Astrophysics

Yes, black holes are an example of negative pressure. This is because they exert gravitational force so strong that nothing, not even light, can escape from them, creating a region of extreme gravitational pressure.

Saving the full explanation of the processes of a star, just a short rundown: Stars are massive, so massive that their own gravity tries to collapse the star so it has to fuse hydrogen to exert an outward force to overcome its own gravity. During these processes, atoms are being stripped apart into free-floating nuclei, electrons and protons, accumulating in the core for the life of the star. When a star runs out of hydrogen fuel, it collapses and is stopped by the core getting hot enough to fuse helium (Product of hydrogen fusion), and that keeps happening up the atomic chain until the star starts fusing nickel, which requires more energy to fuse than is released, this is the end of a star as we know it.

If a star forms a black hole or a neutron star is dependant completely on the star's mass. If it is heavy enough, if will become a black hole, if not, then it will become a neutron star, where gravitational collapse is halted by the accumulated electrons in the core being compressed with free protons, bonding together to form neutron degenerate matter (Basically neutrons) and exerting an outward force that overcomes collapse. This force is known as neutron degeneracy pressure, courtesy of the Pauli exclusion principle of the Fermi-Dirac statistics. The principle states that no two fermions (Particles with a half-integer spin; quarks and leptons) can occupy the same energy state simultaneously, so you get an outward force.

Now if gravity were to overcome said force, the neutrons would then split into their individual quarks, resulting in quark degenerate matter and halting collapse, although very little is known about quark degeneracy or even how the matter splits into quarks. Then into the hypothetical preon degenerate matter and finally a gravitational singularity. Please note that very little is known about quark and preon degeneracy (The latter being generally not accepted as a viable model) as none have been discovered to date.

Finally, if the star wasn't heavy enough to form a neutron star, the core will decay into a large and hot ball of iron (Nickel decays into iron) and float, slowly cooling for the remainder of its existance or until acted upon by external forces.

Geologists determine the age of the Earth and solar system using radiometric dating of meteorites and rocks. This process measures the radioactive isotopes within these materials to calculate their age. By analyzing the decay rates of these isotopes, scientists have established the estimated age of the Earth and solar system to be around 4.6 billion years.

As more it learned about the universe the mysteries keeps changing. Today, the biggest mystery is probably what caused or happened before the "big bang."

Other mysteries are, what is "dark matter" and gravity. Is there a multiverse (multiple universes) and if so, what form do they take.

It can do in special circumstances, but first understand that the Earth rotates on its axis once every 24 hours and this means that for all people round the Earth for 1/2 of this period they are facing the Sun and during this period it is light and daytime. For the other 12 hours they are facing away form the Sun and therefore in the dark shadow of the earth and it is night.
The ONLY time the Moon can make it dark is when the moon passes between the Earth and the Sun during the day (it does this about once a year) and this causes an eclipse. However the shadow of the Moon is only very small only a small bit of the earth goes dark.

The lack of direct evidence for black holes poses a challenge for scientists because black holes, by their nature, do not emit any light or radiation that can be easily detected. Instead, researchers must rely on indirect observations and theoretical models to infer the presence of black holes. This makes it difficult to conclusively prove their existence through direct observation.

A Hertzsprung-Russell diagram is a scatter graph that can be used to plot the relationship between the absolute magnitude (i.e. luminosity) of a star versus it's spectral type / classification and effective temperature. Since a black hole does not have an absolute magnitude, spectral type, or an effective temperature, it cannot be located on an H-R diagram.

The first black hole discovered is Cygnus X-1, which was identified in 1964 as a strong X-ray source in the constellation Cygnus. It is a binary system with a massive, invisible companion that is believed to be a black hole about 15 times the mass of the Sun.

An intermediate-mass black hole is one with a mass significantly greater than the typical stellar-mass black holes, but less than the supermassive black holes such as are found at galactic centers. Their identification remains difficult, and their origins remain in the realm of speculation, although a reasonable theory hints at the likelihood of their formation from accretion of dense stellar clusters... and one possibly is that they are primordial black holes left over from the creation of the universe.

Astrophysics originated as a branch of astronomy that applied physics concepts to study celestial objects and phenomena. The field developed significantly in the 20th century with advancements in technology, such as telescopes and space missions, enabling scientists to explore the universe in more depth. Today, astrophysics encompasses a wide range of topics, from the study of stars and galaxies to black holes and the cosmic microwave background radiation.

A black hole doesn't have depth. Despite it being called a "hole", it is actually a spherical object that has a singularity at it's centre (where gravity and mass is infinite), and an event horizon that marks the point at which the force of gravity is so strong that not even light can escape. If, by "depth" you meant "diameter", the answer still isn't certain since the diameter of a black hole depends on it's mass (which can be almost anything).

It is FAR easier to change the direction of an asteroid than to blow it up. All that is needed to accomplish the former is to nudge the asteroid a little off its collision course with Earth, and this could be done with some small explosions on the side of that asteroid. Blowing up an asteroid would be a complete waste of energy.

Almost every galaxy has a super massive black hole in its centre and this fact is widely accepted now days . Milky way galaxy also have a super massive black hole of its own, weighing more than 4 million times more than our sun's mass.

Andromeda galaxy is our nearest neighbour having a super massive black hole in its centre weighing 114 million solar masses .

To create a black hole in Universe Sandbox, you can add one by using the “Add” tool and selecting a black hole object from the object catalog. You can then adjust its properties such as mass, radius, and velocity to customize its characteristics in the simulation. Simply placing an object with a large amount of mass in a confined space can also lead to the formation of a black hole due to gravitational collapse.

This will sound cynical, but it's not meant to - it is sincere. The highest paying job in astronomy is popular author, if you can write well, and find an audience for your writings. That's where the real money is in that field (think Carl Sagan and others).

Cosmic rays are a bit of a misnomer since they are actually high energy particles like protons or alpha particles traveling at relativistic speeds (matter), not electromagnetic radiation (energy), so they don't have a canonical frequency range such as, for example, visible light, x-rays, gamma rays, and so forth.

Note however that quantum mechanics indicates a duality in matter where it can have wave-like properties including motion with wave characteristics similar in some ways to propagating electromagnetic energy (illustrated for example by particle interferometry); all matter can therein be said to "move in waves" although any wavelength associated with that motion is not completely described by classical (or at least, non quantum-mechanical) physics.

Such a black hole is never found, but theoretically it should be possible. If the planets are far enough from the black hole where they circle around they will just orbit the black hole in the same way as they would orbit a star with the same mass if it would replace the black hole. But if it exists it would be very hard to detect, exoplanets are detected because of their interaction with their mother star(They block some light and have gravitational influence that can be detectable), for black holes that is not an option because they are obviously black. The planets themselves won't emit light so there is no way we can detect such a system if it exists.

The Cassini-Huygens spacecraft, the largest and most complex unmanned interplanetary probe yet built, accomplished significant scientific advancement on knowledge of Saturn and its moons; testing of the theory of relativity; and accomplished the first landing amongst the outer planets, on Saturn's moon Titan.

Among its goals were a study of the shape and behavior of Saturn's rings, geology of Saturn's satellites, a study of the dark material on Iapetus, a study of the shape of the magnetosphere and atmosphere, and gathering data on Titan's clouds and surface. During a flyby, observations of Jupiter's atmosphere also helped to revise existing theories on its dynamics. Frequency shifting in radio waves from the spacecraft, altered by the Sun's gravitational field, provided accurate verifications of the general theory of relativity.

NASA extended Cassini's mission to continue study of Saturn and its moons.

Red super-giants form when stars of more than ten solar masses begin to burn their helium. Eventually such a star will burn all of possible fuels and go into gravitational collapse, resulting in a super-nova. If the mass left over from this collapse is large enough (a remnant of three to five solar masses), the remnant will collapse into a black hole.

Meteoroids entering Earth's atmosphere usually reach temperatures of around 1,650 to 2,200 degrees Celsius (3,000 to 4,000 degrees Fahrenheit) due to the friction with the air particles at high speeds.

When cosmic dust goes unswept, it means that these small particles of matter, such as grains of ice and dust, remain in space without being cleared away or disturbed by other celestial bodies. Over time, cosmic dust can accumulate and contribute to the formation of cosmic bodies like planets and moons.

Yes, Stephen Hawking was famous for his work on the theoretical physics of black holes, specifically his discovery that they emit radiation now known as Hawking radiation. He was also well-known for his contributions to the field of cosmology, especially his study of the origins and evolution of the universe. Additionally, Hawking was a renowned science communicator, author, and advocate for promoting scientific understanding and education.

Strictly speaking nothing comes out of a black hole itself, but it's fair to say they can cause a significant amount of radiation due to infalling matter, particularly in the accretion disk, and relativistic jets at their poles. The tremendous power of the polar jets is illustrated by active galactic nuclei or quasars, the most distant and radiant objects known in the universe and powered by a supermassive black hole. These can produce up to something around a thousand times the energy of an entire galaxy of billions of stars.