Not only is our sun very beautiful, it is also marvelously huge and very, VERY powerful. It's light is so intense that, even 93 million miles away from it, staring even a little while directly at the sun can make you temporarily blind, with a chance of permanent eye damage. You remember the mean kid on the playground with the magnifying glass trying to burn ants...? Well, the lens of the eye will do an even more effective job of destroying the retina, if sunlight (even sunlight from 93 million miles away) is allowed to be focused upon it.
I've written a lot lately about different aspects of light. Now I'd like to show some scientific facts about the ultimate material light givers, THE STARS, starting with our sun. But the study of our nearest star (Sol) won't be done from far away, we will take a look up-close.
S O L
Photo showing the Sun in X-ray wavelengths of red at 284 Angstroms.
"An ångström or angstrom (symbol Å) (pronounced /ˈæŋstrəm/; Swedish: IPA: [ˈɔ̀ŋstrœm]) is a non-SI unit of length that is internationally recognized, equal to 0.1 nanometre (nm). It can be written in scientific notations as 1×10−10 m (normalized notation) or 1 E-10 m (exponential notation) — both meaning 1/10,000,000,000 metres. It is sometimes used in expressing the sizes of atoms, lengths of chemical bonds and visible-light spectra..."
More about Angstroms.
Solar Hinode Images
"Hinode (Sunrise) is a project to study the Sun, led by the Japanese Aerospace Exploration Agency (JAXA) in collaboration with NASA, the Science and Technology Facilities Council (STFC), and the European Space Agency (ESA). Hinode's three year mission is to explore the magnetic fields of the Sun, and improve our understanding of the mechanisms that power the solar atmosphere and drive solar eruptions."
More about Hinode.
THE DIFFERENT WAVELENGTHS OF SOLAR LIGHT
Solar Flares X-ray - the Sun at 19.5nm
"An X-ray (or Röntgen ray) is a form of electromagnetic radiation (light) with a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequencies in the range 30 PHz to 30 EHz."
More about X-rays.
Solar Flares Ultraviolet
"Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft X-rays. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet (purple)."
More about Ultraviolet.
Solar Flares Infrared
"Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of microwaves. The name means 'below red' (from the Latin infra, 'below'), red being the color of visible light with the longest wavelength. Infrared radiation has wavelengths between about 750 nm and 1 mm, spanning five orders of magnitude. Humans at normal body temperature can radiate at a wavelength of 10 microns."
More about Infrared Radiation.
The presentations and definitions above start to give you an idea about how complex the idea of light really is.
Generally speaking, gravity is thought to be a rather weak force - some billion, billion, billion times weaker than the electromagnetic (EM) force. But stars are massive gravity machines. They have a gravity so strong that even the explosions upon their surfaces - equal to billions of hydrogen bombs going off continuously - can barely for matter out into space. And deep inside the pressures of gravity pulling in and light pushing out actually force atoms to fuse becoming ever-more massive atoms (higher and higher numbered elements on the periodic table).
Let's look inside the sun...
THE SUN'S INTERNAL STRUCTURE
The Inner Core
"The innermost layer of the sun is the core. With a density of 160 g/cm^3, 10 times that of lead, the core might be expected to be solid. However, the core's temperature of 15 million kelvins (27 million degrees Fahrenheit) keeps it in a gaseous state."
The Radiative Zone
"Throughout this region of the solar interior, energy, in the form of radiation, is transferred by its interaction with the surrounding atoms. In the radiation zone of the Sun the temperature is a little cooler than the core and as a result some atoms are able to remain intact."
The Convection Zone
"This is the area that we consider to form the outer shell of the Sun. The atoms in this layer of the Sun have electrons because the temperature is not hot enough to strip them away like it is in the core (15.6X 106 K as opposed to 2 million K). Atoms with electrons are able to absorb and emit radiation, making this region more opaque, like a thick fog."
Subsurface Flows
"Gas on the Sun's surface has been observed to flow away from the equator towards both poles. If the same flow persists to great depths, it could play an important dynamical role in the eleven-year sunspot cycle, by carrying the magnetic remnants of the sunspots to high latitudes."
Photosphere
"As we look down into the atmosphere at the surface of the Sun the view becomes more and more opaque. The point where it appears to become completely opaque is called the photosphere. Thus, the photosphere may be thought of as the imaginary surface from which the solar light that we see appears to be emitted."
Chromosphere
"The chromosphere is 2000-3000 km thick. It glows faintly relative to the photosphere and can only be seen easily in a total solar eclipse. When it can be seen it is reddish in color (because of strong Balmer H-alpha emission). This color is the origin of its name (chromos meaning "color'')."
Corona
"During a total eclipse of the Sun, when for a few minutes the Moon completely covers the Sun's face, a glow appears around the darkened Sun--the solar corona, the Sun's outermost atmosphere. Structures visible in the corona at such times suggest that they are shaped by magnetic fields, and therefore, that the corona consists of plasma. "
Eclipse revealing the sun's corona.
There are other particles that the sun produces...
Gamma Rays
"In the core, fusion reactions produce energy in the form of gamma rays and neutrinos. Gamma rays are photons with high energy and high frequency. The gamma rays are absorbed and re-emitted by many atoms on their journey from the envelope to the outside of the sun. When the gamma rays leave atoms, their average energy is reduced. However, the first law of thermodynamics (which states that energy can neither be created nor be destroyed) plays a role and the number of photons increases. Each high-energy gamma ray that leaves the solar envelope will eventually become a thousand low-energy photons." *
Neutrinos
"The neutrinos are extremely nonreactive. To stop a typical neutrino, one would have to send it through a light-year of lead! Several experiments are being performed to measure the neutrino output from the sun. Chemicals containing elements with which neutrinos react are put in large pools in mines, and the neutrinos' passage through the pools can be measured by the rare changes they cause in the nuclei in the pools. For example, perchloroethane contains some isotopes of chlorine with 37 particles in the nucleus (17 protons, 20 neutrons). These Cl-37 molecules can take in neutrinos and become radioactive Ar-37 (18 protons, 19 neutrons). From the amount of argon present, the number of neutrinos can be calculated." *
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Please check back for the next post about light. :)
A L E X * W A L L
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