Space

Topological space Definition[edit] Neighbourhoods definition[edit] The first three axioms for neighbourhoods have a clear meaning. The fourth axiom has a very important use in the structure of the theory, that of linking together the neighbourhoods of different points of X. More Space Facts - PlanetFacts.net Extremely Interesting Facts on the Planets, Stars and the Universe. If one were to capture and bottle a comet's 10,000 mile vapor trail, the amount of vapor actually present in the bottle would take up less than 1 cubic inch of space. Members of the Dogon tribe in Mali, Africa, for many centuries worshiped a star known today by astronomers as Sirius B. The Dogon people knew its precise elliptical orbit, knew how long it took to revolve around its parent star, Sirius, and were aware that it was made up of materials not found on Earth—all this centuries before modern astronomers had even discovered that Sirius B existed. Deimos, one of the moons of mars, rises and sets twice a day. To an observer standing on Pluto, the sun would appear no brighter than Venus appears in our evening sky.

How Orbits Work What an Orbit Really Is The drawings at the right simplify the physics of orbiting Earth. We see Earth with a huge, tall mountain rising from it. SPACE Blogs: Here's Everything You Need to Know About the Season 3 Premiere of Orphan Black We’ve been patiently (okay, impatiently) waiting for this: news of the season three premiere of Orphan Black, set to air on Space, CTV, Bravo, and MTV at 9pm ET on April 18. We marked the date and time on our calendars. Some of us may have even set an alarm. Low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with an altitude between 160 kilometers (99 mi), with an orbital period of about 88 minutes, and 2,000 kilometers (1,200 mi), with an orbital period of about 127 minutes. Objects below approximately 160 kilometers (99 mi) will experience very rapid orbital decay and altitude loss.[1][2] With the exception of the manned lunar flights of the Apollo program, all human spaceflights have taken place in LEO (or were suborbital). The altitude record for a human spaceflight in LEO was Gemini 11 with an apogee of 1,374.1 kilometers (853.8 mi).

Orbits in Space Atmospheric Re-entry The Kepler formula also applies to elliptical motion, provided R is replaced by the semi-major axis a of the orbit. Over time however orbits stray from exact Keplerian ellipses because to additional forces, such as the attraction of the Moon and the Sun. For elongated ellipses, this causes the lowest point in the orbit ("perigee") to move up and down, ultimately reaching the atmosphere and causing satellite to be lost.

'Superfluid spacetime' points to unification of physics NASA/ESA/ASU/J. Hester Light from the Crab Nebula, shown here in a mosaic of photos from the Hubble Space Telescope, limits the possibilities for fluid space-time. An article by Scientific American. If spacetime is like a liquid — a concept some physicists say could help resolve a confounding disagreement between two dominant theories in physics — it must be a very special liquid indeed.

HSF > Living In Space > SPACE WEAR Astronauts wear various types of clothing for all aspects of a mission to space. Whether preparing for launch, working inside the space shuttle or the space station, working outside in space, or landing back on Earth, astronauts wear the proper garments for both comfort and protection. Space Station Clothing International Space Station crewmembers choose the shirts, shorts and pants they will wear in space months before they are scheduled to launch.

Syntax (logic) Syntax is usually associated with the rules (or grammar) governing the composition of texts in a formal language that constitute the well-formed formulas of a formal system. In computer science, the term syntax refers to the rules governing the composition of meaningful texts in a formal language, such as a programming language, that is, those texts for which it makes sense to define the semantics or meaning, or otherwise provide an interpretation.[2] A symbol is an idea, abstraction or concept, tokens of which may be marks or a configuration of marks which form a particular pattern. Symbols of a formal language need not be symbols of anything. Milky Way Stars and gases at a wide range of distances from the Galactic center orbit at approximately 220 kilometers per second. The constant rotation speed contradicts the laws of Keplerian dynamics and suggests that much of the mass of the Milky Way does not emit or absorb electromagnetic radiation. This mass has been given the name “dark matter”.[22] The rotational period is about 240 million years at the position of the Sun.[9] The Galaxy as a whole is moving at a velocity of approximately 600 km per second with respect to extragalactic frames of reference. The oldest known star in the Galaxy is at least 13.6 billion years old and thus must have formed shortly after the Big Bang.[6] Surrounded by several smaller satellite galaxies, the Milky Way is part of the Local Group of galaxies, which forms a subcomponent of the Virgo Supercluster. Appearance[edit] The Milky Way has a relatively low surface brightness.

Formal language Structure of a syntactically well-formed, although nonsensical English sentence (historical example from Chomsky 1957). History[edit] The first formal language is thought be the one used by Gottlob Frege in his Begriffsschrift (1879), literally meaning "concept writing", and which Frege described as a "formal language of pure thought."[2] Axel Thue's early Semi-Thue system which can be used for rewriting strings was influential on formal grammars. Milky Way (chocolate bar) The Milky Way bar was created in 1923 by Frank C. Mars and originally manufactured in Minneapolis, Minnesota. The name and taste were taken from a famed malted milk drink (milkshake) of the day – not the Earth’s galaxy, as many contend.[1][2] On March 10, 1925, the Milky Way trademark was registered in the U.S., claiming a first-use date of 1922.[3] In 1924, the Milky Way bar was introduced nationally and sold USD800,000 that year. The chocolate for the chocolate coating was supplied by Hershey's.[4] In 1935 the slogan was "The sweet you can eat between meals

Cultural relativism Compare moral relativism, aesthetic relativism, social constructionism, and cognitive relativism. Cultural relativism is a principle that was established as axiomatic in anthropological research by Franz Boas in the first few decades of the 20th century and later popularized by his students. Boas first articulated the idea in 1887: "...civilization is not something absolute, but ... is relative, and ... our ideas and conceptions are true only so far as our civilization goes.

Black hole A black hole is defined as a region of spacetime from which gravity prevents anything, including light, from escaping.[1] The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole.[2] Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return. The hole is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.[3][4] Quantum field theory in curved spacetime predicts that event horizons emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater. Objects whose gravity fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.