Tag Archives: radio waves

Strange radio waves picked up from center of Milky Way baffle astronomers

The Milky Way still contains plenty of unknowns. (Photo: Pixabay)

The Milky Way offers up a lot of unknows, one reason that scientists are always on the lookout for new stuff. An international team of researchers might have just found some when they discovered unusual radio waves coming from the direction of the galactic core. The waves fit no current pattern of radio sources and could mean a brand spanking new class of stellar objects.

“The strangest property of this new signal is that it is has a very high polarization. This means its light oscillates in only one direction, but that direction rotates with time,” said Ziteng Wang, lead author of the new study and a Ph.D. student in the School of Physics at the University of Sydney. “The brightness of the object also varies dramatically, by a factor of 100, and the signal switches on and off apparently at random. We’ve never seen anything like it.”

Many types of stars emit some sort of variable light across the electromagnetic spectrum. Radio waves have become a larger part of discoveries with ongoing advances. Some of the more significant finds from radio telescopes are pulsars, supernovae, flaring stars and fast radio bursts (and even Apollo landing sites).

“At first we thought it could be a pulsar – a very dense type of spinning dead star – or else a type of star that emits huge solar flares,” said Wang. “But the signals from this new source don’t match what we expect from these types of celestial objects.”

An artist’s impression of the ASKAP J173608.2-321635 source. Image credit: Sebastian Zentilomo.

Wang and his group found the unknown waves using the CSIRO’s ASKAP radio telescope in Western Australia. Follow-up observations were performed with the South African Radio Astronomy Observatory’s MeerKAT telescope. They had been surveying the universe since 2020 through a project known as Variables and Slow Transients (VAST).

Coined “ASKAP J173608.2-321635” after its coordinates (which doesn’t exactly roll off the tongue), the object started out invisible, became bright, faded away and then reappeared, a behavior that Tara Murphy, Wang’s Ph.D. supervisor called “extraordinary.”

After detecting six radio signals from the source over nine months in 2020, the astronomers tried to find the object in visual light. They found nothing. So they turned to the Parkes radio telescope in Australia. Again nothing.

After a switch to the more sensitive MeerKAT radio telescope in South Africa, they were able to pick up the lead.

“Luckily, the signal returned, but we found that the behavior of the source was dramatically different – the source disappeared in a single day, even though it had lasted for weeks in our previous ASKAP observations,” said Murphy.

The astronomers plan to keep their eyes peeled to look for more clues as to what it might be. They hope to learn more with the unveiling of the transcontinental Square Kilometre Array radio telescope. The total collecting area of the new telescope will be a square kilometer, making it 50 times more sensitive than any current radio instrument.

The findings appeared in the Astrophysical Journal.

Radio-wave treatment shows some promise against liver cancer

New research from the Wake Forest School of Medicine has shown that targeted radio wave treatments are safe to use against hepatocellular carcinoma (HCC), the most common type of liver cancer, and shows benefits for the patient’s overall survival rates.

Image credits Qasim Zafar / Flickr.

The researchers used a hand-held device called TheraBionic P1, produced by TheraBionic GmbH in Ettlingen that works by delivering specific, amplitude-modulated radiofrequency electromagnetic fields (AM RF EMF), meant specifically for use against HCC.

Radio treatment

“HCC accounts for nearly 90% of all liver cancers, and current survival rates are between six and 20 months,” said Boris Pasche, M.D., Ph.D., chair of cancer biology and director of Wake Forest Baptist’s Comprehensive Cancer Center. “Currently, there are limited treatment options for patients with this advanced liver cancer.”

“Our findings show an improvement in overall survival of more than 30% in patients with well-preserved liver function and also in those with more severe disease”.

This device emits radio waves that are spread through the patient’s body in an attempt to inhibit the growth of liver cancer cells without damaging healthy ones. A spoon-shaped antenna is placed under each patient’s tongue during the treatment, which is administered in three one-hour sessions per day. According to the paper, the low-level radiofrequency electromagnetic fields emitted by the antenna spread through the patient’s body.

Previously, the device was proven to be effective at blocking the growth of liver cancer cells, and it received breakthrough designation from the FDA in 2019.

The current study worked with 18 patients with advanced HCC, all of whom were enrolled for this type of treatment. Data from another 41 patients from a previous phase II study, as well as data from control participants from earlier clinical trials, was also factored into the study. 

Although the authors also kept an eye out for side effects, no patients stopped the treatment due to adverse reactions. The team reports that participants’ overall survival showed an improvement, although how much depended on their baseline health conditions at the start of the trial. Those who still maintained high levels of liver functionality showed a roughly 30% improvement in survival odds.

While the results are quite exciting, especially in conjunction with previous research on the subject, there is still a long way to go. The current study is limited by the small sample size used and “selection bias inherent in the use of historical control data”, according to Pasche.

The paper “Safety and Efficacy of amplitude-modulated radiofrequency electromagnetic fields in advanced hepatocellular carcinoma” has been published in the journal 4open.

Instruments at the Green Bank Telescope in West Virginia identified 15 mysterious high-energy radio signals which are still unattributed.

Intelligent alien life hunters pick up 15 high-energy bursts far across the universe

Instruments at the Green Bank Telescope in West Virginia identified 15 mysterious high-energy radio signals which are still unattributed.

Instruments at the Green Bank Telescope in West Virginia identified 15 mysterious high-energy radio signals which are still unattributed.

Brief but intense radio pulses have been recorded emanating from FRB 121102, a dwarf galaxy some 3 billion years away. Scientists working at Breakthrough Listen — a $100 million effort to search for alien signals — have identified 15 such high-energy radio bursts. It’s far too early, however, for us to say that these are indeed signs of advanced alien technology.

“Bursts from this source have never been seen at this high a frequency,” said in a statement Andrew Siemion, director of the Berkeley SETI Research Center and of the Breakthrough Listen program.

Is this alien technology?

The radio signals beamed from FRB 121102 might be the most promising kind of evidence in decades, sought after alien-hunting researchers working with the famous SETI. Many of SETI’s leading researchers are also part of Breakthrough Listen, which has access to the world’s most advanced telescopes and ample funding.

[panel style=”panel-danger” title=”The mysterious high energy bursts” footer=””]

The streaks across the colored energy plot are the bursts appearing at different times and different energies because of dispersion caused by 3 billion years of travel through intergalactic space. In the top frequency spectrum, the dispersion has been removed to show the 300 microsecond pulse spike. Credit: Berkeley University.

The streaks across the colored energy plot are the bursts appearing at different times and different energy levels due of dispersion caused by 3 billion years of travel through intergalactic space. In the top frequency spectrum, the dispersion has been removed to show the 300-microsecond pulse spike. Credit: Berkeley University.

The high-energy short burst radio emissions were detected on August 26 by the Green Bank Telescope in west Virginia, USA.

During the first scan, 12 such blips were recorded and another 3 appeared during the second scan. No further emissions could be identified during eight subsequent scans.

The data was reported in The Astronomer’s Telegram.

[/panel]

The project launched in January 2016 and is expected to run for at least ten years. We’re already seeing good progress, though the nature of such an inquiry demands extreme scrutiny and healthy skepticism.

That’s because there are natural phenomena that can explain the radio signals. For instance, rotating neutron stars with strong magnetic fields could produce the effect, though some astronomers were quick to point out that such objects shouldn’t be able to exist in a dwarf galaxy such as FRB 121102.

“It is surprising that the host would be a dwarf galaxy,” said Shriharsh Tendulkar of McGill University in Montreal, Canada. “One would generally expect most FRBs to come from large galaxies which have the largest numbers of stars and neutron stars. Neutron stars – remnants of massive stars – are among the top candidates to explain FRBs.”

Interstellar sailing

One heart-racing, though speculative explanation, is that the radio beams are evidence of powerful laser beams used by an extraterrestrial civilization to power spacecraft. Though wild, such an idea is rooted in scientific plausibility.

Avi Loeb and Manasvi Lingam from the Harvard-Smithsonian Center for Astrophysics published a paper in early 2017 where they explore the technical feasibility of building an alien transmitting device. Their calculations suggest that light hitting an area twice the size of Earth would be sufficient to generate the observed energy in such bright radio pulses.

The aim of such a device could be to signal other life forms of its alien presence. Alternatively, such a set up could be used for interstellar travel in the form of a light sail. We, humans, are already toying with such technology.

The Planetary Society, a non-profit organization founded by Carl Sagan and now coordinated by Bill Nye, is working with a satellite-sized object called the LightSail which is completely propelled by light. The sail is made out of thin Mylar and when stretched out measures 345 square feet.

Though photons have no mass, they do have momentum and energy. Once these reflect of a receiver, which could look something like a very thin sail, some of that energy is transferred, pushing the craft. While this pressure is minute, the catch is that it builds momentum over time.

Breakthrough Listen has an even crazier idea — but crazy enough to work. They plan to send tiny space probes to our nearest star system, Alpha Centauri (4.4-light-years away), and check out its planets. The so-called “Starchips” would be carried on light sails propelled by Earth-based lasers in just 20 years, by traveling at a fifth the speed of light. The video below briefly shows how this might work.

“We envision a beamer that emits the radio waves as a method of launching a light sail,” Loeb told Gizmodo. “In the same way that a sailboat is pushed by wind, a lightsail is pushed by light and can reach up to the speed of light.”

According to NASA scientist Philip Lubin, if we fired laser pulses with the same energy used today to launch rockets into space onto a light sail, we could push a 100kg payload to Mars in three days or one month for a large craft — the kind able to carry humans. “There is no known reason why we could not do this,” said Lubin.

Lubin and colleagues have now received a proof-of-concept grant from NASA to assess whether or not a photonic propulsion system for long distance space applications is viable.

Nevertheless, returning to our very interesting high-energy signal, it’s best to be cautious. No one is saying aliens are definitely involved. It’s just that there’s no water-tight hypothesis that can explain these signals. Furthermore, though I hate to be a buzz killer, it’s quite important to be aware that by the time these signals reached Earth, billions of years have elapsed since they were transmitted. Life on Earth was mostly comprised of single celled organisms when the bursts fired, and it’s possible that while we evolved down here, any aliens beaming the signals went extinct.

Hopefully, more information and insight might appear once the researchers involved are ready to publish in a peer-reviewed journal.

“Whether or not fast radio bursts turn out to be signatures of extraterrestrial technology, Breakthrough Listen is helping to push the frontiers of a new and rapidly growing area of our understanding of the universe around us,” Siemion said.

UW computer scientists and electrical engineers have generated “passive” Wi-Fi transmissions that use 10,000 times less power than current methods.University of Washington

Passive Wi-Fi uses 10,000 less energy and can power devices

Wi-Fi use can account for up to 60 percent of the phone’s total energy consumption. Even if you aren’t actually connected to a network, having it on will drain a lot of energy because the device is constantly searching for a signal. University of Washington researchers want to flip Wi-Fi energy use upside down. They’ve invented a new protocol and technique that uses 10,000 less energy. The same signal can be used to power devices without the need of an external power source. Cameras, temperature or motion sensors can all be power and connected to the internet at the same time using ‘passive Wi-Fi.’

UW computer scientists and electrical engineers have generated “passive” Wi-Fi transmissions that use 10,000 times less power than current methods.University of Washington

UW computer scientists and electrical engineers have generated “passive” Wi-Fi transmissions that use 10,000 times less power than current methods.University of Washington

Wireless electricity is far from new, but getting a device to also communicate is a bit more challenging. The team showed that it’s possible to turn weak signals into power and also communicate through a process called backscattering. The gist is that an additional device is used to reflect incoming radio waves from a source, and it’s this reflected signal that’s picked up by the devices. This is how an RFID chip inside a contactless card works. But a key difference is the technology developed at University of Washington doesn’t need a special device to read the signal, as is the case of contactless cards.

For instance, one version of the tech developed by the researchers called ‘passive Wi-Fi’  lets battery-free gadgets connect with conventional devices such as computers and smartphones by backscattering Wi-Fi signals.

There’s a digital and analog side to radio transmission. While the digital side has become extremely energy efficient in the past two decades, the same can’t be said of the analog side. So, what the researchers did was effectively decouple the analog and the digital signals. The Passive Wi-Fi architecture assigns the analog, power-intensive functions – like producing a signal at a specific frequency — to a single device in the network that is plugged into the wall.

In Passive Wi-Fi, power-intensive functions are handled by a single device plugged into the wall. Passive sensors use almost no energy to communicate with routers, phones and other devices. Image: University of Washington

In Passive Wi-Fi, power-intensive functions are handled by a single device plugged into the wall. Passive sensors use almost no energy to communicate with routers, phones and other devices. Image: University of Washington

Next, an array of sensors produce  Wi-Fi packets of information using very little power by simply reflecting and absorbing that signal using a digital switch. Prototype passive Wi-Fi devices have transfered data as far as 100 feet and made connections through walls. Data was transferred at 11 megabits per second.

“All the networking, heavy-lifting and power-consuming pieces are done by the one plugged-in device,” said co-author Vamsi Talla, an electrical engineering doctoral student. “The passive devices are only reflecting to generate the Wi-Fi packets, which is a really energy-efficient way to communicate.”

“Our sensors can talk to any router, smartphone, tablet or other electronic device with a Wi-Fi chipset,” said co-author and electrical engineering doctoral student Bryce Kellogg. “The cool thing is that all these devices can decode the Wi-Fi packets we created using reflections so you don’t need specialized equipment.”

The system uses  10,000 times less energy than conventional methods, and uses a thousandth as much power as the Bluetooth LE and ZigBee communications standards.

“Even though so many homes already have Wi-Fi, it hasn’t been the best choice for that,” said co-author Joshua Smith, UW associate professor of computer science and engineering and of electrical engineering. “Now that we can achieve Wi-Fi for tens of microwatts of power and can do much better than both Bluetooth and ZigBee, you could now imagine using Wi-Fi for everything.”

Passive Wi-Fi was  named one of 10 breakthrough technologies of 2016 by MIT Technology Review.

The WiTrack system provides significantly increased accuracy in tracking a person’s movement, and can even detect motion through walls and obstructions. (c) MIT

Highly accurate 3-D positioning system could change the face of gaming

The WiTrack system provides significantly increased accuracy in tracking a person’s movement, and can even detect motion through walls and obstructions.  (c) MIT

The WiTrack system provides significantly increased accuracy in tracking a person’s movement, and can even detect motion through walls and obstructions. (c) MIT

The way people play Battlefield or Call of Duty could change forever by bringing the heat of action to your living room. More specifically, by making action video games into real-life action as the gamer’s movements are tracked and reflected in the virtual world. The idea isn’t new, but a new 3-D positioning system developed at MIT looks so promising that finally we might be able to see a working version of such gaming possibilities in the near future.

Called WiTrack, the system uses radio-waves, instead of WiFi or image recognition like other motion tracking systems employ, to pinpoint the movement and individual actions like waving a hand or holding an object with extreme accuracy. According to the MIT researchers, WiTrack can pinpoint within 10 to 20 centimeters — about the width of an adult hand.

“Today, if you are playing a game with the Xbox Kinect or Nintendo Wii, you have to stand right in front of your gaming console, which limits the types of games you can play,” says Dina Katabi, a professor of computer science and engineering and co-director of the MIT Center for Wireless Networks and Mobile Computing. “Imagine playing an interactive video game that transforms your entire home into a virtual world. The game console tracks you as you run down real hallways away from video game enemies, or as you hide from other players behind couches and walls. This is what WiTrack can bring to video gaming.”

A different, more efficient type of motion tracking

Previously, Katabi and her graduate student Fadel Adib unveiled WiVi, developed a system that detects humans through walls and can track the direction of their movement using WiFi signals. Similarly, WiTrack can also locate a person through walls and obstructions, but instead of WiFi it uses radio signals. This translates in a huge energy saving, since there bandwidth limitations. Other tracking systems use things like image processing which causes intense strain on computing resources, and can’t ‘see’ through walls.

“Because of the limited bandwidth, you cannot get very high location accuracy using WiFi signals,” Adib says. “WiTrack transmits a very low-power radio signal, 100 times smaller than WiFi and 1,000 times smaller than what your cell phone can transmit. But the signal is structured in a particular way to measure the time from when the signal was transmitted until the reflections come back. WiTrack has a geometric model that maps reflection delays to the exact location of the person. The model can also eliminate reflections off walls and furniture to allow us to focus on tracking human motion.”

Here’s how it works: the system is comprised of four antennas – one is a transmitter, while the other three act as receivers; the radio signals that are reflected by a person inside a room are caught by the three antennas and the travel distance is measured for each. An algorithm creates a geometrical model of the user’s location and can track both two-dimensional and three-dimensional movement using specialized radio waves.

[ALSO READ] Virtual game for the blind

Live action

What makes the WiTrack particularly appealing is that you can use it without actually needing to carry any hardware at hand. There’s no need to have a WiFi transmitter or anything, and users can roam spaces freely while still providing high-accuracy localization. Check the video below for a great explanation and demonstration of the WiTrack in action.

“Motion tracking has generally been accomplished by analyzing images captured from strategically placed cameras inside the room. A limitation of such systems is that they only work when the moving object is directly in the camera’s line of sight,” Bahl says. “Another problem is [that] image analysis is a computationally heavyweight operation.”

“The technology Professor Katabi and her students have developed does not have these limitations,” he adds. “Their system detects movement without requiring a huge amount of computational power, and without having to be placed inside the room. The surprising thing is that it is very accurate. There is still more research to be done, but the approach is promising.”

The researchers involved in the project say such a device for commercial use can be made relatively cheaply. Next, they plan on advancing the WiTrack system so that it can track more than one person in motion at a time.

The Radiation Belt Storm Probes are on a two-year mission to explore the Van Allen Belts. (c) NASA

How Earth sounds like from outer space

The Radiation Belt Storm Probes are on a two-year mission to explore the Van Allen Belts. (c) NASA

The Radiation Belt Storm Probes are on a two-year mission to explore the Van Allen Belts. (c) NASA

Surrounding our planet are rings of plasma, part of Earth’s magnetosphere, which are pulsing with radio waves. These aren’t audible to the human ear, but radio dishes and antennas always pick them up. Recently, NASA scientists recorded some of the Earth’s pulses and transformed them into acoustic waves – the end result is a short song chanted by our very planet.

Dubbed “Chorus”, the song is made of radio waves that oscillate at acoustic frequencies, between 0 and 10 kHz. Actually, similar sounds are often picked up by ham radio operators on Earth. You can listen to it in the player embedded below.

“Chorus emissions are front and center for the Storm Probe mission,” says Craig Kletzing of the University of Iowa. “They are thought to be one of the most important waves for energizing the electrons that make up the outer radiation belt.”

The sounds were picked up by the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) on NASA’s recently launched Radiation Belt Storm Probes. The two probes are orbiting inside the radiation belts, sampling electromagnetic fields, counting the number of energetic particles, and listening to plasma waves of many frequencies. Though usually harmless, sometimes high-energy particles can endanger both satellites and astronauts.

source: NASA