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{{For|the computer programming term|spaghetti code}} | |||
[[File:Field tidal.png|thumb|260px|[[Tidal forces]] acting on a spherical body in a non-homogeneous gravitational field. The effect originates from a source to the right (''or'' to the left) of the diagram. Longer arrows indicate stronger forces.]] | |||
In [[astrophysics]], '''spaghettification''' (sometimes referred to as the '''noodle effect'''<ref>{{citation | |||
|title=Cosmic catastrophes: exploding stars, black holes, and mapping the universe, 2nd edition | |||
|first1=J. Craig | |||
|last1=Wheeler | |||
|publisher=Cambridge University Press | |||
|year=2007 | |||
|isbn=978-0-521-85714-7 | |||
|page=182 | |||
|url=http://books.google.be/books?id=j1ej8d0F8jAC}} | |||
</ref>) is the vertical stretching and horizontal compression of objects into long thin shapes (rather like [[spaghetti]]) in a very strong non-homogeneous gravitational field, and is caused by extreme [[tidal forces]]. In the most extreme cases, near [[black hole]]s, the stretching is so powerful that no object can withstand it, no matter how strong its components. Within a small region the horizontal compression balances the vertical stretching so that small objects being spaghettified experience no net change in volume. | |||
In his book ''[[A Brief History of Time]]'' (1988), [[Stephen Hawking]] describes the flight of a fictional [[astronaut]] who, passing within a black hole's [[event horizon]], is "stretched like spaghetti" by the gravitational gradient (difference in strength) from head to toe. However, the term "spaghettification" was established well before this; [[Nigel Calder]], for example, uses it in his book ''[[The Key to the Universe|The Key to the Universe: A Report on the New Physics]]'' (Viking Press, 1977), a companion to a one-off [[BBC]] TV documentary: ''The Key to the Universe''. | |||
==A simple example== | |||
[[File:Spaghettification.gif|center]] | |||
The four objects follow the lines of the gravitoelectric field,<ref>Thorne, Kip S. ♦ [http://einstein.stanford.edu/content/sci_papers/papers/nz-Thorne_101.pdf#page=3&view=FitV Gravitomagnetism, Jets in Quasars, and the Stanford Gyroscope Experiment] From the book "Near Zero: New Frontiers of Physics" (eds. J. D. Fairbank, B. S. Deaver, Jr., C. W. F. Everitt, P. F. Michelson), W. H. Freeman and Company, New York, 1988, pp. 3, 4 (575, 576) ♦ ''"From our electrodynamical experience we can infer immediately that any rotating spherical body (e.g., the sun or the earth) will be surrounded by a radial gravitoelectric (Newtonian) field '''''g''''' and a dipolar gravitomagnetic field '''''H'''''. The gravitoelectric monopole moment is the body's mass M; the gravitomagnetic dipole moment is its spin angular momentum S."''</ref> directed towards the celestial body's centre. In accordance with the [[inverse-square law]], the lowest of the four objects experiences the biggest gravitational acceleration, so that the whole formation becomes stretched into a filament. Now imagine that the green blobs in the diagram are parts of a larger object. A rigid object will resist distortion—internal elastic forces develop as the body distorts to balance the tidal forces, so attaining mechanical equilibrium. If the tidal forces are too large, the body may yield and flow plastically before the tidal forces can be balanced, or fracture. | |||
==Examples of weak and strong tidal forces== | |||
In the gravity field due to a point mass or spherical mass, for a uniform rope or rod oriented in the direction of gravity, the [[tensile force]] at the center is found by integration of the tidal force (see [[Tidal_force#Mathematical_treatment|magnitude of tidal force]]) from the center to one of the ends. This gives <math> \frac{\mu l m}{4 r^3}</math>, where <math>\mu</math> is the [[standard gravitational parameter]] of the massive body, ''l'' is the length of the rope or rod, ''m'' is its mass, and ''r'' is the distance to the massive body. For non-uniform objects the tensile force is smaller if more mass is near the center, and up to twice as large if more mass is at the ends. In addition, there is a horizontal compressive force toward the center. | |||
For massive bodies with a surface, the tensile force is largest near the surface, and this maximum value is only dependent on the object and the average density of the massive body (as long as the object is small relative to the massive body). For example, for a rope with a mass of 1 kg and a length of 1 m, and a massive body with the average density of the Earth, this maximum tensile force due to the tidal force is only 0.4 μN. | |||
Due to the high density, the tidal force near the surface of a [[white dwarf]] is much stronger, causing in the example a maximum tensile force of up to 0.24 N. Near a [[neutron star]], the tidal forces are again much stronger: if the rope has a tensile strength of 10,000 N and falls vertically to a neutron star of 2.1 solar masses, setting aside that it would melt, it would break at a distance of 190 km from the center, well above the surface (the typical radius is about 12 km).<ref>An 8 m piece of the same type of rope, hence with a mass of 8 kg, would in each case break already at a distance that is 4 times as high.</ref> | |||
While in the previous case objects would actually be destroyed and people killed by the heat, not the tidal forces, near a [[black hole]] (assuming that there is no nearby matter), objects would actually be destroyed and people killed by the tidal forces, because there is no radiation. Moreover, a black hole has no surface to stop a fall. As an object falls into a black hole, the tidal forces increase to infinity, so nothing can resist them. Thus, the infalling object is stretched into a thin strip of matter. Close to the [[Gravitational singularity|singularity]], the tidal forces even tear apart molecules. | |||
==Inside or outside the event horizon== | |||
The point at which tidal forces destroy an object or kill a person will depend on the black hole's size. For a [[supermassive black hole]], such as those found at a galaxy's center, this point lies within the [[event horizon]], so an astronaut may cross the event horizon without noticing any squashing and pulling, although it remains only a matter of time, as once inside an event horizon, falling towards the center is inevitable. For small black holes whose [[Schwarzschild radius]] is much closer to the singularity, the tidal forces would kill even before the astronaut reaches the event horizon.<ref>{{cite book | |||
|title=General relativity: an introduction for physicists | |||
|first1=Michael Paul | |||
|last1=Hobson | |||
|first2=George | |||
|last2=Efstathiou | |||
|first3=Anthony N. | |||
|last3=Lasenby | |||
|publisher=Cambridge University Press | |||
|year=2006 | |||
|isbn=0-521-82951-8 | |||
|page=265 | |||
|url=http://books.google.com/books?id=5dryXCWR7EIC&pg=PA265}}, [http://books.google.com/books?id=5dryXCWR7EIC&pg=PA265 Chapter 11, p. 265] | |||
</ref><ref>{{cite book | |||
|title=Astronomy: a physical perspective | |||
|edition=2 | |||
|first1=Marc Leslie | |||
|last1=Kutner | |||
|publisher=Cambridge University Press | |||
|year=2003 | |||
|isbn=0-521-52927-1 | |||
|page=150 | |||
|url=http://books.google.com/books?id=2QVmiMW0O0MC}}, [http://books.google.com/books?id=2QVmiMW0O0MC&pg=PA150 Chapter 8, p. 150] | |||
</ref> For example, for a black hole of 10 Sun masses<ref>The smallest black hole that can be formed by natural processes at the current stage of the universe has over twice the mass of the Sun.</ref> and the above-mentioned rope at 1000 km distance, the tensile force halfway along the rope is 325 N. It will break at a distance of 320 km, well outside the Schwarzschild radius of 30 km. For a black hole of 10,000 Sun masses it will break at a distance of 3200 km, well inside the Schwarzschild radius of 30,000 km. | |||
==References== | |||
{{reflist}} | |||
* {{cite book | author=Melia, Fulvio | title= The Black Hole at the Center of Our Galaxy | publisher=Princeton University Press | year=2003 | id=ISBN 0-691-09505-1}} | |||
* {{cite book | author=Hawking, Stephen | title= A Brief History of Time | publisher=Bantam Books | year=1988 | id=ISBN 0-553-38016-8}} | |||
*[http://www.youtube.com/watch?v=h1iJXOUMJpg Neil DeGrasse Tyson: Death by Black Hole (clear explanation of the term)] | |||
{{Black holes}} | |||
[[Category:Black holes]] | |||
[[Category:Effects of gravitation]] | |||
[[Category:Fictional astronauts]] | |||
[[Category:Metaphors referring to food and drink]] | |||
Revision as of 07:59, 20 December 2013
28 year-old Painting Investments Worker Truman from Regina, usually spends time with pastimes for instance interior design, property developers in new launch ec Singapore and writing. Last month just traveled to City of the Renaissance.
In astrophysics, spaghettification (sometimes referred to as the noodle effect[1]) is the vertical stretching and horizontal compression of objects into long thin shapes (rather like spaghetti) in a very strong non-homogeneous gravitational field, and is caused by extreme tidal forces. In the most extreme cases, near black holes, the stretching is so powerful that no object can withstand it, no matter how strong its components. Within a small region the horizontal compression balances the vertical stretching so that small objects being spaghettified experience no net change in volume.
In his book A Brief History of Time (1988), Stephen Hawking describes the flight of a fictional astronaut who, passing within a black hole's event horizon, is "stretched like spaghetti" by the gravitational gradient (difference in strength) from head to toe. However, the term "spaghettification" was established well before this; Nigel Calder, for example, uses it in his book The Key to the Universe: A Report on the New Physics (Viking Press, 1977), a companion to a one-off BBC TV documentary: The Key to the Universe.
A simple example
The four objects follow the lines of the gravitoelectric field,[2] directed towards the celestial body's centre. In accordance with the inverse-square law, the lowest of the four objects experiences the biggest gravitational acceleration, so that the whole formation becomes stretched into a filament. Now imagine that the green blobs in the diagram are parts of a larger object. A rigid object will resist distortion—internal elastic forces develop as the body distorts to balance the tidal forces, so attaining mechanical equilibrium. If the tidal forces are too large, the body may yield and flow plastically before the tidal forces can be balanced, or fracture.
Examples of weak and strong tidal forces
In the gravity field due to a point mass or spherical mass, for a uniform rope or rod oriented in the direction of gravity, the tensile force at the center is found by integration of the tidal force (see magnitude of tidal force) from the center to one of the ends. This gives , where is the standard gravitational parameter of the massive body, l is the length of the rope or rod, m is its mass, and r is the distance to the massive body. For non-uniform objects the tensile force is smaller if more mass is near the center, and up to twice as large if more mass is at the ends. In addition, there is a horizontal compressive force toward the center.
For massive bodies with a surface, the tensile force is largest near the surface, and this maximum value is only dependent on the object and the average density of the massive body (as long as the object is small relative to the massive body). For example, for a rope with a mass of 1 kg and a length of 1 m, and a massive body with the average density of the Earth, this maximum tensile force due to the tidal force is only 0.4 μN.
Due to the high density, the tidal force near the surface of a white dwarf is much stronger, causing in the example a maximum tensile force of up to 0.24 N. Near a neutron star, the tidal forces are again much stronger: if the rope has a tensile strength of 10,000 N and falls vertically to a neutron star of 2.1 solar masses, setting aside that it would melt, it would break at a distance of 190 km from the center, well above the surface (the typical radius is about 12 km).[3]
While in the previous case objects would actually be destroyed and people killed by the heat, not the tidal forces, near a black hole (assuming that there is no nearby matter), objects would actually be destroyed and people killed by the tidal forces, because there is no radiation. Moreover, a black hole has no surface to stop a fall. As an object falls into a black hole, the tidal forces increase to infinity, so nothing can resist them. Thus, the infalling object is stretched into a thin strip of matter. Close to the singularity, the tidal forces even tear apart molecules.
Inside or outside the event horizon
The point at which tidal forces destroy an object or kill a person will depend on the black hole's size. For a supermassive black hole, such as those found at a galaxy's center, this point lies within the event horizon, so an astronaut may cross the event horizon without noticing any squashing and pulling, although it remains only a matter of time, as once inside an event horizon, falling towards the center is inevitable. For small black holes whose Schwarzschild radius is much closer to the singularity, the tidal forces would kill even before the astronaut reaches the event horizon.[4][5] For example, for a black hole of 10 Sun masses[6] and the above-mentioned rope at 1000 km distance, the tensile force halfway along the rope is 325 N. It will break at a distance of 320 km, well outside the Schwarzschild radius of 30 km. For a black hole of 10,000 Sun masses it will break at a distance of 3200 km, well inside the Schwarzschild radius of 30,000 km.
References
43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.
- 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534 - 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534 - Neil DeGrasse Tyson: Death by Black Hole (clear explanation of the term)
- ↑ Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
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Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - ↑ Thorne, Kip S. ♦ Gravitomagnetism, Jets in Quasars, and the Stanford Gyroscope Experiment From the book "Near Zero: New Frontiers of Physics" (eds. J. D. Fairbank, B. S. Deaver, Jr., C. W. F. Everitt, P. F. Michelson), W. H. Freeman and Company, New York, 1988, pp. 3, 4 (575, 576) ♦ "From our electrodynamical experience we can infer immediately that any rotating spherical body (e.g., the sun or the earth) will be surrounded by a radial gravitoelectric (Newtonian) field g and a dipolar gravitomagnetic field H. The gravitoelectric monopole moment is the body's mass M; the gravitomagnetic dipole moment is its spin angular momentum S."
- ↑ An 8 m piece of the same type of rope, hence with a mass of 8 kg, would in each case break already at a distance that is 4 times as high.
- ↑ 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534, Chapter 11, p. 265 - ↑ 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534, Chapter 8, p. 150 - ↑ The smallest black hole that can be formed by natural processes at the current stage of the universe has over twice the mass of the Sun.