National Institute of Standards and Technology (NIST) Achieves Record Quantum Teleportation Distance

Researchers at the National Institute of Standards and Technology (NIST) have "teleported" or transferred quantum information carried in light particles over 100 kilometers (km) of optical fiber, four times farther than the previous record.

The experiment confirmed that quantum communication is feasible over long distances in fiber. Other research groups have teleported quantum information over longer distances in free space, but the ability to do so over conventional fiber-optic lines offers more flexibility for network design. The experiment used photons to transfer the information.

A photon is a single particle of light. It is an elementary particle that exhibits both particle and wave properties; wave–particle duality. The study of photons usually falls under but not limited to quantum mechanics.

Photons have many real world applications. Solar energy cells use photons to convert sunlight to energy. Some systems like the Single Photon Emission Computed Tomography (SPECT) use it to generate images. The mass of photons was one of the factors that lead researchers at CERN in the Large Hadron Collider to help discover the Higgs Particle. Even in science fiction, the photon torpedo or photon gun is part of a spaceship's arsenal.

Entangled Photon Emitter That Fits in Computer Chip Developed

Researchers at the Università degli Studi di Pavia in Italy has developed a component that can generate a steady stream of entangled photons. This device, called a micro-ring resonator, is tiny enough to fit in a standard silicon computer chip.

Entanglement may be the foundation of a new way to connect and transmit information. Entanglement is the mysterious connection between two particles where they interact with each other physically even when separated; regardless of distance. Einstein was quoted as describing this property as 'spooky action at a distance'.

In theory, even if the two photons are galaxies apart, they still interact with each other.

Current entangled photon emitters are too big to fit in a computer chip. The development of this micro-ring resonator is a step forward to secure communications and faster computers.

The resonators are loops etched onto the silicon chip. They can corral and re-emit particles of light as illustrated in the image above of the silicon ring resonator with its access waveguide. In the image, the green wave at the input represents the laser pump, the red and blue wave-packets at the output represent the generated photon pairs, and the infinity symbol linking the two outputs indicates the entanglement between the pair of photons.

Scientists Observe Spatial Coherence in Light Absorbed by Organic Nanostructures

This is the experimental setup used to generate femtosecond laser pulses which serve as an ultrafast "flash" for the camera so that very rapid phenomenon can be filmed.
Credit: Simon Gelinas

Physicists observed that artificial organic nanostructures absorb light the same way expensive inorganic materials absorbs light. The absorbed light quickly separates into formed charges over long distances. This can then be used to generate electricity or for chemical reactions like photosynthesis and solar cell technology.

This phenomenon is called spatial coherence. Spatial coherence allows a charge to travel very quickly over several nanometres and escape from its oppositely charged partner.

Using an ultrafast flash camera, scientist filmed femtosecond (10⁻¹⁵ second) laser pulses that formed charges that spread over multiple molecules rather than limiting the charge to a single molecule. By engineering the arrangement of molecules, they managed to adjust the amplification of the charge separation.

This discovery can lead to inexpensive and energy efficient solar cells.

Photosynthesis Links Quantum Mechanics and Biology

An experiment using lasers and electronic spectroscopy on how photosynthesis works is further explained with quantum mechanics. Plants and other living organisms like algae and bacteria convert light to energy through a process called photosynthesis. Light energy (usually from the Sun) is converted to chemical energy to fuel their growth.

Electronic spectroscopy studies the electronic structure of a model and its dynamics in atoms and molecules.

Plants and other organism uses the light from the Sun as their energy source. More than 10 quadrillion photons of light hits a leaf every second. These photons are captured by the leaf and is utilized to help in the plants growth. By utilizing principles of quantum mechanics, scientists can trace the photosynthesis process on a nanoscale and further its understanding.

This can help in developing technologies that can benefit applications such as solar energy cells and biofuel production.

Superconducting Quantum Interference Devices (SQUID) Open Up Practical Applications For Superconductivity

Devices sensitive enough to detect and measure minute changes of magnetic fields, called superconducting quantum interference devices (SQUIDs), are opening up practical application of superconductivity outside the laboratory. Some applications that can benefit from using SQUIDs are magnetically levitating (maglev) trains, earthquake detectors, and even solar power cells.

Dutch physicist Heike Kamerlingh Onnes discovered superconductivity in 1911 during an experiment involving mercury and liquid helium. When a material's temperature is reduced to a certain threshold, its electrical resistance falls down to zero and the expulsion of its magnetic fields occur. Materials that can achieve superconductive are metals and ceramic materials.

The temperature at which superconductivity occurs vary from material to material. Mercury, for example, achieves superconductivity when its temperature is lowered to 4.1K.

Without electrical resistance, an electric current can persist indefinitely even without a power source. There is no power loss with superconductors and that any existing power in a superconductive wire will forever flow in it. Superconducting wires can conduct much larger currents than ordinary wire which create much more intense magnetic fields around them.

Magnetic Resonance Imaging (MRI) machines, mass spectrometers, and even particle accelerators like the Large Hadron Collider use superconducting magnets (electromagnets made from coils of superconducting wires.).

Last year, a research team at the University of Toronto induced high temperature superconductivity in a semiconductor by just using ordinary scotch tape.

Possible Variable Fine Structure Constant Tested On A White Dwarf Star

Scientists are using the Hubble Space Telescope and a White Dwarf Star (G191-B2B) to test if the Fine Structure Constant, or alpha (α) is not really constant.

The Fine Structure Constant is defined as the charge of an electron squared over the product of Planck's constant multiplied by the speed of light. The resulting value is 1/137 or 7.2973525698(24)×10⁻³.

This constant shows the probability of an electron absorbing a photon or simply the strength of the electromagnetic force exerted in an interaction. It relates to three important aspects of physics, electromagnetism, relativity, and quantum mechanics (through Planck's constant).

The importance of the Fine Structure Constant (α) relates to the existence of life. If the value of α is not as it is, life or intelligent life as it is now, would not exist. A 4% change in the value of α would mean that stellar fusion would not create carbon, making carbon based life impossible. If α were > 0.1, stellar fusion would be impossible and no place in the universe would be warm enough for life as we know it.

Using a white dwarf star with a gravity 30,000 times more than the Earth, scientists are measuring the strength of the electromagnetic force with the help of the Hubble Space Telescope. They will compare that value to that measured on Earth to determine if the Fine Structure Constant is really not constant and that it varies across the Universe.

Chemical Reactions In Space May Be Due To Quantum Tunnelling

Researchers at the University of Leeds School of Chemistry proposed that chemical reactions in space, particularly on how alcohols are created and destroyed, are due to a quantum mechanical phenomenon, known as 'quantum tunnelling'. Their findings are published in Nature Chemistry.

The cold temperatures in space prohibit chemical reactions to take place but scientists have seen evidence that there are reactions happening despite the sub-zero conditions. The researchers at the University of Leeds have proposed that these reactions occur due to quantum tunnelling.

Quantum tunnelling is a phenomenon in quantum mechanics where particles can pass through objects (tunnel through) to reach the other side. In classical mechanics, an object like a ball will likely bounce back when it hits a wall. Quantum tunnelling dictates that the ball, albeit a very small ball the size of an electron, has a finite probability that it can pass through the wall.

Researchers at Leeds have replicated deep space environment under laboratory conditions and have observed that methanol and hydroxyl radicals react with each other to create methoxy radicals twice as fast than at room temperature.

Designing Memory That Can Hold Information Indefinitely For Quantum Computers

Researchers are developing quantum memory that can hold information for long periods of time - a step towards developing practical quantum computers.

Present day computers or classical computers, as they are called, uses bits to store information. A bit is the fundamental unit of information for a classical computer. It can be either On (1) or Off (0). By arranging a series of bits, information or calculations can be carried out by classical computers. This technology is what defines the present day digital age where information is processed in a series of 0s and 1s.

A quantum computer uses a different unit for storing information; a qubit. Qubits are made up of atoms and because of the laws of quantum mechanics, exhibit peculiar behaviors that can be utilized in quantum computing. Instead of storing information in 2 states, qubits can store information in three states; an up state (1), a down state (0), and a superposition state which is both up and down at the same time. This is achieved because of quantum mechanics. Atoms have a spin up stage and a spin down stage that can be interpreted as 1 and 0. But they also can achieve superposition which is both up and down.

In terms of computing power, this means that a quantum computer can theoretically perform a calculation in one step where a classical or digital computer may take several. A classical computer can be programmed to dial a million phone numbers, it will perform this by dialing a phone one million times. A quantum computer can dial the same million numbers all at the same time, in one step.

At the moment there are quantum computers that have been built but because of technological limitations, are as big as a room. And the most a quantum computer have calculated at the moment is finding the factors of the number 15. But given time, just like the massive computers in the early 50s, these will result in smaller, compact computers.

Overcoming Heisenberg's Uncertainty Principle In Polarization of Light Through The Direct Measurement Technique

Weak measurement: as light goes through a birefringent crystal the horizontally and vertically polarized components of light spread out in space, but an overlap between the two components remains when they emerge. In a “strong” measurement the two components would be fully separated.
Credit: Credit: Jonathan Leach

Researchers have developed a new technique that overcomes Heisenberg's Uncertainty Principle in measuring the polarization states of light.

The Uncertainty Principle was developed by a German theoretical physicist, Werner Karl Heisenberg. Known also as Heisenberg's Principle, the Uncertainty Principle states that the position and velocity cannot both be accurately known or measured at the same time. One may know the exact position but not the velocity and vice-versa.

This principle is one of the most famous underlying principle of quantum mechanics. In classical physics, it is easy to determine the exact momentum and position of a passing car at a specific time. But in quantum mechanics, where objects studied are at atomic and sub-atomic sizes, measuring both of these variables accurately at the same time becomes a problem.

This can be observed through the embedded video which shows MIT Professor Walter Lewin demonstrating the uncertainty principle with laser light. In it, he shows that as the position of the photons in the laser becomes more and more accurate, the direction of the laser light becomes wider and wider making it impossible to gauge its direction.

Recently, researchers believe they have a developed a technique that works around this bizarre behavior. This could lead to using light to encode information that can be read by quantum computers.

Quantum Algorithm Performing True Calculation Developed

A team of researchers have demonstrated a working quantum algorithm that performs a true calculation for the first time.

An algorithm is any well defined computational procedures that takes some value or set of values as input and produces some value or set of values as output. A mathematical functions are a kind of algorithm where it performs a procedure to come out with a value based on a problem with a defined set of input value or values.

There are also non-computational algorithms, such as directions to calling a person on the phone. The steps are sequential from picking up the phone, getting the number, dialing the number, etc. etc.

But procedures should cover all possibilities and the subsequent action it must take. Going back to the phone call example, the algorithm should include steps for situations where the phone gets a busy signal or that the phone number cannot be found.

In short, algorithms must take all situations that could arise into consideration.

Classical Computers and Quantum Computers

There are three ways to make a computer work faster. One is to make more computers (using multiple computers for one activity). Another is to make new computers faster. And the third is to make algorithms that lets computer do things faster.

Without an algorithm behind a program or application, computers won't be able to perform as it should.

What Is Antimatter?

Antimatter has been a popular concept in science fiction. But contrary to popular belief, antimatter has been observed and even created as early as 1932 and was theorized to exist years earlier.

What is Antimatter?

Antimatter are particles (antiparticles) that have the same mass as its counterpart but carry the opposite charge and quantum spin. Spin can be compared to how the Earth rotates on its axis while orbiting the Sun.

The antiparticle counter part of the electron is the positron. It carries a positive charge rather than a negative one. The proton's version is the anti-proton and it carries a positive charge.

There is also the antineutron despite the neutron having a neutral charge. This antineutron is made up of antiquarks (the antiparticle of the quark).

A Brief History of Antimatter

In 1929, two scientists in two different experiments observed a particle that exhibited a peculiar behavior. They saw what they believed to be an electron that travelled as if it had a positive charge. Electrons are negatively charged. The two physicists, Dmitri Skobeltsyn and Chung-Yao Chao, disregarded the anomaly and never pursued it afterwards.

Three years later, in 1932, Carl D. Anderson who was studying cosmic rays at the time noticed the same thing in his experiments. Believing this to be an electron but with a positive charge, he successfully created a positron by shooting gamma rays into other materials.

Anderson was awarded the Nobel Prize for Physics in 1936 for this discovery.

This validated Paul Dirac's theory from 1928 on the existence of positrons. At the time, he called them anti-electrons. It was Anderson who named them positrons; short for positive electrons.

The antiproton was discovered in 1955 by physicists Emilio Segrè and Owen Chamberlain while the antineutron by Bruce Cork in 1956.

Photon Detector Reads In Four States With An Error Rate Four Times Lower Than Previous Devices

Researchers at the The Joint Quantum Institute (JQI) established a new standard for reading quantum information in detecting photons with a minimum of uncertainty. By using a network of photon detectors with feedback instead of a single passive detector, the JQI photodetector beats the quantum limit by a factor of 4.

They reported their findings in the journal, Nature Photonics.

PHOTONS

A photon is a single particle of light. It is an elementary particle that exhibits both particle and wave properties; wave–particle duality. The study of photons usually falls under but not limited to quantum mechanics.

Photons have many real world applications. Solar energy cells use photons to convert sunlight to energy. Some systems like the Single Photon Emission Computed Tomography (SPECT) use it to generate images. The mass of photons was one of the factors that lead researchers at CERN in the Large Hadron Collider to help discover the Higgs Particle. Even in science fiction, the photon torpedo or photon gun is part of a spaceship's arsenal.

It is even being studied as a data carrier in quantum computer processors.

PHOTON DETECTORS

The most basic device used in studying photons is the photon detector. It is used to count how many photon particles there are in a beam of light. A photon detector has some surface that absorbs photons and produces some effect (current, voltage) proportional to the number of photons absorbed.

But as with most detectors, there will be "noise" or factors that affect its reading of the data. Especially in quantum mechanics where some fundamental principles are still unclear (like wave-particle duality).

How the Hippies Saved Physics, A Book About California Physicists in the 1970s Is Physics World's Book of the Year

The Institute of Physics' website, physicsworld.com, has chosen, How the Hippies Saved Physics: Science, Counterculture and the Quantum Revival, a book about a group of physicists in California who brought quantum physics to the forefront of mainstream science.

The book by associate professor at the Massachusetts Institute of Technology, David Kaiser, looks at the these new age thinking scientists who called themselves the “Fundamental Fysiks Group” and how they influenced modern physics to focus on the weird world of quantum theory.

Physics World's editor, Matin Durrani, and reviews editor, Margaret Harris help choose 2012's Book of the Year based on factors such as its relevance to science (with emphasis on physics), readability, how well the book is written, it's originality, and scientifically interesting.

David Kaiser was asked why he wrote the book. He says, "I've been interested for a long time in the fortunes of physics as a discipline over they years since World War 2. The physics that came out of the war in a whole new orientation, a whole new place compared to how it ever been..."

Kaiser continues, "There was a temporal boundedness to that kind of post WW2 era of big enrollments tremendous funding, of almost glamour especially in the US to the physics profession. And that came tumbling down horribly quickly around the early 1970s.

Physicists Cool OH Molecules To Near Absolute Zero Through Evaporative Cooling

Researchers have created a process that can cool molecules to near absolute zero temperatures through evaporative cooling. Previous processes were then limited to ultra-cooling atoms.

Ultra cold atom physics deals with atoms that are at a temperature close to absolute 0 or 0 K (kelvins). In this field of science, temperature is measured at the nanoscale or at nano-kelvins (nK).

JILA researchers developed a new magnetic trap and a new technique to achieve "evaporative cooling" of hydroxyl molecules (one hydrogen atom bonded to one oxygen atom). A microwave pulse at a specific frequency converts hot molecules inside the trap to a slightly different energy state. A small electric field is pulsed on briefly to destabilize and eject these converted molecules from the trap. As the microwave frequency is slowly altered, molecules distributed inside the trap (which has a varied magnetic field strength) are progressively converted and removed from the top of the trap, where molecules are hotter, to the bottom, where molecules are cooler.
Credit: Baxley and Ye Group/JILA

Since it is impossible to bring an object to absolute zero (as stated in the Third Law of Thermodynamics), ultracold atom physics study objects that are close to absolute zero. The coldest an atom has been brought down to is 0.45 nK (nano kelvin) or 4.5 x 10^-10 K or 0.00000000045 K.

At these levels, atoms start to behave differently and their properties start to move from classical physics to quantum mechanics.

A property that scientists are interested in is the transformation of atoms into a new form of matter called the Bose-Einstein Condensate (BEC). The Bose-Einstein condensate happens when atoms that are brought down to near absolute zero start to behave like waves rather than particles.

As the temperature goes down, these atoms start to vibrate in the same wavelength. Because of this, they start to behave like a single mass object, the Bose-Einstein condensate.

Laser cooling and evaporative cooling are the two ways that scientists use to lower the temperature of atoms. Laser cooling in simple terms uses laser light on atoms to manipulate photons to lowers the energy level of the atom

With evaporative cooling, atoms with higher energy levels (temperature) are ejected out of an optical or magnetic trap until only atoms with the lowest energy levels are left. BECs and ultracold atoms are at very low temperatures are highly sensitive to heat (2nd Law of Thermodynamics).

Practical applications of ultracold atom physics range from super sensitive sensors to atom chips used in diodes and semiconductors. Current technologies used by magnetic levitation (mag-lev) trains, quantum computers and MRI devices utilize principles behind ultracold atom physics.

Using 'Hidden Influence Inequality' To Explain Quantum Nonlocality

In 1964, physicist John Stewart Bell published his paper, "On the Einstein Podolsky Rosen paradox". In the paper, he derived his theorem, Bells Theorem, that states that - No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics. Local hidden variables refers to realism and the local causality theory where combined, it meant that distant events are assumed to have no instantaneous (or at least faster-than-light) effect on local ones.

This meant that classical mechanics cannot explain everything that is going on in quantum mechanics.

Hybrid Quantum Dot-Superconducting Resonator Device Developed For Quantum Computers

A classical computer holds information in bits. It is comparable to a series of switches that can be either off (0) or on (1). In a quantum computer, the fundamental unit is the qubit. A photon or electron is usually used for this. It is similar to a bit, using its spin, it can be in a 'down' spin (0) or an 'up' spin (1), or it can be both at the same time, a superposition state.

This property is unique in quantum mechanics. Because of superposition, a quantum computer can process a problem much faster than a classical computer can. Instead of solving a problem or initiating a process one step at a time like a classical computer, a quantum computer can do it all in one step.

Physicists Devise A Way Using Squeezed Light In Measuring Distance

Non-classical light is light that has characteristics described through quantum mechanics and not using real world or classical properties. One type of non-classical light is squeezed light.

Squeezed light put simply is light that is manipulated in the quantum level through the generation of photons. Since the number of photons in a beam of light is random, squeezed light is generated with a steady number of photons in the beam. It can be said that the number of photons travelling in the light beam from squeezed light is a constant.

The result of using squeezed light is that quantum noise (random fluctuations in the wavelength) is reduced significantly. This makes measuring distance and targets more precise. Also with less noise, transmitted signals are clearer.

Since the photons are constant in squeezed light with minimal quantum noise, any fluctuations recorded are from outside source and not a result of that noise.

Applications for squeezed light range from using it for communication (fiber optics), measuring distance, and detecting gravitational waves. It is also being used in quantum cryptography where code keys are transmitted via squeezed light.

Light squeezed on a quantum scale

An international team of physicists has pushed the boundaries on ultra-precise measurement by harnessing quantum light waves in a new way.

It is one thing to be able to measure spectacularly small distances using "squeezed" light, but it is now possible to do this even while the target is moving around.

An Australian-Japanese research collaboration made the breakthrough in an experiment conducted at the University of Tokyo, the results of which have been published in an article, "Quantum-enhanced optical phase tracking" in the prestigious journal, Science.

Qubit On A Silicon Based Transistor For Quantum Computing Developed

The next evolution in computers is the quantum computer. With quantum computers, processors within utilize properties of atoms as dictated by quantum mechanics.

Classical computers (computers used today) use bits. Bits can be assigned either a 0 state or a 1 state to create a binary code. Using the 0 or 1 state, calculations are performed, information can be processed, and instructions followed.

Quantum computers use a different kind of bit; the qubit. Atoms generate spin, an up-spin and a down-spin, just like a regular computer bit, the up-spin and down-spin is similar to the 0 or 1 state. What makes the qubit special is that it also has a state called Superposition where the qubit is both up and down at the same time.

It is this superposition that makes quantum computing possible. An example would be an instruction to dial one million numbers. The classical computer would go about this by dialing the numbers one at a time. A quantum computer would dial all numbers in one step.

Technology is still far from constructing a practical quantum computer but each day, new developments are bringing it closer and closer to fruition. Early stage quantum computers the size of a room have already been built.

An often used principle when it comes to quantum computing is Moore's law. Moore's Law states that computer processing power continues to double every 18 months. This means that by the year 2030 or earlier, we will find that the circuits on a microprocessor will approach the atomic scale and quantum computing will be the norm.

Single-atom writer a landmark for quantum computing

A research team led by Australian engineers has created the first working quantum bit based on a single atom in silicon, opening the way to ultra-powerful quantum computers of the future.

In a landmark paper published today in the journal Nature, the team describes how it was able to both read and write information using the spin, or magnetic orientation, of an electron bound to a single phosphorus atom embedded in a silicon chip.

"For the first time, we have demonstrated the ability to represent and manipulate data on the spin to form a quantum bit, or 'qubit', the basic unit of data for a quantum computer," says Scientia Professor Andrew Dzurak. "This really is the key advance towards realising a silicon quantum computer based on single atoms."

High Temperature Superconductivity Achieved Using Ordinary Scotch Tape

University of Toronto physics professor Ken Burch with experimental apparatus and tape.
Credit: Diana Tyszko, Faculty of Arts & Science University of Toronto

Superconductivity occurs when objects or materials that are super cooled or cooled below a certain temperature achieves no (zero) electrical resistance and expulsion of magnetic fields. Required temperatures usually approaches absolute zero. This phenomenon is quantum mechanical in nature and is characterized by the Meissner effect.

The Meissner effect is an expulsion of a magnetic field from a superconductor during its transition to the superconducting state.

The electrical resistance of a material slowly goes down as temperature is lowered. When it is cooled below its critical temperature, a superconductor's resistance drops to zero. Without any electrical resistance, an electric current can persist indefinitely even without a power source. Simply put, there is no power loss with superconductors and that any existing power in a superconductive wire will forever flow in it.

University of Toronto led team induces high temperature superconductivity in a semiconductor with Scotch tape

An international team led by University of Toronto physicists has developed a simple new technique using Scotch poster tape that has enabled them to induce high-temperature superconductivity in a semiconductor for the first time. The method paves the way for novel new devices that could be used in quantum computing and to improve energy efficiency.

"Who would have thought simply sticking things together can generate entirely new effects?" said team leader and U of T physicist Ken Burch. High-temperature superconductors are materials that conduct electricity without heating up and losing energy at liquid nitrogen temperatures. They are currently in use for transmitting electricity with low loss and as the building blocks of the next generation of devices (quantum computers).

Quantum Effects in Cold Atom Physics Through Pre-Thermalization Are More Than Expected

On an atom chip (top), clouds of ultracold atoms (red) are created. They are allowed to interfere, creating an ordered matter-wave interference pattern (bottom).
Credit: Vienna University of Technology

Absolute zero is measured at 0 kelvins. The 3rd law of thermodynamics dictate that it is impossible to cool down an object to exactly 0 kelvins. Since cold is the absence of heat, absolute zero would mean that there is no heat left in the object or system. In 2003, MIT Researchers achieved the lowest temperature which is .45 nK (nano kelvin) or 4.5 x 10-10 K or 0.00000000045 K.

Ultracold atoms are atoms that are maintained at temperatures close to absolute zero. The study that uses ultracold atoms in relation to fundamental quantum phenomena is called Cold Atom Physics. Applications for this technology range from quantum computers, and quantum simulators to ultra-high-precision atomic clocks and quantum metrology.

One of the basic underlying phenomenon of cold atom physics is the Boss-Einstein Condensate (BEC). This is a new state of mater that forms in very low temperatures. When atoms are cooled down to very low temperatures, they start to behave in wave like properties, as the temperature keeps going down, they start to merge and behave like one singular wave like particle. This was predicted by Satyendra Nath Bose and Albert Einstein in 1924–25 and was successfully produced and observed in 1995.

Ultracold atoms reveal surprising new quantum effects

Every day we observe systems thermalizing: Ice cubes in a pot of hot water will melt and will never remain stable. The molecules of the ice and the molecules of the water will reach thermal equilibrium, ending up at the same temperature. Well-ordered ice crystals turn into a disordered liquid.

Experiments at the Vienna Center for Quantum Science and Technology (VCQ) at the Vienna University of Technology have shown that in the quantum world the transition to thermal equilibrium is more interesting and more complicated than assumed so far.