World-record laser transmission could prove Einstein's theory

Researchers devise a record-breaking laser transmission that avoids atmospheric interference.

World-record laser transmission could prove Einstein's theory

University of Western Australia's rooftop observatory.

Credit: ICRAR
  • 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.

Iron Age discoveries uncovered outside London, including a ‘murder’ victim

A man's skeleton, found facedown with his hands bound, was unearthed near an ancient ceremonial circle during a high speed rail excavation project.

Photo Credit: HS2
Culture & Religion
  • A skeleton representing a man who was tossed face down into a ditch nearly 2,500 years ago with his hands bound in front of his hips was dug up during an excavation outside of London.
  • The discovery was made during a high speed rail project that has been a bonanza for archaeology, as the area is home to more than 60 ancient sites along the planned route.
  • An ornate grave of a high status individual from the Roman period and an ancient ceremonial circle were also discovered during the excavations.
Keep reading Show less

Surprising new feature of human evolution discovered

Research reveals a new evolutionary feature that separates humans from other primates.

Human evolution.

Credit: Adobe Stock
Surprising Science
  • Researchers find a new feature of human evolution.
  • Humans have evolved to use less water per day than other primates.
  • The nose is one of the factors that allows humans to be water efficient.
Keep reading Show less

Skepticism: Why critical thinking makes you smarter

Being skeptical isn't just about being contrarian. It's about asking the right questions of ourselves and others to gain understanding.

Videos
  • It's not always easy to tell the difference between objective truth and what we believe to be true. Separating facts from opinions, according to skeptic Michael Shermer, theoretical physicist Lawrence Krauss, and others, requires research, self-reflection, and time.
  • Recognizing your own biases and those of others, avoiding echo chambers, actively seeking out opposing voices, and asking smart, testable questions are a few of the ways that skepticism can be a useful tool for learning and growth.
  • As Derren Brown points out, being "skeptical of skepticism" can also lead to interesting revelations and teach us new things about ourselves and our psychology.
Keep reading Show less
Mind & Brain

New study suggests placebo might be as powerful as psychedelics

New study suggests the placebo effect can be as powerful as microdosing LSD.

Quantcast