Aarushhh/wikipedia-simple-splitted huggingface dataset:
Antivirus software protects computers in many different ways. For starters, most antiviruses offer more than just "virus" protection. They protect computers from all different kinds of malware, like spyware, rootkits, phishing, and ransomware. For this reason, antiviruses are frequently interchangeably referred to as "anti-malware" programs. There are a few more ways that antiviruses protect against malware, but the most used way is through a regular scan of all the data and files on a computer's hard disk. In an antivirus scan, the software will look through every file on a computer, and it will compare each computer file's genetic makeup with the genetic makeup of already-known viruses. If a file has the same genetic makeup as a known piece of malware, it will be flagged as a problem. This is known as signature-based detection, and it is only effective when a malware file has been previously identified and shared with the community of malware researchers who maintain the malware database
. Another typical kind of malware detection is through behavior analysis. This is when the antivirus software identifies an abnormal behavior in a computer file or program, causing the antivirus to flag that issue and assess whether or not the abnormality has been caused by malware or by something else.
Problems with antivirus software 
Most tests and experts claim that while antivirus software is extremely useful in preventing some cyber attacks, but it is unable to all attacks. That is because once a piece of malware has been identified, hackers know that this malware will be added to the list of already-known viruses, and it will no longer be able to pass through most signature-based detection systems. Also, antivirus software is not completely perfect, and there are more new and emerging threats that mostly sneak by a computer's defenses.

Installing more than one antivirus is never a good idea. The two different antivirus software may interfere with each other and causes damage.

Sometimes antivirus software sees viruses in files that do not actually have viruses. This is called a false positive.  The antivirus software will may remove files from the computer that do not have to be removed. This may cause other programs to not work correctly.

References 

Software
Computer security
Tangerine Dream is a German music band that was started in 1967. The band was very important for the development of what is known as electronic music today. Together with Ash Ra Tempel and Agitation Free they made Berlin School possible. Their early works are usually seen as a type of Krautrock. Many people classify their music as New Age.  The band does not see itself in this category though. Their music is sometimes seen as symphonic, or as a kind of ambient music, with a focus on electronically making the sounds used. They often let themselves be influenced by  rock music.

German rock bands
New wave bands
Electronic music bands
Fulton County can be any one of the following eight counties in the United States:

 Fulton County, Arkansas
 Fulton County, Georgia
 Fulton County, Illinois 
 Fulton County, Indiana 
 Fulton County, Kentucky 
 Fulton County, New York 
 Fulton County, Ohio 
 Fulton County, Pennsylvania
The steeplechase is a kind of horse racing that is done in the United Kingdom, United States, France, Ireland and Australia. The horses have to jump a number of hurdles (like a fence) that are put up across the track.

Horse racing
Maley & Taunton were a tram and tramway engineering company. They were at Wednesfield in Staffordshire, England.

Maley & Taunton sent its products all over the world. Its trucks used in the Lisbon trams and in the UK on the Blackpool tramway. The company principals were Alfred Walter Maley and Edmund MacKenzie Taunton. They held patents for Tram and tramway machinery and equipment.

Their equipment was used on the Manx Electric Railway.

Notes

Tram transport in the United Kingdom
Aalst can be any of the following:

 Aalst, Belgium, a city and municipality in Belgium
 Aalst, a village in the Netherlands, in the province of North Brabant
 Aalst, a village in the municipality of Zaltbommel, in the province of Gelderland
Alken, as a person, may refer to:

Samuel Alken (1756-1815), English artist
Henry Thomas Alken (1785-1851), English painter and engraver

Alken, as a place, may refer to:

Alken, Belgium
Alken, Germany
Beaumont can refer to:

Places 
 Beaumont, Belgium, in the province of Hainaut
 Beaumont, Ardèche, a commune in France
Beaumont-en-Auge, Calvados, a commune in France

Other 
William Beaumont Hospital, Royal Oak, Michigan
Bever may refer to:

Bever, Belgium, a municipality in the Belgian province of Flemish Brabant
Bever, Switzerland, a municipality in the district of Maloja of the Canton of Grisons, Switzerland
Bever, a tributary to the river Ems
Bever, a tributary to the river Oste
Bever, a tributary to the river Weser
Bever, a tributary to the river Wupper
Beringen may mean:

Beringen, Belgium, a municipality in the Belgian province of Limburg
Beringen, Switzerland, a municipality in the canton of Schaffhausen in Switzerland
The name Beloeil or Belœil is the name of two municipalities. It has also been applied to various events and locations linked with these two municipalities.

Municipalities
The name has been applied to two municipalities. Despite the similarity, it appears the two names have independent linguistic origins.

Belœil, a municipality in Hainaut, Belgium famous for its castle, with a population of 13 347 inhabitants.
Beloeil, a city in Quebec, Canada, near Montreal, with a population of 18 927 inhabitants.

Related Locations and Events
The Château of Belœil, a castle in the Belgian Belœil, seat of the House of Ligne.
Mont Beloeil, an older name for Mont Saint-Hilaire, a mountain across the Richelieu River from the Canadian Beloeil.
The Seigneury of Beloeil, a French colonial administrative division including what is now Beloeil, Quebec.
The Beloeil train disaster, an alternate name for the St-Hilaire train disaster, which killed 99 on June 29, 1864 near Beloeil, Quebec.
Bree may refer to:

People
 Bree Amer, Australian television personality
 Bree Olson, American pornographic actress
 Bree Sharp, American singer and songwriter
 Bree Turner, American actress
 Bree Walker, American television news anchor
 Bree de Wilder, English musician
 Brianna (given name), a female given name

Places
 Bree, Belgium
 Bree, County Wexford, Republic of Ireland
 Maasbree, Netherlands, formerly called "Bree"
 Brée, a commune in the Mayenne department in France

Fictional characters and places
 Bree (Middle-earth), a fictional village in J. R. R. Tolkien's Middle-earth
 Bree (Narnia), a fictional talking horse from the Narnia novel The Horse and His Boy by C. S. Lewis
 Bree Timmins, a character on the Australian soap Neighbours
 Bree Van de Kamp, a character on the American television series Desperate Housewives
 Bree Avery, fictional main character from the web video series lonelygirl15
 Bree, A newborn vampire in the novel Eclipse, from the Twilight Series
Related pages
Brie, a soft cheese
Brianna (disambiguation), for a list of people named Brianna
Breeing, a vocal technique
is a puzzle video game made by Nintendo for the Nintendo Entertainment System and Game Boy video game systems, released in 1990. It is like the game Tetris.

1 Player Gameplay 
The gameplay of 1 player Dr. Mario is to make sure vitamins of the same color are lined-up together to defeat viruses. There are three colors of vitamins (red, blue, yellow). The goal is to clear all the capsules without going to the top. The player can pick any default level from 0-20, with a set number of viruses to clear depending what level the player is on. The virus count goes as high as 84, and does not increase after you pass level 20. There are over 40 levels in the game.

The player can also set up the skill level and music (Fever, Chill).
2 Player VS Gameplay 
The gameplay of 2-Player Vs. is to defeat your opponent by killing all the viruses first, or making your opponent lose.  By clearing viruses enough, halves of vitamins fall onto the opponents screen.  They must wait until all the vitamins fall down before they make their next move.

Reviews 
Dr. Mario was rated the 134th best game made on a Nintendo System in Nintendo Power's Top 200 Games list. Dr. Mario was also rated by ScrewAttack as the seventh best Mario game of all time. Overall, Dr. Mario has scored a press average of 7.6 on GameStats.

References 

1990 video games
Nintendo Entertainment System games
Game Boy games
Mario video games
Puzzle video games
A convergent plate boundary is the boundary that occurs when two tectonic plates collide with each other.  This causes very large earth movements.  Plate collisions can produce earthquakes, volcanoes, the formation of mountains, and other geological events over time.  The Himalayas were formed by such a collision.  Earthquakes and volcanoes are common near convergent boundaries.  This is because of pressure, friction, and plate material melting in the mantle.

The diagram shows some differences between the two types of subduction. 
 Oceanic crust moves under. A deep ocean trench forms at the coast, and an arc of mountainous volcanoes forms inland. Seen along the west edge of the Americas.
 Continental crust moves under. The edge of the continental plate folds into a huge mountain range. Behind it is a high plateau. The Himalayas and the Tibetan plateau are a perfect example of this.

References 

Plate tectonics
The Scottish Tramway and Transport Society was set up on the 27th June 1951. It was called the "Scottish Tramway Museum Society". It had that name until 1983 when it changed to the current one. It was made by people interested in trams and tramways. They wanted to preserve a Glasgow "Room and Kitchen" type single deck tramcar. There is now one at the Glasgow Museum of Transport. 

Light rail in the United Kingdom
Tram transport in the United Kingdom
Organisations based in Scotland
1951 establishments in the United Kingdom
Alexandre Guilmant (born Boulogne-sur-Mer, 12 March 1837; died Meudon 29 March 1911) was a French organist and composer.

Life

Early life and career
Alexandre Guilmant was born in Boulogne-sur-Mer. His father was an organist and organ builder, and gave young Alexandre lessons. Otherwise Alexandre was largely self-taught. He did study with Belgian teacher Jacques-Nicolas Lemmens, but by that time he was already a very good organist. From the 1860s he travelled widely in Europe, playing organs and becoming famous. Later he also visited the United States. In 1871 he became organist of the Trinité church in Paris. He kept this job until 1901.
His teaching
Guilmant became well known in France as a teacher. Together with two other musicians, Charles Bordes and Vincent d’Indy, he started the Schola Cantorum, a private college where students could study music. He taught the organ there. Earlier he had succeeded Charles-Marie Widor as organ teacher at the Paris Conservatoire. His Conservatoire pupils included Joseph Bonnet, Nadia Boulanger and Marcel Dupré.

Influence as organist
Guilmant did not just play the organ for church services. He became very famous for giving organ recitals. Often he played on organs which had been constructed by the brilliant organ builder Aristide Cavaillé-Coll. He helped to make these organs popular in France, and they were a very important influence on the way that organists composed music for their instrument.

Both Guilmant and Widor produced large works for the organ which they called “symphonies”. These usually had at least four movements each, and gave the player opportunities to use many different sound effects.
His compositions

Guilmant wrote eight organ symphonies, as well as a symphony for organ and orchestra, and several shorter works for the same combination. He composed a great many miniatures, not just for organ but also for harmonium. This was useful for musicians in smaller churches which had a harmonium instead of a big organ. He wrote a book on how to play the organ, and for many years he edited collections of organ music which had been written by earlier composers.

References
The New Grove Dictionary of Music & Musicians, ed. Stanley Sadie; 1980; 

1837 births
1911 deaths
20th-century French composers
French organists
People from Boulogne-sur-Mer
The Battle of Gettysburg (locally , with an ss sound), was fought July 1–3, 1863. The battle took place in and around the town of Gettysburg, Pennsylvania. It was the battle with the largest number of casualties in the American Civil War. Gettysburg is often called the war's turning point. Union Major General George G. Meade's Army of the Potomac stopped attacks by Confederate General Robert E. Lee's Army of Northern Virginia. This ended Lee's second invasion of the North. Lee began to move his men back to Virginia on July 4. Between 46,000 and 51,000 soldiers from both armies were casualties in the three-day battle.

The Siege of Vicksburg ended on the same day, also a Union victory.

That November, a cemetery for those who died there was opened at the Gettysburg National Cemetery. President Abraham Lincoln gave a speech called the Gettysburg Address at the ceremony to open the cemetery and honor the dead soldiers on both sides.
Lee's army won an important battle at Chancellorsville in Virginia in May 1863. Afterwards, he led his army north through the Shenandoah Valley. His plan was to start his second invasion of the North (called the Gettysburg Campaign). Lee had several objectives in mind. He intended to take Harrisburg, Pennsylvania, the state capital. This, he hoped, would embarrass the Lincoln administration and force Northern politicians to give up the war. At this point, Lee was playing politics. He knew that if he was successful in Pennsylvania it would encourage the Northern peace movement. He hoped it would get foreign recognition for the Confederacy. It could also force the Union to negotiate for peace, allowing the Confederate states to become an independent country. Lee badly needed supplies and intended to get them in Pennsylvania. In addition to being the state capital, Harrisburg was also the site of Camp Curtin, the largest training camp for Union soldiers. It was a major railroad center
. More importantly it was a major supply depot and also a prisoner of war camp.
Neither Lee nor Meade intended a battle take place at Gettysburg and neither were there when the battle started. On June 30, 1863, Confederate General Henry Heth had a division at Cashtown, Pennsylvania, Lee's gathering place before moving on to Harrisburg. Heth sent his division to nearby Gettysburg to look for, as he later wrote in his report, "army supplies (shoes especially), and return the same day." This started the myth that the Battle of Gettysburg started over shoes. Heth did this without scouting ahead to see what was at Gettysburg. The job of scouting belonged to the Confederate cavalry under J.E.B. Stuart. But they had been gone for over a week. So, blind to what was ahead of them, his soldiers ran directly into a Union cavalry division commanded by General John Buford. This started the fighting even though Heth and other commanders were under orders from Lee not to start a battle. But, as each side brought in more troops, it became a full-scale battle. Lee started moving much of his army there
. One of his goals was to fight the Union army and destroy it. Now, he would have to do it at Gettysburg.
About 5.30 a.m. on the morning of July 1, the battle started. Heth probed ahead cautiously to a point about two miles west of Gettysburg. Buford's cavalry was deliberately slowing his progress. At about 10 a.m. the Union I Corps arrived commanded by General John F. Reynolds. They set themselves up along McPherson's Ridge to oppose Heth's Confederates. During the fighting Reynolds was killed but the Confederates were driven back. Meanwhile, both sides brought up reinforcements. The Union set up defenses of the town with I Corps defending the western approaches with XI Corps to the north. The flanks were covered by Buford's cavalry. One Union division was held in reserve on Cemetery Ridge. In the afternoon, when Lee arrived, the Confederates still did not know the strength of the Union forces they were facing. They also had not scouted the terrain. One division of Ewell's Corps had attacked the Union I Corps just after noon. At about 2 p.m. Heth's division joined Ewell's troops in the attack on I Corps
. At about 3 p.m., another of Ewell's Confederate divisions, commanded by General Jubal Early, attacked the flank of the Union XI Corps. By 4 p.m., both of the Union corps retreated through Gettysburg and took up positions on Cemetery Ridge. So far, the Union had lost about 9,000 men including about 3,000 who had been captured. The Confederates had lost about 6,500 men by this point. So the first day of battle was technically a Confederate victory numbers-wise. But Federal troops held the high ground as more reinforcements were still arriving. Based on the first day's fighting, Lee was convinced he could defeat Meade at Gettysburg.
Late in the day, Lee sent the famous order to Confederate General Richard S. Ewell to take cemetery ridge "if practicable.” While he had been awaiting orders from Lee, Ewell had ridden out to take a closer look at Cemetery Ridge. Based on what he saw and the confusing order, he decided it was not practicable to take the hill and set up camp. Instead, he decided to leave the assault for the next day. This was the first major mistake of the battle for the South. The Army of the Potomac would end the day with around 21,900 men strongly positioned on Culp's Hill and Cemetery Ridge. The Army of Northern Virginia would have around 27,000 men from Benner's Hill to Seminary Ridge.

July 2
On the second day of battle, most of both armies had arrived. The Union line held the high ground in a defensive formation that looked like a fishhook. On July 2, Lee ordered General James Longstreet, commander of the Confederate I Corps, to attack the Union left flank as early in the day as possible. At the same time General A. P. Hill's corps was to attack the Union center. General Ewell was to make diversionary attacks and "if practicable" attack the Union Army's right flank. Lee felt that if everything went according to his plan and the Union line was destroyed, the battle, and possibly the war, would be won on the second day. Lee's coordinated attack required getting all the infantry into position and moving up artillery to support them. Longstreet had the furthest to go and midway in their march realized the Union lines could see them. They went back and had to take a different route. Longstreet could not get his corps into position until about 4 p.m. when he began his attack
. His attack on the Union line lasted for over three hours but could not break the Union line. Hill's Corps failed to be effective in the center. Ewell did not attack Cemetery Ridge as instructed in Lee's confusing order, but made some progress in taking Culp's Hill.
Union Major General Daniel Sickles, a political general commanding III Corps, disobeyed Meade's orders and moved his troops forward to the Peach Orchard. He had been ordered to take up a position on Little Round Top connecting with Union forces on both his right and left. By doing this he left a large hole in the Union line. He marched to a position nearly  in front of the Union line with no support on either side. Within an hour, his entire III Corps was nearly wiped out by Longstreet. Sickles was badly wounded by a cannonball and lost a leg. Being wounded was all that saved him from a court-martial. Sickles' blunder nearly lost the entire battle for the Union.
On the night of July 2, Longstreet's largest division commanded by General George Pickett arrived and was placed in the center of the Confederate line. Lee's plan for the next day was to attack on both the Union right and left, just as he had done the day before. Lee was still certain he could break the Union line and win the battle. That day Stuart's cavalry had caught up with Lee's army and Lee ordered Stuart to ride around the East side of Gettysburg and attack the Union rear. Ewell had also been reinforced and was ordered to take Culp's Hill the next morning.

Meade ordered the Union XII Corps to drive Ewell's forces off the captured trenches on Culp's Hill. They were to move at daylight the next morning. He was determined the remainder of the Union Army would hold its position and wait for Lee to attack.
July 3 
Ewell began fighting on Culp's Hill at first light. Lee rode to Longstreet's headquarters only to find Longstreet had misunderstood his orders. He was planning a turning movement against the Union left. Now, with no hope of a coordinated attack, Lee changed the plan. Longstreet was to attack the Union center on Cemetery Ridge. Ewell's forces failed in their counterattacks and were forced to withdraw from Culp's Hill by about 11:00 a.m. Lee pinned all his hopes on Longstreet's attack on the center. Longstreet had the last fresh division in Lee's army. It was made up of three brigades, commanded by generals James L. Kemper, Richard B. Garnett, and Lewis A. Armistead, led by Pickett.
Cannons 
First, a bombardment by about 140 Confederate cannons on the Union lines was ordered. The bombardment started about 1 p.m. About 80 Union cannons returned fire. The cannons duel lasted for between one and two hours, depending on the source (most say about an hour). The Confederate artillery chief, General Edward Porter Alexander, had only intended it to last for about 25 minutes. But he then realized it had done little damage to the Union line so he continued. But he also had to worry about running out of ammunition and not have enough to support the charge that was Pickett was about to make. When the Union guns fell silent, Porter thought he had knocked them out. But it was a trick by the Union artillery chief. His guns were waiting for the charge the Union forces knew was coming. Alexander sent word to Pickett he could start his attack.
The cannonade could be heard as far away as Philadelphia. The noise was so loud the gunner's ears bled. It was probably the loudest noise that had ever been heard on the North American continent up to that time. In the end the Confederate cannons may have killed as many as 200 Union soldiers in the area that would later become known as the "bloody angle". But the Union guns may have killed more Confederate troops.

Pickett's Charge
Pickett's Charge 

Calling the Confederate attack on the Union center "Pickett's Charge" is misleading for two reasons. First, Pickett commanded only one of the three units in the assault. Second, it was not a charge, which is a rapid advance towards the enemy, it was an attack which moved forward more slowly and over a longer distance. These Virginia units were joined by several smaller units of Confederates (some from North Carolina, Tennessee and Alabama) whose numbers had been reduced by the fighting over the first two days. When the cannons stopped, Pickett went to Longstreet to ask permission to begin the attack. Longstreet, sure the attack would fail, silently nodded his head and gave a wave of his hand. Longstreet had tried to get Lee to call off the attack, but Lee would not listen.
Over 12,000 Confederates stepped out from the trees and formed up for the long march forward. Waiting for them behind a low stone fence on Cemetery Ridge were about 5,000 Union troops, most of whom belonged to General Winfield Scott Hancock's II Corps. Depending on the source, this was between 2:00 and 3:00 p.m. As they marched forward across the  distance, Union artillery killed large numbers of troops. Rifle fire from the Union line was intense. The Union troops used four lines of soldiers. As the line in front fired, they moved back to reload while the next line moved up to fire. Only a few hundred of the Virginians reached the Union line. Within minutes they were dead or dying. Some were captured. The attack lasted about an hour with over 7,000 Confederate soldiers killed. As the remaining Confederate troops retreated, Lee was seen riding his horse saying "this was all my fault". He then told Pickett to rally his division. Pickett famously replied, "General, I have no division."
Lee brought an army into Pennsylvania that numbered 75,054 men and lost 22,638 casualties or about 30% of his army. Meade lost so many field grade officers that the Army of the Potomac would not recover for the rest of the war. Both the Union I Corps and III Corps lost so many men they had to be combined with II Corps. The battle took more American lives than any other battle in United States history. Gettysburg is still the largest battle to ever be fought on American soil. The Union victory over the Confederacy ended Lee's invasion of the north. Lee would never try to invade the Union again. The Army of Northern Virginia would never get their strength back. However the supplies taken during their time in Pennsylvania would keep the Confederate army going. The wagon train of supply wagons and ambulances for the wounded was over  long. Lee never had more than 51,000 men the rest of the war. Numbers from the Union forces wore down Lee and his army
. This is why Gettysburg is said to be the turning point of the American Civil War. After the battle the confederates figured out that there was a slave spy.
Meade was severely criticized for not counterattacking Lee after the third day of battle. The next day Meade sent out skirmishers, but did not attack. Lee had his army hold its position on Seminary Ridge all day on July 4. The more than 10,000 wounded men would be moved by wagon train  to Williamsport and cross the Potomac to Virginia. The rest of Lee's army followed on the night of July 4–5, screened by Jeb Stuart's cavalry. The next day, on discovering the Confederates had left the battlefield, the Union army cautiously followed. At the Battle of Falling Waters, Lee's army was waiting for the flooded Potomac River to go down so his army could cross. Meade's forces caught up with them there but the battle had no clear victor. The Battle of Falling Waters was the last battle in the Gettysburg Campaign.

Notes

References

Other websites 
 Battle of Gettysburg, 1863; YouTube
 If the Civil War Had a Different Ending; The National Interest
 Cannons of Gettysburg; YouTube
 Battle of Gettysburg -Citizendium
Gettysburg, Battle of
Gettysburg, Pennsylvania
1863 in Pennsylvania
July 1863 events
The New International Version or NIV is an English translation of the Christian Bible.  It is made by the Zondervan Company. It became one of the most popular modern translations made in the twentieth century. The NIV was last updated in 2011.

References

Bible versions
The New American Bible is a Roman Catholic translation of the Bible into English. It was translated from the Bible's original languages and first made in 1970.

Other websites
The New American Bible  online edition

Bible versions
1970 books
TED is short for "Technology, Entertainment, Design". It is a conference that began in 1984 and met every year at Long Beach, California until 2014. Since then, it has met in Vancouver. People give talks about many things, for example, science, art, and business. Famous people like Bill Clinton, Al Gore, Ray Kurzweil, Aubrey de Grey, Elon Musk, and Bill Gates have all talked at TED. The talks have been online for people to watch for free since 2006.

Other websites
 Official website
 YouTube page

1984 establishments in the United States
Technology
A plutoid or ice dwarf is a dwarf planet that orbits the sun farther than Neptune. Four objects are now classified as plutoids:

Pluto
Haumea
Makemake
Eris

Others might be included in the same class someday:
Sedna
Quaoar
2007 OR10

Dwarf planets
The Radcliffe Line became the international border between India and Pakistan (which also included what is now Bangladesh) during the partition of India. The line divided Bengal into Indian held West Bengal and East Bengal which became East Pakistan in 1956. The line was decided by the Border Commissions headed by , who was to divide equitably  of territory with 88 million people.
The line took effect on 17 August 1947 after the Partition of India. When the partition was implemented, there were some problems:
The Chittagong Hill Tracts had a moslty Buddhist population, but they were given to East Pakistan (now Bangladesh).
To counterbalance the relatively small share of Gurdaspur district awarded to Pakistan, Radcliffe attempted to instead transfer Ferozpur and Zira tehsils in Muslim-Majority Ferozpur District to Pakistan. This was opposed by the Maharaja of Bikaner because Harike headworks on the confluence of the Sutlej and the Beas rivers, from where a canal originated, was the only source of water for his desert state was in Ferozepore. It was only after he threatened Lord Louis Mountbatten, that he would accede his princely state to Pakistan if Firozpur was awarded to West Punjab province, that the award was changed at the last minute and all of Firozpur District was awarded to East Punjab in the Republic of India.
The Gurdaspur District was moslty Muslim, but was given to India.
Sometimes the line  divided villages, so one part of the village was in each country. At other instances, it went through houses, different rooms of the same house were in different countries.
Related pages
 Punjab (India)
 Bengal (India)

Borders of Pakistan
Borders of India
Geography of Bangladesh
Pakistan Movement
Partition of India
These are some of the largest onshore wind farms in the UK:

Wind energy
United Kingdom-related lists
The Dipsacales are an order of flowering plants, included within the asterid group of dicotyledons. Under the APG II definition some well-known members of Dipsacales are honeysuckle, elder, viburnum, and valerian.

Dipsacales
A planetary nebula is a nebula that is made up of gas and plasma. They are made by certain types of stars later in their life. They look like planets through small optical telescopes. They do not last for long compared to a star, only tens of thousands of years.

At the end of a normal-sized star's life, in the red giant phase, the outside layers of a star are ejected. Because the outside is gone, the star shines brightly and is very hot. The ultraviolet radiation given off by the center of the star ionizes the gas and plasma that was thrown out from the star. This is what causes a planetary nebula to look like it does.
While some planetary nebulae look similar, others have very distinct and unique shapes. Scientists are not sure why planetary nebulae can look so different from one another. Scientists think that binary stars, stellar winds and magnetic fields might be some of the reasons planetary nebulae can look so varied. In the early 21st century some astronomers began calling them “globular nebulas” to avoid confusing them with the protoplanetary nebulas that make planets.

Observations

Planetary nebula are not very bright. None of them are bright enough to see without a telescope. The first one discovered was the Dumbbell nebula. 
Astronomers did not know what these objects were until the first spectroscopic experiments were done in the 1800's. William Huggins used a prism to look at galaxies. He noticed that they looked a lot like stars.
When he looked at the Cat's Eye nebula, it did not look the same. He saw an emission line at a place that no one had seen before. This meant that it looked like an element that no one had ever seen before. Scientists thought it might be a new element. They decided to call it nebulium.

Later, physicists showed that it is possible for gasses with a very low density to look like something else. It turned out that the gas they were looking at was oxygen, and not nebulium.

The stars in planetary nebulae are very hot. They are not very bright, though. This means that they must be very small. The only time that stars get that small is when they are dying. That means that they are one of the last steps in a star's death. Astronomers saw that all planetary nebula are expanding. This meant that they were caused by a star's outer layers being thrown into space at the end of its life.
Origins
Stars weighing more than eight solar masses will become supernovae. Stars of lesser mass will form planetary nebulae. After billions of years of stellar evolution a star will have no more hydrogen. This makes the surface of the star colder, and makes the core smaller. The sun's core is about 15 million degrees Kelvin. When it runs out of hydrogen, the smaller core will cause it to rise to about 100 million degrees Kelvin.

The outer layers of the star become much bigger because of the heat of the core, and become much cooler. The star becomes a red giant. The core gets even smaller and hotter. When its reaches 100 million K, helium begins to fuse into carbon and oxygen. When this happens, the core stops shrinking. Helium burning soon forms a core of carbon and oxygen, with both a helium and a hydrogen shell surrounding it.
Because helium in fusion reactions is not very stable, the core starts to grow and shrink very quickly. Strong stellar winds blow the gas and plasma in the outer layer of the star outwards. These gases form a cloud around the core of the star. As more and more of the gas moves away from the star, deeper and deeper layers at higher and higher temperatures are sent out. When the gas heats up to around 30,000 degrees kelvin, the gas starts to glow. The cloud has then become a planetary nebula.

Numbers and position 
We know of about 3,000 of these nebulae in our galaxy, compared to 200 billion stars.<ref>Parker Q.A. et al. 2006. The Macquarie/AAO/Strasbourg H-alpha Planetary Nebulae Catalogue: MASH, MNRAS 373, 79</ref> Their very short lifetime compared to a star is why there are not that many compared to stars. They are found mostly in the plane of the Milky Way, and there are more and more the closer you get to the center of the Milky Way.
Shape
Only about twenty percent of planetary nebulae are spheres (like Abell 39). The rest of them have various shapes. The reason for these shapes is not understood. It may be because of the gravitational pull of secondary stars (for example, if it is a binary star system). A second theory is that planets near the star might change how the nebula forms. A third theory is that magnetic fields cause the shapes.  .

Problems
A problem in studying planetary nebulae is that astronomers can not always work out how far away they are. When they are close, astronomers use something called expansion parallax'' to  estimate how far away they are, but this takes a long time. If they are not close, there is not yet a good way to find how distant they are.

Related pages
 Interstellar medium
 Nebula
 Stellar evolution
 White dwarf

References
References

Other websites
 Entry in the Encyclopedia of Astrobiology, Astronomy, and Spaceflight
 Press release on recent observations of the Cat's Eye nebula
 Planetary Nebulae , SEDS Messier Pages
 The first detection of magnetic fields in the central stars of four planetary nebulae 
 WWW search for Galactic planetary nebulae 
 Planetary nebulae - Information and amateur observations
 Planetary nebula on arxiv.org

Nebulae
An emission nebula is a cloud of plasma emitting light in many colors. The glowing is caused by a star being near the nebula. There are many types of emission nebula. H II regions are caused when stars are forming and are very hot, causing the plasma to heat up. Planetary nebulae are made when where a dying star has thrown off its outer layers. This causes the core of the star to heat up the plasma.

General information
A nebula's color depends on what chemicals are in it, and how ionized it is. Because most of the universe is made of hydrogen, many emission nebulae appear red. Hydrogen glows red when it is hot. If the nebula is very hot, other types of gas will be heated and the it might also glow blue and green. By looking at which colors are glowing in a nebula, one can figure out what it is made of.

Emission nebulae sometimes look like they have dark areas in them. This is because clouds of dust block the light when it is traveling between the nebula and the Earth.
Related pages
Reflection nebula
Planetary nebula

Nebulae
In astronomy, a reflection nebula is a cloud of dust which reflects the light of a star or many stars. The light from the nearby stars is not hot enough to ionize the gas of the nebula to make an emission nebula. However, is enough to make the dust visible because the light reflects off of the dust. 

Reflection nebulae are usually blue because the scattering works better for blue light than red (this is the same reason that the sky is blue and sunsets are red).

Reflection nebulae and emission nebulae are usually seen together and sometimes are called 'diffuse nebulae'. A good example of this is the Orion nebula.

Reflection nebulae may also be the site of star formation.

Related pages
 Variable nebula

References 
 James B. Kaler (1998). Kosmische Wolken. Materie-Kreisläufe in der Milchstraße. Spektrum Akademischer Verlag.

Nebulae
A variable nebula is a reflection nebula that gets brighter and darker because of changes in its star.

Nebulae
Ionization is the physical process of giving or taking away electrons from an atom. That makes the atom into an ion, because ions have electrical charge. 

In the process of ionization, an electrically neutral atom becomes either positively or negatively charged. Some substances are easier to ionize than others. This depends on the ionization energy. Ionizing radiation is a common cause, but ionization can also be done by high temperature, radioactive decay, or other causes.

References 

Physics
Nucleosynthesis is the physical process where lighter elements are changed into heavier elements. This usually happens in the center of a star, both during its life and especially during its violent death. It is also thought that this happened at the beginning of the universe, in the big bang.

Related pages 
Stellar nucleosynthesis
Big Bang nucleosynthesis

Astrophysics
Nuclear physics
Stellar wind is gas being thrown off from the upper atmosphere of a star.  Different types of stars have different types of stellar winds.  The Sun's stellar wind is called solar wind.  Most stars, especially very bright ones, show continuous outflows of gas from their surfaces making the stellar wind.  Radiation pressure is thought to be the main force that pushes the gas away, but modern research uses computer simulations and observations with the most powerful telescopes to understand it further.

References

Astrophysics
The Dumbbell nebula (sometimes called Messier 27, M 27, or NGC 6853) is a planetary nebula in the constellation Vulpecula. It is about 1,360 light years away from earth. The Dumbbell nebula was the first planetary nebula to be discovered; by Charles Messier in 1764.

Other websites
 SEDS Messier page on M27 
 M27 Dumbbell Nebula
 M27 image taken by Stargazer Observatory 

Nebulae
Charles Messier (June 26, 1730 – April 12, 1817) was a French astronomer who is remembered for publishing a list of famous objects in space that came to be called the 103 "Messier objects".

Messier's life
Messier was born in Badonviller in the Lorraine region of France. Six of his brothers and sisters died as children and in 1741, his father died. Charles became interested in astronomy after he saw the great six-tailed comet in 1744 and by a solar eclipse on July 25, 1748.

In 1751 he started working for Joseph Nicolas Delisle, the astronomer of the French Navy, who told him to write down everything he saw.

Messier discovered thirteen comets :

 C/1760 B1 (Messier)
 C/1763 S1 (Messier)
 C/1764 A1 (Messier)
 C/1766 E1 (Messier)
 C/1769 P1 (Messier)
 D/1770 L1 (Lexell)
 C/1771 G1 (Messier)
 C/1773 T1 (Messier)
 C/1780 U2 (Messier)
 C/1788 W1 (Messier)
 C/1793 S2 (Messier)
 C/1798 G1 (Messier)
 C/1785 A1 (Messier-Mechain)

Related pages
 Messier object
 List of Messier objects
 Messier marathon

References
References

Other websites
 Amateur Photos of Charles Messier Objects 
 Messier Marathon  Tries to find as many Messier objects as possible in one night.
 New General Catalog and Index Catalog revisions
 Clickable table of Messier objects 

1730 births
1817 deaths
French astronomers
Astronomical spectroscopy is the science of using spectroscopy to figure out what elements astronomical bodies, such as stars, planets and nebulae, are made of. It can also be used to work out how those objects are moving, using doppler shift.

The study of spectroscopy and spectra is used in astronomy to help scientists study the whole spectrum of electromagnetic radiation, including visible light, which radiates from stars and other hot celestial objects. Spectroscopy can be used to find properties of distant stars and galaxies. It can find out their chemical composition, temperature, density, mass, distance, luminosity, and relative motion using doppler effect measurements.

Chemical properties of stars 

Isaac Newton used a prism to split white light into a spectrum of color, and Fraunhofer's high-quality prisms allowed scientists to see dark lines of an unknown origin.
It was not until the 1850s that Gustav Kirchoff and Robert Bunsen explained the dark lines. Hot solid objects produce light with a continuous spectrum, and hot gasses emit light at specific wavelengths. However, hot solid objects surrounded by cooler gasses show a near-continuous spectrum with dark lines corresponding to the emission lines of the gasses. By comparing the absorption lines of the
Sun with emission spectra of known gasses, the chemical composition of stars can be discovered.

References 

Astrophysics
Spectroscopy
Sir William Huggins, KCB, OM, FRS, (7 February 1824–12 May 1910) was an English astronomer best known for his work in astronomical spectroscopy.

Life and work 
William Huggins was born at Cornhill, Middlesex in 1824.  He married Margaret Lindsay, who was also an astronomer. 
Huggins built his own observatory from where he and his wife looked at spectral emission lines and absorption lines of astronomical objects.  He was the first person to figure out the difference between nebulae and galaxies. 
Huggins was president of the Royal Society between 1900 and 1905.

1824 births
1910 deaths
English astronomers
Order of Merit
Knights Commander of the Order of the Bath
Presidents of the Royal Society
Fellows of the Royal Society
The emission spectrum of an element or compound is how bright certain frequencies are when energy is added to the atoms or molecules.

Each atom's emission spectrum has different spectral lines and can be used to figure out if that atom is part of a compound

Physics
Luminosity is the amount of power given off by an astronomical object.

Stars and other objects emit energy in the form of radiation. It is measured in joules per second, which are equal to watts. A watt is one unit of power. Just as a light bulb is measured in watts, the Sun can also be measured in watts. The sun gives off . This amount of power is known as 1 sol, the symbol for which is .  

There are other ways to describe luminosity. The most common is apparent magnitude, which is how bright an object looks to an observer on Earth. It only applies to light, that is, visible wavelengths. Apparent magnitude is contrasted with absolute magnitude, which is an object's intrinsic brightness at visible wavelengths, irrespective of distance.  The apparent magnitude is the less, for objects more than 32.6 light years away.

When talking about the total power output across all wavelengths, that is called bolometric magnitude.  

Laws of physics
Solar mass is a unit of measurement of mass. It is equal to the mass of the Sun, about 332,950 times the mass of the Earth, or 1,048 times the mass of Jupiter. Masses of other stars and groups of stars are listed in terms of solar masses. Its mathematical symbol and value are:

 (kg being kilograms)

Astronomy
Units of mass
In astronomy, the interstellar medium (sometimes called the ISM) is the tenuous gas and dust that fills the void between stellar systems in galaxies, that consisting mainly of huge clouds of ionized, neutral, or molecular hydrogen. This gas and dust not distributed uniformly in interstellar space, but displays significant variations in density, temperature, and ionisation state.

Various gases exist in outer space. Most common are hydrogen and helium. Interstellar cosmic dust makes nebulae.

References 

Astronomy
Myopia, also called near-sightedness or short-sightedness, is a problem with the focusing ability of the eye. It is when the eye is not able to focus properly on objects in the distance. This condition is very common and it often occurs with many members of the same family. It happens when the lens becomes a different shape (too curved) from usual, or when the eye is longer than normal, so light entering the eye focuses on a point in front of the retina, rather than right on it. This makes distant objects look blurry. People with myopia often squint while watching television or trying to see distant objects. Sudden myopia can often be the first symptom of Type II Diabetes. 

In most cases, it can be fixed easily using glasses, contact lenses, or surgery. 

Diseases and disorders of the eye
Luster (or lustre) is a description of the way light interacts with the surface of a crystal, rock, or mineral. For example, a diamond has an adamantine lustre and pyrite has a metallic lustre. The term is also used to describe other items with some kind of sheen (for example, fabric, especially silk and satin, or metals).

The word lustre comes from the Latin word lux, meaning "light", and generally implies radiance, gloss, or brilliance.

Minerals
Carbonation is the process of carbon dioxide dissolving in a liquid. For example, carbon dioxide is added to flavored water under pressure to make it "fizz" as a carbonated water soft drink.

Geology
When rain passes through the atmosphere, it takes in or mixes with carbon dioxide, turning it into a weak carbonic acid.  When the rain falls in limestone, it dissolves the calcium carbonate in the rock, turning it into calcium bicarbonate and taking it away.  Holes and large cracks can form in the rock.  Such a place is called karst.  If a stream or river passes through it, it could be swallowed up by a hole called a swallow hole.  It  can go through a series of underground caves and may appear on the surface again.  An example of a karst area is the Burren National Park, in County Clare, Ireland.

Chemistry
Chemistry

Carbon dioxide is weakly soluble in water, therefore it separates into a gas. The process of carbon dioxide bubbling out (effervescing) from a solution is represented by the following chemical reaction. This shows aqueous carbonic acid converts to carbon dioxide and water:

Biochemistry

Carbonation also describes the incorporation of carbon dioxide into chemical compounds. Carbon-based life originates from a carbonation reaction that is most often catalysed by the enzyme RuBisCO. This carbonation process is so important that a significant fraction of leaf mass consists of this carbonating enzyme.

References

Matter
Physics
Geochemistry
A Feynman diagram is a diagram that shows what happens when elementary particles collide.

Feynman diagrams are used in quantum mechanics. A Feynman diagram has lines in different shapes—straight, dotted, and squiggly—which meet up at points. The points in Feynman diagrams represent a meeting between three particles at the same point in space at the same time. The lines in a Feynman diagram represent the probability amplitude for a particle to go from one place to another.

In Feynman diagrams, the particles are allowed to go both forward and backward in time. When a particle is going backward in time, it is called an antiparticle. The meeting points for the lines can also be interpreted forward or backwards in time, so that if a particle disappears into a meeting point, that means that the particle was either created or destroyed, depending on the direction in time that the particle came in from.