KillerMuffin
Seraphically Disinclined
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- Jul 29, 2000
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Note: No more tags from me, it's stealing bandwidth.
Go here! [url]http://www.seds.org/hst/97-12.html[/url]
It's a picture of M84's black hole.
This is so incredibly cool!
- Thread starter KillerMuffin
- Start date
JazzManJim
On the Downbeat
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- Sep 12, 2001
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That's a great site, KM!
Have you discovered The Astronomy Picture of the Day ? They glean from the Hubble Library as well as other places, and have links to more detailed information on stuff in their summaries. Lots of brain food there.
And there's a cool pic in the archives, a couple days back, of the asteroid Eros with actual regolith all over it. The detail was incredible.
Have you discovered The Astronomy Picture of the Day ? They glean from the Hubble Library as well as other places, and have links to more detailed information on stuff in their summaries. Lots of brain food there.
And there's a cool pic in the archives, a couple days back, of the asteroid Eros with actual regolith all over it. The detail was incredible.
EvilBrat74
Literotica Guru
- Joined
- Jan 10, 2002
- Posts
- 565
KillerMuffin said:
cymbidia
unrepentant pervert
- Joined
- Mar 8, 2001
- Posts
- 8,786
What's a black hole?
Very cool pics, Muff. I *love* astronomy. It's my second favorite unti to teach after Evolution. (Here Todd!)
In plain English (of the 8th grade variety), i present:
What the fuck is a black hole, anyway?
(This is taken directly from the notes i use for lectures when i'm teaching this subject.)
I. The Life of a Star
A. Like a human life, the life of a star can be divided into several stages:
1. Birth
a. the concentration of gases and dust
2. Infancy
a. the contracting stage
3. Maturity
a. moving on to the Main Sequence
4. Old age
a. the Red Giant stage
5. Death
a. White Dwarfs, neutron stars, black holes
B. The star's mass at birth determines everything about it, including
1. the class of star it will become
2. the length of it's life
3. the kind of death it will meet
C. Life expectancy of stars varies from several million years for the most massive stars to many billions of years for the least massive.
D. At any given moment, there are many billions of stars in every stage of stellar evolution spread all over the universe.
1. Some have just been born
2. Others, like our sun, are in the prime of thier lives.
3. Still others are in their declining years.
<snip everything until Stellar Maturity>
Stellar Maturity
I. "MAIN SEQUENCE STAR"
A. Star that falls into the area of the same name on the H-R Diagram. (http://astrosun.tn.cornell.edu/courses/astro201/hr_diagram.html: i'll explain this disgram and it's important to the understanding of stellar life cycles if anyone wants me to explain it but most of you will stop reading if i go there [assuming, of course, there's anyone actually reading this in the first place])
1. Makes up 90% of the stars in the sky.
II. Eventually a nebula stops contracting and the object begins emitting energy into space as light and heat.
III. These stars will shine steadily for billions of years.
IV. Just how long it remains a main sequence star before it evolves into the next stage depends on how much mass the star has to begin with.
A. REPEAT THIS
B. Overhead
V. Red dwarfs are the least massive stars.
A. Because of their low mass, their core temperatures are just barely hot enough to start nuclear fusion reactions.
B. These stars shine with a cool red light, burn up thier hydrogen very slowly, and have very long lives - maybe 100 billion years or so.
1. These small red dwarfs evolve so slowly that even one formed in the earliest days of the universe is still burning unchanged and will continue for the entire lifetime of the universe.
VI. Yellow stars, like our Sun, are about 10X more massive than the red dwarfs
A. They use up their hydrogen much more rapidly and have shorter lives, only about 10 billion years or so.
VII. Bluish-white stars that are about 35X more massive than our sun.
A. These stars are very hot energy spenthrifts and use up their fuel supply rapidly.
B. Their lives span only a few billion years.
Stellar Old Age
vocab: "RED GIANT"
-----> An old star that swells up into a red, giant star just before it dies.
I. All stars, no matter how much or how little mass they have, will eventually swell up into a red giant before they burn out in a couple of ways.
A. The star's mass determines how dramatically it ends it's days.
II. Eventually the fusion process that causes the star to shine uses up all of the hydrogen and helium.
III. The core of the star collaspes.
IV. This results in another increase in temperature (more mass and pressure), which causes the gaslike outside layers to expand.
V. As the gaseous outer layers expand, they begin to cool down.
VI. The thin (very little mass) outside layer cannot absorb all the radiation coming from the hot core, so most of it reaches the surface and escapes as radiation.
A. The brightness of the star inreases as the temp decreases.
VII. Depending on the original mass of the star, it has now become a red giant or a super giant.
Stellar Death
vocab: "WHITE DWARF"
-----> A small, dense star that results from the collapse of a Red Giant.
I. For stars less than 4X the mass of the sun :
II. After becoming red giants, these stars use their remaining fuel very rapidly.
A. Then they begins to cool and contract.
III. Eventually the star shrinks to about the size of the earth.
IV. It now has so little surface area from which to send out it's energy that it only shines with a faint white light.
A. It has become a white dwarf.
V. Over billions of years, it continues to cool, gets dimmer and dimmer, fades from white to yellow to red and finally just goes out.
A. Becomes a lump of cold dead ash.
VI. It has become a black dwarf. A dead star.
vocab: "BLACK DWARF"
-----> A cold, black object in space that has lost all it's energy.
Supernova
Vocab: "SUPERNOVA"
-----> The suden, cataclysmic explosion of a star.
I. Massive stars, at least 4X more massive than our sun keep the fusion process going until their cores are almost pure iron (instead of hydrogen and helium).
II. Layers and layers of other elements are wrapped around this core.
A. Silicon, carbon, oxygen, helium, hydrogen - all fusing into the next element
III. At this point, the dying star is a red supergiant that has expanded large enough to fill most of our solar system.
IV. A high mass star with an iron core keeps getting hotter and hotter until it finally, at about 600 million degrees, the core detonates and causes the entire star to explode.
A. This exploding star is called a supernova.
V. A supernova can outshine billions of suns.
A. The most recent one was seen in 1987.
1. That supernova exploded so far out in space that its light had been travelling for about 163,000 years before it reached Earth.
B. The first supernova ever recorded by scientists was all the way back in the year 1054 by Chinese astronomers.
1. We've been watching them for much longer though.
VI. Anyone have any gold or silver on?
A. As far as we know, all the elements that are heavier than iron - including gold and silver - are not and cannot be fused in a star's core.
B. These elements can only be formed in the catastrophic few moments when a star goes supernova.
VII. Dying stars, then, are the element factories of the universe.
Neutron Stars (Pulsars)
vocab: "NEUTRON STARS"
-----> A very dense object made up of neutrons.
I. Stars that are from 4 to 10X more massive than our sun become neutron stars
A. These are tiny objects that are only about 10 miles across.
1. That's only halfway from here to Santa Rosa.
B. Super dense, too
1. Contains a large part of the star's original mass in it's 10 miles.
II. They are made up of sub-atomic (means smaller than atoms) particles called neutrons.
A. Neutrons don't have any electrical charge, so they don't repel each other and can be packed together extremely tightly.
III. Radio astronomers first detected neutron stars in 1967.
IV. Some emit huge amounts of radiation and shine steadily toward earth.
V. Others emit a continuous beam of radiation but they spin very rapidly as they do it.
A. Each time this beam crosses earth, astronomers can detect a "pulse".
B. These rotating neutron stars are called pulsars.
VI. All neutron stars and pulsars eventually just fade away (the pulsars slow down bit by bit, first.......).
vocab: "PULSARS"
-----> Rotating neutron stars.
Black Holes
vocab: "BLACK HOLE"
-----> A stellar object so dense that even light cannot escape it's gravity.
I. Stars even more massive than those that become neutron stars have a very strange fate in store.
A. They become black holes.
B. The very first black hole was found in the mid-1990's, since then, we've found many.
II. Black holes have been described as an object that dug a hole, jumped in, then pulled the hole in after itself!
III. This is how it works: when a massive burned out star shrinks to about 130 miles in diameter, it becomes very special.
A. It's so dense, and it's gravity is so strong, that virtually nothing can escape from it, not even light.
IV. At this time, the star disappears inside itself, and no event that happens inside the black hole can be seen from the outside.
vocab: "EVENT HORIZON"
-----> The point at which no event that happens inside a black hole can be seen from the outside.
V. After the dying star contracts into a black hole, it continues to contract until it is just a tiny point called a singularity.
vocab: "SINGULARITY"
-----> The center of a black hole in which in infinitly strong gravitational field exists.
VI. So, if nothing, not light or any other kind of energy, can escape from a black hole, how do we find them?
VII. Gases should get pulled violently into black holes from nearby stars.
A. Just before this matter gets pulled over the black holes event horizon and disappears, it gets hot and sends out strong bursts of X-rays.
B. These X-ray bursts are our best evidence of black holes.
VIII. To date there are a number of new candidates for black holes. Work in this area continues.
IX. Most astronomers believe that at the center of most galaxies are black holes that are millions of times more massive than our own sun.
Remember: test next Monday, open note. I'll collect your notes with the test and grade those, too. You may go.
Very cool pics, Muff. I *love* astronomy. It's my second favorite unti to teach after Evolution. (Here Todd!)
In plain English (of the 8th grade variety), i present:
What the fuck is a black hole, anyway?
(This is taken directly from the notes i use for lectures when i'm teaching this subject.)
I. The Life of a Star
A. Like a human life, the life of a star can be divided into several stages:
1. Birth
a. the concentration of gases and dust
2. Infancy
a. the contracting stage
3. Maturity
a. moving on to the Main Sequence
4. Old age
a. the Red Giant stage
5. Death
a. White Dwarfs, neutron stars, black holes
B. The star's mass at birth determines everything about it, including
1. the class of star it will become
2. the length of it's life
3. the kind of death it will meet
C. Life expectancy of stars varies from several million years for the most massive stars to many billions of years for the least massive.
D. At any given moment, there are many billions of stars in every stage of stellar evolution spread all over the universe.
1. Some have just been born
2. Others, like our sun, are in the prime of thier lives.
3. Still others are in their declining years.
<snip everything until Stellar Maturity>
Stellar Maturity
I. "MAIN SEQUENCE STAR"
A. Star that falls into the area of the same name on the H-R Diagram. (http://astrosun.tn.cornell.edu/courses/astro201/hr_diagram.html: i'll explain this disgram and it's important to the understanding of stellar life cycles if anyone wants me to explain it but most of you will stop reading if i go there [assuming, of course, there's anyone actually reading this in the first place])
1. Makes up 90% of the stars in the sky.
II. Eventually a nebula stops contracting and the object begins emitting energy into space as light and heat.
III. These stars will shine steadily for billions of years.
IV. Just how long it remains a main sequence star before it evolves into the next stage depends on how much mass the star has to begin with.
A. REPEAT THIS
B. Overhead
V. Red dwarfs are the least massive stars.
A. Because of their low mass, their core temperatures are just barely hot enough to start nuclear fusion reactions.
B. These stars shine with a cool red light, burn up thier hydrogen very slowly, and have very long lives - maybe 100 billion years or so.
1. These small red dwarfs evolve so slowly that even one formed in the earliest days of the universe is still burning unchanged and will continue for the entire lifetime of the universe.
VI. Yellow stars, like our Sun, are about 10X more massive than the red dwarfs
A. They use up their hydrogen much more rapidly and have shorter lives, only about 10 billion years or so.
VII. Bluish-white stars that are about 35X more massive than our sun.
A. These stars are very hot energy spenthrifts and use up their fuel supply rapidly.
B. Their lives span only a few billion years.
Stellar Old Age
vocab: "RED GIANT"
-----> An old star that swells up into a red, giant star just before it dies.
I. All stars, no matter how much or how little mass they have, will eventually swell up into a red giant before they burn out in a couple of ways.
A. The star's mass determines how dramatically it ends it's days.
II. Eventually the fusion process that causes the star to shine uses up all of the hydrogen and helium.
III. The core of the star collaspes.
IV. This results in another increase in temperature (more mass and pressure), which causes the gaslike outside layers to expand.
V. As the gaseous outer layers expand, they begin to cool down.
VI. The thin (very little mass) outside layer cannot absorb all the radiation coming from the hot core, so most of it reaches the surface and escapes as radiation.
A. The brightness of the star inreases as the temp decreases.
VII. Depending on the original mass of the star, it has now become a red giant or a super giant.
Stellar Death
vocab: "WHITE DWARF"
-----> A small, dense star that results from the collapse of a Red Giant.
I. For stars less than 4X the mass of the sun :
II. After becoming red giants, these stars use their remaining fuel very rapidly.
A. Then they begins to cool and contract.
III. Eventually the star shrinks to about the size of the earth.
IV. It now has so little surface area from which to send out it's energy that it only shines with a faint white light.
A. It has become a white dwarf.
V. Over billions of years, it continues to cool, gets dimmer and dimmer, fades from white to yellow to red and finally just goes out.
A. Becomes a lump of cold dead ash.
VI. It has become a black dwarf. A dead star.
vocab: "BLACK DWARF"
-----> A cold, black object in space that has lost all it's energy.
Supernova
Vocab: "SUPERNOVA"
-----> The suden, cataclysmic explosion of a star.
I. Massive stars, at least 4X more massive than our sun keep the fusion process going until their cores are almost pure iron (instead of hydrogen and helium).
II. Layers and layers of other elements are wrapped around this core.
A. Silicon, carbon, oxygen, helium, hydrogen - all fusing into the next element
III. At this point, the dying star is a red supergiant that has expanded large enough to fill most of our solar system.
IV. A high mass star with an iron core keeps getting hotter and hotter until it finally, at about 600 million degrees, the core detonates and causes the entire star to explode.
A. This exploding star is called a supernova.
V. A supernova can outshine billions of suns.
A. The most recent one was seen in 1987.
1. That supernova exploded so far out in space that its light had been travelling for about 163,000 years before it reached Earth.
B. The first supernova ever recorded by scientists was all the way back in the year 1054 by Chinese astronomers.
1. We've been watching them for much longer though.
VI. Anyone have any gold or silver on?
A. As far as we know, all the elements that are heavier than iron - including gold and silver - are not and cannot be fused in a star's core.
B. These elements can only be formed in the catastrophic few moments when a star goes supernova.
VII. Dying stars, then, are the element factories of the universe.
Neutron Stars (Pulsars)
vocab: "NEUTRON STARS"
-----> A very dense object made up of neutrons.
I. Stars that are from 4 to 10X more massive than our sun become neutron stars
A. These are tiny objects that are only about 10 miles across.
1. That's only halfway from here to Santa Rosa.
B. Super dense, too
1. Contains a large part of the star's original mass in it's 10 miles.
II. They are made up of sub-atomic (means smaller than atoms) particles called neutrons.
A. Neutrons don't have any electrical charge, so they don't repel each other and can be packed together extremely tightly.
III. Radio astronomers first detected neutron stars in 1967.
IV. Some emit huge amounts of radiation and shine steadily toward earth.
V. Others emit a continuous beam of radiation but they spin very rapidly as they do it.
A. Each time this beam crosses earth, astronomers can detect a "pulse".
B. These rotating neutron stars are called pulsars.
VI. All neutron stars and pulsars eventually just fade away (the pulsars slow down bit by bit, first.......).
vocab: "PULSARS"
-----> Rotating neutron stars.
Black Holes
vocab: "BLACK HOLE"
-----> A stellar object so dense that even light cannot escape it's gravity.
I. Stars even more massive than those that become neutron stars have a very strange fate in store.
A. They become black holes.
B. The very first black hole was found in the mid-1990's, since then, we've found many.
II. Black holes have been described as an object that dug a hole, jumped in, then pulled the hole in after itself!
III. This is how it works: when a massive burned out star shrinks to about 130 miles in diameter, it becomes very special.
A. It's so dense, and it's gravity is so strong, that virtually nothing can escape from it, not even light.
IV. At this time, the star disappears inside itself, and no event that happens inside the black hole can be seen from the outside.
vocab: "EVENT HORIZON"
-----> The point at which no event that happens inside a black hole can be seen from the outside.
V. After the dying star contracts into a black hole, it continues to contract until it is just a tiny point called a singularity.
vocab: "SINGULARITY"
-----> The center of a black hole in which in infinitly strong gravitational field exists.
VI. So, if nothing, not light or any other kind of energy, can escape from a black hole, how do we find them?
VII. Gases should get pulled violently into black holes from nearby stars.
A. Just before this matter gets pulled over the black holes event horizon and disappears, it gets hot and sends out strong bursts of X-rays.
B. These X-ray bursts are our best evidence of black holes.
VIII. To date there are a number of new candidates for black holes. Work in this area continues.
IX. Most astronomers believe that at the center of most galaxies are black holes that are millions of times more massive than our own sun.
Remember: test next Monday, open note. I'll collect your notes with the test and grade those, too. You may go.
april-wine
Deviant Lesbo!
- Joined
- Apr 21, 2001
- Posts
- 13,215
Holy Crap I suck at taking notes.........
Cool pics KM, thanks for the link.........
Cool pics KM, thanks for the link.........
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