A Physicist’s Christmas

By Bob Englehart – courant.com


Mobile Phone in Faraday Cage

Placing a phone in the tin

M M J French
A Faraday cage is an interesting physics phenomena where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material.
The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can!
The background of the physics behind this is described in some detail followed by a explanation of some demonstrations and experiments which I have used….
Read more: http://arxiv.org.pdf

The exponential decrease of the magnitude of an electric f eld inside a conductor

Type III Dyson Sphere of Highly Advanced Civilizations ….

… around a Super Massive Black Hole

Schematic picture around SMBH. Items are not to scale. In this picture, an example of power plants with transmitters is shown partly. BLR stands for the Broad Line Region. The SMBH and accretion disk will not be fully covered by the collectors of power plants, so as not to prevent jets emanating from somewhere in this area, and accretion flow coming out of the central region. A twin jet is thought to emanate perpendicular to the plane of accretion disk, seen about 10% of AGN. The energy from the power plants is transferred by electro-magnetic waves to habitats of advanced civilizations. In this picture, the beams are directed to a galactic plane on which a galactic club is formed. However, the planes of the accretion disk and the host galaxy may not necessarily be in the same plane

Makoto Inoue, Hiromitsu Yokoo
We describe a new system for a society of highly advanced civilizations around a super massive black hole (SMBH), as an advanced Type III “Dyson Sphere“, pointing out an efficient usage of energy for the advanced civilizations. SMBH also works as a sink for waste materials. Here we assume that Type III civilisations of Kardashev classification [1] form a galactic club [2] in a galaxy, and the energy from the SMBH will be delivered to the club members, forming an energy control system similar to power grids in our present society. The energy is probably transmitted by a sharp beam with coherent electro-magnetic waves, which provide a new concept for the search for extraterrestrial intelligence (SETI) via detection of such energy transmission signals. This expands the search window for other intelligences within the Universe….
Figure 1 shows a schematic picture of the power plants and others around SMBH. The condition around SMBH is very promising for an advanced intelligence to manage energy issues in terms of both energy generation and disposition.This idea comes from a combination of Type III and Dyson Sphere. The strong radiation from the accretion disk rotating around SMBH is mainly used, and the waste energy is returned toward the SMBH. The available energy is huge compared to Dyson Sphere of stellar scale, and this type ofcivilization could be called Type III Dyson Sphere. The search for this type of civilization, however, would not likely be revealed from “unintended” communication signal, but detection by coherent radiation from power stations may be more promising….
Read more: http://arxiv.org/pdf

Inside Euler’s Head Or how to see a telescope through the walls of its dome

As night was falling over ESO’s La Silla Observatory in Chile on 20 December 2009, the sky was not yet dark enough for the telescopes to start observations. But conditions were perfect to perform a clever trick with the dome of the Swiss 1.2-metre Leonhard Euler Telescope: allowing us to peer inside with this photograph apparently taken through the dome.

This image is a 75-second exposure taken while the slit of the Euler telescope’s dome was performing half a rotation at full speed. Through the ghostly blur of the moving dome walls, the telescope is clearly visible. A dim light was switched on in the interior of the building especially for the purpose of this photo.

The picture was taken by Malte Tewes, a young astronomer from the École Polytechnique Fédérale de Lausanne in Switzerland, who had just finished a two-week observing run at the telescope on the evening in question. The next observer, Amaury Triaud, and the telescope’s technician, Vincent Mégevand (both pictured), were on site so they could operate the dome from the inside while Malte took the photograph from outside.

The road that leads to ESO’s nearby 3.6-metre telescope is visible lined by a chain of lights to the left of the image. In addition to the 3.6-metre telescope, the New Technology Telescope, and the MPG/ESO 2.2-metre telescope, La Silla Observatory also hosts several national and project telescopes that are not operated by ESO. The Euler telescope, named after the famous Swiss mathematician Leonhard Euler, is one of them.

LOFT, the Large Observatory For X-ray Timing

Left panel: Sketch of the LOFT satellite. The 6 deployable panels of the LAD, the WFM and the solar array are indicated. Right panel: effective area of the LOFT/LAD as a function of energy

E. Bozzo, J. W. den Herder, M. Feroci, L. Stella, on the behalf of the LOFT consortium

The Large Observatory For X-ray Timing, LOFT, was selected by the European Space Agency as one of the four Cosmic Vision M3 candidate missions to compete for a launch opportunity at the start of the 2020s.
Thanks to an innovative design and the development of large-area monolithic silicon drift detectors, the Large Area Detector (LAD) on board LOFT will operate in the 2-30 keV range (up to 50 keV in expanded mode), and achieve an effective area of ~10 m2 at 8 keV, a time resolution of ~10 μs, and a spectral resolution of ~260 eV (FWHM at 6 keV). These characteristics make LOFT a perfectly suited instrument to perform high-time-resolution X-ray observations of collapsed objects in our galaxy and brightest supermassive black holes in active galactic nuclei.
LOFT will yield unprecedented information on strongly curved spacetimes and matter under extreme conditions of pressure and magnetic field strength, thus addressing two of the fundamental questions of the Cosmic Vision Theme “Matter under extreme conditions”: does matter orbiting close to the event horizon follow the predictions of general relativity? What is the equation of state of matter in neutron stars?
Read more: http://arxiv.org/pdf

The Physics of Santa Claus

089:32:50 Mattingly: Apollo 8, Houston. [No answer.]
089:33:38 Mattingly: Apollo 8, Houston.
089:34:16 Lovell: Houston, Apollo 8, over.
089:34:19 Mattingly: Hello, Apollo 8. Loud and clear.
089:34:25 Lovell: Roger. Please be informed there is a Santa Claus.
089:34:31 Mattingly: That’s affirmative. You’re the best ones to know. -NASA

Apollo 8, the first manned mission to the Moon, entered lunar orbit on Christmas Eve, December 24, 1968. The three astronauts aboard, Commander Frank Borman, Command Module Pilot Jim Lovell and Lunar Module Pilot William Anders, made a live television broadcast in which they sent Christmas greetings back to the Earth. Above, an image of the Earth taken near the moon during Apollo 8 (www.space.com)

The world is an awfully big place now. Santa’s job has to be tougher than its ever been before, with more and more people relying on his deliveries each year. From Australia to Scandinavia to Queens, NY, Santa is undoubtedly the hero of the holiday season…….
Read more: scienceblogs.com

NORAD and Satellite Technology Help Santa Deliver

NORAD Tracks Santa. Credit: NORAD

According to the U.S. Department of Commerce Census Bureau, the world’s population is approximately 7 billion (6,979,978,073+) people. Santa Claus has had to adapt over the years to having less and less time to deliver gifts to more people. To better assure prompt deliveries and safe flights, higher technology systems are increasingly being used by the United States Northern Command at Peterson Air Force Base, Colo., to support the North American Aerospace Defense Command (NORAD).

NORAD is a joint United States and Canadian organization which provides aerospace warning and control. The United States Air Force (USAF) uses ground based radars, National Oceanic and Atmospheric Administration (NOAA) operational satellites provided by NASA Goddard Space Flight Center, as well as Santa Cams, Google maps, and jet fighter aircraft.

Global Positioning System (GPS) satellite information and carefully timed gravity assists from the sun, moon, and/or Earth are used to speed Santa’s sleigh faster and more precisely than ever before.

Multi-variable numerical modeling improvements in the solar wind, auroras, geomagnetic force fields, and space/Earth weather predictions are also being credited for important improved sleigh routing efficiencies. Rudolph (the red-nosed lead reindeer) provides a great infrared (warm) signature for the satellite instruments to focus on. The satellite data indicates where fog is and Rudolph can take over the reins from Santa as they use microwave data to know where the rain, snow, and ice are for those precise landing adjustments.

From 22,300 miles in space, NORAD will use for the first time the GOES-15 (covers the U.S. west coast and Pacific Ocean areas) significantly improved Earth location accuracy and heat detection infrared equipment from various satellites. Rudolph’s nose gives off an infrared signature similar to a small missile launch and satellites can detect Rudolph’s bright red nose very precisely.

Artist's concept of GOES-15 in orbit being used to help track Santa. Image Credit: NASA/Honeywell Tech Solutions, C. Meaney

NOAA, NASA, and the USAF have satellites expertly positioned and additional volunteers are supporting the improved Santa tracking beginning after sundown on Christmas Eve December 24. Near “real time” public updates of progress should be available from the web site http://www.noradsanta.org/ NORAD Santa and thanks to worldwide corporate and international support updates will be provided in eight languages.

NASA is in the process of checking out the new NPOESS Preparatory Project (NPP) satellite, launched in October. NPP will provide even more precise and more timely updates of weather information in the years ahead so Santa and his reindeer team can safely deliver more and more presents in all weather conditions in one night!

To track Santa using NORAD, visit: http://www.noradsanta.org