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Astrophysics
Astrophysics is the scientific discipline concerned with the events that are taking place on the grandest of stages; the universe. Questions about the formation and evolution of the planets, solar systems, stars, and galaxies found within the universe, as well as questions regarding black holes, cosmic rays, particle and nuclear astrophysics, nucleosynthesis, and magnetohydrodynamics should be directed here.
1,304 Questions
No. There are no black holes in our solar system. Based on current models, the smallest stellar mass black holes are at the very least about 3 times the mass of the sun. Therefore, if there were a black hole in our solar system the sun would either orbit it or the two would orbit about a common center of mass.
What is a planet in the early stages of formation called?
It is called a 'proto-planet', this is the 'before-planet'-stage; It has gathered enough mass to form a large gravity field and cause a spherical shape.
The onset of nuclear fusion in the core of a star occurs when the the hydrogen in the core reaches a temperature of about 10 million degrees Kelvin. The gravitational force needed to achieve this requires a stellar mass of at least 8.3% of the mass of Earth's Sun.
How do gravitons escape from black holes?
It's safe to assume gravitons, if they exist, don't escape from black holes, or at least, do not escape directly; but this does raise the interesting question as to how mass can interact with other mass if one of them is "hidden" behind an event horizon - could a force-carrier, including a force-carrier particle for gravity escape "outwards" through the event horizon. Gravitons remain in the theoretical realm, and only a few of their properties can be presumed, such as their class, their spin, and their mass (zero). If they are fit into the standard model it will require a theory of quantum gravity, particularly to resolve differences between known properties of the current standard model, since gravitons likely would require the background independence considered fundamental to general relativity. Until that time, general relativity, which proposes that matter affects space and the gravity is a component of spacetime (in other words, gravitation reflects a curvature in spacetime) might provide the most accurate description of how mass 'behind' the event horizon can affect matter outside it, and thus could obviate questions about force-carrier mediations relating to mass.
Quantum effects could in theory support models of particle interactions of the gravity force carrier near the event horizon, based on similar theories consistent with quantum mechanics; Hawking radiation for example has been explained by fluctuations in spacetime boosted by gravity causing virtual particles located just outside the event horizon to become real, and thus allowing mass within the black hole to be 'carried away'; another theory posits that particles can escape from just inside the event horizon by exploiting tunneling (or quantum nonlocality) to 'escape.'
Until gravitons are more fully described (or detected and their existence proven) the question itself could be shown to presume facts not in evidence and/or that theories describing the method of their escape from a black hole should be considered speculative.
Can you make a portal using a black hole?
Portals made from black holes are highly speculative. You are more likely to encounter such portals (usually called wormholes) in science fiction (because it suits the plot), than in serious astronomical literature.
What makes up 98 percent of your solar system?
About 98 percent of the mass of the solar system is in the Sun.
What certain alignments of Earth the Moon and the Sun cause?
It can cause lunar eclipses, and solar eclipses.
How many Galactic years old is your solar system?
Since the Solar System is thought to be about four and a half billion years old, and the galactic year calculated to be around 250 million years, the Solar System's age in terms of galactic or cosmic years would be roughly eighteen.
Can you destroy the black hole?
Yes the black hole can be destroyed. However, man-made objects cannot resist the gravity without getting sucked in. The only thing that can destroy a black hole is time in a process called Hawking Radiation in which the black hole evaporates over time. The smaller the black hole, the faster the process.
No, and I blame the fools in the media for making people think otherwise. Black holes are points in space where gravity reaches infinite levels. And, like a bubble, but for different levels, everything is spherical. Bubbles do it because the surface area is least. Blakc holes do it because the volume is filled most efficiently that way.
Furthermore, if it were, say a cube in shape, the corners of the structure would be pulled in, as there's less to support them than in a sphere.
Where is the black hole located in the galaxy?
Black holes can technically be any where. Some scientists believe that there is a black hole in the center of our galaxy along with many other galaxies. Because black holes are so difficult to detect, they can be very dangerous.
What if black holes are actually planets with an atmosphere that does not reflect back any light?
Black holes aren't actually holes, they're just humongous 'objects' that are so big that they have huge gravitational pulls and therefore pull everything into themselves, hence the name 'holes'.
How do black holes form in the middle of gallaxies?
Note: There exists variant theories for the existence of Black Holes; one hypothesis has Black Holes being created from the collapsed stellar core of larger than three solar masses, while another has black holes predating stars and forming upon the instance of the Big Bang. In fact, the concept of a star growing or shrinking has little to do with gravitational accretion. So if a Black Hole is just a converted state of stellar evolution, then should we expect that the Black Hole size should be dependent on the amount of material being attracted and annihilated upon its Event Horizon? Per the current consensus, there is not a relevant relationship between the observable size of the accumulated bulge about the Black Hole and the size of the Black Hole itself.
And considering the Black Hole radiation jets act as the safety valve for the reactions within a Black Hole, one might speculate that, like a star, the size of the Black Hole has more to do with its internal reactions and less to do with the matter being converted upon its Event Horizon. Still another such theory has their formations predating galaxies and or even predating normal matter itself, existing unto the moment of the Big Bang itself (i.e. unfolding of SpaceTime into a traditional fourth dimensional condition).
What wavelengths can astronomers detect from earth?
Only those which aren't absorbed too much by the atmosphere. Those are visible light, and radio waves.
Is it possible for a Faraday cage to interdict a gamma pulse?
No. At least, I don't think it's reasonable to assume that. The reason it won't work is that, while a gamma ray is still an electromagnetic wave (just like a radio wave is), the wavelength of a gamma ray pulse is extremely short compared to the grid size of a Faraday cage, or even of the individual atoms.
What can I do after completing a BS in physics?
It will depend on your overall career goals and objectives. You must acquire a vision for yourself; A clearly articulated picture of the future you intend to create for yourself. It's a passion for want you want to do as a career. Once you have this, you will be able to retrieve information on the educational requirements of that field, and your path will become clear. You really need to find that vision - your career dream. Without a clear and specific goal, you will just drift aimlessly. First comes the vision, then the development of a road-map with short-term objects that will lead you to your overall career goal, and lastly 100% commitment, perseverance, and dedication until your vision becomes a reality. So many individuals do it backwards. They take a degree (maybe because they like the program or course work) then they ask, "well now that I have the degree, what can I do with it." They really should have acquired a vision first, then asked, "How do I make that vision a reality." So what they have done in completed a degree, then looked for a vision, when they should have acquired the vision first, and took the appropriate degree to get them there.
What is a brief description of each major American sport?
American football is a sport where two opposing teams attempt to score points by moving an inflated oval ball past a goal line. The ball can be advanced by carrying the ball or throwing it from one teammate to the other. Points are scored when a member of either team carries the ball across the opposing team's goal line and into their end zone, or when the ball is kicked from anywhere in the field of play and through the upright goal posts. The team with more points when time has expired wins. It is sometimes considered the most popular spectator sport in the United States. The major professional league is the NFL.
Basketball is a sport in which two teams of five players each try to score points by throwing a ball through a hoop. It is primarily an indoor sport, played in a relatively small playing area, called the court. The speed and grace of the game, combined with the close proximity of the spectators to the action, make basketball an exciting spectator sport. It is one of the most popular sports in the United States, and is also popular in other parts of the world.
Ice hockey is a team sport played on ice. It is one of the world's fastest sports, with players on skates capable of going high speeds on natural or artificial ice surfaces. It is very popular in Canada but has a comparably strong following in certain regions of the United States, notably the Northeast, the Northern Midwest, and Alaska.
A cosmic storm is a powerful disturbance in space that can affect planets, stars, and other celestial bodies. These storms can involve high-energy particles, electromagnetic radiation, and other phenomena that can impact space weather and communication systems on Earth. Examples include solar flares and geomagnetic storms.
What programs do astrophysicists use for modeling?
Astrophysicists use a variety of programs for modeling, such as N-body simulations like GADGET, hydrodynamics codes like FLASH, and radiative transfer codes like RADMC-3D. They also often utilize general-purpose programming languages like Python and Fortran for custom simulations and data analysis. Ultimately, the choice of program depends on the specific research questions being addressed.
What planet has the largest number of moons in your solar system?
To date, Jupiter is in the lead with 67 confirmed moons; Saturn is a close second with 62 moons with confirmed orbits.
Dark matter is so named because it does not interact electromagnetically and thus isn't observed directly with visible light; yet possesses mass. Dark matter is significant to cosmology due to unsolved questions arising from observations about the apparent mass of the universe. Several candidates have been proposed for the makeup of dark matter including near-massless subatomnic particles such as neutrinos.
The term 'black material' by contrast would imply something far more mundane, the simple property of matter wherein its surface would tend to absorb a significant fraction of incident light and thus have a black appearance to an observer.
How is background radiation caused from rocks soil and cosmic rays?
Rocks and soil contain small amounts of naturally occurring radioisotopes as well as various amounts of fallout from atmospheric nuclear testing and the Chernobyl reactor accident. Cosmic rays are in large part nuclei ejected with high velocity by ancient supernovas.
Why did is stop raining in Holes?
It stopped raining in the book because of the curse of his great great great grandfather when he didn't come back to carry madam Zeroni up the mountain.
