scholarly journals Mach–Zehnder fiber interferometer test of the anisotropy of the speed of light

2009 ◽  
Vol 87 (9) ◽  
pp. 999-1008 ◽  
Author(s):  
Victor de Haan
Keyword(s):  
Optical Fiber ◽  
Phase Difference ◽  
Main Direction ◽  
The Other ◽  
Earth Surface ◽  
Temperature Stabilization ◽  
Speed Of Light ◽  
The Earth ◽  
Better Than ◽  
Phase Differences

Two optical fiber Mach–Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer consisted of a length of 12 m optical fiber in each arm, with the main direction of the arms perpendicular to each other while the other consisted of a length of 2 m optical fiber in each arm, where the main direction of the arms are parallel, and served as a control. In each arm, 1 m of fiber was wound around a ring made of piezo material, enabling the control of the length of the arms by means of an applied voltage. The influence of the temperature on the optical phase difference between the interferometer arms was measured. The temperature change induced a variation of the interaction region of the optical fiber couplers. Further, the influence of rotation of the interferometers at the Earth surface on the observed phase differences was determined. For one interferometer (with the long and perpendicular arms), it was found that the phase difference depends on the azimuth of the interferometer. For the other one (with the short and parallel arms), no relevant dependence on the azimuth has been measured.

scholarly journals Asymmetric Mach–Zehnder fiber interferometer test of the anisotropy of the speed of light

2009 ◽  
Vol 87 (10) ◽  
pp. 1073-1078 ◽  
Author(s):  
Victor de Haan
Keyword(s):  
Optical Fiber ◽  
Phase Difference ◽  
Path Length ◽  
Main Direction ◽  
The Other ◽  
Temperature Stabilization ◽  
Speed Of Light ◽  
Atmospheric Air ◽  
Better Than ◽  
Phase Differences

Two optical fiber Mach–Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer with a length of 2 m optical fiber in each arm with the main direction of the arms parallel to each other. A path (length 175 mm) filled with atmospheric air is inserted in one arm. Another interferometer with a length of 2 m optical fiber in each parallel arm acts as a control. In one of the arms in each interferometer, 1 m of fiber was wound around a ring made of piezo material enabling the control of the length of the arms by means of a voltage. The influence of rotation of the interferometers at the Earth's surface on the observed phase differences was determined. For one interferometer (with the air path) it was found that the phase difference depends on the azimuth of the interferometer. For the other one no relevant dependence on the azimuth has been measured.

scholarly journals Gravity Field Theory

2021 ◽  
Author(s):  
Ahmed Shehab Ahmed Al-Banna
Keyword(s):  
Field Theory ◽  
Gravity Field ◽  
Geophysical Methods ◽  
The Other ◽  
Earth Surface ◽  
Gravity Method ◽  
Geophysical Model ◽  
The Earth ◽  
Figure Of The Earth ◽  
Model Understanding

Gravity keep all things on the earth surface on the ground. Gravity method is one of the oldest geophysical methods. It is used to solve many geological problems. This method can be integrated with the other geophysical methods to prepare more accepted geophysical model. Understanding the theory and the principles concepts considered as an important step to improve the method. Chapter one attempt to discuss Newton’s law, potential and attraction gravitational field, Geoid, Spheroid and geodetically figure of the earth, the gravity difference between equator and poles of the earth and some facts about gravity field.

Why Newtonian gravity is an electromagnetic wave

2020 ◽  
Vol 33 (1) ◽  
pp. 23-26
Author(s):  
Nicolus Rotich
Keyword(s):  
Electromagnetic Wave ◽  
Gravitational Waves ◽  
Newtonian Gravity ◽  
Earth Surface ◽  
Speed Of Light ◽  
The Earth ◽  
Planetary Bodies ◽  
The Waves

In this brief communication, we have hypothesized that since Newtonian gravity intimately interacts with classical gravitational waves, it must also be perceivable and mathematically expressible as a wave. It has been shown that Newtonian gravity can be represented as an electromagnetic wave of a particular wavelength <mml:math display="inline"> <mml:mi>λ</mml:mi> </mml:math> , propagating at the speed of light, c and with a radius of <mml:math display="inline"> <mml:mrow> <mml:mi>z</mml:mi> <mml:mo>=</mml:mo> <mml:mi>λ</mml:mi> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> <mml:mi>π</mml:mi> </mml:mrow> </mml:math> . The waves period is given by T = c/g, and thus acceleration due to gravity is representable as g = cf, where f is position dependent, and thus unique for all orbiting planetary bodies. On the Earth surface, this value is ≅32.71 nHz.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Basis for the technique of the external control of the optical equipment for the remote sensing of the Earth surface

1997 ◽  
Vol 3 (3-4) ◽  
pp. 50-53
Author(s):  
O.D. Fedorovskyi ◽  
◽  
V.I. Kononov ◽  
K.Yu. Sukhanov ◽  
◽  
...  
Keyword(s):  
Remote Sensing ◽  
External Control ◽  
Earth Surface ◽  
The Earth

MUNDANE MIRACLES IN AWADH. ENCOUNTERS WITH THE REVEALED AND THE HIDDEN

2020 ◽  
pp. 130-140
Author(s):  
Maxim B. Demchenko ◽  
Keyword(s):  
The Other ◽  
Local People ◽  
Natural Phenomena ◽  
Mughal Empire ◽  
The Public ◽  
British Raj ◽  
The Subject ◽  
Other World ◽  
Better Than

The sphere of the unknown, supernatural and miraculous is one of the most popular subjects for everyday discussions in Ayodhya – the last of the provinces of the Mughal Empire, which entered the British Raj in 1859, and in the distant past – the space of many legendary and mythological events. Mostly they concern encounters with inhabitants of the “other world” – spirits, ghosts, jinns as well as miraculous healings following magic rituals or meetings with the so-called saints of different religions (Hindu sadhus, Sufi dervishes),with incomprehensible and frightening natural phenomena. According to the author’s observations ideas of the unknown in Avadh are codified and structured in Avadh better than in other parts of India. Local people can clearly define if they witness a bhut or a jinn and whether the disease is caused by some witchcraft or other reasons. Perhaps that is due to the presence in the holy town of a persistent tradition of katha, the public presentation of plots from the Ramayana epic in both the narrative and poetic as well as performative forms. But are the events and phenomena in question a miracle for the Avadhvasis, residents of Ayodhya and its environs, or are they so commonplace that they do not surprise or fascinate? That exactly is the subject of the essay, written on the basis of materials collected by the author in Ayodhya during the period of 2010 – 2019. The author would like to express his appreciation to Mr. Alok Sharma (Faizabad) for his advice and cooperation.

Temperature Effects during Endodormancy Induction on Subsequent Anthesis and Growth of Peach Trees

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 452c-452 ◽  
Author(s):  
Schuyler D. Seeley ◽  
Raymundo Rojas-Martinez ◽  
James Frisby
Keyword(s):  
Temperature Effects ◽  
Shoot Length ◽  
The Other ◽  
Nighttime Temperatures ◽  
Peach Trees ◽  
Better Than

Mature peach trees in pots were treated with nighttime temperatures of –3, 6, 12, and 18 °C for 16 h and a daytime temperature of 20 °C for 8 h until the leaves abscised in the colder treatments. The trees were then chilled at 6 °C for 40 to 70 days. Trees were removed from chilling at 40, 50, 60, and 70 days and placed in a 20 °C greenhouse under increasing daylength, spring conditions. Anthesis was faster and shoot length increased with longer chilling treatments. Trees exposed to –3 °C pretreatment flowered and grew best with 40 days of chilling. However, they did not flower faster or grow better than the other treatments with longer chilling times. There was no difference in flowering or growth between the 6 and 12 °C pretreatments. The 18 °C pretreatment resulted in slower flowering and very little growth after 40 and 50 days of chilling, but growth was comparable to other treatments after 70 days of chilling.

Sign in / Sign up

Export Citation Format

Share Document