Faster-than-light communications and travel are the conjectural propagation of information or matter faster than the speed of light. The special theory of relativity implies that only particles with zero rest mass may travel at the speed of light. Tachyons, particles whose speed exceeds that of light, have been hypothesized, but their existence would violate causality, the consensus of physicists is that they cannot exist. On the other hand, what some physicists refer to as "apparent" or "effective" FTL depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal or undistorted spacetime. According to the current scientific theories, matter is required to travel at slower-than-light speed with respect to the locally distorted spacetime region. Apparent FTL is not excluded by general relativity. Examples of apparent FTL proposals are the traversable wormhole. In the context of this article, FTL is the transmission of information or matter faster than c, a constant equal to the speed of light in a vacuum, 299,792,458 m/s or about 186,282.397 miles per second.

This is not quite the same as traveling faster than light, since: Some processes propagate faster than c, but cannot carry information. In some materials where light travels at speed c/n other particles can travel faster than c/n, leading to Cherenkov radiation. Neither of these phenomena violates special relativity or creates problems with causality, thus neither qualifies as FTL as described here. In the following examples, certain influences may appear to travel faster than light, but they do not convey energy or information faster than light, so they do not violate special relativity. For an earth-bound observer, objects in the sky complete one revolution around the Earth in one day. Proxima Centauri, the nearest star outside the Solar System, is about four light-years away. In this frame of reference, in which Proxima Centauri is perceived to be moving in a circular trajectory with a radius of four light years, it could be described as having a speed many times greater than c as the rim speed of an object moving in a circle is a product of the radius and angular speed.

It is possible on a geostatic view, for objects such as comets to vary their speed from subluminal to superluminal and vice versa because the distance from the Earth varies. Comets may have orbits which take them out to more than 1000 AU; the circumference of a circle with a radius of 1000 AU is greater than one light day. In other words, a comet at such a distance is superluminal in a geostatic, therefore non-inertial, frame. If a laser beam is swept across a distant object, the spot of laser light can be made to move across the object at a speed greater than c. A shadow projected onto a distant object can be made to move across the object faster than c. In neither case does the light travel from the source to the object faster than c, nor does any information travel faster than light. Since there is no "retardation" of the apparent position of the source of a gravitational or electric static field when the source moves with constant velocity, the static field "effect" may seem at first glance to be "transmitted" faster than the speed of light.

However, uniform motion of the static source may be removed with a change in reference frame, causing the direction of the static field to change at all distances. This is not a change of position which "propagates", thus this change cannot be used to transmit information from the source. No information or matter can be FTL-transmitted or propagated from source to receiver/observer by an electromagnetic field; the rate at which two objects in motion in a single frame of reference get closer together is called the mutual or closing speed. This may approach twice the speed of light, as in the case of two particles travelling at close to the speed of light in opposite directions with respect to the reference frame. Imagine two fast-moving particles approaching each other from opposite sides of a particle accelerator of the collider type; the closing speed would be the rate. From the point of view of an observer standing at rest relative to the accelerator, this rate will be less than twice the speed of light.

Special relativity does not prohibit this. It tells us that it is wrong to use Galilean relativity to compute the velocity of one of the particles, as would be measured by an observer traveling alongside the other particle; that is, special relativity gives the correct velocity-addition formula for computing such relative velocity. It is instructive to compute the relative velocity of particles moving at v and −v in accelerator frame, which corresponds to the closing speed of 2v > c. Expressing the speeds in units of c, β = v/c: β rel = β + β 1 + β 2 = 2 β 1 + β 2 ≤ 1. If a spaceship travels to a planet one light-year away from Earth at high speed, the time taken to reach that planet could be less than one year as measured by the traveller's clock (although it will always b

All stars but one can be associated with an IAU constellation. IAU constellations are areas of the sky. Although there are only 88 IAU constellations, the sky is divided into 89 irregularly shaped boxes as the constellation Serpens is split into two separate sections, Serpens Caput to the west and Serpens Cauda to the east; the only star that does not belong to a constellation is the Sun. The Sun travels through the 13 constellations along the ecliptic, the 12 of the Zodiac and Ophiuchus. Among the remaining stars, the nearer ones exhibit proper motion, so it is only a matter of time before some of them cross a constellation boundary and switch constellations as a consequence. In 1992, Rho Aquilae became the first star to have its Bayer designation "invalidated" by moving to a neighbouring constellation—it is now a star of the constellation Delphinus. Stars are listed in the appropriate lists for the constellation, as follows: Stars named with a Bayer, Flamsteed, HR, or Draper designation. Stellar extremes or otherwise noteworthy stars.

Notable variable stars. Nearest stars. Stars with planets. Notable neutron stars, black holes, other exotic stellar objects/remnants. Note that these lists are unfinished, there may be stars missing that satisfy these conditions. If you come across one, please feel free to add it. Lists of astronomical objects Lists of constellations Lists of stars Lists of star names List of proper names of stars The Astronomical Almanac. Roy L. Bishop, ed; the Observer's The Royal Astronomical Society of Canada. Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System, Vols. 1, 2, 3. N. D. Kostjuk, HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index. Alphabetical listing of constellations Star Names Star Names by constellation Stars: Index of Proper Names Studies of Occidental Constellations and Star Names to the Classical Period: An Annotated Bibliography Common Star Names

Takuboku Ishikawa was a Japanese poet. He died of tuberculosis. Well known as both a tanka and "modern-style" or "free-style" poet, he began as a member of the Myōjō group of naturalist poets but joined the "socialistic" group of Japanese poets and renounced naturalism, his major works were two volumes of tanka poems plus his diaries: Ichiaku no Suna 1910 Kanashiki gangu published posthumously in 1912 Ishikawa wrote some of his diaries in the Latin script transliteration of Japanese so that his wife could not read them. 1886 - Born at Joko Temple, Hinoto-mura, Minami-Iwate-gun, Iwate Prefecture, to Ittei, the father, the priest of the temple, Katsu, his mother. 1887 - Moved to Shibutami-mura 1891 - Attended Shibutami Elementary School 1895 - Attended Morioka Upper Elementary School 1898 - Attended Morioka Middle School 1899 - Published a literary booklet “Choji-kai”, printed by hand using a method called hectograph 1900 - Formed a self-study group, “Union Club”, to learn English. First and second issues of “Choji Magazine” were published.

Fell in love with Setsuko Horiai, a student at Morioka Girls’ Middle School. 1901 - Published the third issue of “Mikazuki”, a magazine for circulating, the first issue of “Nigitama”. His tankas appeared on Iwate Nippo under the pen name of “Suiko”, the first public appearance of his works. 1902 - His tankas appeared in “Myōjō”, a literary magazine, under the pen name of “Hakuhin”. Dropped out of Morioka Middle School because of his aspiration for literature. Went to Tokyo and made the acquaintances of Tekkan and Akiko Yosano. 1903 - Went home to Shibutami. Serial articles “Ideas of Wagner” appeared in Iwate Nippo. Poem ”Shucho” appeared in “Myōjō”; the pen name of “Takuboku” was used for the first time. In November, he joined the circle of poets “Shinshisha”. 1904 - Serial articles “Senun Yoroku” appeared in Iwate Nippo. This was right after the outbreak of the Russo-Japanese War. 1905 - The first collection of poems “Akogare” was published by Odajima Shobo. Married Setsuko Horiai. Published the literary magazine “Sho-Tenchi”.

1906 - Became a substitute teacher at Shibutami Upper Elementary School. Wrote the novel “Kumo wa Tensai dearu”, never published during his lifetime, his novel “Soretsu” appeared in the literary magazine “Myōjō”. 1907 - Became a substitute teacher at Hakodate Yayoi Elementary School, a freelance reporter at Hakodate Nichinichi Shinbun. There at the Hakodate Yayoi Elementary School, he met Chieko Tachibana, he was awestruck by her beauty. Although Takuboku only encountered Chieko in person twice, she left a lasting impression on him, 22 of the tanka written in "Wasuregataki-Hitobito" in "Ichiaku-no-Suna" were written about Chieko Tachibana. Despite efforts to visit Chieko in her home in Sapporo, to pursue courtship, he had learned from her father that she had married; because of the great fire in Hakodate, he left Hakodate. Employed at places like Hokumon Shinpo or Otaru Nippo 1908 - Employed at Kushiro Shinbun, wrote “Benifude-dayori”. Moved to Hongo, Tokyo in spring. 1909 - Employed at Asahi Shimbun as a proof reader.

Issued literary magazine “Subaru” as a publisher. 1910 - First collection of tankas “Ichiaku-no-Suna” was published by Shinonome-do Shoten. 1911 - Moved to Koishikawa because of health reasons. 1912 - In March, his mother Katsu died. He himself died of tuberculosis on April 13, being looked after by his friend Bokusui Wakayama and his wife Setsuko, at age of 27. After his death, his second collection of tankas “Kanashiki Gangu” was published by Shinonome-do Shoten. 1926 - In August, his grave was erected by both Miyazaki Ikuu, his brother-in-law, a poet, Okada Kenzo, the chief of Hakodate Library. 1988 - The main-belt asteroid 4672 Takuboku is named in his honor. Ishikawa Takuboku, On Knowing Oneself Too Well, translated by Tamae K. Prindle, Syllabic Press, © 2010. ISBN 978-0-615-34562-8 Ishikawa Takuboku, Romaji Diary and Sad Toys, translated by Sanford Goldstein and Seishi Shinoda. Rutland, Charles E. Tuttle Co. 1985. Ishikawa Takuboku, Takuboku: Poems to Eat, translated by Tokyo. Kodansha International, 1966.

Ueda, Modern Japanese Poets and the Nature of Literature, Stanford University Press © 1983 ISBN 0-8047-1166-6 Donald Keene, The First Modern Japanese: The Life of Ishikawa Takuboku. New York: Columbia University Press, 2016. E-texts of Ishikawa Takuboku's works at Aozora bunko Takuboku and Socialism Works by or about Takuboku Ishikawa at Internet Archive Works by Takuboku Ishikawa at LibriVox