Binary Neutron Stars

About 5% of all known neutron stars are members of a binary system. The formation and evolution scenario of binary neutron stars is a rather exotic and complicated process.

The companion stars may be either ordinary stars, white dwarfs or other neutron stars. According to modern theories of binary evolution it is expected that neutron stars also exist in binary systems with black hole companions. 

Such binaries are expected to be prime sources for emittinggravitational waves. Neutron stars in binary systems often emit X-rays which is caused by the heating of material (gas) accreted from the companion star. 

Material from the outer layers of a (bloated) companion star is sucked towards the neutron star as a result of its very strong gravitational field. 

As a result of this process binary neutron stars may also coalesce into black holes if the accretion of mass takes place under extreme conditions.

It has been proposed that coalescence of binaries consisting of two neutron stars may be responsible for producing short gamma-ray bursts. Such events may also be responsible for creating all chemical elements beyond iron, as opposed to thesupernova nucleosynthesis theory.

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Mengenal Bintang Neutron

A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. 

Such stars are composed almost entirely of neutrons, which are subatomic particles without net electrical charge and with slightly larger mass than protons. Neutron stars are very hot and are supported against further collapse by quantum degeneracy pressure due to the phenomenon described by the Pauli exclusion principle. 

This principle states that no two neutrons (or any other fermionic particles) can occupy the same place and quantum state simultaneously.

A typical neutron star has a mass between about 1.4 and 3.2 solar masses (see Chandrasekhar Limit), with a corresponding radius of about 12 km.

In contrast, theSun's radius is about 60,000 times that. Neutron stars have overall densities of 3.7×10¹⁷ to 5.9×10¹⁷ kg/m³ (2.6×10¹⁴ to 4.1×10¹⁴ times the density of the Sun), which compares with the approximate density of an atomic nucleus of 3×10¹⁷ kg/m³. 

The neutron star's density varies from below 1×10⁹ kg/m³ in the crust, increasing with depth to above 6×10¹⁷ or 8×10¹⁷ kg/m³ deeper inside (denser than an atomic nucleus). This density is approximately equivalent to the mass of a Boeing 747 compressed to the size of a small grain of sand.

In general, compact stars of less than 1.44 solar masses – the Chandrasekhar limit – are white dwarfs, and above 2 to 3 solar masses (the Tolman–Oppenheimer–Volkoff limit), aquark star might be created; however, this is uncertain. Gravitational collapse will usually occur on any compact star between 10 and 25 solar masses and produce a black hole.

Some neutron stars rotate very rapidly and emit beams of electromagnetic radiation as pulsars.

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Kebijakan Pembangunan Sciences

Science policy is an area of public policy concerned with the policies that affect the conduct of the scientific enterprise, including research funding, often in pursuance of other national policy goals such as technological innovation to promote commercial product development, weapons development, health care and environmental monitoring. 

Science policy also refers to the act of applying scientific knowledge and consensus to the development of public policies. Science policy thus deals with the entire domain of issues that involve the natural sciences.

In accordance with public policy being concerned about the well-being of its citizens, science policy's goal is to consider how science and technology can best serve the public.

State policy has influenced the funding of public works and science for thousands of years, dating at least from the time of the Mohists, who inspired the study of logic during the period of the Hundred Schools of Thought, and the study of defensive fortifications during the Warring States period in China. 

In Great Britain, governmental approval of the Royal Society in the 17th century recognized a scientific community which exists to this day.

The professionalization of science, begun in the 19th century, was partly enabled by the creation of scientific organizations such as the National Academy of Sciences, the Kaiser Wilhelm Institute, and State funding of universities of their respective nations. 

Public policy can directly affect the funding of capital equipment, intellectual infrastructure for industrial research, by providing tax incentives to those organizations that fund research. 

Vannevar Bush, director of the office of scientific research and development for the United States government, the forerunner of the National Science Foundation, wrote in July 1945 that "Science is a proper concern of government" 

Science and technology research is often funded through a competitive process, in which potential research projects are evaluated and only the most promising receive funding. 

Such processes, which are run by government, corporations or foundations, allocate scarce funds.

Total research funding in most developed countries is between 1.5% and 3% of GDP.

In the OECD, around two-thirds of research and development in scientific and technical fields is carried out by industry, and 20% and 10% respectively by universities and government. 

The government funding proportion in certain industries is higher, and it dominates research in social science and humanities. 

Similarly, with some exceptions (e.g. biotechnology) government provides the bulk of the funds for basic scientific research. In commercial research and development, all but the most research-oriented corporations focus more heavily on near-term commercialisation possibilities rather than "blue-sky" ideas or technologies (such as nuclear fusion).

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