SCIENCE/SPACE/TIME - a meeting of the minds!

[Charger527]

[QUOTE=The Deuce;4800694]


Kinda Makes ya think... here's some pics of a SUPER MASSIVE BLACK HOLE...



[QUOTE]


Those are not actual photos though right?? they are just how we think it might look??

[Hazard]

A supermassive black hole is a black hole with a mass of the order of between 10(to the 5th power) and 10(to the 10th power) solar masses. Most, if not all, galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers....

Supermassive black holes have properties which distinguish them from their relatively low-mass cousins:

The average density of a supermassive black hole (measured as the mass of the black hole divided by its Schwarzschild volume) can be very low, and may actually be lower than the density of air. This is because the Schwarzschild radius is directly proportional to mass, while density is inversely proportional to the volume. Since the volume of a spherical object (such as the event horizon of a non-rotating black hole) is directly proportional to the cube of the radius, and mass merely increases linearly, the volume increases at a greater rate than mass. Thus, average density decreases for increasingly larger radii of black holes.

[ALMOST SCHWARZENEGGER... hahaha...)

The tidal forces in the vicinity of the event horizon are significantly weaker. Since the central singularity is so far away from the horizon, a hypothetical astronaut travelling towards the black hole center would not experience significant tidal force until very deep into the black hole.

Astronomers are confident that our own Milky Way galaxy has a supermassive black hole at its center, in a region called Sagittarius A* because:

• The star S2 follows an elliptical orbit with a period of 15.2 years and a pericenter (closest distance) of 17 light hours from the central object
  
• Early estimates indicated that the central object contains 2.6 million solar masses and has a radius of less than 17 light hours. Only a black hole can contain such a vast mass in such a small volume.
  
• Further observations strengthened the case for a black hole, by showing that the central object's mass is about 3.7 million solar masses and its radius no more than 6.25 light-hours.

SO... Just so you know we have a goddamned SUPERMASSIVE BLACKHOLE At the VERY CENTER of our own GALAXY !!!



Kinda Makes ya think... here's some pics of a SUPER MASSIVE BLACK HOLE...

Isn't that 2nd picture a "quasar"? I believe the "light beam" comming out from the middle are gamma rays.....

~Haz~

[Flagg]

http://www.bbc.co.uk/iplayer/episode...Spark_of_Life/

Bump for one of my favourite threads.

Did anyone in the UK watch this? Its been a 3 part mini series on Cells and part 3 was about how Scientists are close to creating a synthetic life form. It spoke about how Bio Technology began, Stanley Miller and how DNA works and how we're close to literally, creating a living cell out of nothing. A true Scientific first, life starting from scratch for the second time on Earth.

Some of you may have heard of this:
http://en.wikipedia.org/wiki/Miller%...rey_experiment

It was a experiment conducted by Stanley Miller back in the 1950's. He basically managed to recreate in the lab, conditions on earth from some 4 billion years ago and more, when the earth was lifeless, boiling and hostile. The experiment used water , methane , ammonia , and hydrogen, and used some sort of super heating through electricity. Long story short, the experiment was left to run for a few days, and a few days later, Amino Acids had formed within this soup. It would prove to be a massive breakthrough in understanding how life began. It would also go on for Scientists to harness the power of the Cell as a year later after this experiment, DNA was discovered.

Sometimes physics seems a cooler science, but I really love biology. I mean I think this sort of stuff is incredible. For instance, what are the ramifications of creating a synthetic life form, a first? Is it exciting or dangerous stuff? What if we accidently create a super virus, and because it is synthetic in origin, has no natural counter agent in nature? Will we being seeing massive breakthroughs in medicine or even fuel? They showed how Sugars could be induced to turn into synthetic oil.

Science is a brilliant but sometimes scary thing. I mean, are there things we shouldn't toy with? Does science have a dark side..the more information and understanding we get, the more doors are open, the further we delve...are we going to open pandoras box one day?

[Undercover]

I can't watch the BBC thing. Every scientific discovery comes with ups and downs, but we should keep moving forward imo. I want to be an evil scientist when I'm older.

[Flagg]

I can't watch the BBC thing. Every scientific discovery comes with ups and downs, but we should keep moving forward imo. I want to be an evil scientist when I'm older.

Mate that picture is great. You should download BBC Iplayer and check it out. Very interesting stuff. Some of this stuff ive heard of before like the Miller Experiment, but the stuff that is going on in Harvard University right now is really amazing.

[Bio-boosted]

They created a bacterium that produces diesel as byproduct. Amazing!

[Hazard]

very cool man..... i loves me some science.....

~Haz~

[Undercover]

Mate that picture is great. You should download BBC Iplayer and check it out. Very interesting stuff. Some of this stuff ive heard of before like the Miller Experiment, but the stuff that is going on in Harvard University right now is really amazing.

I did. Apparently, you can only watch if you're in the UK.

[*El Diablo*]

Yesterday i was watching BBC channel and they had a program called "Atoms" and it was about the Big Bang Theory etc, and today, for the first time, i am starting to understand the basics of science. Anyway, the Narrator made a very interesting statement and said that the a human being gives off more heat than the sun per square Meter....

[Charger527]

Yesterday i was watching BBC channel and they had a program called "Atoms" and it was about the Big Bang Theory etc, and today, for the first time, i am starting to understand the basics of science. Anyway, the Narrator made a very interesting statement and said that the a human being gives off more heat than the sun per square Meter....

Well the sun is pretty big, though we dont let of light

[*El Diablo*]

Well the sun is pretty big, though we dont let of light

For sure, but i thought that it was pretty amazing that the sun gives off less heat than a human being, its not sumthing i would have expected...

[Flagg]

Yesterday i was watching BBC channel and they had a program called "Atoms" and it was about the Big Bang Theory etc, and today, for the first time, i am starting to understand the basics of science. Anyway, the Narrator made a very interesting statement and said that the a human being gives off more heat than the sun per square Meter....

That doesn't sound right, or is it all about ratio? As in, if the human body was the size of a star, it would emit more heat than the star?

Humans do emit light to a degree, but it's very low intensity:
http://www.sciencedaily.com/releases...0729064343.htm

This explains a little why, and how its our own magnetic field that causes this.

[*El Diablo*]

That doesn't sound right, or is it all about ratio? As in, if the human body was the size of a star, it would emit more heat than the star?

Humans do emit light to a degree, but it's very low intensity:
http://www.sciencedaily.com/releases...0729064343.htm

This explains a little why, and how its our own magnetic field that causes this.

Sorry Flagg, The narrator was standing infront the camera, and he was reffering to the object as himself, and that he gives off less heat than the Sun, now i think he was reffering to as If the sun was the same size as the Narrator ie 6'1, 250lb's etc. :-)

It was on BBC Prime Channel called "Atoms" ... Awesome stuff

[*El Diablo*]

Flagg, who can u refer me too, ie book or Movie etc, Anyhow, so watching the whole Atoms program they showed how the "big Bang" theory started, ie Hydrogen in the Atmosphere blah blah, Can u tell me what started the Big Bang? ..

[Flagg]

Flagg, who can u refer me too, ie book or Movie etc, Anyhow, so watching the whole Atoms program they showed how the "big Bang" theory started, ie Hydrogen in the Atmosphere blah blah, Can u tell me what started the Big Bang? ..

I need to pop out to get a gift for someone. I'll go into a bit more detail about this when I get back.

[*El Diablo*]

I need to pop out to get a gift for someone. I'll go into a bit more detail about this when I get back.

That would be appreciated.

[Hazard]

I just saw something a few days ago on TV about the "quasars" that emit X-ray beams......

They said that right now there are 2 galaxies where the center of them is pointing directly at us. If these galaxies die (and we have no idea when they will) they will emit a beam of X-Ray directly at us. Effectively killing our galaxy.....

I believe they are pictured above - post #161 - second picture down.

~Haz~

[*El Diablo*]

I just saw something a few days ago on TV about the "quasars" that emit X-ray beams......

They said that right now there are 2 galaxies where the center of them is pointing directly at us. If these galaxies die (and we have no idea when they will) they will emit a beam of X-Ray directly at us. Effectively killing our galaxy.....

I believe they are pictured above - post #161 - second picture down.

~Haz~

But if they die Haz, then how could they still emit light?

[*El Diablo*]

It's incalculable to even comprehend the size of our Universe. I'm not sure it it is infinite..I don't think infinity can exist personally, but the last two pictures of Galaxies dwarving our own, of such a size to defy the laws of physics truly defies the human mind as well. For this was but one small segment of our sky, what of the rest mapped?

Looking at Stars in the sky you are actually looking backward in time. We may never have the time or the technology to explore the Universe but wouldn't it be something if we could invent a telescope that truly see into the farthest reaches in Space. I sometimes wonder if there is somewhere in space where we can witness the Big Bang happening.

Does this mean that the closer we come to the Black hole the slower well age ?

[Hazard]

But if they die Haz, then how could they still emit light?

I forget how they emit the X-Ray beam...... but it's part of the process of the galaxy dying. I'm gunna look it up lol

~Haz~

[*El Diablo*]

I forget how they emit the X-Ray beam...... but it's part of the process of the galaxy dying. I'm gunna look it up lol

~Haz~

LOL, okay, but the question on my mind that puzzles me, and everytime i speak to my G-friend about this one she brings "god" in the equation, is "what started the Big Bang". I want to get down to the Farking bottom of this ......

[Hazard]

What is your definition of a quasar?

This is best answered with history. When radio telescopes were first turned on the heavens, point sources of radio waves were discovered (along with spread-out regions of emission along our Milky Way). Astronomers using ordinary visible-light telescopes turned toward these radio points and looked to see what was there. In some cases a supernova remnant was found, in others, a large star-birth region, in others a distant galaxy. But in some places where point sources of radio waves were found, no visible source other than a stellar-looking object was found (it looked like a point of like --- like a star does). These objects were called the "qausi-stellar radio sources", or "quasars" for short. Later, it was found these sources could not be stars in our galaxy, but must be very far away --- as far as any of the distant galaxies seen. We now think these objects are the very bright centers of some distant galaxies, where some sort of energetic action is occurring, most probably due to the presence of a supermassive black hole at the center of that galaxy (supermassive = made up from a mass of about a billion solar masses).
What do quasars have to do with black holes?

See the above answer. It is thought the infall of matter into the supermassive black hole can result in very hot regions where huge energies are released, powering the quasar (i.e., producing the emitted light, etc.).

~Haz~

[Hazard]

LOL, okay, but the question on my mind that puzzles me, and everytime i speak to my G-friend about this one she brings "god" in the equation, is "what started the Big Bang". I want to get down to the Farking bottom of this ......

Well..... there are a bunch of theory's about what "caused" the big bang. Most notably are the "Bubble theory" and the "Brain Theory" - go search those as i'm sure you can have them better explained to you. Here is my really short version.

For either the "Bubble Theory" or the "Brain Theory" you have to be open to the fact that we are NOT the only "Universe" - you heard me correct..... there are other universes out there. Either theory pretty much states that two universes hit eachother causing a huge explosion. The two theories are different in that they universes are shaped differently and act differently..... but regarding the "big bang" - they both pretty much say that 2 universes collided.

I may be off mark a little LOL - you should research both of those theories - you'd enjoy it.

~Haz~

[Hazard]

Also...... we're sending up a new telescope to space. This telescope is even more powerful than Hubble and according to the scientists - it will be able to see back to ONE TRILLIONTH of a second after the big bang happened. Think about that LOL...... not even a second after the explosion...... ONE TRILLIONTH OF A SECOND! Scientists think with this new Telescope and with the new Particle accelerator they are working on..... they may be able to start seeing what it was like BEFORE the big bang.....

~Haz~

[Flagg]

Also...... we're sending up a new telescope to space. This telescope is even more powerful than Hubble and according to the scientists - it will be able to see back to ONE TRILLIONTH of a second after the big bang happened. Think about that LOL...... not even a second after the explosion...... ONE TRILLIONTH OF A SECOND! Scientists think with this new Telescope and with the new Particle accelerator they are working on..... they may be able to start seeing what it was like BEFORE the big bang.....

~Haz~

Very, very interesting. What if nothing is there, what if this was the first Universe? Can we really peer into oblivion, nothingness? This telescope will go a long way to mapping the Universe. For example, pinpointing the location of the big bang. What about outside of the universe? Because of the nature of the universe and size, we'd never be able to see outside unfortunately. Simply because the information we pick up will be too old, and if we're going by the knowledge that the Universe is expanding, it is probably expanding at a rate faster than we can keep up with.

[Flagg]

Does this mean that the closer we come to the Black hole the slower well age ?

I've heard about this, and according to the laws of physics that is exactly what would happen. Also, try and wrap your head round this. Apparantly, if you walked through a door slow enough (for thousands of years) and kept in motion, eventually you would phase into two. Obviously no1 can live that long and there is more to that story than i've let on, i'll have to ask my mate to be a bit more specific about it. I always wondered what would happen if you could travel at the speed of light and then turned a torch on. Or better still, what would happen if you could go faster than the speed of light and then turn a torch on? Would the light bend around the torch?

[Flagg]

Flagg, who can u refer me too, ie book or Movie etc, Anyhow, so watching the whole Atoms program they showed how the "big Bang" theory started, ie Hydrogen in the Atmosphere blah blah, Can u tell me what started the Big Bang? ..

This is what I know of the Big Bang, based on various readings and Uni work.

The so called Big Bang formed about 15-20 billion years ago. At that instant, thermal energy was so high that no matter could exist, not even at the subatomic level. After about a second from the point of the first expansion the Universe had cooled to about 5 billion degrees celcius. At this temperature protons and nuetrons could start forming. 800,000 years after the initial burst, the Universe had cooled further and the first two elements could form, H and He. The only matter in the early universe were massive "hot clouds" of Hydrogen and Helium. These clouds would become the first nebulas and some even exist today still, this is where stars would form, the first galaxies. These nubulae would start gyrating around a central mass, what we know as a super black hole. Every galaxy has one, and it's known as the Galactic Core. As these nubulaes start to create stars due to massive pressure and gravitational forces, lots of protostars begin to colide, lots of H atoms collide, creating nuclear fusion. Our sun is quite small, as shown previously in this thread, and so cannot generate elements heavier than Iron. Massive stars can sustain the development of iron atoms, but burn up very quickly. Elements heavier than Iron has been theorised to have formed in the last stages of a supernova of a dying Giant Star, when nuetron flux becomes so intense that heavier elements are formed by nuetron capture. The ejecta from the exploding supernova mega stars joins the rest of space and get involved in the new accumilation of "next generation stars". Our sun for example is thought to be a 3rd or 4th generation star.

Our solar system is thought to have formed some 5 billion years ago. By this stage, all 92 natural elements are present in the universe. Some have formed by intense heat, pressure or collisions. The gas cloud around our early sun would then see elements turn into molecules, then dust particles, solid pieces of rock, which would start colliding with each other due to gravitational influence of the star and the first planets would form. Mercury, Venus, Earth and Mars are mostly made of rock and metal, mostly due to meteorite impacts, where as Jupitor, Saturn, Uranus, Neptune are gas giants...also due to solar wind being weaker further out.

Earth forms about 4.6 billion years ago. The removal of lighter elements by solar winds left earth to be mostly comprised of Iron, Oxygen, Silicon and Magnesium. Earth starts getting extremely hot at this stage, for about 500 million years, "melts" and all the iron sinks to form our core. This allowed some lighter elements to start becoming predominate. Volcanic gasses then would form the first atmosphere which was mostly nitrogen, methane, sulphure, carbon dioxide and carbon monoxide.

Around 4 billion years ago, the earth finally starts cooling enough for the first proto continents to form. The first evidence of life dates back to about 3.8 billion years, probably when a breathable atmosphere stabilised, but thats a whole different story!

[Hazard]

I believe the Oxygen level on earth was once SO high that thunderstorms were 10x as bad as they are now but it also accelerated the evolutionary process - allowing water born creatures to adapt to "land" quicker.....

~Haz~

[*El Diablo*]

I've heard about this, and according to the laws of physics that is exactly what would happen. Also, try and wrap your head round this. Apparantly, if you walked through a door slow enough (for thousands of years) and kept in motion, eventually you would phase into two. Obviously no1 can live that long and there is more to that story than i've let on, i'll have to ask my mate to be a bit more specific about it. I always wondered what would happen if you could travel at the speed of light and then turned a torch on. Or better still, what would happen if you could go faster than the speed of light and then turn a torch on? Would the light bend around the torch?

Very interesting Flagg, thanks for that

This is what I know of the Big Bang, based on various readings and Uni work.

The so called Big Bang formed about 15-20 billion years ago. At that instant, thermal energy was so high that no matter could exist, not even at the subatomic level. After about a second from the point of the first expansion the Universe had cooled to about 5 billion degrees celcius. At this temperature protons and nuetrons could start forming. 800,000 years after the initial burst, the Universe had cooled further and the first two elements could form, H and He. The only matter in the early universe were massive "hot clouds" of Hydrogen and Helium. These clouds would become the first nebulas and some even exist today still, this is where stars would form, the first galaxies. These nubulae would start gyrating around a central mass, what we know as a super black hole. Every galaxy has one, and it's known as the Galactic Core. As these nubulaes start to create stars due to massive pressure and gravitational forces, lots of protostars begin to colide, lots of H atoms collide, creating nuclear fusion. Our sun is quite small, as shown previously in this thread, and so cannot generate elements heavier than Iron. Massive stars can sustain the development of iron atoms, but burn up very quickly. Elements heavier than Iron has been theorised to have formed in the last stages of a supernova of a dying Giant Star, when nuetron flux becomes so intense that heavier elements are formed by nuetron capture. The ejecta from the exploding supernova mega stars joins the rest of space and get involved in the new accumilation of "next generation stars". Our sun for example is thought to be a 3rd or 4th generation star.

Our solar system is thought to have formed some 5 billion years ago. By this stage, all 92 natural elements are present in the universe. Some have formed by intense heat, pressure or collisions. The gas cloud around our early sun would then see elements turn into molecules, then dust particles, solid pieces of rock, which would start colliding with each other due to gravitational influence of the star and the first planets would form. Mercury, Venus, Earth and Mars are mostly made of rock and metal, mostly due to meteorite impacts, where as Jupitor, Saturn, Uranus, Neptune are gas giants...also due to solar wind being weaker further out.

Earth forms about 4.6 billion years ago. The removal of lighter elements by solar winds left earth to be mostly comprised of Iron, Oxygen, Silicon and Magnesium. Earth starts getting extremely hot at this stage, for about 500 million years, "melts" and all the iron sinks to form our core. This allowed some lighter elements to start becoming predominate. Volcanic gasses then would form the first atmosphere which was mostly nitrogen, methane, sulphure, carbon dioxide and carbon monoxide.

Around 4 billion years ago, the earth finally starts cooling enough for the first proto continents to form. The first evidence of life dates back to about 3.8 billion years, probably when a breathable atmosphere stabilised, but thats a whole different story!

Flagg, Thanks for that, i read it about 2 minutes ago, but i will have to read it again later, and probably AGAIN later, i just cant phatom all the information and then trying to imagine what it was like, Once again, thanks for the explanation........ i have alot of years of reading to do before i can get on you and Haz's knowledge level about Science and time.

I believe the Oxygen level on earth was once SO high that thunderstorms were 10x as bad as they are now but it also accelerated the evolutionary process - allowing water born creatures to adapt to "land" quicker.....

~Haz~

Good read.

[Charger527]

I've heard about this, and according to the laws of physics that is exactly what would happen. Also, try and wrap your head round this. Apparantly, if you walked through a door slow enough (for thousands of years) and kept in motion, eventually you would phase into two. Obviously no1 can live that long and there is more to that story than i've let on, i'll have to ask my mate to be a bit more specific about it. I always wondered what would happen if you could travel at the speed of light and then turned a torch on. Or better still, what would happen if you could go faster than the speed of light and then turn a torch on? Would the light bend around the torch?

I thought that the amount of energy it would take to get to the speed of light, would thus turn you and any other objects travelling at that speed into light?? maybe?

[Flagg]

BUMP for one of my favourite threads on the board.

Read an interesting article in the Observer today, really interesting as I wrote about this in a Distinction I was writing up a coupla years back.
http://www.guardian.co.uk/environmen...xth-extinction



"At first sight it seems an unlikely topic for a landmark publishing deal: a fee of about half a million dollars for a book about dead animals – or, to be more precise, extinct animals.

Nevertheless the subject of eradicated species has become publishing hot property after a bidding battle in the US saw Henry Holt, a publisher, beat its rivals to buy The Sixth Extinction by Elizabeth Kolbert last week. According to the New York Times, a "mid-six-figure advance" has now been agreed between writer and publisher.

"The idea of mass extinctions as the next step after talking about the perils of global warming is the most crucial subject," said Gillian Blake of Holt, after completing the deal with Kolbert, a writer for the New Yorker on environmental issues. Her last book, Field Notes from a Catastrophe, outlined evidence collated from sites across the planet showing how global warming is changing the world. The book was well reviewed on both sides of the Atlantic, with the Observer praising it as "a superbly crafted, diligently compressed vision of a world spiralling towards destruction".

Now, Kolbert is to focus on humanity's impact on the animal world, and in particular will look at the species that are today being rendered extinct by men and women. Scientists say the number of species being lost is approaching levels reached during five pivotal extinction events that have swept the planet over the past 600 million years. Among these catastrophes was the event that wiped out the dinosaurs 65 million years ago. Kolbert's task will to be show whether or not humanity – with its spiralling population, widespread habitat destruction, over-fishing and global warming – is rivalling these.

The theme is intriguing but not new. Nor is the title. In 1996 the distinguished palaeontologist Richard Leakey, with journalist Roger Lewin, produced his version of The Sixth Extinction, in which he argued that the five previous mass extinction events were now being matched by a sixth. "Homo sapiens is poised to become the greatest catastrophic agent since a giant asteroid collided with the Earth 65 million years ago, wiping out half the world's species in a geological instant," he says.

Other distinguished scientists, including EO Wilson and Norman Myers, have also produced works on this theme. None received advances like the one agreed between Holt and Kolbert, however. So what has changed? Why have extinctions become the subject of such attention and finance?

Answers have much to do with timing. Over the past decade, there has been a revolution in concerns about the environment – on both sides of the Atlantic. A succession of reports from United Nations wildlife experts and climate scientists have shown that our planet is in peril and that thousands of species are now hovering on the brink of extinction. For a decade, the public has been deluged with stories about the vulnerability of the tiger, coral reefs, amphibians and a host of other creatures. Hence the interest in Kolbert's new book.

In publishing terms, the move is also a significant one because it represents a shift from big-money outlays on works of fiction which have dominated the market in recent years. Huge sums, for example, have been paid to novelists such as Audrey Niffenegger for works – such as her latest, Her Fearful Symmetry – that have had disappointing sales. A dose of eco-horror might prove rewarding, it is thought.

Certainly, extinctions make a riveting and disconcerting subject. As Professor Norman MacLeod, keeper of palaeontology at the Natural History Museum in London, told the Observer: "We now know that 99.9% of all lifeforms that have ever existed on Earth have gone extinct. That means, to a first order approximation, that all life is extinct."

Obviously this latter, rather disturbing, scenario has not quite arrived. Nevertheless it does indicate that the constant eradication of lifeforms has been the norm throughout the history of life on Earth. It is the fate of all species to become extinct, a notion that should concentrate the minds of Kolbert's readers. The question is: what forces are responsible for the loss of vast numbers of species in such a short period?

Answers depend on individual cases, it transpires. For example, a huge asteroid crashing on Earth 65 million years ago is generally thought to have done for the dinosaurs. The vast plume thrown up by the impact coated the planet in dust and triggered a devastating climate change. As a result, 47% of marine genera (groups of related species) and 18% of land vertebrate families, including the dinosaurs, were wiped out.

And as evidence geologists point to the Chicxulub crater near the Yucatán peninsula, beneath the Gulf of Mexico, as the impact point of the asteroid.

Similarly the Triassic extinction, which occurred between 199 million and 214 million years ago, was most likely caused by massive floods of lava erupting from the Atlantic Ocean. These created a wave of global warming. In this case, around 22% of marine families and 52% of marine genera were eradicated.

Then there was the Permian-Triassic extinction, about 250 million years ago, which has been linked to both asteroid impacts and volcanism. This was Earth's worst mass extinction, killing 95% of all species, including an estimated 70% of land species such as plants, insects and vertebrate animals. Before that, the Late Devonian extinction, about 360 million years ago, killed 57% of marine genera. Its cause remains unknown. And finally, there was the Ordovician-Silurian extinction, about 440 million years ago, which has been linked with changes in sea levels and which led to the eradication of 60% of marine genera.

Life on Earth has, on some occasions, become remarkably unpleasant in a short space of time, to say the least – though this has not always been the prevailing view among scientists. In fact, Darwin thought extinction was a slow, painful business. "The complete extinction of the species of a group is generally a slower process than their production," he once remarked, a view that held sway for more than a century. Indeed it was only in the latter half of the 20th century that scientists uncovered evidence – the Chicxulub crater – that an asteroid crash must have been involved in the demise of dinosaurs. Extinctions could be sudden, they realised.

However, MacLeod urged caution in interpreting such discoveries. "Most palaeontologists dislike the idea that any single cause was responsible for one of the main extinctions," he said.

"Life is very robust and it takes a sequence of events to produce large-scale extinctions."

Thus the dinosaurs were wiped out at a time of considerable volcanic activity on Earth. Plumes of material were already sweeping the planet, plunging it into a period of global cooling. The crashing asteroid then administered a planetary coup de grace.

On top of volcanoes and errant astronomical objects, other factors involved in these mass extinctions include extreme ice ages which coated the planet in ice from pole to equator, and eruptions of deep-sea methane deposits that set off massive global warming. The resulting death toll is measured in millions of species.

What remains unclear is the degree to which humans are now repeating this bloodletting, to the extent that we are about to set off a sixth extinction wave. If so, we will be the first single, biological cause of this kind of catastrophe. "If you add up the numbers of species that have been wiped out over the past few hundred years, then you find the figures fall well short of a mass extinction," said MacLeod. "It is only when you look at the numbers of creatures that are poised at the brink of eradication does the picture become alarming."

Tigers, coral reefs and all the marine life they support, amphibians such as the golden frog of Panama, orang-utans, sharks, mountain gorillas, the marine iguanas of the Galápagos, albatrosses, chimpanzees and thousands of other creatures now face obliteration: hunted, rendered homeless, and poisoned by humans.

More to the point, this predation has been going on, not for hundreds of years, but for tens of thousands of years.

Whenever Homo sapiens has moved into new territory, this has been followed quickly by the disappearance of most large land mammals, palaeontologists have found. For example, the Clovis people, ancient hunters armed with fearsome stone-tipped spears, arrived in North America 12,000 years ago.

A total of 75 species, including woolly mammoths, mastodons, four-horned antelopes and lumbering sloths the size of giraffes were killed off almost immediately. A thousand years later, the slaughter continued in South America when humans arrived there.

The glyptodon (a giant armadillo-like animal), several species of rodent and various llama-like animals were wiped out. And a similar bloodbath occurred in Australia with the arrival of the first members of Homo sapiens.

In short, humanity has a great deal of blood on its hands, spears and guns. Whether we maintain this kind of eradication of our fellow Earthlings remains to be seen. Most experts predict grim times, an outcome that will provide Kolbert with the core of her ambitious look at the fate of our planet – and at the fate of the animals who are trying, unsuccessfully, to share it with human beings."

It's a really interesting article, but the skinny is that is it possible we'll be responsible for a 6th Mass Extinction. If we are, it'll be a first...a biotic factor being responsible rather than an Abiotic factor. Due to agriculture, hunting, habitat destruction, persecution, many many species of animals are hovering on the brink of extinction. Tigers, coral reefs (which includes all the marine life they support), amphibians, Galapogas Island species, albatrosses and thousands of other species face obliteration through human action. I hate to see any of these species destroyed because of us, but chimps, orang-utans and gorillas also face this. These are our closest ancestors. Sharks are also under threat, what is alarming about this is that Sharks have survived all 5 previous Mass Extinctions, they are some of the oldest creatures on the planet, half a billion years old, yet in 50 years of hunting and persecution they too also face obliteration.

Now life on Earth always has a way of bouncing back, but the fate of Homo Sapiens is also of concern. Not only do we do this to other animals, we do this to ourselves. We have no predators. 5 people are born every second to every 3 that die, in other words, 2 people are added to the population every second. We consume our finite resources at a ridiculous rate. Advances in Medical Science seems to prevent humans from dying any time soon.

Are we not in jeapordy of eventually starving ourselves? By 2050 our population is supposed to be some 11 billion. We'll need 50% more water than we have now to compensate for that, and water is a dwindling resource. By 2099, our population will be 19 billion. Oil will have run out by then, how are we supposed to feed, clothe and home that many people? By the time you will have read this last paragraph, some 50 human beings will have been added to the human population.

[*El Diablo*]

....Bump for great thread
I have found this, Its got daily images of Astronomy, Im sure people like Flagg, Haz, etc will really enjoy this....

http://antwrp.gsfc.nasa.gov/apod/archivepix.html

[Flagg]

....Bump for great thread
I have found this, Its got daily images of Astronomy, Im sure people like Flagg, Haz, etc will really enjoy this....

http://antwrp.gsfc.nasa.gov/apod/archivepix.html

That's a cool lil find there Diablo. To make it a bit more interesting, prehaps some of us could say something about the picture that coincides with your birthday? For instance, a picture of Deimos was taken on my birthday. If im not mistaken, I think each year Deimos is pulled nearer and nearer to Mars. Eventually it will collide with Mars itself.

Edit: ARGH! Actually its Phobos that is being pulled to Mars where it will eventually be pulled apart by gravitational forces or impact itself. We dont have to worry as it wont happen for about 100,million years. Okay, well another "fact" about Deimos is that it's not spherical like most moons and has been thought to be an asteroid caught in Mars gravitational pull. It has a longer orbit than Phobos, whose orbit is shorter every year.

[*El Diablo*]

That's a cool lil find there Diablo. To make it a bit more interesting, prehaps some of us could say something about the picture that coincides with your birthday? For instance, a picture of Deimos was taken on my birthday. If im not mistaken, I think each year Deimos is pulled nearer and nearer to Mars. Eventually it will collide with Mars itself.

March 16th?.. Wow i didnt even know it existed.... I thought u might have liked it..

[Flagg]

March 16th?.. Wow i didnt even know it existed.... I thought u might have liked it..

Yeah March 16th, but I got my fact wrong which I corrected in my edit. Its Phobos that gets pulled closer to Mars each year. Deimos is likely an asteroid and a fairly recent one by stellar timescales as it's not spherical yet.

[Flagg]

Sept 20th is a cool shot of Ganymede, biggest moon in our solar system. I didnt know it was bigger than Pluto and Mercury. Places like this fascinate me because it has the potential to be terraformed one day for life to exist.

[*El Diablo*]

Sept 20th is a cool shot of Ganymede, biggest moon in our solar system. I didnt know it was bigger than Pluto and Mercury. Places like this fascinate me because it has the potential to be terraformed one day for life to exist.

Definitely looks livable... Very much Earth like..

WOW there are some really outstanding pictures in these archives going back till June 16, 1995....... I dont know which is most beautifull....

[*El Diablo*]

I thought this was quite cool,Comet Between Fireworks and Lightning

[*El Diablo*]

Cool Explanation...

[Hazard]

I like that pic..... very cool. I just watched something on that 2 nights ago.....

~Haz~