and heat rely on the same basic principle, what has been translated as the so called unitary formalism. In doing so, we profited from a Master thesis on heat radiation and…

Radiation, radiation detection and radiation protection are topics in physics and its applications which generate a wide interest in the public. This interest is either generated through medical procedures, applications of nuclear energy or nuclear accidents. The technical nature of these topics usually means that they are not well covered in the…

As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances. (Contains 1 table and 2…

Maxwell's discovery of the relation between electricity, magnetism, and light was one of the most important ones in physics. With his added displacement current term, Maxwell showed that the equations of electricity and magnetism produced a radiation solution, electromagnetic (EM) radiation, that traveled with a speed of c=1/v(e0µ0). The…

In this article we propose an activity aimed at introductory students to help them understand the Stefan-Boltzmann and Wien's displacement laws. It only requires simple materials that are available at any school: an incandescent lamp, a variable dc energy supply, and a computer to run an interactive simulation of the blackbody spectrum.…

The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

The spatial variation in phase and the propagating wave-front of plane wave electromagnetic radiation are widely familiar text-book territory. In contrast, the developing amplitude and phase of radiation emitted by a dipole or multipole source generally receive less attention, despite the prevalence of these systems. There is additional complexity…