相关论文: The Cable to the Moon: Veritasium's Light Bulb Exp…
We report on a very simple and inexpensive method for determining the speed of an electrical wave in a transmission line. The method consists of analyzing the roundtrip time for ethernet packets between two computers. It involves minimal…
Presented is a successful two week lab involving real sky observations of the Moon in which students make telescopic observations and analyze their own images. Originally developed around the 35 mm film camera as a common household object…
A typical introductory treatment of electromagnetism culminates with the investigation of Maxwell's equations, showing the beautiful connection between the concepts covered in the many prior weeks. The lab described here is an experimental…
We present a simple thought experiment in which a beam of light of a finite length (a light-pulse) enters a detection device that consists of a wave detector and a light bulb. We examine the experiment from the reference frame where the…
In this comment on "How many principles does it take to change a light bulb ... into a laser?" by Howard M. Wiseman, Physica Scripta 91 (3), 033001 (2016) I am analyzing this extremely nicely formulated question in the framework of the…
We present a new robust setup that explains and demonstrates the quantum of electrical conductance for a general audience and which is continuously available in a public space. The setup allows users to manually thin a gold wire of several…
In this paper, we demonstrate a low-cost method to measure the speed of light. It uses instruments which are readily available in any undergraduate laboratory in a developing country and some components which are inexpensive. The method is…
When a light bulb is turned on, light moves away from it at speed $c$, by definition. When light from this bulb illuminates a surface, however, this illumination front is not constrained to move at speed $c$. A simple proof is given that…
Author offers and researches a new idea - filling tubes by electronic gases. He shows: If the insulating envelope (cover) of the tube is charged positively, the electrons within the tube are not attracted to covering. Tube (as a whole)…
The information carrier of today's communications, a weak pulse of light, is an intrinsically quantum object. As a consequence, complete information about the pulse cannot, even in principle, be perfectly recorded in a classical memory. In…
When shared between remote locations, entanglement opens up fundamentally new capabilities for science and technology [1, 2]. Envisioned quantum networks distribute entanglement between their remote matter-based quantum nodes, in which it…
The answer to the question {\it How far can one send a photon?} depends heavily on what one means by {\it a photon} and on what one intends to do with that photon. For direct quantum communication the limit is of about 500 km. For…
In July 5th 2014 an occultation of Mars by the Moon was visible in South America. Citizen scientists and professional astronomers in Colombia, Venezuela and Chile performed a set of simple observations of the phenomenon aimed to measure the…
A small tabletop experiment for a direct measurement of the speed of light to an accuracy of few percent is described. The experiment is accessible to a wide spectrum of undergraduate students, in particular to students not majoring in…
We report the first experimental demonstration that two light pulses were made motionless and interacted with each other via a medium. The interaction time is, in principle, as long as possible and a considerable efficiency can be achieved…
Efforts are underway to measure the global 21 cm signal from neutral hydrogen, which is a powerful probe of the early universe, using NASA radio telescopes on the far side of the Moon. Physics-based models of the signal are computationally…
The LHCb experiment will operate for about five years at a luminosity of 2x10^32 cm^-2 s^-1 and plans are to accumulate a data sample of ~10 fb^-1. Here we present the physics programme and detector design for a future high luminosity phase…
We consider the transmission of a single bit over the continuous-time Poisson channel with noiseless feedback. We show that to send the bit reliably requires, on the average, half the energy of a photon. In the absence of peak-power…
We report order-of-magnitude improvements in performance of field-deployable hollow-core fiber cables evidenced by a 38.4Tb/s (800Gb/s-x-48WDM-channels) 20.5km lab-trial using commercial terminal equipment and the demonstration of…
A do-it-yourself (DIY) light-wave sensing (LWS) and communication project was developed to generate interest and clarify basic electromagnetic (EM) and wireless communication concepts among students at different education levels from middle…