Tesla's Dream Coming True?

...."In 2015, researchers at the University of Washington introduced power over Wi-Fi, which trickle-charges batteries and powered battery-free cameras and temperature sensors using transmissions from Wi-Fi routers.^[82][83] Wi-Fi signals were shown to power battery-free temperature and camera sensors at ranges of up to 20 feet. It was also shown that Wi-Fi can be used to wirelessly trickle-charge nickel–metal hydride and lithium-ion coin-cell batteries at distances of up to 28 feet.

In 2017, the Federal Communication Commission (FCC) certified the first mid-field radio frequency (RF) transmitter of wireless power.^[84]"...

^{https://en.wikipedia.org/wiki/Wireless_power_transfer#Microwaves}

It's a bit different from what Tesla envisioned, beamed not broadcast.

I'm wondering how the laser guard beams are affected by weather. Also, I would think there could be interference with Bluetooth and Wifi. Data microwave links only operate on a few watts, but with transferring power, it wouldn't take much leakage.

What happens when a hapless pigeon or worse (from the human perspective) an aeroplane flies through the beam?

If it's a Frenchman it would be French Fries.

"Fry the frenry skies of United".

MIcrowave NO, ELF Maybe

Tiny amounts of water vapor, liquid water, and ice crystals will disrupt line of sight electromagnetic power transmission with absorption and dispersing reradiation. The basic problem is the wide range of vibration modes of the water molecules with their 105 degree angle between the two hydrogens. These vibration mode frequencies are significantly affected by temperature and temperature varies a lot through any useful distance of atmosphere. Basically, somewhere along the path your absorption minima will be shifted to where you do not want them to be and the atmosphere will significantly diffuse your beam, spread your frequency, and attenuate your power transmission. Note that a cup of water in a microwave oven gets hot. There goes your power. Notice that the article does not specify a frequency of operation other than "microwave". So, even if you can find some frequency in the microwave spectrum where water absorbs least, that frequency will vary with temperature along the path and somewhere the atmosphere will suck up most of your power besides spreading the beam out losing your line of sight and your frequency tuning sharpness.

Tesla was using mechanical means of generating his electromagnetic energy and was therefore generating a large portion of his radiated energy at much lower frequencies than microwave. There might still be some hope of transmitting large power at these lower frequencies with broadcasting(huge volumes of atmosphere involved so energy density is lower), ground effect(lower frequencies bend around curves with vop gradients) , and tiny fraction of a wavelength(eg. energy sucking ferrite rod) antennae which can overcome the mismatch of the antenna size relative to the volume through which the huge wavelength energy is transmitted. On the other end you might be able to take advantage of the significant absorption minimum at visible blue light and get back roughly to line of sight. I think microwaves through miles of atmosphere is doomed from the get-go for power transmission because Earth has a lot of water in its air. Satellite microwave transmission might be able to establish short vertical microwave trips through the atmosphere to lose less power but you will then have serious safety issues for using it near humans. Radar technicians have a much higher rate of cataract development than the general population as is reported in this 1977 article( https://bjo.bmj.com/content/bjophthalmol/61/6/380.full.pdf)

There may be hope at the ELF spectrum using distributed active devices along a transmission line(a novel distributed Beverage antenna) or by returning to Tesla's large scale tuned circuits with huge capacitor balls or toroids atop slow-wave huge-dimension inductors to create passive resonators. All the ELF techniques are probably doomed to relatively large scale(and therefore high cost) if they are to handle significant power levels.

You could experiment yourself with visible blue light LED power transmission. Let us know what powers you reach over what distances. Someday, some beyond Terahertz tech may make this one worthwhile.

____________

thewildotter

Much of Tesla's files were lost or classified as "lost" or simply classified,but from the little that has been discovered,he was trying to use the earth's magnetic field,or the ionosphere as a carrier for the power.

Does anyone know what he was up to? Is the idea feasible? What was he thinking?Much of his work was kept in his head, after some documents were lost in a fire,and Marconi stole his radio transmission notes and was credited with the first transatlantic radio broadcast. Marconi's patent was later taken away and given to Tesla, but too late to help him; it was 6 months after he died.

I tried to edit this post to make the correction of Marconi,instead of Morse,but the editing link would not make the change,even though the review of the edit was correct,it did not make the change,and there was plenty of time left to edit.

Schumann Resonance

Using the ionosphere as a carrier for power is mostly understood. The ground and the ionosphere are both conductive and thus form a spherical shell waveguide around the Earth. The main concept is not lost and you can read up by searching on Schumann resonance. You can perceive it (cheaply) by receiving ELF and analyzing "whistlers" from lightning. It is leaky depending on the frequency. It also means that nearly all of the human population is within that waveguide and therefore dangerously irradiated if you power it up on some global power grid scale. There is some chance of being able to draw energy from it by managing lightning discharges. This energy is solar driven and mostly generated triboelectrically and by electrohydrodynamic mechanisms. This "free energy" is not easy to intercept on any reliable basis or we would be doing it. Some speculate that HAARP and other research projects had a gleam in their eye toward harnessing it. It is inherently on a global scale. Some believe that Tesla had these mechanisms figured out to some degree more than his peers. The fact that Tesla had three phase power figured out lends some credence to these speculations. There may be important nuances that Tesla had grasped which WERE lost or just poorly understood. I buy into this to some degree and believe that they involve better awareness of the phase sensitivities resonators exhibit as stored power increases. That is, a fixed specific frequency for resonance is a red herring which detracts from focusing on the better control parameter to use which is phase (phase tracking is used in phase locked loops, etc.)

_______________

thewildotter

Nothing new here, Back in the 1960's I read an article in Scientific American where they placed the forerunner of a quad copter above a microwave dish and beamed enough power to the receiver to keep the aircraft aloft at a considerable height.

I wish I still had the magazines from way back where they explored homopolar generators, super conductors and all thing interesting. Anybody got the old copies?

Not exactly what Tesla had envisioned from my reading, but definitely a game changer for remote areas of the world.