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Topic: Horizon problem

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	problem concept from the Astronomy knowledge base (Site not responding. Last check: 2007-10-13)
		See also horizon problem., The puzzle of why the universe today is so close to the boundary between open and closed, that is, why it is almost flat.
		horizon problem (6 facts) (homogeneity problem) - A quandary in standard big bang theory, which indicates that few of the particles of the early universe would have had time to be in causal contact with one another at the outset of cosmic expansion.
		See also flatness problem., Cosmological puzzle associated with the fact that regions of the universe that are separated by vast distances nevertheless have nearly identical properties such as temperature.
	www.site.uottawa.ca:4321 /astronomy/problem.html (876 words)

	horizon problem concept from the Astronomy knowledge base (Site not responding. Last check: 2007-10-13)
		The horizon problem is also called the causality puzzle.
		The problem is seen most clearly in the cosmic background radiation, which is believed to have been released at about 300000 years after the big bang, and has been observed to have the same temperature in all directions to an accuracy of one part in 100,000.
		Since no energy or information can be transported further than one horizon distance, the observed uniformity can be reconciled only by postulating that the universe began in a state of near-perfect uniformity.
	www.site.uottawa.ca:4321 /astronomy/horizonproblem.html (380 words)

	horizon -- IPW Base Program (Site not responding. Last check: 2007-10-13)
		horizon computes the local horizon angles toward the direction azimuth, where azimuth=0 is toward the south and positive angles are counter-clockwise.
		horizon reads elevations from image (default: standard input) and writes to the standard output an image whose pixels encode the local horizon angles in the direction azimuth degrees (ranging from -180 to 180) from south (positive east).
		horizon is a shell script than skews and/or transposes the input image to orient its scan lines in the direction azimuth, then calls hor1d to perform the actual horizon calculations.
	www.ecst.csuchico.edu /~jacobsd/epa/ipw/horizon.html (417 words)

	Horizon effect - Wikipedia, the free encyclopedia
		The horizon effect (or horizon problem) is an unsolved problem in AI.
		This results in the horizon effect where a significant change exists just over the "horizon" (slightly beyond the depth the tree has been searched) meaning that evaluating the partial tree gives a misleading result.
		An example of the horizon effect occurs when some negative event is inevitable but postponable, but because only a partial game tree has been analysed, it will appear to the system that the event can be avoided when in fact this is not the case.
	en.wikipedia.org /wiki/Horizon_problem_in_computer_programs (225 words)

	Design of component-supply contract with commitment-revision flexibility
		At the beginning of the planning horizon (the length of the horizon is usually a year), the buyer makes purchasing commitments to the supplier for every period (usually a month) in the horizon.
		In solving the news-vendor problem, the purchasing decisions are made sequentially, which means that at the beginning of every period, the decision maker observes the state of the system (inventory on hand and in the pipeline and orders for finished products) and then makes a purchasing decision.
		It does capture the dynamic nature of the problem by maximizing the probability of reaching the base-stock levels that are optimal for the news-vendor problem and provides a mechanism to determine the static commitments.
	www.research.ibm.com /journal/rd/416/bassok.html (5743 words)

	GET: horizon problem (Site not responding. Last check: 2007-10-13)
		The second problem is much more serious - some homogeneous distribution may have caused by something else, last not least homogeneous initial values seem to be a meaningful assumption, based on Occam's razor.
		Even if the horizon may be finite (if Einstein's cosmological constant is greater zero) the horizon size is nonetheless greater than the observable universe.
		The GR solution of this problem is inflation of the early universe.
	www.ilja-schmelzer.de /GET/horizon.html (337 words)

	Cosmological Models
		This problem is one of the lines of thought which led to the inflationary hypothesis put forth by Alan Guth in the early 1980's.
		The answer to the horizon problem from the inflationary point of view is that there was a period of incredibly rapid inflation very early in the big bang process which increased the size of the universe by 10
		If the universe inflated by 20 to 30 orders of magnitude, then the properties of an extremely tiny volume which could have been considered to be intimately connected were spread over the whole of the known universe today, contributing both extreme flatness and the extremely isotropic nature of the cosmic background radiation.
	hyperphysics.phy-astr.gsu.edu /hbase/astro/cosmo.html (991 words)

	warp drive superluminal control?
		The problem discuses is the problem of controlling a warp drive spacetime once it has gone beyond the classic Einstein barrier of light.
		The rear horizon is not a problem for controlling the bubble because it is simply towed with us, however when the barge is out of range of our imaginary walkie-talkie we can not signal the barge to slow down and it continues on, this is the "horizon problem" of the warp drive.
		Although some of the problem discussed by the author have been put into question by some recent research, its still a good read for the horizon problem and for general warp geometries.
	members.tripod.com /da_theoretical1/horizons2.html (1015 words)

	Lecture 43: The Very Early Universe
		The homogeneity, or smoothness, of the universe is referred to by cosmologists as the horizon problem.
		The density of the universe divided by the critical density is a dimensionless number that is usually called the density parameter, and is symbolized by the Greek letter Omega.
		Before the year 1980, cosmologists were baffled by the horizon problem and the flatness problem.
	www-astronomy.mps.ohio-state.edu /~ryden/ast162_10/notes43.html (1234 words)

	Before the Big Bang?
		Therefore the horizon size is finite, because the integral converges as t -> 0 for m<1, and it is much smaller than necessary to account for the isotropy observed in the cosmic microwave backgound.
		To make the horizon integral diverge or grow extremely large would require a Universe that expanded more rapidly than is possible using matter or radiation in the Einstein equations.
		The horizon size predicted by the existing Big Bang model is too small to account for the observed isotropy in the cosmic microwave background to have evolved naturally by thermalization.
	superstringtheory.com /cosmo/cosmo4a.html (794 words)

	Lost horizon: membership 'horizon' problem preceded demise of MCP Rural Cooperatives - Find Articles
		While the demise of MCP as a producer-owned business has been well covered in the press, the spotlight has perhaps not focused as sharply as it should on the membership horizon problem the co-op was lacing at the time.
		It's a problem nearly every co-op faces to some extent, and is certainly a factor in some of the other recent proposed co-op sales and conversions.
		Another major factor was a horizon problem, in which the supposedly marketable equity shares in the co-op could not be sold due to a lack of other producers interested in investing in the plant.
	www.findarticles.com /p/articles/mi_m0KFU/is_4_71/ai_n6200003 (934 words)

	Light-travel time: a problem for the big bang
		The problem is this: even assuming the big bang timescale, there has not been enough time for light to travel between widely separated regions of space.
		The horizon problem remains a serious difficulty for big bang supporters, as evidenced by their many competing conjectures that attempt to solve it.
		It is not a problem for a creation model; God may have created the distant regions of the universe with the same temperature from the beginning.
	www.answersingenesis.org /creation/v25/i4/lighttravel.asp (1637 words)

	Horizon (Site not responding. Last check: 2007-10-13)
		The horizon problem arises because light moves with a finite speed.
		horizon ~ age x speed of light ===> the older the Universe is, the larger the horizon and therefore the larger the size of the region which can communicate.
		A simple calculation indicates that at the time of recombination, material which was in causal contact (able to communicate) are currently separated by around 0.8 angular degrees on the sky.
	zebu.uoregon.edu /~imamura/123/lecture-9/horizon.html (124 words)

	Warp Drive and Horizons
		Section I introduced the scientific interpretation of warp drive, section II discussed its problems and reasons the theory can be rejected with our present understanding of physics.
		The Krasnikov Tube is perhaps the simplest warp drive model because it does not suffer from "horizon" problems, however it also requires the need for a spacecraft capable of approaching the speed of light (which creates problems of its own).
		One way to solve the horizon problem is with Cosmology itself, although the Big Bang is generally excepted as scientific fact, little is known on what may have caused its rapid inflation.
	members.tripod.com /da_theoretical1/horizons.html (985 words)

	Hartman Publications (Site not responding. Last check: 2007-10-13)
		The optimal solution to the infinite horizon equipment replacement problem with stationary costs is to continually replace an asset at its economic life.
		We explore whether applying the infinite horizon solution to a finite horizon problem is justified, as we conjecture this may occur often in practice.
		While many methods have been presented in the literature to deal with this problem, we believe ours to be unique in that it does not rely on the computation of another measure of worth, but rather, the identification of the {\em relevant} rate of return from the set of internal rates of return.
	www.lehigh.edu /~jch6/publications.html (4917 words)

	Horizon (Site not responding. Last check: 2007-10-13)
		horizon ~ time ===> the older the Universe is, the larger the horizon and therefore the larger the size of the region over which communication could have taken place
		A simple calculation indicates that at the time of recombination, particles which were in causal contact (able to communicate) are currently separated by around 0.8 angular degrees on the sky.
		According to simple arguments, this meand that the sky could only mix over 0.8 degrees and so, there is no rational reason to believe that the sky should look the same > 1 degree apart, much less 180 degrees apart.
	zebu.uoregon.edu /~imamura/209/may1/horizon.html (138 words)

	The Horizon Problem - Philosophy Forum
		The Horizon Problem is this: According to pre-Inflation models, the Universe is too big for these disparate regions to come to thermodymanic equilibrium.
		No signal could have crossed the Universe in the early phases of the Universe, because the distance between regions was larger than light could have crossed in the time since the beginning of the Universe.
		The Horizon Problem states, in essence (as I understand it), that once the Universe had expanded away from the initial singularity the temperatures of different areas of the Universe diverged.
	forum.darwinawards.com /index.php?showtopic=2068 (1616 words)

	[No title]
		The problems and issues to be resolved were then discussed one by one...
		Also, when it says the "problem should only be short term," how short is "short term?" Currently, there is nothing to test, and it is not certain how often during the day the batch program could be run.
		Horizon bib records can be skeletal, even to the point of having only a title.
	www.indiana.edu /~catcong/minutes/minutes.1196.html (1770 words)

	Horizon problem - Wikipedia, the free encyclopedia
		The horizon problem is a problem with the standard cosmological model of the Big Bang which was identified in the 1970s, but may have been answered by inflationary theory.
		Since information can travel no faster than the speed of light, there is a limit to the region of space that is in causal contact with any particular point in the universe.
		The particle horizon is closely related to this idea and is where the problem gets its name from.
	en.wikipedia.org /wiki/Horizon_problem (498 words)

	Cosmology Curiosity: Cosmology's 'horizon problem'
		That may not seem surprising until you consider that the two edges are nearly 28 billion light years apart and our universe is only 14 billion years old.
		Problem is, it takes at least 30 minutes to discuss the thing to the one seated beside.
		To recap: (a) the 30-minute factor is the speed of light; (b) the classroom is the observable universe; (c) the maximum of two nearby students whose answers one can know would be the 'horizon'.
	woodside.blogs.com /cosmologycuriosity/2006/05/the_horizon_pro.html (391 words)

	Before the Big Bang?
		The cosmic microwave background is the cooled remains of the radiation density from the radiation-dominated phase of the Big Bang.
		But in the expanding Universe that we appear to live in, photons moving at the speed of light cannot get from one side of the Universe to the other in time to account for this observed isotropy in the thermal radiation.
		The horizon size of our Universe today is too small for the isotropy in the cosmic microwave background to have evolved naturally by thermalization.
	www.superstringtheory.com /cosmo/cosmo4.html (728 words)

	13 things that do not make sense
		This "horizon problem" is a big headache for cosmologists, so big that they have come up with some pretty wild solutions.
		A variation in the speed of light could also solve the horizon problem - but this too is impotent in the face of the question "why?" In scientific terms, the uniform temperature of the background radiation remains an anomaly.
		But to get to the bottom of the problem what scientists really need is a mission designed specifically to test unusual gravitational effects in the outer reaches of the solar system.
	www.sixside.com /13_things_that_do_not_make_sense.htm (4059 words)

	Horizon Credit Union (Site not responding. Last check: 2007-10-13)
		Your Horizon Visa card also gives you instant cash 24 hours a day, 7 days a week at over 4,250 ATMs bearing the Visa symbol.
		You can use your Horizon Credit Union Visa card to pay most council rates, utilities and other bills over the phone.
		With monthly statements and itemised accounts, your Horizon Credit Union Visa card gives you control over your finances - and, unlike cash, you can keep track of every cent you spend.
	www.horizon.org.au /our_services/visa_card.asp (230 words)

	The Horizon Problem (Site not responding. Last check: 2007-10-13)
		The uniformity of cosmic background radiation--varying by no more than one part in 10,000, where ever you look--posed a problem to Standard Big Bang cosmology.
		The horizon problem gets worse if we travel back to the time when radiation was released from matter.
		The universe was 100,000 years old--meaning that the horizon was 100,000 light years across.
	archive.ncsa.uiuc.edu /Cyberia/Cosmos/HorizonProblem.html (345 words)

	Horizon Problem
		An important side effect is that if we cannot see beyond the horizon, then neither can we be affected by any physical effect from beyond the horizon.
		If we calculate the size of the horizon in the sky for the Universe at the epoch of decoupling, it turns out to be approximately one degree (about twice the angular diameter of the Moon).
		The fact that the spectrum and intensity of the CMBR are essentially the same for patches much larger than this size is very hard to explain since our scenario does not allow these patches to communicate with each other and conspire to determine their physical characteristics.
	aether.lbl.gov /www/science/horizon.html (460 words)

	horizon problem on Flickr - Photo Sharing!
		The gentle curve of the wall, the joltingly sublime light and shadow on the tower (I could stare at that for an hour) and the alignment of the tower's horizontal line with the horizon's.
		The only 'horizon problem' is a 1 to 2 degree tilt to the right...
		I love the color and mood of this photo, and the way the horizon coincides with the horizontal rule of the building.
	www.flickr.com /photos/cdm/254649157 (404 words)

	Skeletal Morphogenesis Horizon Problem (Site not responding. Last check: 2007-10-13)
		This is the problem I have with Morphogenesis.
		And the problem is that the rule acts on a tiny scale (protein production in cells) and produces consistent, diverse large scale effects despite variation in the small scale.
		I have no problem with the fact that we evolved 5 (not 4 or 6) fingers.
	c2.com /cgi/wiki?SkeletalMorphogenesisHorizonProblem (1569 words)

	JR radio problem, Horizon's 'help'
		I had the problems when I purchased it I just didn't realize it was the radio at the time.
		I'm a bit mystified by your problem, obviously you are well aware of the shift issue and would well expect the positive shift receivers to work with your new JR tranny, by any chance have you tried using your old (Airtronics, I assume) tranny with the new Jr Rx to see what range you get?
		There's your problem, first you must get proper ch 50 crystals for those old receivers you want to use, an Airtronics ch 50 dual conversion for the Airtronics rx and new ch 50 crystals for the other recivers based on whether they are dual or single conversion receivers.
	www.rcuniverse.com /forum/m_4719800/tm.htm (2335 words)

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