Stray Black Hole Turned Cosmic Gas Cloud into Speeding 'Bullet'

A stray black hole may be responsible for turning a gas cloud into a speeding cosmic bullet trillions of miles long.

The wandering black hole was discovered lurking just outside a supernova remnant, a shell of expelled material left behind after a massive star explodes. Using the Atacama Submillimeter Telescope Experiment (ASTE) in Chile and the 45-meter (148 feet) Radio Telescope at Nobeyama Radio Observatory, astronomers found that the black hole had been previously hidden by a compact gas cloud emerging from the remnant.

The cloud itself has now been named "the Bullet," because of its long, cone shape and its incredible speed — part of the cloud is moving away from the supernova remnant at more than 60 miles per second [100 kilometers per second], "which exceeds the speed of sound in interstellar space by more than two orders of magnitude," Nobeyama Radio Observatory scientists said in the statement. The researchers now suspect that the black hole might have played a role in forming the gaseous "bullet."

The supernova remnant, called W44, is located 10,000 light-years from Earth. The Bullet, which is about 2 light-years long [11.76 trillion miles, or 18.9 trillion km], is so energetic that it moves backward against the rotation of the Milky Way galaxy, according to the Nobeyama Radio Observatory statement.

"Most of the Bullet has an expanding motion with a speed of 50 km/s [31 miles per second], but the tip of the Bullet has a speed of 120 km/s [75 miles per second]," Masaya Yamada, lead author of the new study and a graduate student at Keio University in Japan, said in the statement. "Its kinetic energy is a few tens of times larger than that injected by the W44 supernova. It seems impossible to generate such an energetic cloud under ordinary environments."

So what could possibly send such a huge amount of molecular gas streaming out of the supernova remnant at such high speeds? The discovery of the hidden black hole may offer an explanation.

The researchers developed two possible scenarios for how the Bullet might have formed. The first, called the explosion model, suggests that the cloud passed by a static black hole and was pulled in by the black hole's strong gravitational forces. This could have created a powerful explosion of gas that was spit back out into space, Nobeyama scientists said.

Another theory, called the irruption model, proposes that a high-speed black hole tore through the dense molecular cloud, and the black hole's powerful gravitational pull left a stream of gas in its wake. Further research is required to determine which model best explains the origin of the Bullet, according to the study, published Dec. 29, 2016, in The Astrophysical Journal Letters.

Although millions of black holes are thought to exist in the Milky Way, it is often difficult to locate them because they are completely black. However, this study has revealed a new way for astronomers to detect these types of elusive, stray black holes — by their influence on molecular gas clouds — that would otherwise float alone in space and remain unnoticed with no observable emissions, the scientists said in the statement.

“Elementary fermions are grouped into three generations, each comprising two leptons and two quarks. The first generation includes up and down quarks, the second strange and charm quarks, and the third bottom and top quarks. All searches for a fourth generation of quarks and other elementary fermions have failed,[18][19] and there is strong indirect evidence that no more than three generations exist.[nb 2][20][21][22]

Particles in higher generations generally have greater mass and less stability, causing them to decay into lower-generation particles by means of weak interactions. Only first-generation (up and down) quarks occur commonly in nature.

Heavier quarks can only be created in high-energy collisions (such as in those involving cosmic rays), and decay quickly; however, they are thought to have been present during the first fractions of a second after the Big Bang, when the universe was in an extremely hot and dense phase (the quark epoch). Studies of heavier quarks are conducted in artificially created conditions, such as in particle accelerators.[23]

Having electric charge, mass, color charge, and flavor, quarks are the only known elementary particles that engage in all four fundamental interactions of contemporary physics: electromagnetism, gravitation, strong interaction, and weak interaction.[12] Gravitation is too weak to be relevant to individual particle interactions except at extremes of energy (Planck energy) and distance scales (Planck distance). However, since no successful quantum theory of gravity exists, gravitation is not described by the Standard Model.

See the table of properties below for a more complete overview of the six quark flavors’ properties.”

https://en.wikipedia.org/wiki/Quark#Classification

Origin of the Elements

Approximately 73% of the mass of the visible universe is in the form of hydrogen. Helium makes up about 25% of the mass, and everything else represents only 2%. While the abundance of these more massive (”heavy”, Atomic # greater than 4) elements seems quite low, it is important to remember that most of the atoms in our bodies and Earth are a part of this small portion of the matter of the universe.

The low-mass elements, hydrogen and helium, were produced in the hot, dense conditions of the birth of the universe itself. The birth, life, and death of a star is described in terms of nuclear reactions. The chemical elements that make up the matter we observe throughout the universe were created in these reactions.

Approximately 15 billion years ago the universe began as an extremely hot and dense region of radiant energy, the Big Bang. Immediately after its formation, it began to expand and cool. The radiant energy produced quark-antiquarks and electron-positrons, and other particle-antiparticle pairs. However, as the particles and antiparticles collided in the high energy gas, they would annihilate back into electromagnetic energy. As the universe expanded the average energy of the radiation became smaller. Particle creation and annihilation continued until the temperature cooled enough that pair creation became no longer energetically possible.

One of the signatures of the Big Bang that persists today is the long-wavelength radiation that fills the universe. This is radiation left over from the original explosion. The present temperature of this “background” radiation is 2.7 K. (The temperature, T, of a gas or plasma and average particle kinetic energy, E, are related by the Boltzmann constant, k = 1.38 x 10-23 J/K, in the equation E = kT.) Figure 10.1 shows the temperature at various stages in the time evolution of the universe from the quark-gluon plasma to the present time.

Fig. 10-1. The evolution of the universe

At first quarks and electrons had only a fleeting existence as a plasma because the annihilation removed them as fast as they were created. As the universe cooled, the quarks condensed into nucleons. This process was similar to the way steam condenses to liquid droplets as water vapor cools. Further expansion and cooling allowed the neutrons and some of the protons to fuse to helium nuclei. The 73% hydrogen and 25% helium abundances that exists throughout the universe today comes from that condensation period during the first three minutes. The 2% of nuclei more massive than helium present in the universe today were created later in stars.

The nuclear reactions that formed 4He from neutrons and protons were radiative capture reactions. Free neutrons and protons fused to deuterium (d or 2H) with the excess energy emitted as a 2.2 MeV gamma ray,

n + p Æ d + g.

These deuterons could then capture another neutron or free proton to form tritium (3H) or 3He,

d + n Æ 3H + g and d + p Æ 3He + g.

Finally, 4He was produced by the reactions:

d+ d Æ 4He + g, 3He + n Æ 4He + g and 3H + p Æ 4He + g.

Substantial quantities of nuclei more massive than 4He were not made in the Big Bang because the densities and energies of the particles were not great enough to initiate further nuclear reactions.

It took hundreds of thousands of years of further cooling until the average energies of nuclei and electrons were low enough to form stable hydrogen and helium atoms. After about a billion years, clouds of cold atomic hydrogen and helium gas began to be drawn together under the influence of their mutual gravitational forces. The clouds warmed as they contracted to higher densities. When the temperature of the hydrogen gas reached a few million kelvin, nuclear reactions began in the cores of these protostars. Now more massive elements began to be formed in the cores of the very massive stars.

http://www2.lbl.gov/abc/wallchart/chapters/10/0.html

Question
What is Planck length? What is Planck time?

Answer
The Planck length is the scale at which classical ideas about gravity and space-time cease to be valid, and quantum effects dominate. This is the “quantum of length”, the smallest measurement of length with any meaning.

And roughly equal to 1.6 x 10-35 m or about 10-20 times the size of a proton.

The Planck time is the time it would take a photon traveling at the speed of light to across a distance equal to the Planck length. This is the “quantum of time”, the smallest measurement of time that has any meaning, and is equal to 10-43 seconds.

No smaller division of time has any meaning. With in the framework of the laws of physics as we understand them today, we can say only that the universe came into existence when it already had an age of 10-43 seconds.

Answered by: Dan Summons, Physics Undergrad Student, UOS, Souhampton

http://www.physlink.com/education/askexperts/ae281.cfm

There is currently no proven physical significance of the Planck length; it is, however, a topic of theoretical research. Since the Planck length is so many orders of magnitude smaller than any current instrument could possibly measure, there is no way of examining it directly.

According to the generalized uncertainty principle (a concept from speculative models of quantum gravity), the Planck length is, in principle, within a factor of 10, the shortest measurable length – and no theoretically known improvement in measurement instruments could change that.[citation needed]

In some forms of quantum gravity, the Planck length is the length scale at which the structure of spacetime becomes dominated by quantum effects, and it is impossible to determine the difference between two locations less than one Planck length apart. The precise effects of quantum gravity are unknown; it is often guessed that spacetime might have a discrete or foamy structure at a Planck length scale.[citation needed]

The Planck area, equal to the square of the Planck length, plays a role in black hole entropy. The value of this entropy, in units of the Boltzmann constant, is known to be given by (see link), where A is the area of the event horizon. The Planck area is the area by which the surface of a spherical black hole increases when the black hole swallows one bit of information, as was proven by Jacob Bekenstein.[3]

If large extra dimensions exist, the measured strength of gravity may be much smaller than its true (small-scale) value. In this case the Planck length would have no fundamental physical significance, and quantum gravitational effects would appear at other scales.

In string theory, the Planck length is the order of magnitude of the oscillating strings that form elementary particles, and shorter lengths do not make physical sense.[4] The string scale ls is related to the Planck scale by (see link), where gs is the string coupling constant. Contrary to what the name suggests, the string coupling constant is not constant, but depends on the value of a scalar field known as the dilaton.

In loop quantum gravity, area is quantized, and the Planck area is, within a factor of 10, the smallest possible area value.

In doubly special relativity, the Planck length is observer-invariant.

The search for the laws of physics valid at the Planck length is a part of the search for the theory of everything.[clarification needed]

https://en.wikipedia.org/wiki/Planck_length#Theoretical_significance

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