The cause of the phenomenon 'plasma is generated when grapes are microwaved in the microwave' finally reveals

Plasma emission will occur if you ginch in a microwave grape cut in half with a little leather connected. Although this phenomenon was observed, the researcher investigated while destroying 12 microwave ovens that the cause was not elucidated so far.

Linking plasma formation in grapes to microwave resonances of aqueous dimers
https://www.pnas.org/cgi/doi/10.1073/pnas.1818350116

The wrath of grapes: A tale of 12 dead microwaves and plasma-spewing grapes | Ars Technica
https://arstechnica.com/science/2019/02/these-scientists-broke-12-microwaves-to-learn-how-grapes-create-plasmas/

The state of plasma generation when grapes are placed in a microwave oven can be confirmed from the following movie. You can see how plasma is generated from around 1 minute and 40 seconds.

Grape + Microwave = Plasma - YouTube


Place the transparent glass on the grape cut in half with a little skin tied and put it in the microwave oven.

Then the grapes glow.

The light of the plasma fluctuates in the glass.

Although the phenomenon of "plasma is generated when a grape that bisects and leaves a little bit of glued in a microwave oven is generated" is well known in the scientific community, the reason why plasma is generated is clear I did not. So research teams such as Aaron Slepkov and Hamza Khattak of Trent University in Canada have investigated this cause.

In order to confirm this phenomenon, researchers were forced to reshuffle the microwave oven first. I removed the door so that the state inside could be confirmed firmly, some holes were opened in the main body of the microwave oven, and it was covered with a mesh so that electromagnetic waves do not leak from the hole. However, if you operate a microwave oven with mostly "grapes" in it, the unabsorbed radiation will damage the microwave oven itself, so 12 microwave ovens will break in the course of this experiment, "We have a" microwave graveyard "in the lab," Khattak said.

Generally "Reason why plasma is generated when graping is done" was that electromagnetic waves were concentrated in the tissues of very small grapes and charged ions were generated when several molecules were torn. In the electromagnetic field generated in the microwave oven, at least initially the ion will flow through the skin to which it is connected and flow from half of the grape to the other half, but after a while it is released into the air to generate plasma light .

In this hypothesis, half of the grapes have a role like an antenna, and the current is explained as flowing through a connected "bridge of leather". However, as a result of new experiments, it was shown that "bridges of the leather" are not necessarily required for plasma generation, and need not necessarily be grapes in the first place.

Infrared images and computer simulations were used in the new research, but Pablo Bianucci of the University of Concordia who was in charge of computer simulation explained that the plasma is generated as a pure bulk effect from the electromagnetic " hot spot " .

Grapes have a suitable refractive index and size to capture electromagnetic waves, so if you put the halved grapes close together, it seems that hot spots will concentrate energy between the two. Grapes rather than antennas, like a trombone to amplify the vibrations that with . The trombone amplifies only the oscillation of a specific wavelength and suppresses other wavelengths when sound is generated, but the same thing happens even in grapes put in a microwave oven. The electromagnetic waves amplified in two grapes cut in half are concentrated in one hot spot, and when atoms and molecules are heated in this hot spot and electrons can not be held, plasma light is emitted about.

As a result of repeated experiments and observations, researchers have discovered that it can occur not only in grapes but also in currant fruits and large black berries, quail eggs, hydrogel beads and the like. The size of grape size is optimum for making hot spot which amplifies electromagnetic waves and concentrates extremely.