HAMNET Report 11th April 2021

ScienceDaily says Researchers at the National Institute of Standards and Technology (NIST) and collaborators have demonstrated an atom-based sensor that can determine the direction of an incoming radio signal, another key part for a potential atomic communications system that could be smaller and work better in noisy environments than conventional technology.

NIST researchers previously demonstrated that the same atom-based sensors can receive commonly used communications signals. The capability to measure a signal’s “angle of arrival” helps ensure the accuracy of radar and wireless communications, which need to sort out real messages and images from random or deliberate interference.

“This new work, in conjunction with our previous work on atom-based sensors and receivers, gets us one step closer to a true atom-based communication system to benefit 5G and beyond,” project leader Chris Holloway said.

In NIST’s experimental setup, two different-coloured lasers prepare gaseous Caesium atoms in a tiny glass flask, or cell, in high-energy (“Rydberg“) states, which have novel properties such as extreme sensitivity to electromagnetic fields. The frequency of an electric field signal affects the colours of light absorbed by the atoms.

An atom-based “mixer” takes input signals and converts them into different frequencies. One signal acts as a reference while a second signal is converted or “detuned” to a lower frequency. Lasers probe the atoms to detect and measure differences in frequency and phase between the two signals. Phase refers to the position of electromagnetic waves relative to one another in time.

The mixer measures the phase of the detuned signal at two different locations inside the atomic vapour cell. Based on the phase differences at these two locations, researchers can calculate the signal’s direction of arrival.

To demonstrate this approach, NIST measured phase differences of a 19.18 gigahertz experimental signal at two locations inside the vapour cell for various angles of arrival. Researchers compared these measurements to both a simulation and a theoretical model to validate the new method. The selected transmission frequency could be used in future wireless communications systems, Holloway said.

With further development, atom-based radio receivers may offer many benefits over conventional technologies. For example, there is no need for traditional electronics that convert signals to different frequencies for delivery because the atoms do the job automatically. The antennas and receivers can be physically smaller, with micrometre-scale dimensions. In addition, atom-based systems may be less susceptible to some types of interference and noise.

So your future radio receiver might have two lasers embedded in it, and a vapour cell, be able to receive the transmitted signal, and tell you which direction it came from. Impressive indeed!

I watched the pre-flight press briefing for Mars Ingenuity helicopter on Friday night, and the excitement in the demeanours of the group being interviewed was palpable. No earlier than Monday morning (tomorrow) at 09h30 Central African Time, Ingenuity will be programmed to spin up its rotors to 2500 rpm, and attempt to fly up to an altitude of 3 metres, hover there for 30 seconds and then return gently to the ground. It will be observed from a distance of about 60 metres by Perseverance, taking pre-programmed 2.5 second vignettes of it doing so, hopefully to catch some part of the flight, for immediate download to earth. Far more importantly, all the technical data of the flight will be downloaded  as quickly as possible, so engineers can study all the recorded parameters, to see if it behaved as expected, or developed flight anomalies impossible to predict before the time.

If successful, this flight will be the first flight off a planet’s surface since the Wright brothers managed to do it on Earth on 17th December 1903, so these special events don’t come round very often!

If you are near an internet connection, watch the event live tomorrow morning from 09h30 our time, as nasa.gov/nasalive streams it, or download the NASA app on all the usual platforms, or watch it on YouTube or FaceBook channels. There may not be much to see, but history is being made, so try to be a part of it!

Now for the computer gamers amongst us, MedicalExpress reports that Elon Musk’s Neuralink start-up has managed to get a Macaque monkey called Pager to play the video game called Pong, using thought only.

The monkey, with electrodes implanted on both sides of his brain, was monitored while he played Pong with a joystick, so that researchers could learn how to interpret his brain waves while he controlled the joystick. A banana-smoothie through a straw was used to reward him for his successful actions.

Then the joystick was removed, and he was given the game scene on the screen to contemplate, and he was able to move the paddles using only brain-wave monitoring and no physical activity on his part. He became amazingly good at MindPong by thought association!

[Note two things: firstly this was a male monkey, and secondly he was satisfied with the relatively insignificant reward of a banana smoothie. I think all the women in the world will snort and speculate that all men are more closely related to monkeys than they are!]

However, the researchers suggest that the decoder in the computer software could be calibrated to enable a person to guide a cursor on a computer screen, potentially letting them type emails, text messages, or browse the internet just by thinking, according to a blog post at neuralink.com.

“Our first goal is to give people with paralysis their digital freedom back,” the Neuralink team said in the post.

Members of the team last year shared a “wish list” that ranged from technology returning mobility to the paralyzed and sight to the blind, to enabling telepathy and the uploading of memories for later reference—or perhaps to be downloaded into replacement bodies.

For now, Neuralink is being tested in animals with the team working on the potential for clinical trials.

I’m sure even the women of the world will agree these lofty ideals outweigh the time wastage demonstrated by your teenage son on the couch all weekend playing video games, drinking non-nutritious stuff and eating junk-food when he should have been out there conquering the world!

This is Dave Reece reporting for HAMNET in South Africa.