BLACK HOLE

   black holes

  By their very nature, black holes are black.  This is the first image of a black hole since April 2019.  Light forms a bright circle that rotates around a black hole under intense gravity, which is 6.5 billion times wider than our Sun.  This black hole is at the center of the galaxy M87, 55 million light years from Earth.  Photo courtesy of Event Horizon Telescope.

  What are black holes?

  Black holes have such strong gravity that nothing, not even light, can escape them.  That's why black holes are black.  We cannot see them directly.  But we can see how black holes affect the space around them.  Black holes can be as large as millions or billions of stars.  Or they could be as small as a few stellar masses that are crushed at high densities during supernova explosions.  And last year we learned that there are intermediate mass black holes.  In addition, there may be micro-black holes.

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  From theory to reality

  In his general theory of relativity since 1915, Albert Einstein was the first to suggest that our universe consists of such strange, dense, massive objects.  As a natural consequence of massive star deaths and falls, black holes emerge from Einstein's general relativity equation.  In 1916, German mathematician Carl Schwarzschild was the first to mathematically create black holes.  Theoretical physicist John Wheeler first named the black hole many years later, in 1967.

  Until the 1970s, black holes were only mathematical curiosity.  Then, in 1971, scientists discovered the first physical black hole, the Cygnux X-1.

  Stellar massive black holes

  We know of three types of black holes.  The first is the so-called stellar mass black hole.  These are the remnants of huge stars.  When, at the end of its life, a star about five times the mass of our Sun explodes as a supernova, gravity suddenly and violently compresses its center.

  Depending on the mass of the star, it could stop falling and become a neutron star.  But if its mass is sufficient, the core will continue to break, forming a black hole.  Stellar mass black holes range from at least five times the mass of our Sun to about 60 times the mass of the Sun.  They are usually between 10 and 30 miles (16-48 km) in diameter.

  Artist's concept of Science X-1.  Astronomers believe that Cygnus X-1 is a typical stellar black hole in the binary star system.  Cygnus X-1 was once a star before falling into a black hole.  The reason we can detect a black hole is that it is its companion, a blue supergiant variable star named HDE 226868.  Image via ESA / Wikimedia Commons.

  Medium black holes

  Scientists have announced the discovery of a medium-sized black hole in 2021.  This type of black hole bridges the gap between small, large star-shaped black holes and supermassive black holes hidden in the center of galaxies.  The newly discovered "Gold Locks" black hole has a volume of 55,000 suns.  Astronomers have discovered the middle black hole by locating something far behind it: a gamma-ray signal.  The gravitational lens of the burst emission sent scientists into a medium-sized black hole.

  Intermediate mass black holes, larger than those formed by individual stars - but smaller than the supermassive at the centers of galaxies - should theoretically exist.  Astronomers say they have discovered a gamma-ray burst that has been lensed by a black hole in terms of gravity.  In this diagram, the gamma ray burst is shown on the right.  At the center, a large black hole is acting as a beam of light emitted by gamma rays.  Photo by Carl Knox / Oz Grow / University of Melbourne.

  Massive black holes

  The third type of black hole is the supermassive black hole.  They can contain billions of suns.  Astronomers believe that most galaxies have large black holes at their centers.  At the center of our own Milky Way galaxy, Sagittarius A *, is about 4 million times the mass of our Sun and has a diameter of about 37 million miles.

  Another example of a supermassive black hole is in the center of the quasar called TON 618.  Its central black hole is estimated to be 66 billion solar masses.  Huge black holes could have formed from large collapsing clouds of interstellar hydrogen in the early history of the universe, although their origins are not clear and this is an area of ​​very active research.  They may also have accumulated extra mass on Evans by merging with other black holes.

  The artist's imagination represents the atmosphere of a large black hole in the heart of many galaxies.  The black hole is surrounded by a magnificent action disc of very hot, falling material and dusty torus (donut-shaped ring).  Black hole poles often carry high-speed jets of material that can travel very long distances in space.  Image via ESO / Wikimedia Commons.

  The fourth type of black hole

  There could be another type of black hole, a micro black hole.  These stars will be smaller in size than black holes.  So far, they are still fictitious, and no one's existence has been proven.

  What's inside a black hole?

  By definition, we cannot observe what is inside a black hole, because no light - no information of any kind - can escape.  But astronomical theories suggest that, at the center of a black hole, the mass of all black holes is concentrated in a small point of infinite density.  This point is known as unity.

  This is the point - this uniformity - that creates the incredibly strong gravitational field of the black hole.  Note, however, that uniformity does not exist.  This is because all known physics breaks down in extreme conditions at the center of a black hole, where quantum effects undoubtedly play a large part.  Since we do not yet have a quantum theory of gravity, it is impossible to say what is actually at the center of the black hole.

  Black hole boundaries

  The extent of the black hole is its event horizon.  This is not a physical edge.  It is just a point in space beyond which it is impossible to escape the gravity of the black hole.  Once anything falling into a black hole passes through the horizon of the event, it can never leave the black hole again.  It inevitably and inevitably pulls towards the center of the black hole.  Within the event horizon, any solid object explodes under intense gravity and its component is reduced to subatomic particles.  On the horizon of the event, the speed of escape of the black hole reaches the speed of light.

  Observation of black holes

  Without emissions from black holes, scientists can only observe the effects of their gravity on nearby objects in space.  If there are stars or gases near the black hole, it is actively "feeding" them.  That is, a black hole can pull material from nearby objects.  In that case, there would be an action disk in the black hole.  This is where the matter moves inward before the black hole eats it, like water in a drain.  The action disk can rotate at a significant percentage of the speed of light: friction between the particles colliding in the disk raises its temperature to millions of degrees, which produces large amounts of X-rays which can be detected by special binoculars.  Is.

  In April 2019, the Event Horizon Telescope Project revealed for the first time a live image of a black hole, the supermassive black hole at the center of the giant elliptical galaxy M87.  A global array of radio telescopes captured the image.  This undoubtedly shows that there are black holes.  Scientists were able to directly test the general relativity models of the black hole's behavior and found that the M87's black hole is very accurate.

  Picture of the Hubble Space Telescope, a jet-powered jet from the center of the Galaxy M87.  The jet consists of electrons and other subatomic particles that travel at approximately the speed of light.  Photo by Hubble Heritage Team (STScI / AURA) / NASA / ESA / esahubble.org.

   A black hole is an area of ​​space in which the field of gravity is so strong that nothing, even light, can escape it.  Black holes come in three sizes, possibly four.

FOOD

 Food is any substance that is used to nourish an organism.  Food is usually made from plants, animals, or fungi, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals.  Matter is eaten by an organism and is absorbed by the cells of the organism to provide energy, sustain life, or stimulate growth.  Different species of animals have different eating behaviors that meet their unique metabolism requirements, which are often designed to fill a specific ecological space within a specific geographical context.

     Display of different foods

     Omnivorous humans are highly adaptable and have adapted to food in many different ecosystems.  Historically, humans have received food in two main ways: hunting and gathering, and agriculture.  As agricultural technology progressed, humans adopted an agricultural lifestyle with food according to the geographical opportunities in their geography.  Geographical and cultural differences have led to the creation of many foods and cuisines, including a wide range of ingredients, herbs, spices, techniques and dishes.  As cultures have merged through forces such as international trade and globalization, ingredients have become more widely available than their geographical and cultural origins, leading to a cosmopolitan exchange of different food traditions and practices.

     Today, much of the food energy needed by the world's ever-growing population is supplied through the industrial food industry, which produces food with extreme agriculture and distributes it through complex food processing and food distribution systems.  ۔  This conventional agricultural system relies heavily on fossil fuels, which means that food and agricultural systems are one of the major contributors to climate change, accounting for 37% of total greenhouse gas emissions.  [1] The carbon footprint of the food system and food waste are important measures to mitigate the global response to climate change.

     The food system has significant effects on a wide range of other social and political issues, including: sustainability, biodiversity, economics, population growth, water supply, and access to food.  The right to food is a human right derived from the International Covenant on Economic, Social and Cultural Rights (ICESCR), which includes "the right to a decent standard of living, including adequate food" as well as the "fundamental right to liberty".  Has been recognized.  "Because of these fundamental rights to hunger, food security is often a priority international policy activity. For example, Sustainable Development Goal 2" Zero Hunger "aims to end hunger by 2030. Food Safety and Food Security  Supervised by international agencies such as the International Association for Food Protection, the World Resource Institute, the World Food Program, the Food and Agriculture Organization, and the International Food Information Council.  And Drug Administration.

     Definition and rating

     Food sources

     Classification and food types

     Taste perception

     Original article: Taste

     Animals, especially humans, have five different tastes: sweet, sour, salty, bitter and imami.  As animals have evolved, the flavors that provide the most energy (sugar and fat) are most pleasant to eat while others, such as bitter ones, do not enjoy. [84]  It is important for survival, it has no taste.  On the other hand, fats, especially saturated fats, are thick and rich and are therefore considered more palatable.

     sweet

     Structure of sucrose

     Commonly known as the sweetest taste, sweetness is almost always caused by a type of simple sugar such as glucose or fructose, or disaccharides such as sucrose, a molecule that combines glucose and fructose. [86]  Complex carbohydrates are long chains and thus do not taste sweet.  Artificial sweeteners such as sucrose are used to mimic sugar molecules, creating a sweet feeling without calories.  Other types of sugar include raw sugar, which is known for its amber color because it is unprocessed.  As sugar is essential for energy and survival, sugar tastes good.

     The stevia plant contains a compound called steviol which, when extracted, is 300 times sweeter than sugar and has a minimal effect on blood sugar. [87]

     Sour

     Sourness is caused by the taste of acid, such as vinegar in alcoholic beverages.  Sour foods include lemons, especially lemons, lime and, to a lesser extent, oranges.  Sour is important for evolution because it symbolizes a food that can be spoiled by bacteria. [88] However, many foods are slightly acidic, and help stimulate taste buds and enhance flavor.  Do

     Salty

     Salt dunes in Bolivia

     Salinity is the taste of alkali metal ions such as sodium and potassium.  It is found in almost every food in moderate amounts to enhance the taste, although eating pure salt is considered extremely unpleasant.  There are many different types of salt, each with varying degrees of salinity, including sea salt, fluoride salt, kosher salt, mining salt, and gray salt.  In addition to enhancing the taste, it is important that the body needs and maintains a delicate electrolyte balance, which is the function of the kidneys.  Salt can be iodized, meaning it contains iodine, an essential nutrient that promotes thyroid function.  Some canned foods, especially soups or packaged soups, have high salt content to keep food safe for longer.  Historically, salt has long been used as a preservative for meat, as it promotes water excretion.  Similarly, dry foods also promote food safety.

     Bitter

     Bitterness is a feeling that is often considered unpleasant, characterized by a sharp, pungent taste.  Without sweet chocolate, caffeine, lemon peel and some fruits are bitter.

     امامی

     This section is an excerpt from Imami.

     امامی

     Soy sauce, ripe tomatoes, and muesli are examples of foods rich in ingredients.

     Imami (/ uːˈmɑːmi / from Japanese: Japanese pronunciation: [ɯmami]), or flavor, is one of the five basic flavors.  It has been described as delicious and is characteristic of broths and cooked meats

     People taste amaranth through taste receptors that typically respond to glutamate and nucleotides, which are abundant in meat broths and fermented products.  Glutamate is usually added to some foods in the form of monosodium glutamate (MSG), and nucleotides are usually added in the form of inosine monophosphate (IMP) or guanosine monophosphate (GMP).  Because imams have their own receptors, rather than originating from a combination of traditionally recognized flavors, scientists now consider imams to be a distinct flavor.

     Foods with strong amami flavors include meat, shellfish, fish (including fish sauce and preserved fish such as Maldivian fish, sardines and anchovies), tomatoes, mushrooms, hydrolyzed vegetable protein, meat liqueur, yeast liqueur, cheese  And soy sauce.  .

HUMAN EYE

 Human eye

  The human eye, in humans, is the specialized sensory organ capable of receiving visual images, which are then transmitted to the brain.

  Cross section of human eye

  The eye is protected from mechanical injury by being enclosed in a socket, or orbit, which forms a four-sided pyramid with several bone parts of the skull, the top of which points to the head.  Thus, the floor of the orbit is made up of parts of the maxilla, zygomatic and palatine bones, while the roof is made of the orbital plate of the frontal bone and behind it, the short arm of the sphenoid.  The optic pharynx, the hole through which the optic nerve goes back to the brain and enters the orbit of the large eye, is towards the nostril.  The superior orbital fissure is a large hole through which large veins and nerves pass.  These nerves can carry non-visual sensory messages - such as pain - or they can be motor nerves that control the eye muscles.  There are other cracks and canals that carry nerves and blood vessels.  The eyeball and its active muscles are surrounded by a layer of orbital fat that acts like a cushion, allowing the eyeball to rotate smoothly around a fixed point, the center of rotation.  ۔  Protosis of the eyeballs is caused by the accumulation of fluid in the orbital fatty tissue in the exophthalmic goiter.

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  Human organs

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  Eyelids

  It is important that the front surface of the eye hair, the cornea, remains moist.  This is achieved through the lashes, which regularly wipe the surface of the tear glands and other glandular secretions during waking hours and which cover the eyes during sleep and prevent evaporation.  The reflex action of the eyelids in the lids has the added function of preventing injuries from foreign bodies.  The lids are basically layers of tissue that cover the front of the orbit and leave an almond-shaped aperture when the eye is opened.  Almond points are called canthi.  Near the nose is the inner canthus, and the other is the outer canthus.  The lid can be divided into four layers: (1) the skin, which contains glands that open at the marginal surface of the lid, and the eyelids;  (2) A layer of muscle consisting primarily of the orbicularis oculi muscle, which is responsible for closing the lid.  (3) A fibrous layer that gives the lid mechanical stability, its main parts are the tarsal plates, which are directly attached to the opening between the lids, called palpebral aperture.  And (4) the innermost layer of the lid, a part of the conjunctiva.  The conjunctiva is a viscous membrane that connects the eyeball to the orbit and the lids, but allows the eyeball to rotate considerably in orbit.

  Eyelash

  Upper and lower eyelids.

  Isra SU

  conjunctiva

  Conjunctivitis lines the lids and then bends back to the surface of the hair follicles, forming an outer covering on the front of it and ending at the transparent area of ​​the eye, the cornea.  The part that lines the lids is called the palpebral part of the conjunctiva.  The part that covers the whites of the eye's hair is called the bulbar conjunctiva.  Between the bulbar and the palpebral conjunctiva are two loose, spare parts that return to the equator of the world.  These holidays are called upper and lower forensics, or conjunctival sacs.  It is the looseness of the conjunctiva in these places that makes the movement of the lids and eyeballs possible.

  Fibrous layer

  The fibrous layer, which gives the lid mechanical stability, is made up of thick, and relatively stiff, tarsal plates, which appear directly on the palpebral aperture, and a thinner palpebral fascia, or sheet of connective tissue;  Together they are called septum orbitals.  When the lids are closed, the entire septum is covered by this septum.  The two ligaments, the medial and lateral palpebral ligaments, connected to the orbit of the orbit and the septum, strengthen the position of the lids in relation to the globe.  The medial ligament is still strong.

  The muscles of the lids

  Closure of the lids is achieved by contraction of the orbicularis muscle, a single elliptical sheet of muscle extending from the forehead and facial areas and into the lids around the orbit.  It is divided into orbital and palpebral parts, and it is mainly the palpebral part, inside the lid, which causes the lid to close.  The palpebral portion passes through the lids through a ligament called the medial palpebral ligament and forms a band of fibers in a series of hemispheres to the neighboring bone of the orbit that meet outside the outer corner of the eye, the lateral kineths.  raphe.  The extra parts of the orbicularis are given different names - Horner's muscle and Revlon's muscle;  They come in close contact with the tear gas and help to drain the tears.  Revolving muscles, lying close to the edge of the lid, help keep the lids close.  The orbital part of the orbicularis is not usually associated with the eyelid, which can be done entirely through the palpebral part.  However, it has to do with closing the eyes tightly.  The skin of the forehead, temples and cheeks is then pulled towards the middle of the orbit (nose), and the rays produced by this process of the orbital part, eventually lead to the so-called well feet of the elderly.  .  It should be noted that both parts can be activated freely.  In this way, the orbital part can shrink, causing wrinkles in the eyebrows, which reduces the amount of light coming from above, while the palpebral part is relaxed and the eyes are left open.

  Opening of the eye is not only the result of inactive relaxation of the muscles of the orbicularis but also the effect of contraction of the levator palpebrae superioris muscles of the upper lid.  This muscle begins with the extravascular muscle at the top of the orbit as a narrow tendon and progresses to the upper lid as a wide tendon, the levator aponeurosis, which attaches to the anterior surface of the tarsus and covers the upper.  Skin  Lid.  Muscle contraction causes elevation of the upper eyelid.  The nerve connections to this muscle are closely related to the extracular muscles needed to lift the eye, so when the eye looks upwards, the upper eyelid converges and rises.

  The orbicularis and levator are striped muscles in voluntary control.  The lids also contain smooth (involuntary) muscle fibers that are activated by the sympathetic distribution of the autonomic system and widen the pelvic fissure (opening of the eye) by the height of the upper and the depression of the lower lid.

  In addition to the muscles described earlier, other facial muscles often assist in the process of closing or opening the lid.  Thus, the muscles of the corrugator supercilii pull the eyebrows towards the bridge of the nose, creating a characteristic trench in the forehead, forming a "roof" at the middle angle of the eye.  The roof is mainly used to protect the eye from sunlight.  The pyramid, or processor, muscles occupy the bridge of the nose.  They originate in the lower part of the nasal bones and are attached to the skin of the lower part of the forehead on either side of the midline.  They pull the skin into translucent skins.  When the lid is opened, the frontalis muscle rises high on the forehead, between the coronal sutures, a suture in the upper part of the skull, and the orbital border is attached to the skin of the eyebrows.  The contraction therefore causes the eyebrows to be raised and resists the action of the orbital part of the orbicularis.  Muscles are used especially when one looks upwards.  It is also practiced when vision is presented with difficulty either due to distance or lack of sufficient light.

  Quick

  The outermost layer of the lid is the skin, the characteristics of which are not very different from the skin of the rest of the body, with the possible exception of the large pigment cells, which, although found elsewhere, are very much in the skin of the lid.  Are  Cells can wander, and these are the movements of pigment cells that determine color changes in some people as health changes.  The skin contains sweat glands and hair.  As the connection between the skin and the conjunctiva develops, the hair changes its character and becomes mahram.

  Glandular device

  Moisture from the tear glands (tear glands) keeps the eye moist.  These almond-shaped glands extend inward from the outer corner of each eye under the upper lid.  Each gland has two parts.  One part of the eye socket is in a shallow depression formed by the frontal bone.  The second part projects into the back of the upper lid.  The ducts that come out of each gland, in numbers three to 12, open into the superior conjunctival pharynx, or sac.  From the pharynx, tears flow across the eye and into the pancreatic lacrimal, with small holes in the margins of each eyelid near the inner corner.  Pentacles have holes in the tear ducts.  They carry tears to the sacs, the wide upper end of the nasolabial ducts, which carry the tears to the nose.

  When tears vapor flow into the eye, the secretion of oil and mucus through other glands is largely prevented.  Thus, the meibomian, or tarsal gland, consists of a series of long glands that spread through the tarsal plates.  They release an oil that rises to the surface of the margin of the lid and acts as a barrier to tear fluid, which accumulates in the ducts between the eye hair and the lid barrier.