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https://theconversation.com/device-transmits-radio-waves-with-almost-no-power-without-violating-the-laws-of-physics-196271>
"A new ultra-low-power method of communication at first glance seems to violate
the laws of physics. It is possible to wirelessly transmit information simply
by opening and closing a switch that connects a resistor to an antenna. No need
to send power to the antenna.
Our system, combined with techniques for harvesting energy from the
environment, could lead to all manner of devices that transmit data, including
tiny sensors and implanted medical devices, without needing batteries or other
power sources. These include sensors for smart agriculture, electronics
implanted in the body that never need battery changes, better contactless
credit cards and maybe even new ways for satellites to communicate.
Apart from the energy needed to flip the switch, no other energy is needed to
transmit the information. In our case, the switch is a transistor, an
electrically controlled switch with no moving parts that consumes a minuscule
amount of power.
In the simplest form of ordinary radio, a switch connects and disconnects a
strong electrical signal source – perhaps an oscillator that produces a sine
wave fluctuating 2 billion times per second – to the transmit antenna. When the
signal source is connected, the antenna produces a radio wave, denoting a 1.
When the switch is disconnected, there is no radio wave, indicating a 0.
What we showed is that a powered signal source is not needed. Instead, random
thermal noise, present in all electrically conductive materials because of the
heat-driven motion of electrons, can take the place of the signal driving the
antenna."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
