The black holes

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational pull.While most stars end up aswhite dwarfsorneutron stars, black holes are the last evolutionary stage in the lifetimes of enormous stars that had been at least10 or 15 times as massive as our own sun.When giant stars reach the final stages of their lives they often detonate in cataclysms known assupernovae. Such an explosion scatters most of a star into the void of space but leaves behind a large"cold" remnant on which fusion no longer takes place.In younger stars, nuclear fusion creates energy and a constant outward pressure that exists in balance withthe inward pull of gravity caused by the star's own mass. But in the dead remnants of a massive supernova, no force opposes gravity—so the star begins to collapse in upon itself.With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.Black holes pull matter and even energy into themselves—but no more so than other stars or cosmic objects of similar mass. That means that a black hole with the mass of our own sun would not"suck" objects into it any more than our own sun doeswith its own gravitational pull.Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

Small But Powerful: Black holes are small in size. A million-solar-mass hole, like that believed to be at the center of some galaxies, would have a radius of just about two million miles (three million kilometers)—only about four times the size of the sun. A black hole with a mass equal to that of the sun would have a two-mile (three-kilometer) radius.Because they are so small, distant, and dark, black holes cannot be directly observed. Yet scientists have confirmed their long-held suspicions that they exist. This is typically done by measuring mass in a region of the sky and looking for areas of large, dark mass.Many black holes exist inbinary star systems. These holes may continually pull mass from their neighboring star, growing the black hole and shrinking the other star, until the black hole is large and the companion star has completely vanished.Extremely large black holes may exist at the center ofsome galaxies—including our own Milky Way. These massive features may have the mass of 10 to 100 billion suns. They are similar to smaller black holes but grow to enormous size because there is so muchmatter in the center of the galaxy for them to add. Black holes can accrue limitless amounts of matter; they simply become even denser as their mass increases.Black holes capture the public's imagination and feature prominently in extremely theoretical concepts like wormholes. These "tunnels" could allow rapid travel through space and time—but there is no evidence that they exist.
posted from Bloggeroid

posted from Bloggeroid

Aliens, the mystery continues

Deep Universe

Aliens and Area 51 : Its secretive nature and undoubted connection to classified aircraft research, together with reports of unusual phenomena, have led Area 51 to become a focus of modern UFO and conspiracy theories. Some of the activities mentioned in such theories at Area 51 include:

The storage, examination, and reverse engineering of crashed alien spacecraft (including material supposedly recovered at Roswell), the study of their occupants (living and dead), and the manufacture of aircraft based on alien technology.
Meetings or joint undertakings with extraterrestrials.
The development of exotic energy weapons for the Strategic Defense Initiative (SDI) or other weapons programs.
The development of means of weather control.
The development of time travel and teleportation technology.
The development of unusual and exotic propulsion systems related to the Aurora Program.
Activities related to a supposed shadowy one world government or the Majestic 12 organization.
Many of the hypotheses concern underground facilities at Groom or at Papoose Lake (also known as "S-4 location"), 8.5 miles (13.7 km) south, and include claims of a transcontinental underground railroad system, a disappearing airstrip (nicknamed the "Cheshire Airstrip", after Lewis Carroll's Cheshire cat) which briefly appears when water is sprayed onto its camouflaged asphalt, and engineering based on alien technology. Publicly available satellite imagery, however, reveals clearly visible landing strips at Groom Dry Lake, but not at Papoose Lake.

In the mid-1950s, civilian aircraft flew under 20,000 feet while military aircraft flew under 40,000 feet. Once the U-2 began flying at above 60,000 feet, an unexpected side effect was an increasing number of UFO sighting reports. Sightings occurred most often during early evenings hours, when airline pilots flying west saw the U-2's silver wings reflect the setting sun, giving the aircraft a "fiery" appearance. Many sighting reports came to the Air Force's Project Blue Book, which investigated UFO sightings, through air-traffic controllers and letters to the government. The project checked U-2 and later OXCART flight records to eliminate the majority of UFO reports it received during the late 1950s and 1960s, although it could not reveal to the letter writers the truth behind what they saw.[25]:72–73 Similarly, veterans of experimental projects such as OXCART and NERVA at Area 51 agree that their work (including 2,850 OXCART test flights alone) inadvertently prompted many of the UFO sightings and other rumors:

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The shape of OXCART was unprecedented, with its wide, disk-like fuselage designed to carry vast quantities of fuel. Commercial pilots cruising over Nevada at dusk would look up and see the bottom of OXCART whiz by at 2,000-plus mph. The aircraft's titanium body, moving as fast as a bullet, would reflect the sun's rays in a way that could make anyone think, UFO.

They believe that the rumors helped maintain secrecy over Area 51's actual operations. While the veterans deny the existence of a vast underground railroad system, many of Area 51's operations did (and presumably still do) occur underground.

Bob Lazar
See: S-4 (facility) for further information
Several people have claimed knowledge of events supporting Area 51 conspiracy theories. These have included Bob Lazar, who claimed in 1989 that he had worked at Area 51's "Sector Four (S-4)", said to be located underground inside the Papoose Range near Papoose Lake. Lazar has stated he was contracted to work with alien spacecraft that the U.S. government had in its possession.
Bruce Burgess
Similarly, the 1996 documentary Dreamland directed by Bruce Burgess included an interview with a 71-year-old mechanical engineer who claimed to be a former employee at Area 51 during the 1950s. His claims included that he had worked on a "flying disc simulator" which had been based on a disc originating from a crashed extraterrestrial craft and was used to train US Pilots. He also claimed to have worked with an extraterrestrial being named "J-Rod" and described as a "telepathic translator".
Dan Burisch
In 2004, Dan Burisch (pseudonym of Dan Crain) claimed to have worked on cloning alien viruses at Area 51, also alongside the alien named "J-Rod". Burisch's scholarly credentials are the subject of much debate, as he was apparently working as a Las Vegas parole officer in 1989 while also earning a PhD at State University of New York (SUNY).