Jan 7th 2021
ALL THE technologies discussed in this report are moving forward apace. The companies which provide machinery to solar-cell manufacturers are ceaselessly trying to make more efficient use of silicon and less costly modules. In universities and elsewhere researchers are looking at ways to add a second layer to such cells so as to capture energy at wavelengths silicon ignoresthough their best attempts so far do not last very long outdoors.
Advances in manufacturing and design are making LEDs ever better sources of illumination. In more and more screens they backlight the liquid-crystal shutters which brighten pixels by detenebration. Some screens already do without shuttering, using liquid-crystal-free arrays of micro-LEDs to produce images that offer better contrast and use less energy. In information technology the division of labour that sees data processing done by electrons and data transmission by photons is under attack; switches that could be programmed to do some information processing while keeping that information in the form of photons would allow data to flow around data centres more quickly and efficiently. Laser beams of slightly different wavelengths are being packed ever more densely into optical fibres, with more bits encoded into every symbol stamped on to their light. The current record for data transfer down a single fibre, held by researchers at UCL, a British university, is 178 terabits a second.
But if you want to see lasers which push the boundaries of the possible in the most dramatic of ways, you have to turn to those made, not for practical applications, but to further science. Wherever researchers require ludicrous amounts of power or precision, theres every chance that they are using a laser, some sort of digital photon detector, or both. To see the cutting edge of what light can do, head for a lab.
The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California is a case in point: walking its halls evokes a sense of the technological sublime which is all but visceral. The 192 laser beams from the 100-metre-long, xenon-pumped beamlines that fill its two warehouse-sized clean rooms converge on a peculiarly perforated spherical chamber. When NIF is operational a tiny bubble at the centre of that chamber is illuminated with 500 terawatts, which is to say 500,000GW.
Given that the worlds total electricity generating capacity is less than 5TW, how is a 500TW system possible? The answer is brevity. Because power is energy divided by time, a relatively small amount of energy can provide a huge amount of power if it is delivered quickly enough. The NIF fires for only a few tens of nanoseconds (billionths of a second) at a time. Each blink-and-you-miss-it 500TW blast thus delivers only a kilowatt-hour or so of energy.
Using such a gargantuan device to provide such a modest amount of energy seems bizarre. But NIFs job requires the energy to be delivered with great spatial precision and almost instantaneously. Only then can it heat the lasers tiny targets to temperatures and pressures otherwise reached only in the centres of stars and the blasts of nuclear weaponsconditions which can fuse atomic nuclei. Congress paid billions for the NIF on the basis that it might open the way to making nuclear fusion of this sort a practical energy source. It has not delivered on those dreams. But it has provided new insights into astrophysics as well as experimental data relevant to the design and maintenance of hydrogen bombs, which is Lawrence Livermores main concern.
Physicists are not the only scientists entranced by lasers. One of the workhorses of genetic engineering is green fluorescent protein (GFP). The instructions for making GFP are easily added to genes for other proteins. When poked with finely focused lasers these modified proteins fluoresce, thus revealing their whereaboutsa handy way of learning which proteins cells put where.
A remarkable refinement of this technique, first demonstrated in 2011, is to turn the cell itself into a laser. Engineer a cell to produce GFP, put it between two mirrors and pump energy in and the proteins light will be amplified in just the same way as it would in a piece of ruby or neodymium-doped glass. Light-emission microscopy based on this possibility amplifies the light given off by fluorescent proteins and other light-emitting markers.
Photons can also be used to change how cells behave. By engineering proteins to be sensitive to light and then turning that light on and off, researchers can change what cells doincluding the ways they do, or dont, transmit nerve impulses. Laser light flashed on to the nerves of a suitably engineered flatworm, or shone down optical fibres into the brain of a mouse, allows researchers to turn different parts of the nervous system on and off and observe the changes in behaviour that follow. This optogenetic puppeteering provides all sorts of new insights into the machinery of the brain. With all due respect to those using photons to explore the strange interconnectedness of things in quantum mechanicswhich Einstein famously described as spookyphotons that can literally change a mind in mid-thought may be the spookiest of all.
The degree to which light-based techniques are changing sciences across the board can be seen in the past decades decisions by the Nobel Physics Committee. In 2014 the committee recognised a physical breakthrough in the production of lightthe development of blue LEDs, a technical tour de force which made the production of white light cheaper and easier than ever before. Since then the physics prize has been awarded to three different ways of using lasers either for experiments in the lab or observations of the world. A tour of these prize-winning accomplishments allows a last celebration of this golden age of light.
Start with pure power. A technique called chirped-pulse amplification, developed by Donna Strickland and Grard Mourou when they were both at the University of Rochester, allows lasers far more powerful than the NIFlasers which work in the petawatt range. It provides a way around the unfortunate fact that, above a certain power level, even a very short pulse will melt any laser trying to amplify it further. Chirp amplification solves the problem by stretching pulses out in both space and time. An intense packet of photons that is, say, a millimetre long, and thus passes through any machine in just three trillionths of a second, can be chirped into one that is a metre long and lasts a full three billionths of a second. This stretched pulse is low-power enough to be amplified, after which it can be compressed back into its original form as a burst just as short as ever but now containing many more photons.
Labs around the world now use this technique to produce bursts of light both far shorter and far more powerful than those at NIF using much cheaper equipment. This allows them to study nuclear processes that are even more extreme than fusion. If the pulses can be made 1,000 times shorter stillwhich Dr Mourou, at least, thinks is possible, given a decade or sothey could achieve something no other technology has yet managed: the creation of matter (and antimatter) from scratch.
Einsteins work dispensed with the need for an all-pervading luminiferous aether. But the fields evoked by quantum electrodynamics (QED), the mid-20th-century culmination of work on electromagnetism, quantum theory and relativity, populate empty space with something else instead: very faint possibilities. And QED says that, if light gets sufficiently intense, its photons will interact with these possibilities to bring forth brand new electrons from empty space. Einsteins insight that mass can be converted into energy has been proven many times, most terribly in nuclear weapons. Creating material particles from massless light alone would be a remarkable turning of the tables, and one that ought to provide new insight into the quantum fields involved.
After power, pressure. The momentum of photons is tiny; but when applied to tiny things it can do useful work. In the 1960s Arthur Ashkin of Bell Labs realised that, if a small transparent object is placed on the edge of a laser beam it will move to the beams centre (provided that the beam is brighter at the centre than the edge). This is because the photons that pass through the object have their path bent outward, away from the beam: conservation of momentum requires the object thus diverting them to move in the opposite direction. If, once caught up in the beam, the object strays from its bright centre, the light pressure will bring it back.
In the 1970s Dr Ashkin put this idea into practice, using laser beams as optical tweezers with which to manipulate microscopic beads. In the 1980s he got the technique to work on individual bacteria and virus particles, while his student Steven Chu used a variant to trap individual atomswork that won Dr Chu and colleagues a Nobel prize in 1997. The increasing use made of his tweezers in biology saw Dr Ashkin follow in his students footsteps in 2018, sharing the prize with Dr Strickland and Dr Mourou.
And then there is precision. Einsteins general theory of relativity, promulgated in 1915, explains gravity in terms of the distortions masses impose on spacetimespacetime being, to Einstein, simply the thing that clocks and rulers measure. His special theory of relativity had laid out the case for light being the ultimate ruler, a view that measurement professionals now share; the General Conference on Weights and Measures defines the metre not as the length of a specific rod in a vault in Paris, as it once did, but as the distance a photon in a vacuum travels in 1/299,792,458 of a second. Thus if you want to see ripples in spacetimesuch as those which relativity says must be produced when two very large masses pirouette around each otherlight is the best sort of ruler to use.
The Laser Interferometer Gravitational-wave Observatory (LIGO) consists of two such rulers. Its twin detectors, one in Louisiana and one in Washington state, both feature 4km-long perpendicular arms along which laser beams of truly phenomenal stability bounce back and forth (see chart). Instruments mounted at the point where the beams cross compare their phases in order to detect transitory differences in the arms lengths. Their precision is equivalent to that which would be needed to detect a hairs-breadth change in the distance to a nearby star.
On September 14th 2015 LIGO picked up the shiver in spacetime produced by the merger of two black holes 1.3bn light-years away. In 2017 the Nobel Physics Committee, free of naysaying ophthalmologists, awarded the prize to Rainer Weiss, Kip Thorne and Barry C. Barish, the three scientists who had done most to make that observation happen.
Their extraordinary measurement was treated, quite rightly, as a slightly late 100th-birthday present for Einsteins truly remarkable intellectual achievement. It was also an extraordinary demonstration of what can be done with photons. A century of work by scientists and engineers has taken the energy packets that Einstein first imagined in 1905 and produced a range of technologies with capabilities little short of the miraculousa collective achievement far greater than any single act of genius. Relativity is remarkable. Putting photons to use has been revolutionary.
This article appeared in the Technology Quarterly section of the print edition under the headline "New enlightenments"
Read more here:
- The windswept German island that inspired quantum physics - Spectator.co.uk - April 8th, 2021
- A Tiny Particles Wobble Could Upend the Known Laws of Physics - The New York Times - April 8th, 2021
- New computing algorithms expand the boundaries of a quantum future - Fermi National Accelerator Laboratory - April 8th, 2021
- Quantum Computing Revolution: Is it the next big thing? - Analytics Insight - April 8th, 2021
- Scientists Are Baffled By A Mysterious Particle That Defies Physics And Violates The Laws Of The Universe - BroBible - April 8th, 2021
- Officials Aim to Diversify the U.S. Quantum Workforce Early On - Nextgov - April 8th, 2021
- Searching for New Physics in the Subatomic World - SciTechDaily - April 8th, 2021
- Herms collaborates with artists on Watches and Wonders 2021 scenography - Wallpaper* - April 8th, 2021
- Quantum Physics to Disrupt Geospatial Industry over the Coming Decade - GIM International - April 4th, 2021
- The mystery of the muon's magnetism | symmetry magazine - Symmetry magazine - April 4th, 2021
- 6 Quantum Computing Stocks to Invest in This Decade - Investment U - April 4th, 2021
- Can science explain the mystery of consciousness? - The Irish Times - April 4th, 2021
- 'Spacekime theory' could speed up research and heal the rift in physics - Big Think - April 4th, 2021
- Where did the antimatter go? - The Express Tribune - April 4th, 2021
- Small things misbehaving leads to the greatest question of all - Spectator.co.uk - April 4th, 2021
- Ultracold Quantum Collisions Have Been Achieved in Space for the First Time - Scientific American - March 23rd, 2021
- I'm Agonizing over My Naive Realism - Scientific American - March 23rd, 2021
- Six fabulous facts about the Standard Model - Symmetry magazine - March 23rd, 2021
- Cryptocurrency: Can it be climate conscious, and if so, how? - Landscape News - March 23rd, 2021
- Physicists Create Quasiparticles That Bind Together Two Differently Colored Particles of Light - SciTechDaily - March 6th, 2021
- Element Sixs DNV-B1 Announced Winner for the Quantum Category at the 13th Edition of the SPIE Prism Awards - AZoM - March 6th, 2021
- Tech that sees through the earth could help build cities of the future - The Times - March 6th, 2021
- Physicists Just Found 4 New Subatomic Particles That May Test The Laws of Nature - ScienceAlert - March 6th, 2021
- Living in a simulation: Is Universe a Neural Network? - The Indian Wire - March 6th, 2021
- This Is the Fastest Random-Number Generator Ever Built - Scientific American - March 4th, 2021
- Physics - The Tiniest Superfluid Circuit in Nature - Physics - March 4th, 2021
- New research indicates the whole universe could be a giant neural network - The Next Web - March 4th, 2021
- New History of the Physics Department by Raj Gupta and Paul Sharrah Published - University of Arkansas Newswire - March 4th, 2021
- International Business Machines : The Decade of Quantum Computing Is Upon Us, IBM Executive Says - Marketscreener.com - March 4th, 2021
- Quantum Tunneling in Graphene Advances the Age of High Speed Terahertz Wireless Communications - SciTechDaily - March 4th, 2021
- Subtle quantum phenomenon found to alter chemical reactivity for the first time - Chemistry World - March 4th, 2021
- Physicists believe faster-than-light travel is indeed possible with new warp drive - ZME Science - March 4th, 2021
- Exclusive! Ashwin Sanghi on his dream to cast Sushant Singh Rajput in 'Keepers Of The Kalachakra' series: He was like an excited child when it came to... - March 4th, 2021
- Can god be disproved using the laws of physics? An expert explains how it depends on perspective - Scroll.in - March 4th, 2021
- Global Quantum Computing Technologies Market will grow to at CAGR 15.89% from 2020 to 2027 KSU | The Sentinel Newspaper - KSU | The Sentinel... - March 4th, 2021
- Quantum Technology Innovation Hub to transform local businesses - University of Birmingham - March 4th, 2021
- And So It Begins Quantum Physicists Create a New Universe With Its Own Rules - The Daily Galaxy --Great Discoveries Channel - February 18th, 2021
- Quantum Theory May Twist Cause And Effect Into Loops, With Effect Causing The Cause - ScienceAlert - February 18th, 2021
- Extracting information stored in 100,000 nuclear quantum bits - Advanced Science News - February 18th, 2021
- Light and a Single Electron Used to Detect Quantum Information Stored in 100,000 Nuclear Quantum Bits - SciTechDaily - February 18th, 2021
- IBM Adds Future Developer And Software Details To Its Quantum Roadmap - Forbes - February 18th, 2021
- Physics - A Superconducting Qubit that Protects Itself - Physics - February 18th, 2021
- Black Quantum Futurism receives the Knight Foundations new art and technology fellowship - WHYY - February 18th, 2021
- Resolving to read more in 2021 - Powell Tribune - February 18th, 2021
- Warp Drives Are No Longer Science Fiction - Applied Physics - Business Wire - February 18th, 2021
- RI local and star of 'Ghost Hunters' + 'Kindred Spirits' on her search for the paranormal - The Providence Journal - February 18th, 2021
- Quantum Theory Proposes That Cause and Effect Can Go In Loops - Universe Today - February 14th, 2021
- The search for dark matter gets a speed boost from quantum technology - The Conversation US - February 14th, 2021
- A Magnetic Twist to Graphene Could Offer a Dramatic Increase in Processing Speeds Compared to Electronics - SciTechDaily - February 14th, 2021
- Yale Quantum Institute Co-sponsored Event - Alternative Realities for the Living - Quantum Physics & Fiction - Yale News - February 14th, 2021
- In Violation of Einstein, Black Holes Might Have 'Hair' - Quanta Magazine - February 14th, 2021
- Scientists narrow down the 'weight' of dark matter trillions of trillions of times - Livescience.com - February 5th, 2021
- Switching Nanolight On and Off | Columbia News - Columbia University - February 5th, 2021
- Photoelectric effect of physics in technology - The National - February 5th, 2021
- Quantum Physics Story Helgoland to Be Adapted by Fremantles The Apartment, CAM Film (EXCLUSIVE) - Variety - February 2nd, 2021
- 29 Scientists Came Together in the "Most Intelligent Photo" Ever Taken - My Modern Met - February 2nd, 2021
- Silence your stoner friends with this video of a room entirely constructed out of mirrors - The A.V. Club - February 2nd, 2021
- Valuable contributor to society - The Tribune India - February 2nd, 2021
- A Zoom with a view: Wintersession offers a virtual journey from the kitchen to Hollywood - Princeton University - February 2nd, 2021
- IBMs top executive says, quantum computers will never reign supreme over classical ones - The Hindu - January 31st, 2021
- Tech 24 - Welcome to the quantum era - FRANCE 24 - January 31st, 2021
- Physicists Are Reinventing the Laser - Gizmodo - January 31st, 2021
- Record-Breaking Source for Single Photons Developed That Can Produce Billions of Quantum Particles per Second - SciTechDaily - January 31st, 2021
- How Universes Might Bubble Up and Collide - WIRED - January 31st, 2021
- Insiders say Comedy Central's top creative executives tokenized employees of color and fostered an environment - Business Insider India - January 31st, 2021
- Copperizing the Complexity of Superconductivity - Newswise - January 31st, 2021
- The Convergence of Internet of Things and Quantum Computing - BBN Times - January 31st, 2021
- Who You Really Are And Why It Matters | Practical Ethics - Practical Ethics - January 31st, 2021
- Improving LIDAR and GPS: Breaking Through the Resolution Barrier With Quantum-Limited Precision - SciTechDaily - January 18th, 2021
- Amy Noelle Parks Brings The Romance of Math and Science To YA - The Nerd Daily - January 18th, 2021
- Surprising Discovery of Unexpected Quantum Behavior in Insulators Suggests Existence of Entirely New Type of Particle - SciTechDaily - January 18th, 2021
- If Wormholes Are Lurking in Our Universe, This Is How We Could Find Them - ScienceAlert - January 18th, 2021
- New quantum technology projects to solve mysteries of the universe - Open Access Government - January 14th, 2021
- Exploring the unanswered questions of our universe with quantum technologies - University of Birmingham - January 14th, 2021
- Wormholes may be lurking in the universe and new studies are proposing ways of finding them - The Conversation UK - January 14th, 2021
- University of Sheffield to lead multi-million pound project which could open up a new frontier in physics - University of Sheffield News - January 14th, 2021
- Raytheon UK part of team transforming the Royal Navy's technology, training and learning solutions - PRNewswire - January 14th, 2021
- Optical selection and sorting of nanoparticles according to quantum mechanical properties - Science Advances - January 14th, 2021
- The unhackable computers that could revolutionize the future - CNN - January 8th, 2021
- Birds Have a Mysterious 'Quantum Sense'. For The First Time, Scientists Saw It in Action - ScienceAlert - January 8th, 2021