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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
Do Christians think that the universe will be destroyed?
No, Jehovah promises us in the
bible that the earth will remain forever (Ecclesiastes 1:4)(Genesis 8:22) He goes on to state that (faithful) mankind will always inhabit the earth (Psalms 37:9.29). Thus the universe, especially earth will not be destroyed.
What percentage of stars are binary stars?
Roughly half of all stars in the galaxy are estimated to be part of binary or multiple star systems. This means approximately 50% of stars are binary stars.
Does a black hole destroy things?
When an object falls into a black hole, it is stretched and compressed due to the intense gravitational forces. This process, known as spaghettification, destroys the object's physical structure. Additionally, intense tidal forces near the black hole can tear apart the object into its constituent atoms and particles.
What kind of stars form a black hole?
A supernova is an enormous explosion that marks the death of a massive star. A black hole is a super-dense remnant of a supernova; an object around which gravity is so intense that even light cannot escape. -Science In Action 9 Textbook
How big is a Micro black hole?
The term microscopic black holes usually appears in context of the big bang, since they may have been created by conditions in the early universe. Since it implies microscopic, an easy answer would be that their size is "smaller than would be visible". One important fact about black holes to remember is that they could potentially have any radius - there is no lower limit to this, all the way down to approaching zero. This is because the radius of a black hole is a direct function of their mass. The Schwarzschild radius of a black hole is simply twice the gravitational constant times the mass, divided by the square of the speed of light. If an object has a radius smaller than its own Schwarzschild or gravitational radius, it is a black hole; if it is larger, then it is not, so in this sense their existence is defined by their density. The Earth has a gravitational radius that would make it about the size of a marble; the Sun's is about 3km.
The reason for the scant evidence of microcopic black holes might relate to the mechanisms by which black holes are created. The most common mechanism is believed to be associated with stellar evolution wherein, at the end of a star's life when it has exhausted its fuel and can no longer resist the inward pull of its own gravity, it will collapse; but the mass required to do this would not create a microscopic one. Whether the big bang created any microscopic black holes is still a subject of research; other microscopic ones may come into existence in association with collisions of extremely powerful cosmic rays.
One factor working against the existence of microscopic black holes is Hawking radiation, a mechanism by which they can lose mass and "evaporate". Although Hawking radiation is weak, the intensity of the radiation is inversely proportional to their size - so microscopic black holes are expected to be short-lived.
What effect will be there on rotation of the earth if sun collapse to black hole?
If the Sun were to collapse into a black hole, its mass would remain the same, so the Earth's orbit and rotation around the black hole would continue as normal. However, without the Sun's light and heat, the Earth would quickly cool down and life would cease to exist.
What make a black hole invisible?
What is a black holes life cycle?
A black hole starts as a dying star. As the star gets smaller as it dies, the inner pressure becomes so powerful that the star implodes. When this happens, the smashed atoms of the dead star come together to form a neutron star. When this is crushed to nothing, a black hole is formed. If a black hole does not get enough energy, it will decrease in size and eventually explode.
Can comets turn into black holes?
Anything "can" turn into a black hole, as long as it is massive enough and dense enough. For example, Earth can turn into a black hole if all its mass is squeezed into a point about a centimeter in radius. The only reason that we don't see this happening is because you can't just make Earth denser than it already is (ever try to squeeze a chunk of putty?). Just because the odds of it turning into a black hole is very small doesn't mean it can't turn into one.
{ADDED} No, a comet cannot become a black hole. It is far too small and light (low mass), and loses material every time its orbit brings it relatively close to the Sun - the characteristic tail is that lost material, which like the head, reflects Sun light so is visible. The only objects cable of becoming black holes are the extremely dense cores of very, very large stars that die as supernovae, and even then, not all them become black holes.
This answer depends on the size of the black hole. Black holes devour anything that falls onto the event horizon. As a black hole eats any and everything around it, it will grow. These black holes will exist as long as the universe exists. Small black holes do evaporate and disappear. This is because of something known as Hawking Radiation. Hawking Radiation is present in all Black Holes but its effects are inversely proportional to the mass of the black hole. This means that the larger the mass of the black hole the less the effect of the radiation is. A Black hole the mass of the Moon would evaporate almost instantly and the smaller the mass, the faster it will evaporate. You may think that a black hole that is larger but has nothing to consume will eventually evaporate, but you'd be wrong. Black Holes not only absorb stars and other objects, but it also feeds on the heat in space. Space is 2.7 kelvin, this is known as the Cosmic Microwave Background. A Black hole with a Solar mass of the sun will have a Hawking Temperature of about 100 Nanokelvins. This is far less then the 2.7 kelvins that space is. This is why large black holes will live as long as the universe itself, and small black holes such as those that could possibly be made with the Large Hadron Collider will never just stay open and consume the Earth. It is physically impossible due to the Hawking Radiation.
Answer #2. #1 is correct however I would like to correct the everlasting black holes bit. No black holes will last as long as the universe. Supermassives have the advantage of accreting from the CMB right now. As the CMB cools they'll get less and less energy. Eventualy it's gonna hit an equilibrium where they're radiating as much mass as they're gaining through the CMB, then the scales will tip and all black holes will start slowly evaporating like their stellar-sized cousins did, ableit vastly slower, unless they continue accreting matter. Problem is, when that happens, the universe will be essentially dead, there will be no more stars to eat. Just vast nothingness full of supermassive black holes slowly dying and drifting masses of carbon (Black dwarf stellar remnants). So basically, no black holes live forever.
Why the whole density is concentrated at a point in a black hole?
We do not actually know what is happening within a black hole. It is clear that the currently accepted theories of Physics cannot explain what exists within the Schwartzchild radius of a black hole (and the Schwartzchild radius, or event horizon, is much larger than a point). There are some interesting new theories, but it unlikely that we will soon be able to place instruments near enough to a black hole to test these theories. Once the Large Hadron Collider at CERN is up and running, it may give us some data which will help to test these new theories.
What planet has the most helium in it?
By mass or volume, in our solar system Jupiter is the planet with the most helium, the fraction being about 10% of its composition (or a quarter of its mass). The smaller planet Saturn by comparison is believed to be about 3%. There are of course many extrasolar planets identified (orbiting stars other than our Sun), which are known to be gas giants and have much larger quantities of helium in them (including one which is about 17 times as large as Jupiter), but composition is hard to estimate with accuracy at such great distances.
Are black holes mass heavier than your sun?
Black holes suck in everything around it for billions of miles, all of that matter is compressed into something smaller than a tennis ball. If you could calculate its weight, it would way many times the weight of our sun!
How to solve The planets of solar system 12 worksheet?
To solve the worksheet, carefully read each question and refer to your knowledge of the planets in the solar system. Use any resources available to research and find the answers to the questions provided. Make sure to double-check your answers before submitting the completed worksheet.
How do you make a black hole for a science fair project?
You can't really "make" a black hole, but you can do research, present on the research and do a small demonstration of one of the properties of a black hole.
For example, there are lots of experiments you can set up to measure the force of attraction between two objects. You can use that as a launch pad, then compare that to the estimate gravitational force of a black hole.
He said that the sun is the center of the solar system?
Although there were several thinkers which proposed something like the heliocentric model before him, Copernicus is identified most with the idea; and it took his name, the Copernican system, contrasting with the geocentric model that identified Earth as the center, known as the Ptolemaic model.
Does titan could be a planet too?
Titan and Ganymede are both larger (but less massive) than Mercury and could certainly be called planets if they qualified under the IAU criteria. The conditions include a requirement that they orbit the Sun, and not Saturn or Jupiter, respectively, which currently make them moons, not true planets. They would further need to have cleared their orbits if they were in solar orbit.
How long would it take in earth days to get to the supermassive blackhole from earth?
probably not long.
My Answer:This is one of those questions that will depend on where you are observing from.If you are the one in a black hole and the most basic measure of time and death are used: Once you are in the Black hole your death would be instant.
Traveling into the hole and dieing may take virtually forever because of the way a Black Hole distorts time and gravity.
If you could figure out how to watch from out side no human could live long enough to see a person die and confirm that he/she was dead. Again this is due to distortion of time.
How does planet move in their axis?
A planet rotates (spins) about its own axis, giving rise to its day. Earth's day is about 24 hours. This motion is distinct from the orbital motion (revolution about the Sun) which is the planet's year.
Why is light attracted to a black hole?
Light is not only attracted to a black hole, in fact, its attracted to you, to me and to everything made of matter in the universe. The problem is that light is affected by gravity, and the black holes have so much that light significantly change trajectory or the black holes absorb the photons
What telescope discovered black holes?
Black holes,were theorized since the 1800's,it was predicted by Einstein's theory that they were really real.Since then this forced astronomers to think such a thing is real,and yet they are,but there very rare to find,so we don't really know what telescope discovered a black hole.So we thing the Hubble telescope did because well,its the hubble telescope.
What is a place for viewing the stars and planets called?
An observatory is a place specifically designed for viewing stars and planets, usually equipped with telescopes and other scientific equipment. These facilities are often located in areas with minimal light pollution to maximize visibility of celestial objects.
If a black hole is black how do astronomers see them?
Scientists "see" things through specialized equipment that identify waves that are invisible to a human eye i.e. microwaves, gamma waves, etc.
Also because we are in the Milky Way, right? SO There are many stars in our galaxy. So, they can see it because it was a big black gap right in our galaxy and they could see stars flowing in it being sucked into it. Like when you drain the bathetub after a bubble bath. You can see the little torpido of water in it. Even when it's the same color. You get it?Black holes don't give off gamma rays or microwaves. That's the whole point. (Except hawking radiation, of course, but that is hard to detect as the effect is so small in large objects.)Seeing objects that don't reflect light is tricky business. And black holes are as mysterious as a target can be. Not even light can escape them. This is a pretty tricky problem for scientists, whose instruments usually rely on light-- whether it's visible light, radio waves, X-rays or infrared-- to observe objects in space.
One method to see black holes has been to watch the fate of an object falling into one of these cosmic graves. If material actually falls into a black hole, it gets shredded apart and it heats up. As it heats up, it starts emitting light and this radiation we can observe. In particular, we can often see X-rays coming from black holes. When gas orbits around a black hole it tends to get very hot because of friction. It starts emitting X-rays and radio waves. So a lot of times black holes can be found and studied by looking for bright sources of X-rays and radio waves in the sky.
These X-rays do not get through the Earth's atmosphere and can only be seen with telescopes positioned in space, such as the Hubble telescope.
The strong gravitational attraction of a black hole affects the motion of nearby objects. When astronomers see a star circling around something, but they cannot see what that something is, they may suspect it is a black hole. Astronomers can even figure the mass of a black hole by measuring the mass of the star and its speed. The same kind of calculation can be done with black holes at the center of many galaxies, including our own galaxy, the Milky Way. In fact, at the very center of our galaxy, radio and X-ray telescopes have detected a powerful source called 'Sagittarius A', identified as this massive black hole.
How many centimeters would represent the distance to a star that is 100 light-years from earth?
One light-year is about 9.461 trillion kilometers. Converting this distance into centimeters gives us 9.461 x 10^17 centimeters per light-year. So, 100 light-years would be approximately 9.461 x 10^19 centimeters.
