Extraterrestrial high-tech
This paper tries to show some of the possible ways the aliens' apparatuses could be built.
The flying saucers are spaceships without a jet engine. One can suppose that the principle of the saucer's engine is as follows: The engine has the form of a cross. Alternating current flows through the vertical conductor of the cross and divides into three directions in its center.
The current in the vertical conductor generates a magnetic field. The currents in the horizontal conductors flow in opposing directions and their magnetic fields compensate. Ampere's force influences the horizontal conductors of the cross from the vertical conductor's magnetic field's direction. This force moves the engine forward.
We have created a working model of such an engine in our laboratory. A powerful source of high frequency alternating current is necessary for the engine's feeding. One might suppose that the aliens get the current from the vacuum (ether).
What is ether? In our laboratory a system of hypothesizes on the crystal-like ether structure has been created. We call the ether 'nanoworld'. The nanoworld is a hypothetical carrier of electromagnetic waves, the linear sizes of its elements are 10 to the -35th power meters.
The nanoworld has inner energy. Its concentration is formula, which is 93-96 orders more than in nuclear fuel.
The structural elements of the ether are active, having a special form of inner energy (rotary). And the most important - it can be transformed into the wave-like electromagnetic form, accessible to us.
We think that the inner energy of the nanoworld can be transformed into the energy of UHF-waves using high quality conducting and dielectric resonators of a special form. Such resonators have been invented in our laboratory. Among them one might note the flat-sided and curve-sided figures with axis symmetry.
A characteristic representative of the first group is the precise diamond cutting, of the second - a sphere, modulated by a screw-like spiral. The common property of these forms is the formation of a system of standing waves in different phases. Supposedly, such a difference of the phases allows creating a gradient of the nanoworld's inner energy. A part of the nanoworld elements' rotary energy transforms into the energy of their oscillations in antinodes. Hence, the level of inner energy in the antinodes' neighborhoods is lower than the average.
Contrariwise, in the area of the nodes the rotary energy is above the average level. Placing the nodes of one standing wave against the antinodes of another standing wave we create conditions for the equalization rotary energies of the nanoworld's elements.
As a result of the equalization, a part of the rotary energy transforms into oscillations. Although we have not yet managed to generate energy in this way, the received results allow ground for optimism.
One of the main problems in creating a microwave energy source is the choosing of the form for resonators. It turned out that the forms and structures of our energy transformers and engines are constantly reproduced in traditional ornaments and adornments, in architecture details and whole buildings (primarily temples), in the elements of trellises and fences, ceremonial clothes, objects of cult, gods' attributes and in the letters of Greek and Cyrillic alphabets... In short, in an immense number of things and pictures, most of them ritual, magical or decorative. It is also known that these last ones have had their own sacral meaning, which was forgotten later. And here a question is bound to arise: what, if such forms were given birth to by real counterparts - UHF-transformers of aliens, who visited Earth in the ancient times?
Let us allow that the portable energy sources were interpreted by our ancestors as magical rods, their flying apparatuses as flying carpets, etc. In the popular film "Remembering the future" a straw airplane, copied by the aborigines from an American bomber, is shown. Why are aliens' ships worse?
As it is known, we live in the galaxy's suburbs. Therefore, the aliens would decide to visit Earth only if they were able to travel with super-light speeds. Is it possible? We think that it is.
If you place sound (a microworld process) into a container made of microworld elements and put the container into a jet airplane, the sound will move with a supersonic speed. Similarly, if a microworld process (an electromagnetic wave, an encircled electromagnetic wave-electron, an atom, a molecule) is put into a container made from nanoworld elements and speed it up with a nanoworld engine, it will be able to reach a super-light speed, because the nanoworld structure has a higher rigidity than the microworld structure and transmits perturbations with super-light speed. Now let us consider the aliens' weapons, starting with the defensive ones.
The aliens' armor differs significantly from the Earthlings' armor; it does not detain the projectile using matter, melting and evaporating the bullet or shell with a microwave field instead. Thus, the armor is in fact the nearfield of a microwave resonator.
Nowadays many matters are being heated, melted and evaporated in microwave heaters. In particular, most metals can be melted this way. The speed of heating, melting and evaporating depends on the power transmitted to the heated object. Let us consider the scheme and the principle of functioning of the attacking weapon of the aliens - the Neptune's trident.
The trident is a combination of a microwave resonator and a sharp ond of the conductor, emitting a flow of ions. It is known that a sharpened end of a conductor emits ions. An example of a static air ionizer is the Chizhevski lustre. The flow of ions looses its speed a few centimeters away from the sharp point of the Chizhevski lustre.
In the trident the flow of ions is pulsing, because it has been modulated by high frequency oscillations. The pulsing flow of ions, streaming from the trident's spike, resonates with the electromagnetic waves, spreading in the same direction as the flow of ions. This process is very similar to the process, taking place inside of a magnetron. In a magnetron the energy of a pulsing electron ray is transformed into the energy of electromagnetic oscillations.
Contrariwise, in the trident the energy of the electromagnetic wave supports the pulsation of the ion ray. As a result of such a support, the ion ray is not extinguished as in the Chizhevski lustre, keeping its structure unaltered for a long distance (hundreds of meters in atmosphere and millions of kilometers in vacuum).
The power of ion-microwave rays formed by the tridents depends on the power of the trident's energy source.
For the meter-diapason tridents the power reaches 10 kilowatts. For the decimeter-diapason tridents it reaches 100-300 kilowatts. For the centimeter-diapason tridents with energy sources consisting of hundreds of crystalline elements it reaches 10 megawatts.
Such a trident can be used to take ground samples, evaporating the tested material for further spectral analysis.
A powerful ray can cut the rocks, creating tunnels in the mountains. In the open space the ray of a trident or a more powerful apparatus received by its rotation, i.e. firework-vase can clear the space from meteors on the way of the starship.
Thus, we see that the extraterrestrial technology can be understood from the point of view of modern physics.
Literature
1. A microwave engine A. Kushelev, S. Polischuk, E. Nedelko, D. Kozhevnikov and S. Pisarzhevsky AIRCRAFT ENGINEERING AND AEROSPACE TECHNOLOGY: Volume 72, #4, 2000, pp. 365-366, © University Press, ISSN 0002-2667
2. An ecologically pure source of energy (in print).
Legends to the figures:

Fig.1. The principle of working of the microwave engine.

Fig.2A. The nanoworld's structure in orthogonal projection.

Fig.2B. The nanoworld's structure in hexagonal projection.

Fig.3. Some cult forms, having resonator properties.

Fig.4. Some cult forms, having the form of the Neptune's trident.