ULF waves seem to have extraterrestrial sources (they seem to “result from interactions between plasma emitted from the sun (solar wind) and the Earths [magnetic] field”). Geomagnetic pulsations were first observed by Balfour Stewart in 1859, and he published his findings in 1861. Some people are interested in the sounds produced by ULF waves, VLF waves (very low frequency), and ELF waves (extremely low frequency). There is also speculation and research into the possibility that micropulsations may have an affect on peoples health and on womens menstrual cycles.
The electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength. All electromagnetic waves travel at the speed of light (c = 3.0 × 108 m/s) in a vacuum. There seem to be no upper and lower limits to the frequency or wavelength of electromagnetic waves and no gaps in the spectrum. However, electromagnetic waves have been observed with incredibly long wavelengths — these waves are known as ultra low frequency (ULF) waves, or micropulsations. Since frequency and wavelength are inversely proportional (v = fλ, for electromagnetic waves c = fλ), the name “ultra low frequency”is equivalent to “ultra long wavelength” — although nobody refers to them as such. The range of wavelengths which refer to ULF waves is disputable, and different sources cite different ranges. The consensus seems to be that the wavelength of the longest electromagnetic wave is in the range from 106 to 1011 M. However, it is not impossible to discover a wave with a wavelength approaching infinity.
Electromagnetic Waves:
Electromagnetic waves are light waves. They are transverse in shape and able to travel through the vacuum of space. Electromagnetic waves include waves like light waves, X-rays and radio waves.
The Sun is the dominant source for visible-light waves our eyes receive. The outer-most layer of the Suns atmosphere, the corona, can be seen in visible light. But it is so faint it cannot not be seen except during a total solar eclipse because the bright photosphere overwhelms it. The photograph below was taken during a total eclipse of the Sun where the photosphere and chromosphere are almost completely blocked by the moon. The tapered patterns—coronal streamers—around the Sun are formed by the outward flow of plasma that is shaped by magnetic field lines extending millions of miles into space.
All electromagnetic radiation is light, but we can only see a small portion of this radiation—the portion we call visible light. Cone-shaped cells in our eyes act as receivers tuned to the wavelengths in this narrow band of the spectrum. Other portions of the spectrum have wavelengths too large or too small and energetic for the biological limitations of our perception.
Laser altimetry is an example of active remote sensing using visible light. NASAs Geoscience Laser Altimeter System (GLAS) instrument onboard the Ice, Cloud, and land Elevation Satellite (ICESat) enabled scientists to calculate the elevation of Earths polar ice sheets using lasers and ancillary data. Changes in elevation over time help to estimate variations in the amount of water stored as ice on our planet. The below shows elevation data over the West Antarctic Ice Streams.
Close examination of the visible-light spectrum from our Sun and other stars reveals a pattern of dark lines—called absorption lines. These patterns can provide important scientific clues that reveal hidden properties of objects throughout the universe. Certain elements in the Suns atmosphere absorb certain colors of light. These patterns of lines within spectra act like fingerprints for atoms and molecules. Looking at the Suns spectrum, for example, the fingerprints for elements are clear to those knowledgeable about those patterns.
FAQ
What is the longest wavelength light?
As the full spectrum of visible light travels through a prism, the wavelengths separate into the colors of the rainbow because each color is a different wavelength. Violet has the shortest wavelength, at around 380 nanometers, and red has the longest wavelength, at around 700 nanometers.
Is radio the longest wavelength?
What are the wavelength from longest to shortest?
What is the longest wavelength of EM radiation?
