Researchers devise a record-breaking laser transmission that avoids atmospheric interference.
- Researchers from Australia and France team up for a record-breaking laser transmission.
- The new technique avoids atmospheric interference.
- It can be used to test aspects of Einstein's theory of relativity and advance communications.
Scientists achieved the most stable transmission of a laser signal through the atmosphere ever made, beating a world record. The team managed to send laser signals from one point to another while avoiding interference from the atmosphere. Their very precise method can allow for unprecedented comparisons of the flow of time in separate locations. This can enable scientists to carry out new tests of Einstein's celebrated theory of general relativity, and have wide applications across different fields.
For the record transmission, the researchers combined phase stabilization technology with advanced self-guiding optical terminals. They used two identical phase stabilization systems, which had their transmitters located in one building while receivers were in another. One system used optical terminals to send the optical signal over a 265-meter free-space path between the buildings. Another system transmitted using a 715 meter-long optical fiber cable, essentially to keep tabs on the performance of the free-space link. The terminals were outfitted with mirrors to prevent interference like phase noise and beam wander.
The scientists hailed from Australia's International Centre for Radio Astronomy Research (ICRAR) and the University of Western Australia (UWA), as well as the French National Centre for Space Studies (CNES) and the French metrology lab Systèmes de Référence Temps-Espace (SYRTE) at Paris Observatory.
The study's lead author Benjamin Dix-Matthews, a Ph.D. student at ICRAR and UWA, highlighted the innovation and potential of their technique. "We can correct for atmospheric turbulence in 3-D, that is, left-right, up-down and, critically, along the line of flight," said Dix-Matthews in a press release. "It's as if the moving atmosphere has been removed and doesn't exist. It allows us to send highly stable laser signals through the atmosphere while retaining the quality of the original signal."
Credit: Dix-Matthews, Nature Communications
Block diagram (above) of the experimental link that shows two identical phase stabilization systems on the CNES campus. Both of the systems have their transmitter in the Auger building (local site), and both receivers are located in the Lagrange building (remote site). One transmits the optical signal over a 265 m free-space path in-between the buildings while utilizing tip-tilt active optics terminals. The other transmits using 715 m of optical fiber.
Dr. Sascha Schediwy, ICRAR-UWA senior researcher, envisioned numerous applications for their technology, whose precise performance beats even the best optical atomic clocks. Putting one of these optical terminals on the ground while another one is on a satellite in space would help the exploration of fundamental physics, according to Schediwy. Other applications could extend to testing Einstein's theories with greater precision as well as understanding the time-related changes of fundamental physical constants and making advanced measurements in earth science and geophysics.
Optical communications, a field that utilizes light for sending information, could also benefit. The new tech can improve its data rates by "orders of magnitude," thinks Dr. Schediwy. "The next generation of big data-gathering satellites would be able to get critical information to the ground faster," he added.
Check out the new study in Nature Communications.
Physicists create quantum entanglement, making two distant objects behave as one.
Scientists entangled two large quantum objects, both at different locations from each other, in a quantum mechanics first. The feat is a step towards practical application of a rather counterintuitive phenomenon and was accomplished by a team from the Niels Bohr Institute at the University of Copenhagen.
Entanglement is the magical-sounding concept, dubbed "spooky action at a distance" by Einstein. It involves a link is made between two objects that can make them behave like one. This technique is of paramount importance to quantum communication and quantum sensing, explained the University's press release.
The researchers, led by Professor Eugene Polzik, used light particles photons to create an entanglement between a mechanical oscillator ("a vibrating dielectric membrane") and a cloud of atoms, with each acting like a tiny magnet or "spin". They picked these particular objects because atoms can be made to process quantum information while the membrane can store that information.
"With this new technique, we are on route to pushing the boundaries of the possibilities of entanglement," stated professor Polzik. "The bigger the objects, the further apart they are, the more disparate they are, the more interesting entanglement becomes from both fundamental and applied perspectives. With the new result, entanglement between very different objects has become possible."
By entangling the systems, the scientists made them move in correlation with each other. If one object went left, so did the other.
The achievement can pave the way to new sensing technologies. One example would be getting rid of noisy fluctuations currently affecting the Laser Interferometer Gravitational-wave Observatory (LIGO), which detects gravity waves. If the researchers were able to take information from one system and apply it in another, they could get more precise readings.
While the new technology is promising, research into creating useable devices based on quantum mechanics is very challenging, as explained by Ph.D. student Christoffer Østfeldt:
"Imagine the different ways of realizing quantum states as a kind of zoo of different realities or situations with very different qualities and potentials," he shared.
If one was to try to make a device using quantum states that would all have different functions, "it will be necessary to invent a language they are all able to speak. The quantum states need to be able to communicate, for us to use the full potential of the device. That's what this entanglement between two elements in the zoo has shown we are now capable of," Østfeldt added.
Check out the new study in Nature Physics.
How Nobel Prize winner physicist Lev Landau ranked the best physics minds of his generation.
- Nobel-Prize-winning Soviet physicist Lev Landau used a scale to rank the best physicists of the 20th century.
- The physicist based it on their level of contribution to science.
- The scale was logarithmic, with each level being 10 times more valuable.
Lev Landau (1908-1968) was one of Soviet Union's best physicists. He made contributions to nuclear theory, quantum field theory, and astrophysics, among others. In 1962, he won a Nobel Prize in Physics for developing the mathematical theory of superfluidity. Landau also wrote an immensely influential textbook on physics, teaching generations of scientists.
A brilliant mind, Landau liked to classify everything in his life. He ranked people by their intelligence, beauty (he had a penchant for blondes), contributions to science, how they dressed, and even how they talked – often with a healthy dose of sarcasm.
One of the most famous of Landau's classifications that has been passed down is his ranking of the greatest physicists of the 20th century. Of course, it wouldn't have later physicists, as he died in 1968, but these are arguably the most significant names.
This scale is logarithmic, meaning people ranked as rank 1 contributed ten times more (according to Landau) than people ranked as class 2, and so forth. In other words, the higher the number, the less valuable the physicist.
Here's how this scale broke down:
Rank 0.5 – Albert Einstein (1879 - 1955)
Einstein, the creator of the Theory of General Relativity, is in a class of his own. Landau thought he was by far the greatest mind among a very impressive group that redefined modern physics.
Landau added, however, that if the list was to be expanded to scientists of the previous centuries, Isaac Newton (1643 - 1727), the titan of classical physics, would also join Einstein at first place with 0.5.
Rank 0.5 – Albert Einstein
Albert Einstein With Displaced Children From Concentration Camps. 1949.
Photo by Keystone-France/Gamma-Keystone via Getty Images
The group in this class of the smartest physicists included the top minds that developed the theories of quantum mechanics.
Werner Heisenberg (1901 - 1976) - a German theoretical physicist, who's achieved pop-culture fame by being the name of Walter White's alter ego in Breaking Bad. He is known for the Heiseinberg Uncertainty Principle and his 1932 Nobel Prize award flatly states it was for nothing less than "the creation of quantum mechanics".
Erwin Schrödinger (1887 - 1961) - an Austrian-Irish physicist who gave us the infamous "Schroedinger's Cat" thought experiment and other mind-benders from quantum mechanics. The Nobel-prize-winner's Schrödinger equation calculates the wave function of a system and how it changes over time.
Erwin Schrödinger. 1933.
Paul Dirac (1902 - 1984) - another quantum mechanics giant, this English theoretical physicist shared the 1933 Nobel Prize with Erwin Schrödinger "for the discovery of new productive forms of atomic theory."
Niels Bohr (1885 - 1962) - a Danish physicist who made founder-level additions to what we know of atomic structure and quantum theory, which led to his 1922 Nobel Prize in Physics.
Satyendra Nath Bose (1894 - 1974) - an Indian mathematician and physicist, known for his quantum mechanics work. He collaborated with Einstein to develop the Bose-Einstein statistics and the theory of the Bose–Einstein condensate. Boson particles are named after him.
Satyendra Nath Bose. 1930s.
Eugene Wigner (1902 - 1995) - a Hungarian-American theoretical physicist who received the 1963 Nobel Prize in Physics for work on the theory of the atomic nucleus and the elementary particles. Famously, he took part in the meeting with Leo Szilard and Albert Einstein that led to them writing a letter to President Franklin D. Roosevelt which resulted in the creation of the Manhattan Project.
Louis de Broglie (1892 - 1987) - a French theorist who made key contributions to quantum theory. He proposed the wave nature of electrons, suggesting that all matter has wave properties – an example of the concept of wave-particle duality, central to the theory of quantum mechanics.
Enrico Fermi (1901 - 1954) - an American physicist who's been called the "architect of the nuclear age" as well as the "architect of the Atomic bomb". He also created the world's first nuclear reactor and won the 1938 Nobel Prize in Physics for work on induced radioactivity and for discovering transuranium elements.
Enrico Fermi. 1950s.
Wolfgang Pauli (1900-1958) - an Austrian theoretical theorist, known as one of the pioneers of quantum physics. He won the 1945 Nobel Prize in Physics for discovering a new law of nature – the exclusion principle (aka the Pauli principle) and developing spin theory.
Max Planck (1858-1947) - a German theoretical physicist who won the 1918 Nobel Prize in Physics for energy quanta. He was the originator of quantum theory, the physics of atomic and subatomic processes.
Lev Landau. 1962.
Rank 2.5 is where Landau initially ranked himself, rather modestly, thinking he didn't produce any foundational accomplishments. He later moved his prominence, as his achievement mounted, to the higher 1.5.
Controversial physics theory says reality around us behaves like a computer neural network.
- Physicist proposes that the universe behaves like an artificial neural network.
- The scientist's new paper seeks to reconcile classical physics and quantum mechanics.
- The theory claims that natural selection produces both atoms and "observers".
Does the reality around us work like a neural network, a Matrix-like computer system that operates similar to a human brain? A new physics paper argues that looking at the universe that way can provide the elusive "theory of everything".
This controversial proposal is the brainchild of the University of Minnesota Duluth physics professor Vitaly Vanchurin. In an interview with Futurism, Vanchurin conceded that "the idea is definitely crazy, but if it is crazy enough to be true?"
The scientist developed the theory while exploring the workings of machine learning using statistical mechanics. He found that mechanisms involved in the computer learning were similar in some instances to the dynamics of quantum mechanics.
A computer neural network works via nodes, which mimic biological neurons, processing and passing on signals. As the network learns new information, it changes, giving certain nodes more priority, allowing it to connect bits of information in such a way that next time in will know, for example, what are they key traits of a "zebra".
"We are not just saying that the artificial neural networks can be useful for analyzing physical systems or for discovering physical laws, we are saying that this is how the world around us actually works," writes Vanchurin in the paper. "With this respect it could be considered as a proposal for the theory of everything, and as such it should be easy to prove it wrong."
How do you prove his theory wrong? Vanchurin proposes a way. All you have to do is "find a phenomenon which cannot be modeled with a neural network." That, of course, isn't actually so easy to pull off, as Vanchurin himself points out. We don't fully understand how neural network and machine learning work and need to grasp those processes first.
Vanchurin thinks his idea can accomplish another purpose that has been the goal of modern physics – to reconcile classical physics, which describes how the universe works on a large scale, and quantum mechanics, the study of the atomic and subatomic level of existence. The physicist thinks that if you view the universe as working essentially as a neural network, its behavior under certain conditions can be explained by both the quirky equations of quantum mechanics and the laws of classical physics like the theory of general relativity devised by Albert Einstein.
"The learning dynamics of a neural network can indeed exhibit approximate behaviors described by both quantum mechanics and general relativity," writes Vanchurin in his study.
Diving deeper into his theory, Vanchurin thinks it supports such apparent mechanisms of our world as natural selection. He suggests that in a neural network, particles and atoms, but even us, the "observers" would emerge from a natural-selection-like process. On the microscopic level of the network, some structures would become more stable while some would be less so. The stable ones would survive the evolutionary process, while the less stable ones would not.
'On the smallest scales I expect that the natural selection should produce some very low complexity structures such as chains of neurons, but on larger scales the structures would be more complicated," he shared with Futurism.
He sees little reason why this kind of process would only work on just the small scale, writing in the paper:
"If correct, then what we now call atoms and particles might actually be the outcomes of a long evolution starting from some very low complexity structures and what we now call macroscopic observers and biological cells might be the outcome of an even longer evolution."
While he posits the neural network explanation, Vanchurin doesn't necessarily mean we all live in a computer simulation, like proposed by philosopher Nick Bostrom, adding the caveat that even if we did, "we might never know the difference."
Vanchurin's idea has so far been received with skepticism by other physicists but he is undeterred. You can check out his paper for yourself on ArXiv.
Vanchurin on “Hidden Phenomena”:Vitaly Vanchurin speaking at the 6th International FQXi Conference, "Mind Matters: Intelligence and Agency in the Physical World." The Foundational Questions...
- A little-known correspondence between Einstein and Freud reveals his thoughts on war.
- In this letter, Einstein puts forth the idea for a world government run by an intellectual elite.
- His goal in this letter was to get Freud's insight into the psychologial matter of violence and how to solve it.
Albert Einstein is synonymous with genius. While we're all aware of his outstanding contributions to science, much of his brilliance is incomprehensible to us because it pertains to such an advanced domain of physics. That's why it's always enlightening to hear Einstein's personal thoughts on a number of other issues, less scientifically esoteric and more worldly. It's no surprise that for a man as smart as Einstein, he had a number of concerns and opinions on how to contend with some of the greatest challenges civilization faced.
In 1931 the Institute for Intellectual Cooperation invited Einstein to engage in a cross-disciplinary exchange of ideas about world politics and peace. Always up for dialectics and diverse opinions, he went ahead and began a series of letters with Sigmund Freud. This little known correspondence between these two luminaries reveals a great deal about some of Einstein's thoughts on war, mankind and global politics.
Einstein admired Freud's work and believed that some of his psychological ideas could help him unravel the eternal problem of man's affinity for violence. Within these letters, the two of them discuss human nature at length and muse on both tangible and abstract ways of reducing violence and war in the world.
There is a strange sense of foreboding in these series of letters. As the onslaught of World War II had yet to rear its head, their words hold an even greater prescience and importance. Much of what they discuss are problems that still plague the world and persist, albeit with new political actors and much greater apocalyptic means of destruction.
This letter we're going to explore illuminates an aspect of Einstein's thinking on the notion and nature of war and world governance.
Why war? Albert Einstein’s letter to Sigmund Freud
Einstein begins his letter to Freud lamenting a common plight of intellectuals throughout the ages. The fact that we are led by the least among us. Scoundrels, profiteers, ideologues and other moronic factors of society makeup our ruling political classes. That is as true as it was then as it is today.
Referencing men like Goethe, Jesus and Kant – Einstein mentions how great spiritual and moral leaders are universally recognized as leaders even though their ability to directly affect the course of human affairs is quite limited and tangibly ineffective.
"… But they have little influence on the course of political events. It would almost appear that the very domain of human activity most crucial to the fate of nations is inescapably in the hands of wholly irresponsible political rulers.
Political leaders or governments owe their power either to the use of force or to their election by the masses. They cannot be regarded as representative of the superior moral or intellectual elements in a nation. In our time, the intellectual elite does not exercise any direct influence on the history of the world; the very fact of its division into many factions makes it impossible for its members to cooperate in the solution of today's problems."
Historically, this was right around the time that the League of Nations was in effect, which proved to be a futile endeavor. Einstein believed that in order to counteract this ineptitude of the ruling class, an intellectual elite control would need to be established.
"In our time, the intellectual elite does not exercise any direct influence on the history of the world; the very fact of its division into many factions makes it impossible for its members to cooperate in the solution of today's problems. Do you not share the feeling that a change could be brought about by a free association of men whose previous work and achievements offer a guarantee of their ability and integrity?"
Einstein seems to be thinking about the idea of a philosopher-king but in the form of an international council. It would include an international legislative and judicial body, while being able to settle all conflicts. In effect, it would be a perfect world government, led by the greatest among us. Yet even Einstein was even quick to temper this utopian political idea with a note of caution.
"Such an association would, of course, suffer from all the defects that have so often led to degeneration in learned societies; the danger that such a degeneration may develop is, unfortunately, ever present in view of the imperfections of human nature."
Einstein’s main concern
Einstein approached Freud for his insight on the unconscious and because he knew that Freud's "sense of reality is less clouded by wishful thinking." In approaching Freud on this issue, Einstein lays out the concern by charting out man's lust for power, greed, capacity for evil and the psychological roots of an individual being roused to violence, which inevitably leads to the communal death march of mass warfare.
The crux of Einstein's inquiry with Freud could be summed up as the following:
Is there any way of delivering mankind from the menace of war?
"It is common knowledge that, with the advance of modern science, this issue has come to mean a matter of life and death for civilization as we know it; nevertheless, for all the zeal displayed, every attempt at its solution has ended in a lamentable breakdown."
Einstein's solution for an international governance of elites of mind and intellect has to first contend with a number of issues. One of those being nationalism, the crowd outgrowth of all those aforementioned psychological maladies of individual man.
"Thus I am led to my first axiom: the quest of international security involves the unconditional surrender by every nation, in a certain measure, of its liberty of action, its sovereignty that is to say, and it is clear beyond all doubt that no other road can lead to such security."
The early 20th century saw a number of political and philosophical movements that tried to establish this type of world governance. Einstein recognized that fact and realized that there must be something deeper at play in opposition to this goal.
"The ill-success, despite their obvious sincerity, of all the efforts made during the last decade to reach this goal leaves us no room to doubt that strong psychological factors are at work, which paralyse these efforts. Some of these factors are not far to seek. The craving for power which characterizes the governing class in every nation is hostile to any limitation of the national sovereignty."
Einstein points out that within many nations is a small group of people whose sole purpose is to advance their personal interests and power through warfare. This is the logical conclusion for any group that rises to power, regardless of their political disposition. Whether it be leftist or right rhetoric, the only way to enforce and advance their power is through violence and war.
"I have specially in mind that small but determined group, active in every nation, composed of individuals who, indifferent to social considerations and restraints, regard warfare, the manufacture and sale of arms, simply as an occasion to advance their personal interests and enlarge their personal authority."
They manage to pull this off politically by using their control over mass media and other varied institutions.
"Another question follows hard upon it: how is it possible for this small clique to bend the will of the majority, who stand to lose and suffer by a state of war, to the service of their ambitions? An obvious answer to this question would seem to be that the minority, the ruling class at present, has the schools and press, usually the Church as well, under its thumb. This enables it to organize and sway the emotions of the masses, and make its tool of them."
Although Einstein realized there is more than meets the eye to this answer. Underneath the surface lies not only the root of deeper problem, but also a potential solution to this very weighty inquiry into the nature of humanity.
"Yet even this answer does not provide a complete solution. Another question arises from it: How is it these devices succeed so well in rousing men to such wild enthusiasm, even to sacrifice their lives? Only one answer is possible. Because man has within him a lust for hatred and destruction. In normal times this passion exists in a latent state, it emerges only in unusual circumstances; but it is a comparatively easy task to call it into play and raise it to the power of a collective psychosis. Here lies, perhaps, the crux of all the complex of factors we are considering, an enigma that only the expert in the lore of human instincts can resolve."
Poised in Einstein's question to Freud is a desire to be able to identify and then remedy this "enigma of human instincts."
Is it possible to control man's mental evolution so as to make him proof against the psychosis of hate and destructiveness?
"Here I am thinking by no means only of the so-called uncultured masses. Experience proves that it is rather the so-called "Intelligentzia" that is most apt to yield to these disastrous collective suggestions, since the intellectual has no direct contact with life in the raw, but encounters it in its easiest, synthetic form upon the printed page."
Einstein's letter leaves us with a lot to think about. His letter can be read in its entirety here.
Freud's response is equally compelling and seeks to answer a lot of the questions that Einstein put forth.
While on first glance, their conclusions may look dour, especially in light of the tragedies that befall the world only a decade later during World War II. Their blunt honesty and teardown of the problems we all face puts us one step closer to one day remedying the perils of war and unjust world governance.
But my insistence on what is the most typical, most cruel and extravagant form of conflict between man and man was deliberate, for here we have the best occasion of discovering ways and means to render all armed conflicts impossible.