Top 10 discoveries about waves    

Gravitational radiation reminds science of its debts to the physics of waves

Context
surfer on a wave

CATCH A WAVE Physicists are the surfers of science, with a long history of fascination with waves.

Physics fans are a lot like surfers. Both think waves are really fun.

For surfers, it’s all about having a good time. For physicists, it’s about understanding some of nature’s most important physical phenomena. Yet another detection of gravitational waves, announced June 1, further reinvigorates the world’s science fans’ excitement over waves.

Waves have naturally always been a topic of scientific and mathematical interest. They play a part in an enormous range of physical processes, from heat and light to radio and TV, sonograms and music, earthquakes and holograms. (Waves used to even be a common sight in baseball stadiums, but fans got tired of standing up and down and it was really annoying anyway.)

Many of science’s greatest achievements have been discoveries of new kinds of waves or new insights into wave motion. Identifying just the Top 10 such discoveries (or ideas) is therefore difficult and bound to elicit critical comments from cult members of particular secret wave societies. So remember, if your favorite wave isn’t on this list, it would have been No. 11.

10.  Thomas Young: Light is a wave.

In the opening years of the 19th century, the English physician Young tackled a long-running controversy about the nature of light. A century earlier, Isaac Newton had argued forcibly for the view that light consisted of (very small) particles. Newton’s contemporary Christiaan Huygens strongly disagreed, insisting that light traveled through space as a wave.

Through a series of clever experiments, Young demonstrated strong evidence for waves. Poking two tiny holes in a thick sheet of paper, Young saw that light passing through created alternating bands of light and darkness on a surface placed on the other side of the paper. That was just as expected if light passing through the two holes interfered just as water waves do, canceling out when crest met trough or enhancing when crests met “in phase.” Young did not work out his wave theory with mathematical rigor and so Newton’s defenders resisted, attempting to explain away Young’s results.

But soon Augustin Jean Fresnel in France worked out the math of light waves in detail. And in 1850, when Jean-Bernard-Léon Foucault showed that light travels faster in air than water, the staunchest Newton fans had to capitulate. Newton himself would have acknowledged that light must therefore consist of waves. (Much later, though, Einstein found a way that light could in fact consist of particles, which came to be called photons.)

9. Michelson and Morley: Light waves don’t vibrate anything.

Waves are vibrations, implying the need for something to vibrate. Sound vibrated molecules in the air, for instance, and ocean waves vibrated molecules of water. Light, supposedly, vibrated an invisible substance called the ether.

In 1887, Albert A. Michelson and his collaborator Edward Morley devised an experiment to detect that ether. Earth’s motion through the ether should have meant that light’s velocity would depend on its direction. (Traveling with the Earth’s motion, light’s speed wouldn’t be the same as traveling at right angles to the direction of motion.) Michelson and Morley figured they could detect that difference by exploiting the interference phenomena discovered by Young. But their apparatus failed to find any ether effect. They thought their experiment was flawed. But later Einstein figured out there actually wasn’t any ether.

8. James Clerk Maxwell: Light is an electromagnetic wave.

Maxwell died in 1879, the year Einstein was born, and so did not know there wasn’t an ether. He did figure out, though, that both electricity and magnetism could be explained by stresses in some such medium.

Electric and magnetic charges in the ether ought to generate disturbances in the form of waves, Maxwell realized. Based on the strengths of those forces he calculated that the waves would travel at the fantastic speed of 310 million meters per second, suspiciously close to the best recent measurements of the speed of light (those measurements ranged from 298 million to 315 million meters per second). So Maxwell, without the benefit of ever having watched NCIS on TV, then invoked Gibbs’ Rule 39 (there’s no such thing as a coincidence) and concluded that light was an example of an electromagnetic wave.

“It seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field,” he wrote in 1864. His “other radiations, if any” turned out to be an entire spectrum of all sorts of cool waves, from gamma radiation to radio signals.

7. Heinrich Hertz: Radio waves.

Not very many people took Maxwell seriously at first. A few, though, known as the Maxwellians, promoted his ideas. One physicist who had faith in Maxwell, or at least in his equations, was Hertz, who performed experiments in his lab in Karlsruhe, Germany, that successfully produced and detected radio waves, eventually to be exploited by propagandists to spread a lot of illogical nonsense on talk radio.

His success inspired much more respect for the equations in Maxwell’s theory, which Hertz found almost magical: “It is impossible to study this wonderful theory without feeling as if the mathematical equations had an independent life and an intelligence of their own, as if they were wiser than ourselves,” Hertz said. His prime experimental success came in 1887, the same year that Michelson and Morley failed to detect the ether. Hertz died in 1894, long before his discovery was put to widespread use.

6. John Michell: Seismic waves.

Michell, an English geologist and astronomer, was motivated by the great Lisbon earthquake of 1755 to investigate the cause of earthquakes. In 1760 he concluded that “subterraneous fires” should be blamed, noting that volcanoes — “burning mountains” — commonly occur in the same neighborhood as frequent earthquakes.

Michell noted that “the motion of the earth in earthquakes is … partly propagated by waves, which succeed one another sometimes at larger and sometimes at smaller distances.” He cited witness accounts of quakes in which the ground rose “like the sea in a wave.” Much later seismologists developed a more precise understanding of the seismic waves that shake the Earth, using them as probes to infer the planet’s inner structure.

5. Wilhelm Röntgen: X-rays.

Roentgen's first x-ray of his wife's handWhen Hertz discovered radio waves, he knew he was looking for the long-wavelength radiation foreshadowed in Maxwell’s equations. But a few years later, in 1895, Röntgen found the radio wave counterpart of the opposite end of the electromagnetic spectrum — by accident.

Mysterious short-wavelength rays of an unknown type (therefore designated X) emerged when Röntgen shot cathode rays (beams of electrons) through a glass tube. Röntgen suspected that his creation might be a new kind of wave among the many Maxwell had anticipated: “There seems to exist some kind of relationship between the new rays and light rays; at least this is indicated by the formation of shadows,” Röntgen wrote. Those shadows, of course, became the basis for a revolutionary medical technology.

Besides providing a major new tool for observing shattered bones and other structures inside the body, X-rays eventually became essential tools for scientific investigation in astronomy, biology and other fields. And they shattered the late 19th century complacency of physicists who thought they’d basically figured everything out about nature. Weirdly, though, X-rays later turned out to be particles sometimes, validating Einstein’s ideas that light had an alter ego particle identity. (By the way, it turned out that X-rays aren’t the electromagnetic waves with the shortest wavelengths — gamma rays can be even shorter. Maybe they would be No. 11.)

4. Epicurus: The swerve.

Not exactly a wave in the ordinary sense, the swerve was a deviation from straight line motion postulated by the Greek philosopher Epicurus around 300 B.C. Unlike Aristotle, Epicurus believed in atoms, and argued that reality was built entirely from the random collisions of an infinite number of those tiny particles. Supposedly, he thought, atoms would all just fall straight down to the center of the universe unless some unpredictable “swerve” occasionally caused them to deviate from their paths so they would bounce off each other and congregate into complex structures.

It has not escaped the attention of modern philosophers that the Epicurean unpredictable swerve is a bit like the uncertainty in particle motions introduced by quantum mechanics. Which has its own waves. 

3. Louis de Broglie: Matter waves.

In the early 1920s, de Broglie noticed a peculiar connection between relativity and quantum physics. Max Planck’s famous quantum formula related energy to frequency of a wave motion. Einstein’s special relativity related energy to the mass of a particle. De Broglie thought it would make a fine doctoral dissertation to work out the implications of two seemingly separate things both related to energy. If energy equals mass (times the speed of light squared) and energy equals frequency (time Planck’s constant), then voilà, mass equals frequency (times some combination of the constants). Therefore, de Broglie reasoned, particles (of mass) ought to also exist as waves (with a frequency).

That might have seemed wacky, but Einstein read de Broglie’s thesis and thought it made sense. Soon Walter Elsasser in Germany reported experiments that supported de Broglie, and in America Clinton Davisson and coworkers demonstrated conclusively that electrons did in fact exhibit wave properties.

De Broglie won the physics Nobel Prize in 1929; Davisson shared the 1937 Nobel with George Thomson, who had conducted similar experiments showing electrons are waves. Which was ironic, because George’s father, J.J. Thomson, won the 1906 Nobel for the work that revealed the existence of the electron as a particle. Eight decades later Ernst Ruska won a Nobel for his design of a powerful microscope that exploited the electron’s wave behavior.

2. Max Born: Probability waves.

De Broglie’s idea ignited a flurry of activity among physicists trying to figure out how waves fit into quantum theory. Niels Bohr, for instance, spent considerable effort attempting to reconcile the dual wave-particle nature of both electrons and light. Erwin Schrödinger, meanwhile, developed a full-fledged “wave mechanics” to describe the behavior of electrons in atoms solely from the wave perspective. Schrödinger’s math incorporated a “wave function” that was great for calculating the expected results of experiments, even though some experiments clearly showed electrons to be particles.

Born, a German physicist and good friend of Einstein’s, deduced the key to clarifying the wave function: It was an indicator of the probability of finding the particle in a given location. Combined with Werner Heisenberg’s brand-new uncertainty principle, Born’s realization led to the modern view that an electron is wavelike in the sense that it does not possess a definite location until it is observed. That approach works fine for all practical purposes, but physicists and philosophers still engage in vigorous debates today about the true physical status of the wave function.

1. LIGO: Gravitational waves.

graph of gravitational wave detectionSoon after he completed his general theory of relativity, Einstein realized that it implied the possibility of gravitational radiation — vibrations of spacetime itself.  He had no idea, though, that by spending a billion dollars, physicists a century later could actually detect those spacetime ripples. But thanks to lasers (which maybe would have been No. 11), the Laser Interferometer Gravitational-Wave Observatory — two huge labs in Louisiana and Washington state — captured the spacetime shudders emitted from a pair of colliding black holes in September 2015.

That detection is certainly one of the most phenomenal experimental achievements in the history of science. It signaled a new era in astronomy, providing astronomers a tool for probing the depths of the universe that are obscured from view with Maxwell’s “other radiations, if any.” For astronomy, gravitational radiation is the wave of the future. 

Follow me on Twitter: @tom_siegfried


           Exfo WA-7100 Sale price: $10,988.00    

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Exfo-Burleigh WA7100 Wavemeter WA-7600 and WA-7100 Optical Channel Analyzers employ proven scanning Michelson interferometer-based Wavemeter technology to determine the absolute wavelength of an optical signal under test by comparing its interfere...(Continue to site)

          Astronomers Build the Most Advanced Observatory in the World from LEGO®   

It took some of the brightest minds in science and technology to build ESO’s Paranal Observatory in Chile, one of the largest and most sophisticated telescope facilities in the world. Now Dutch astronomer Frans Snik and a team of dedicated helpers have created a unique LEGO® model of the entire Paranal platform, complete with replicas of the four 8.2-metre VLT Unit Telescopes (UT), the four 1.8-metre Auxiliary Telescopes and other astonishingly minute details [1].

This mind-boggling one-of-a-kind model has been handed over to ESO and is on display at the ESO Headquarters in Garching, Germany. When the ESO Supernova Planetarium & Visitor Centre opens at the ESO Headquarters in spring 2018, the model will be displayed there.

The model of the Paranal platform, at a scale of approximately 1:150, comprises the VLT telescopes and their dome structures, and all of the instruments used on the real VLT are also present. It also has accurate models of the VST, VISTA and the Control Building. Each 8.2-metre UT on the VLT platform comprises exactly 3104 parts, and the whole Paranal platform model required over 25 000 individual parts — plus a substantial amount of time and patience! The telescopes rotate and all the dome shutters and vents open and close. The four Auxiliary Telescopes can be moved into position along their tracks, just like the real things, and the VLTI tunnels house a working miniature interferometer that can produce real fringes.

Building a model telescope is an excellent way to understand how complex modern astronomical instruments work and anyone ambitious enough (and with around 5000 euros to spare) can build their own version of these huge telescopes. Frans Snik will be pleased to provide the necessary instructions.

As if that wasn’t enough, ESO’s Extremely Large Telescope, currently being built close to Paranal, can also be built — to the same scale as the Paranal model — out of LEGO®.

Notes

[1] The LEGO® Paranal began its small-scale existence in 2014, when Snik designed and built his first LEGO® model of ESO’s Extremely Large Telescope (ELT). Later on a  LEGO® model of the 8.2-metre VLT Unit Telescopes (UT) was conceived.


          Auf dem Weg zu empfindlicheren Sensoren   
image description
Verschränkte Lichtzustände ermöglichen die Erhöhung der Sensitivität in der optischen Interferometrie, einer Messmethode in der Physik. Hierfür benötigt man sogenannte pfadverschränkte Photonenzustände in zeitlich wohl definierten Pulsen. Bisher war die Erzeugung solcher Zustände jedoch nur begrenzt...
          ‘Bulges’ in volcanoes could be used to predict eruptions   

A team of researchers from the University of Cambridge have developed a new way of measuring the pressure inside volcanoes, and found that it can be a reliable indicator of future eruptions. Using a technique called ‘seismic noise interferometry’ combined with geophysical measurements, the researchers measured the energy moving through a volcano. They found that […]

The post ‘Bulges’ in volcanoes could be used to predict eruptions appeared first on Geology Page.


           The study of point stress effect using double exposure holograph interferometry techniques    
Bidin, Noriah and Kua, Hock Chuan (2003) The study of point stress effect using double exposure holograph interferometry techniques. In: IPTA 2003, 2003, Kuala Lumpur.
           Three-dimension feature reconstruction from differential syntetic aperture radar interferometry (DINSAR)    
Marghany, Maged and Hashim, Mazlan (2009) Three-dimension feature reconstruction from differential syntetic aperture radar interferometry (DINSAR). In: Proceeding of 2009 IEEE International Conference on Antennas, Propagation and Systems (INAS 2009), 2009.
           Elasticity measurement using holographic interferometry double exposure technique    
Chuan, Kua Hock and Bidin, Noriah (2004) Elasticity measurement using holographic interferometry double exposure technique. Jurnal Teknologi, 41 . pp. 55-64.
           Differential synthetic aperture radar interferometry (DINSAR) for 3D coastal geomorphology reconstruction    
Marghany, Maged and Hashim, Mazlan (2009) Differential synthetic aperture radar interferometry (DINSAR) for 3D coastal geomorphology reconstruction. International Journal of Computer Science and Network Security, 9 (5). pp. 59-63. ISSN 1738-7906
          S-au descoperit două găuri negre implicate într-o interacțiune stranie: ele orbitează una în jurul celeilalte. E prima dată când se confirmă existența unui asemenea fenomen!   
Într-o serie de observații recente, în măsură să revoluționeze concepțiile existente cu privire la caracteristicile formațiunilor de acest tip, astronomii au folosit undele radio pentru a cerceta două găuri negre supermasive care se rotesc una în jurul celeilalte, într-un dans gigantic, al titanilor Cosmosului. Această descoperire, combinată cu observațiile referitoare la undele gravitaționale provenite de la LIGO (Observatorul interferometru laser de unde gravitaționale), deschid un drum complet nou în studiul găurilor negre. În prima parte a anului trecut, cei de la LIGO anunțau că au detectat undele gravitaționale. Astronomii au studiat, cu atenție, galaxia 0402+379, localizată la o distantă de nu mai puțin de 750 milioane de ani-lumină de Pământ. Este o galaxie eliptică, descoperită în urmă cu 22 de ani. Această galaxie a reprezentat un important candidat pentru această investigație. Se bănuia că deține două găuri negre supermasive care au intrat în interacțiune ca urmare a fuziunii a două galaxii diferite. Aceste două formațiuni au fost examinate încă din anul 2003, dar acum se poate confirma, pentru prima dată, că ele se rotesc una în jurul celeilalte. Descoperirea este raportată de către Astrophysical Journal. Profesorul Greg Taylor, de la Universitatea din New Mexico, declară că astronomii scrutează de multă vreme cerul pentru [...]
          Ciencias Ocultas. Parte IV. Interferometría.   
Ver más: –Ciencias Ocultas. Parte I. BOMBA ATÓMICA Y EL DILEMA DEL HIDRÓGENO. –Ciencias Ocultas. Parte II. Fuerzas Fundamentales de la Física. –Ciencias Ocultas. Parte III. ELECTRODINÁMICA RELATIVISTA. Interferencia Es el fenómeno que se produce cuando dos o más ondas se superponen en una región del espacio: en cada punto las amplitudes de los campos se suman, de … Sigue leyendo Ciencias Ocultas. Parte IV. Interferometría.
          Ciencias Ocultas. Parte III. ELECTRODINAMICA RELATIVISTA   
Ver más: –Ciencias Ocultas. Parte I. BOMBA ATÓMICA Y EL DILEMA DEL HIDRÓGENO. –Ciencias Ocultas. Parte II. Fuerzas Fundamentales de la Física. –Ciencias Ocultas. Parte IV. Interferometría. http://teoria-de-la-relatividad.blogspot.com/2009/03/electrodinamica-relativista-iii.html “Las Propiedades de los cuerpos en movimiento”. Fuerza de Lorentz: La fuerza total F que actúa sobre la carga será igual a la suma vectorial de FE y de FB: Forma Clásica: E = … Sigue leyendo Ciencias Ocultas. Parte III. ELECTRODINAMICA RELATIVISTA
          Ciencias Ocultas. Parte I. BOMBA ATOMICA Y EL DILEMA DEL HIDROGENO   
Ver más: –Ciencias Ocultas. Parte II. Fuerzas Fundamentales de la Física. –Ciencias Ocultas. Parte III. ELECTRODINÁMICA RELATIVISTA. –Ciencias Ocultas. Parte IV. Interferometría. Explosión de la Fiebre del Oro: Durante la Fiebre del oro de E.E.U.U., se emplearon una gran variedad de explosivos para construir ferrocarriles, extraer oro y otros metales de las montañas, etc…, se probaron … Sigue leyendo Ciencias Ocultas. Parte I. BOMBA ATOMICA Y EL DILEMA DEL HIDROGENO
          (USA-WA-Redmond) Optical Scientist   
**Summary:** Oculus is a world leader in the design of virtual reality systems. We are currently seeking innovative researchers with a passion for technology to develop next generation consumer electronics, including near to eye display and imaging systems, at our research location in Redmond WA. Primary responsibility is developing optical systems, including sensors and visual optics, and related technologies building blocks to enable next generation architectures. **Required Skills:** 1. Drive development of system requirements to create new virtual experiences, and advance technologies necessary to create product architectures that can deliver these requirements. 2. Support modeling and experimentation for next-generation optics and displays 3. Engage cross-functionally with other researchers and engineers to develop concepts that advance the entire product pipeline (hardware, software, integration, infrastructure and applications) **Minimum Qualifications:** 4. PhD and/or postdoctoral assignment in the field of Optical Sciences, Physics, Electrical Engineering or related degree (or Masters Degree with industry experience also accepted) 5. Knowledge of optics including systems design and integration, imaging, illumination, radiometry and photometry, physical and geometric optics, statistics, and polarization 6. Understanding of sources (lasers and LED’s), spatial light modulators, diffractive optics, optical materials, and thin films optics 7. Experience in one or more system optimization and analysis tools, such as Matlab, C++, or Java 8. Experience in one or more optical design tools such as Code V, Zemax, or FRED 9. Knowledge and experience with color science, colorimetry, and visual optics 10. Familiarity with optical metrology tools such as interferometry, image quality testing, etc. **Preferred Qualifications:** 11. 5+ years of industry experience in Optical Research or Design 12. Expertise in optical and sensor system design maturation, including requirement development from physical based modeling, and knowledge of fabrication / vendor processes 13. Background in development of test automation using Labview, Matlab, Mathamatica or another program which enables custom analysis and automation of metrology **Industry:** Internet **Equal Opportunity:** As part of our dedication to the diversity of our workforce, Facebook is committed to Equal Employment Opportunity without regard for race, color, national origin, ethnicity, gender, protected veteran status, disability, sexual orientation, gender identity, or religion. We are also committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. If you need assistance or an accommodation due to a disability, you may contact us at accommodations-ext@fb.com or you may call us at 1+650-308-7837.
          ESA and NASA to collaborate on mission to detect gravitational waves   

The European Space Agency (ESA) is partnering with NASA on a new space mission that will study gravitational waves from space. Known as the Laser Interferometer Space Antenna, or LISA, the project was approved by ESA's Cosmic Vision science program on June 20. Both space agencies will now work together to design the mission and outline a budget for it prior to construction.

The post ESA and NASA to collaborate on mission to detect gravitational waves appeared first on SpaceFlight Insider.


          New Method That Detects Bulges In Volcanoes Can Be Used To Predict Eruptions   
The seismic noise interferometry technique can be used to predict volcanic eruptions in the future.
          Big Bang fans rejoice: LSU professor sharing stage with Stephen Hawking   

LSU professor Gabriela González can add another distinction to her resume: sharing the stage with Stephen Hawking. The former spokeswoman for the Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration, which detected gravitational waves 100 years after Albert Einstein predicted them, will join the renowned British physicist for his 75th birthday public symposium on Sunday. The Stephen...

The post Big Bang fans rejoice: LSU professor sharing stage with Stephen Hawking appeared first on Baton Rouge Business Report.


          Perspective, Perhaps   
Last week, according to some real news, Earth got a wave hello from far away, from some-3-billion-year-old vibrations that were set off when two black holes smashed into each other. (Really? There’s not room for both of you up there?) According to the New York Times, the collision—reported by the Laser Interferometer Gravitational-Wave Observatory, which felt the signal—resulted in […]