This week we will look at a new fibre that will be able to hear everything that you say and all the noise around you. We discover something very strange about the speed of sound on Mars and we examine an AI that will be used to stop you from drink driving. Finally we will marvel at the beauty of some new photographs from the James Webb Telescope. As a bonus we also look at the most detailed photograph ever taken of our sun.
Your shirt is listening to you
MIT and Rhode Island School of Design have developed a new acoustic fabric that will be able to listen to you. The fabric works like a microphone converting sound into mechanical vibrations and then into electrical signals. This is how our ears work.
Every sound vibrates the fabric in our shirts however the movement is on the nanometer scale so not normally felt. The team created a flexible fibre that is woven into fabric and that can bend with the fabric as you move. The fiber is a piezoelectric material meaning that it produces an electrical signal when it is bent or moved. This allows the fabric to capture sounds. It can also capture our heartbeat and spoken words.
The fabric is able to capture sounds ranging from a quiet library to heavy road traffic. It is also able to determine the direction that sounds come from to within 1 degree for sounds created within 3 meters. The material performs as well as a hand held microphone.
Potential uses include assisting hearing, monitoring of heart beats, on buildings to detect cracks and strains and on spacecraft to monitor the accumulation of space dust. The team has also turned the fabric into a speaker by reversing the process. They recorded a string of words and fed the recording in the form of an applied voltage into the fibre. The fibre converted the electrical signals into audible vibrations which a second fibre was able to pick up and decode.
The Speed of Sound on Mars
The Perseverance Rover has confirmed that the speed of sound on Mars is very different to Earth. Higher pitched notes travel faster than bass notes.
The speed of sound is not a universal constant. It depends upon the density and temperature of the medium through which the sound is traveling. The denser the medium the faster it travels. Sound travels at about 343 meters per second in our atmosphere at 20C. It travels at 1,480 mps through water and 5,100 mps through steel.
Mars has a much thinner atmosphere than earth. About 0.02Kg per cubic meter compared to earth with 1.3kg per cubic meter. On Mars the warming of the surface during the day generates convection updrafts that create strong turbulence.
Perseverance has microphones that allow us to hear the sounds of Mars (listen here). Researchers discovered that sound travel at 240mps on Mars but they also noticed a quirk which they were not expecting and have not seen anywhere else. Due to the unique properties of Carbon Dioxide molecules at low pressure, Mars is the only terrestrial planet in the Solar System that experiences a change in the speed of sound in the middle of the audible bandwidth.
At frequencies above 240Hertz the collision activated vibrational modes of carbon dioxide do not have enough time to relax or return to their original state after encountering sound, causing sound at higher frequencies to travel over 10 meters per second faster than lower frequencies.
Because the speed of sound varies at different temperatures the team was also able to measure temperature variations on the surface during the day that could not be picked up by other sensors.
AI to Stop Drink Driving
One of the little discussed features of the recent US Infrastructure Bill was a mandate for car manufacturers to equip new vehicles with advanced drink driving prevention technology. The systems either monitor the drivers behavior or use a Blood Alcohol Breath Test to gate turning the car on. The manufacturers have till 2027 to install the new equipment.
All new cars have Driving monitoring and assistance systems (DMAS) which are automatic and operate without active input from a driver. Some of these systems now focus on the driver, tracking head position, eyelid closure and eye gaze detection to identify driver impairment. If the system detects a impaired driver from the driving behavior it can steer the vehicle to safety.
Newer systems can detect a drivers blood alcohol content from normal breathing in the car. A touch based system uses sensors in the ignition button or gear shift to determine the drivers BAC below the skin surface. If either system detects that the driver is over the limit the car won’t move.
DMAS technology will be required in Europe from July this year, China is investigating mandating the use of these systems and Victoria in Australia is currently testing the systems.
Photographing the Stars
We have followed the progress of the James Webb Telescope over the past few years. NASA has recently released the first alignment evaluation image from the telescope and it is the clearest photograph that we have ever taken of the cosmos.
Here is the previous best image of the same star system.
$US10 Billion well spent.
Whilst we are looking at the stars here is a photo that Astrophotographer, Andrew McCarthy compiled from 150,000 individual pictures of our sun. The whole photo is 300 times larger than a standard photograph. You can see the original here on Instagram.
Paying it Forward
If you have a start-up or know of a start-up that has a product ready for market please let me know. I would be happy to have a look and feature the startup in this newsletter. Also if any startups need introductions please get in touch and I will help where I can.
If you have any questions or comments please comment below.
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Till next week.