Astrophysics

"Black Hole Sun" is a 1994 song by Chris Cornell of Soundgarden; the writer has said he's not sure himself exactly what the lyrics mean. The term "black hole" is used by astrophysicists to refer to an object with a gravitational field so strong that the escape velocity exceeds the speed of light. Our sun is actually too small to become a black hole; the minimum amount of mass required is somewhere between 150% and 300% of the sun's mass.

Sometimes. It depends on the precise conditions. The mass of the star (after blowing off its outer layers in the supernova) has to be at least 1.5 - 3 times the mass of the Sun in order for it to collapse into a black hole.

The remnants of a smaller star (but still larger than the sun; the sun is too small to become a supernova) will probably stop collapsing after the supernova at the neutron star stage.

6/5/2014

Currently, if you would like to know the nearest black hole, it is called A0620-00 and it is 3000 light-years (17,635,499,442,630,040) away. It is located in the constellation Monoceros, the Unicorn. All you have to do is get a spacecraft to take you 3000 light-years in the direction of A0620-00(and survive for several millenia). Once you feel a strong gravitational pull toward an unseen object, you have probably found the black hole.

Quasars are powered by super massive (multimillion solar mass) black holes, spinning rapidly. The spins create accretion disks of galactic size, collapsing, ripping and shredding material into tightly collimated bipolar jets of matter and radiation, spewing highly energized particles out close to the speed of light hundreds of thousands of light years. Some quasar jets exceed a million light years. That kind of energy simply boggles the mind. Quasars are incredible. I had a beautiful poster of one given to me by an astronomer--I wish I could find it again.

Black holes do NOT project light. Hence the name black hole. Their gravity field is so strong that nothing escapes, not even light photons. The only way we know they exist by the bending of the trajectory of photons passing them. Galaxies project light via radiant energy, i.e. photons. In the same way you observe a lightbulb, you observe a galaxy. The primary difference is that we have developed instruments to not just observe galactic energy within the visible spectrum, but the entire electromagnetic spectrum, e.g. radio waves and x-rays. Those instruments would work with a lightbulb too, but they're usually busy looking at galaxies. Actually, black holes probably do give off light (and all other particles). This effect is quantum mechanical in nature and was discovered by Stephen Hawking. However, it is not at present possible to measure this. Whether or not Hawking is right, we can observe black holes, and not just because of light from distant stars bending around them. The event horizon is a very violent place, and materials are being spun around in the vortex just outside of the horizon, and they are being torn apart before entering the horizon as well. All of this creates a massive output of energy that we can observe. We get hints that we are observing a black hole by observing how nearby stars interact with it. Black holes sometimes 'suck up' so much matter that some of it escapes. http://www.tqnyc.org/2006/NYC063368/the_stars.htm

Most Cosmic rays have energies between 107 and 1010 electron volts but one has been detected with an energy 3X 1020 ev. This is about the same energy as decent tennis serve (about 50J) and about 50 000 000 X greater than what the large hadron collider in Europe will be able to achieve when they finally get it going.

Quantum singularities (more commonly refered to as black holes) are in fact, infinitely dense raptures in the fabric of space. Q2+(J/M)2 ≤ M2 is a very common equation to define black holes in space. Some scientists believe that through black holes and the use of anti - gravity we can create wormholes, which could allow instantaenous access to anywhere in the universe.

The Schwarzchild radius of a black hole is linearly dependent on its mass. The relationship is

rs = 2GM / c2

where G is the Newtonian gravitational constant, m is the mass of the black hole, and c is the speed of light. The Schwarzchild radius works out to be 2.95 km per solar mass.

There is nothing at all mysterious about this formula. It comes from the standard classical formula for escape velocity

ve = sqrt(2Gm / r)

by substituting c for the velocity and then solving for r.

It is not likely, the nearest one is 1000s of light years away. The black hole that supposedly exists at the center of our galaxy hasn't eaten the solar system in 5 billion years, it's not likely to do so in the next 5 billion years. Especially since we live in the boondocks of the galaxy - it's outer rim. We all live in the suburbs of the Milky Way.

Gamma rays can be blocked by a thick amount of lead.

Alpha -> goes through thin mica -> then stops at skin or paper.

Beta -> Goes through thin mica - then goes through skin or paper -> gets stopped at lead.

Gamma -> Goes through thin mica -> goes through skin or paper -> then can be slowed down by lead or can be stopped completely by a thick amount of lead.

I may have Beta and alpha mixed up but please excuse me as im writing this out of my book (:

It's your solar system too.

Well we can use maths to work out how long it would take certain things in our and other solar systems to form, and by using models and simulations coupled with the laws of physics.

Me ,a 13 year old boy, have created an experiment that can create a wormhole that we can use to time travel. If you want to read the experiment plan then follow this link...

http://www.ireport.com/docs/DOC-367891#

You can't! Beyond the event horizon nothing can escape even light! It is thought of that you will never return from a black hole as the infinte amount of gravity will kill you instantly although there are several theories which say you will survive.

One theory states that they are wormholes to other universes or even through time whilst another theory called the white hole theory states that all the matter consumed by the black hole will eventually come up in a hypothetical white hole in another part of the Universe.

Hoped i helped you!

:)

You can get as close as you want, as long as your tangential speed is high enough

to maintain an orbit. Inside of some distance, that'll require the speed of light (or

more). The distance depends on the mass of the black hole.

Nothing man-made has been sent to a black hole, the furthest out one of our probes has got is the edge of our solar system. A probe would have to go many orders of magnitude further than that to get to a black hole.

No, because nothing can escape the black hole, not even light. So without light, we can't see anything. but, we can see stars being stretched like spaghetti and then being sucked into the black hole.

The Earth is estimated to be around 4.5 billion years old, while the solar system is thought to have formed around the same time. This estimate is based on radiometric dating of meteorites and rocks from Earth.

Black holes are just a singularity and are thus very small, much smaller in fact than our sun. However, the event horizon (point of no return) can extend much farther in radius than our sun. A stellar mass black hole has an event horizon only a few kilometers across, much smaller than the sun. A supermassive black hole, with a mass millions to billions times that of the sun may have an event horizon far larger than the sun. Lastly, all black holes are many times more massive (amount of mass in them) than our sun. This is because they are all created by suns many times bigger than our own.

astronomy, astrophysics

Suck in isn't quite right. Because relativity says gravity bends space and time, like a tightly stretched sheet, a black hole is like a a very large and thin pole pushed into the sheet - it makes a kind of "bottom of the hill" or a valley in space. Things in space will flow to the lowest "point" of space, which the is end of a black hole. So things fall in rather than are sucked in.

Groundhogs create burrows in the ground by digging and excavating the dirt, which they then push out of the entrance of their burrow. The displaced dirt piles up near the entrance of the hole, creating a telltale mound of soil.