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Answer:

No there is not.

Explanation:

It is not possible for there to be a black hole in the middle of the earth as black holes are made when a large star collapses in on it's self after running out of nuclear energy.

As the earth is not a star, this cannot happen.

Also.

If there was a black hole in the middle of the earth we would not be here because black holes consume (for lack of better word) everything around it.


A black hole works like a vacuum, only using gravity instead of suction. However, a black hole is formed when a very large star dies and goes supernova. Meaning it runs out of nuclear fuel (gases) and explodes (for lack of better word) before collapsing and consuming itself until it's the size of a pin head.

Although it is now the size of a pin head it retains it former mass. Which is quite large considering the size of most stars.
During a star's lifetime it's gravity and pressure are balanced out by its mass. However, when a star collapses gravity gets the upper hand and forces the star to collapse under its own weight.

When this happens the core compacts into such a small size it has practically no volume, but infinite density. Because of this, the black hole starts to consume light. Meaning that the surrounding area becomes a cesspit of darkness that nothing can see through.

It would also require a speed greater than light to escape the gravity. As no object can reach this speed anything that passes into the gravitational field will be trapped forever.

(Copied from my answer to- If we could send a camera into a black hole, what would we see?)


I hope this answered your question.

Kind regards,
Ricey.

Answer:

Black holes are "seen" through their interactions with other objects. The various interactions show up in X-ray emissions, the motion of surrounding stars, and most recently gravitational waves.

Explanation:

X-ray emissions

Most likely black holes are detected through X-ray emissions. If a massive star that has collapsed is part of a binary system, the dense core can pull gas from the remaining "live" star. The gas spirals inwards, gains energy from the gravitational field, and it gets so hot that its emissions are mostly X-rays. A compact object that emits primarily X-rays, next to a light emitting star, is likely a black hole if it appears to have enough mass. Cygnus X-1 is the best known such candidate.

A larger-scale version of this process is seen in the center of some galaxies, producing emissions so bright that that they outshine all the surrounding stars (https://en.wikipedia.org/wiki/Quasar).

Motion of Surrounding Stars

Massive black holes, containing millions of solar masses or more, can exert strong gravitational forces on surrounding stars. We detect this effect through the rapid, sharply curved motion of the stars. The central black hole in our galaxy is detected in this way (http://www.nasa.gov/mission_pages/chandra/multimedia/black-hole-SagittariusA.html).

Gravitational Waves

The most certain way to detect black holes is to detect the gravitational waves produced when they collide with other black holes or other objects. The gravitational waves are made of the same "stuff" as the gravity of the black holes and so offer the clearest indication of such black holes. Recently the Laser Interferometer Gravitational-wave Observatory (LIGO) detected such gravitational waves from a black-hole collision (http://news.mit.edu/2016/second-time-ligo-detects-gravitational-waves-0615).

Answer:

All stars die by collapsing under gravity. The process is different depending on the size of the star.

Explanation:

All main sequence stars are undergoing fusion reactions in their core. The fusion reaction produces a pressure which counteracts gravity which is trying to collapse the star. When the forces are in balance the star is aid to be in hydrostatic equilibrium.

Smaller stars with masses below 8 times that of the sun are fusing hydrogen into helium during the main sequence. When the hydrogen fuel runs out the star collapses under gravity.

As the core collapses it heats up to the point when helium can start to fuse into carbon and oxygen. The outer layers of the star expand to become a red giant.

When the helium fuel runs out and the core is mainly carbon and oxygen, fusion processes stop as the core can't get hot enough to start carbon fusion. The star then collapses into a white dwarf.

Theoretically, if the universe lasts long enough the white dwarfs will cool down over billions of years to become black dwarfs.

Larger stars over 8 solar masses start by fusing hydrogen into helium. Fusion processes fusing helium into carbon and then fusing heavier elements progress almost seamlessly.

When fusion processes produce elements lighter than iron energy is released by the fusion reaction. Fusing reactions which produce elements heavier than iron require additional energy.

When the core is mainly iron no further fusion reactions can take place. The core then starts to collapse under gravity. The pressure in the core reaches the point where atoms can no longer exist and the protons get converted into neutrons. This releases vast numbers of neutrinos which cause the outer layers of the star to explode as a supernova.

The core of the star is then a neutron star. If the mass of the core is large enough the neutron star further collapses into a black hole.

Answer:

People, and possiby even the Great Apes, have been gazing the stars for a long time wondering what they were. What did they conclude?

Explanation:

The first major step in cosmology was realised when mankind became aware that the Cosmos was not a matter of “us” and “them”.
That is us (humans) on this slab floating somehow in space, and them those tiny, or not so tiny, specks of light hovering overhead.

We and those specks of light belonged to the same whole. We were all part of a rather complex system that seemed to have logic and method. There was a vault, comprehensive of most stars, rotating as a whole; and there were a few wanderers that obeyed to the same logic, but followed their own laws.

enter image source here

All ancient people devised some sort of cosmology. Babylonians as well as Incas had chartered the visible sky and could predict the Eclipses. The Greeks even figured out a heliocentric system. Few, very few people believed that the Earth was flat. Simple, everyday’s evidence spoke to the contrary.
The question was: how people could possibly hang on to their soil on the other side. The answer (rather unsatisfactory) was that there were no peoples on the other side; that the other hemisphere was covered by a deep Ocean and water was forced to keep its own level by its very nature.

Even before Ptolemy (100 - 170 aD), and the first scientific approach to Astronomy, philosophers had conjectured that planets did not move by their own accord. Rather, they were glued to a pack of concentric, transparent, spheres rotating about the Earth at different velocities and different axes. The outermost was the Fixed Stars sphere. It contained all stars that maintained a constant reciprocal configuration (such as the well-known constellations including the zodiacal ones). The outer sphere turned around once every day to recover its exact position the following day at the same hour.
Then came the seven spheres of the major Luminaries that could be observed from Earth (Moon, Venus, Mercury, Sun, Mars, Jupiter and Uranus). Each sphere only had one planet on board and chose its own rotating speed and rotational axis.

enter image source here

As these planets showed remarkable mind of their own in choosing their path, and were also influential on the human destinies, they soon became the see of benevolent or less so divinities.

The Moon was the see of Diana (Artemis), Apollyon’s (Phoebus) sister, as beautiful as she was voluble. Mercury, tiny and rapidly spinning about the Sun was the God’s messenger. Venus, the most splendid of all stars shining on all evenings and all dawns (at the lovers hours) was their planet. Mars (the red star) had the colours of war. Jupiter, bright, large and sparkling more than the others had to be the king of kings. As for Saturn (Jupiter’s father), barely visible and so slow that it could be hardly foretold, he represented the time before the time, the unpredictable, the unknown.

There are several other cosmologies in addition to the Greek/Latin one that I attempted to describe.
If you are interested in this one I suggest you read one of the oldest of the Greek poets. His name is Hesiod (VIII century BC) and his poem is called “The Theogony”.

Answer:

Of course! We can use space probes and ground-based telescopes.

Explanation:

Unidentified NEOs (Near Earth Objects) or PHOs (Potentially Hazardous Objects) are unidentified because they absorb so much sunlight (they are so dark) or so far away that instruments on earth and on space probes can't detect the light reflecting off the surfaces of these objects. So you could say they are invisible.

Now your scenario means that the asteroid will indefinitely be illuminated by Sunlight as it passes behind the sun - relative to our perspective that is. So instruments will easily detect this asteroid.

For an example look at this image taken by SOHO
www.nasa.gov
Courtesy NASA http://www.nasa.gov/sites/default/files/thumbnails/image/soho_c3_comet

See how easy it is to make out this comet. So It will take no time to detect. What we should be worried about it how to prepare for it as it may cause biblical like catastrophies.

Answer:

A multitude of variables from external gravitational influences to intergalactic collisions .

Explanation:

Galaxies come in a variety of shapes and sizes. We will first talk about what gives some galaxies their spiral shape.

The most notable scientist who studied the formation spiral galaxies was Bertil Lindblad. He observed the spiral arms seen in spiral galaxies. He quickly realised that spiral arms couldn't be sustained and there must be some sort of mechanism that allowed the spiral arm to be stable. To sustain these spirals we'd have to ignore the laws of physics as the stars at the tips of the spiral arms would have to travel faster than the stars near the centre, but of course, in reality, objects move faster when they are closer to the point they are orbiting. The angular rotational speed was so great and the distance of the spiral arms with to the centre of the galaxy varied, the spiral arms would've compressed more and more each time the galaxy rotated like taffy in a taffy machine. This is called the winding problem. This problem still has not been solved, but there are two leading hypotheses:

  1. The spiral arms are created from density waves in the galactic disc - one theory is that the spiral arms are created from density waves travelling through the galactic disc. Stars pass in and out of these waves filling in what we see as spiral arms. Stars accelerate when they move towards a density wave when it is headed for them and slow down as they move
  2. SSPSF (Stochastic Self-Propagating Star-Formation) model - this theory suggests that in the initial star formation in a galaxy causes a shockwave which causes more star formation. So the idea is that the galaxy's rotation forms these newborn stars into the spiral arms we see, and this cycle repeats.

astronomyonline.org
Courtesy Astronomy Online: This shows how the windup problem affects the shape of a galaxy.

The shape of Elliptical galaxies ranges from extremely flat to more spherical. The shape of Elliptical galaxies are created from collisions between numerous galaxies. After all these collisions in the course of a few hundred million to a few billion years the stars settle to form the featureless elliptical galaxies.

https://en.wikipedia.org/wiki/File:Andromeda_and_Milky_Way_collision.ogv
Courtesy NASA: Visit this link to see how elliptical galaxies form. At the end, we see how the collision between the Milky Way and Andromeda forms an Elliptical galaxy.

.

Irregular galaxies are formed from violent collisions between two or more galaxies which redistributes interstellar matter, dust and stars e.t.c. to form a chaotic mess. This chaotic mess eventually settles to form an elliptical galaxy. Here's a picture of an Irregular galaxy if you were wondering what it looks like.

www.whillyard.com
Courtesy NASA, ESA and HST

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