Originally posted by Ullri don't worry about the unicorns, the unicorns turned into pure joy and fluffyness and then used the rainbow god created after the flood to transport themselves to my little pony land.
Dinos?! Forget the dinos. What happened to the Unicorns?
"Green alligators and long-necked geese
Some humpty backed camels and some chimpanzees
Some cats and rats and elephants, but sure as you're born
Don't you forget My unicorns "
Now I'm craving a pint of Guinness.
i love guiness, but here it's rather expensive compared to the other beer. i rather drink dark beer which is half the price and almost the same taste (especially after a few, one couldn't tell the difference)
Originally posted by RJHindsspeaking of, you seem to have missed my conundrum. you said that dinos and man coexisted (ancient man must have been a badass to survive coexistence with raptors and t-rexes but moving on) and died before the flood because noah didn't bring them on the boat. and i asked the following. would you be a dear and explain to me how you are able to ignore the bible and invent anything you want so that recent discoveries would fit (like hammering a cube into a too small round hole)?
Apparently you think I am very ignorant or stupid.
why not? at what point does it say in the bible that dinos should be left behind?
6:19 You must bring into the ark two of every kind of living creature from all flesh, 58 male and female, to keep them alive 59 with you. 6:20 Of the birds after their kinds, and of the cattle after their kinds, and of every creeping thing of the ground after its kind, two of every kind will come to you so you can keep them alive.
so why don't the dinos get to go on the boat trip? after all, there were snakes, frogs, birds, clean and unclean animals. why don't the dinos fit?
Originally posted by RJHindsI am just a lay person, but I think it is a very dense object with an immense gravity that keeps light from reflecting, and thus it is black. I am sure I butchered that.
Maybe, it is because the wrong word is used for its name or that
I don't understand what they mean. I don't believe a star can burn
a hole in space, if that is what is meant.
Here we go. From wikipedia:
"A black hole is a region of space from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that marks the point of no return. It is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics."
http://en.wikipedia.org/wiki/Black_hole
Originally posted by moon1969Note the last sentence from your quote from the Wikipedia article on
I am just a lay person, but I think it is a very dense object with an immense gravity that keeps light from reflecting, and thus it is black. I am sure I butchered that.
Here we go. From wikipedia:
"A black hole is a region of space from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact st like a perfect black body in thermodynamics."
http://en.wikipedia.org/wiki/Black_hole
"Black hole". I repeat below:
It is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.
Now I quote the following from the Wikipedia article on "Black body":
"A black body is an idealized physical body that absorbs all incident
electromagnetic radiation. Because of this perfect absorptivity at all
wavelengths, a black body is also the best possible emitter of thermal
radiation, which it radiates incandescently in a characteristic, continuous
spectrum that depends on the body's temperature. At Earth-ambient
temperatures this emission is in the infrared region of the electromagnetic
spectrum and is not visible. The object appears black, since it does not
reflect or emit any visible light.
The thermal radiation from a black body is energy converted
electrodynamically from the body's pool of internal thermal energy at any
temperature greater than absolute zero. It is called blackbody radiation and
has a frequency distribution with a characteristic frequency of maximum
radiative power that shifts to higher frequencies with increasing temperature.
As the temperature increases past a few hundred degrees Celsius, black bodies
start to emit visible wavelengths, appearing red, orange, yellow, white, and
blue with increasing temperature. When an object is visually white, it is
emitting a substantial fraction as ultraviolet radiation.
The concept of the black body is an idealization, as perfect black bodies do not
exist in nature. Graphite and lamp black, with emissivities greater than 0.95,
however, are good approximations to a black material. Experimentally,
blackbody radiation may be established best as the ultimately stable steady
state equilibrium radiation in a cavity in a rigid body, at a uniform temperature,
that is entirely opaque and is only partly reflective."
Coal or charcoal comes to my mind. If a "black hole" is like a perfect
"black body" in thermodynamics, then it must also be an idealization that
does not actually exists. So this region of space that is called a "black hole"
must contain a body of black material and is not really a "hole" at all.
P.S. Yes, I believe you are probably right.
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This is a topic that really belongs in the science forum, like me, but as you are
discussing it here...
For an object to be a black hole it has to have enough mass inside a certain radius
for the escape velocity at that radius to reach/exceed the speed of light.
http://en.wikipedia.org/wiki/Schwarzschild_radius
This radius is often known as the 'event horizon' of a black hole, it is not an actual
surface but the point beyond which you can't escape the black hole.
If you were falling into a large enough black hole you could very well pass through
the event horizon without noticing you had done so.
What lies on the inside of the event horizon however is a different matter.
And is open for discussion.
It is possible to construct a Schwarzschild radius around objects other than singularities.
And while singularities are predicted by General Relativity, singularities represent a realm
where both gravity AND quantum effects are important. And thus is the realm of Quantum
Gravity, Which is a realm currently under exploration by physics, but is not yet charted
territory.
Black holes are guaranteed in all solutions of GR and objects matching no other known description
have been detected by astronomers.
Stars significantly larger than the sun can collapse at the end of their lives into objects that are
smaller than their Schwarzschild radius and thus become stellar mass black holes.
The process by which they do this is complicated and would require a lot more time and space
for me to explain, feel free to ask in the science forum if you want to know more.
Larger black hole form in the centre of galaxies, like the one in the middle of our galaxy which
has a mass in excess of 4 million times the mass of our sun.
Observations of the centre of our galaxy show stars orbiting around an optically invisible object
at speeds of a significant fraction of the speed of light.
By analysing their orbits it is possible to calculate the mass of the object they are orbiting.
Quantum theory tells us the strength of the repulsive forces that keep matter from collapsing in
on itself.
The gravitational forces this object creates are vastly in excess of any force that would keep the
constituent matter outside its Schwarzschild radius.
Thus the object must be a black hole.
This is confirmed by observations confirming no detectable light emanating from the object itself
but there is light emanating from that location consistent with an accretion disk around the black hole
made of gas and dust spiralling into it.
Black holes got their name partly in reference to the infamous black Hole of Calcutta
http://en.wikipedia.org/wiki/Black_Hole_of_Calcutta
But also to the fact that having an escape velocity in excess of that of the speed of light means
that they would not only not emit light but that they would swallow any light that fell into them,
thus making them black.
Later work by Stephen Hawking showed that black holes do in fact emit subatomic particles, and
were thus not completely black.
The reasons for this are somewhat complicated, but the basics of it are thus:
Small particle-antiparticle pairs are continually popping in and out of existence.
To do this they have to 'borrow' energy from the vacuum of space.
They exist only for a very tiny faction of a second and then recombine and eliminate each other
thus repaying the energy they borrowed.
However at the mouth of a black hole it is possible for one of the particle pair to cross the event horizon
and thus get swallowed by the black hole while the other particle flies off into space.
The energy need for this to happen comes from the black hole.
This causes the black hole to loose mass, and glow.
The amount it does this is based on the size of the event horizon.
the smaller it is the easier it is for this to happen so the faster it happens.
thus as black holes shrink the faster they emit energy and thus the faster they shrink.
Very small black holes will in fact glow brilliantly, this is one of the many reasons why the small chance
that the LHC might make a black hole is nothing to worry about, as any black hole of that size will last
only a fraction of a second as it burns off its mass in a shower of subatomic particles and light.
Large black holes however emit only tiny amounts of energy.
and are truly black.
If you are actually interested in more info then by all means head over to the science forum where we can
talk in more detail.
EDIT: Black holes are not like black body radiators, except superficially. It is not in my view a helpful analogy
to make.