Invisible space

Had we excited the elements passively by an incident plane wave, the entire scan range would be limited to be between = 0(0°) and Sx = 1 ( 90°). However, if we instead excite the array actively by driving the elements by individual voltage generators, the scan range can be extended into the imaginary (or invisible) space. 

Every time we are inside one of the unit circles, we are in visible space where we observe propagating modes. When outside, we are in invisible space where the modes are evanescent. For more about the grating lobe diagram, see reference 61. 

Note also that as we continue into the invisible space for... 

In some cases, miners use deictic expressions (here, there, etc.) that point to invisible spaces. In these cases, we can only speculate that miners are using gesture to indicate spatial relationships, air flow, curtains, and structural support (timbers) in their testimony ... 

There are several ways to deal with this problem. The simplest in concept is to use liquid imbibed particles that are uniform in structure, such as sugar cubes [12, 13] as already mentioned above. To my knowledge, this has never been done for structure studies. The second is to use NMR-invisible particles, for example, glass, and fill the spaces between the particles with a liquid such as water that can be imaged. The third is to use the usual radially heterogeneous particles and then use software to calculate the parameters. One first determines the centers of each particle and then decides whether the particles are in contact with each other or not by the distances between the centers [14]. 

In office buildings it is very common to have plenums, i.e. spaces above rooms where the air handling system is located, together with electrical wires and cables, as well as abundant wood and other construction materials. These concealed spaces are usually ca. 1 m (3 ft) high and are invisible from the room below. 

Gases are composed of tiny, invisible molecules that are widely separated from one another in empty space. 

Methane has an invisible flame and can be explosive in a closed space such as a fuel tank although it is less flammable than gasoline and results in less severe fires when ignited. Colorants may be added to help identify the flame and baffles or flame arresters at the opening of the tank can be used to repress the accidental ignition of methanol vapors. 

In search of such universality, a language of light must be developed which is common to all forms of electromagnetic radiation, whether they are visible or invisible, reducing colour to a reality which is not coloured, expressed in terms of space, time or energy. 

Kanada, a Nyaya-Vaisheshika philosopher, who lived -600 BCE, considered that matter was composed of four types of atoms, earth, fire, air, and water. Atoms reacted with the aid of an invisible force (adrsta) to form biatomic molecules and triatomic molecules (6-8). He stated that there were five elements earth, fire, air, water, and space. Each atom also had qualities such as odor, taste, color and a sense of touch (S). 

A greenhouse gas is any component of tbe atmosphere that allows visible solar radiation to reach the Earth s surface but prevents invisible infrared radiation (beat) from escaping back into outer space. This mimics the warming action of a greenhouse. If it were not for the atmosphere s greenhouse effect, Earth s average surface temperature would be a chilly -i8°C. 

There it is, the story of the main events in evolution, shrouded in nebula as is the black hole at the center of our galaxy. We can know it is there by the way it pulls in stars and gases as it bends space into a whirlpool of gravity, and we know that the evolutionary events were there by the way they spew finished creatures from an invisible past without much warning and with their origin hidden from our view. 

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