Will this solve the mystery of the expansion of the universe?

The universe was created by a giant bang; the Big Bang 13.8 billion years ago, and then it started to expand. The expansion is ongoing: it is still being stretched out in all directions like a balloon being inflated.

Metamaterial tiles boost sensitivity of large telescopes

A multi-institutional group of researchers has developed new metamaterial tiles that will help improve the sensitivity of telescopes being built at the preeminent Simons Observatory in Chile. The tiles have been incorporated ...

The uncertainties in measuring cosmic expansion

Ninety years after Edwin Hubble discovered the systematic motions of galaxies and George Lemaitre explained them as cosmic expansion from a point using Einstein's equations of relativity, observational cosmology today is ...

Microwaving new materials

Microwave ovens are the mainstay of cooking appliances in our homes. Five years ago, when Reeja Jayan was a new professor at Carnegie Mellon University, she was intrigued by the idea of using microwaves to grow materials. ...

The cosmic confusion of the microwave background

Roughly 380,000 years after the Big Bang, about 13.7 billion years ago, matter (mostly hydrogen) cooled enough for neutral atoms to form, and light was able to traverse space freely. That light, the cosmic microwave background ...

Tracer galaxies probe the cosmic background

The universe, perhaps surprisingly, is not comprised of galaxies randomly distributed throughout space; that is, it is not very homogeneous. Instead, its galaxies are clustered into distinct structures, typically gigantic ...

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Microwave

Microwaves are electromagnetic waves with wavelengths ranging from 1 m down to 1 mm, or equivalently, with frequencies between 0.3 GHz and 300 GHz.

Apparatus and techniques may be described qualitatively as "microwave" when the wavelengths of signals are roughly the same as the dimensions of the equipment, so that lumped-element circuit theory is inaccurate. As a consequence, practical microwave technique tends to move away from the discrete resistors, capacitors, and inductors used with lower frequency radio waves. Instead, distributed circuit elements and transmission-line theory are more useful methods for design and analysis. Open-wire and coaxial transmission lines give way to waveguides, and lumped-element tuned circuits are replaced by cavity resonators or resonant lines. Effects of reflection, polarization, scattering, diffraction and atmospheric absorption usually associated with visible light are of practical significance in the study of microwave propagation. The same equations of electromagnetic theory apply at all frequencies.

While the name may suggest a micrometer wavelength, it is better understood as indicating wavelengths very much smaller than those used in radio broadcasting. The boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary and are used variously between different fields of study. The term microwave generally refers to "alternating current signals with frequencies between 0.3 GHz (3×108 Hz) and 300 GHz (3×1011 Hz)." Both IEC standard 60050 and IEEE standard 100 define "microwave" frequencies starting at 1 GHz (30 cm wavelength).

Electromagnetic waves longer (lower frequency) than microwaves are called "radio waves". Electromagnetic radiation with shorter wavelengths may be called "millimeter waves", terahertz radiation or even T-rays. Definitions differ for millimeter wave band, which the IEEE defines as 110 GHz to 300 GHz.

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