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Posted: Thu Mar 30, 2006 3:44 am
by Martin
I understand that the sun has it's cycles -ty. I don't see how it is relevant to any of my comments.
And for the record.... I'm not aware of anyone ever observing a planet's magnetic field collapsing. So it will be an unusal event for humankind. Especially if the observed planet has an atsmosphere that sustains life.
Posted: Thu Mar 30, 2006 7:47 am
by harry
Hello all
I agree that there is no evidence for the Earth Magnetic field collapsing.
But! there is evidence of it changing position and direction. This is fossilized in the rock formation over time. This evidence takes into consideration plate tectonic movements of the continents and oceanic plates. More so with continental plates because they are billions of years compared to oceanic plates being only a few million years.
Posted: Thu Mar 30, 2006 2:55 pm
by BMAONE23
Martin,
Your comments, while true for the most part, still contain conjecture. Our only point of comparison for our purposes are:
1) The sun and its cycles. How quickly it recovers from its magnetic polar flip.
2) The fossil record and how it is interpreted.
You may be right and we might be in for a world of hurt sometime in the next few million years or (It may begin tomorrow). If it is a fast process, like our sun, (our sun is our only certain method of comparison) we will probably survive. If it takes a long time we would require proper prior planning to survive.
Posted: Thu Mar 30, 2006 7:46 pm
by Qev
harry wrote:Hello All
The amount of molecules escaping the earth is quite minimal.
If the temp of the atmosphere increases by lets say 20 Deg C than the possibilty of greater escape by molecules.
Look at Venus, about the same size as earth and holds most of the water in the atomosphere which has expanded due to the high temp.
Venus actually has almost no water. The clouds are composed of, if I recall correctly, droplets of sulfuric acid (a non-aqueous liquid). Theory suggests that Venus lost its water due to intense heating and ultraviolet radiation cracking water molecules into hydrogen and oxygen. Hydrogen, being a terribly light gas, then easily escaped the planet's atmosphere into space.
Earth doesn't lose much atmosphere, I agree. I'm glad for this.
As for Earth's polar reversals, there's plenty of evidence in the magnetic fossil record documenting this effect. It's happened lots of times, as far as we can tell, and the planet has come through it none the worse for wear. The period where the field is disrupted or absent is relatively short, from what the fossil record tells us; certainly not long enough for there to be significant ablation of the atmosphere.
No guarantees of course.
I'm personally more worried that we're going to get clobbered by an asteroid we don't see coming, though.
Did anyone else see that wretched movie, The Core? I couldn't tell whether I should groan, laugh, or cry my way through that movie. The 'microwave beam' melting the Golden Gate Bridge almost made me spit my soda across the seats in front of me.
Posted: Thu Mar 30, 2006 10:27 pm
by BMAONE23
QEV
When all else fails, laughter works best.
Posted: Fri Mar 31, 2006 7:36 am
by harry
The sun's core is very active, and it does have a spin. When our sun sheds its skin it will be left with a neutron core. Possibly a white dwarf.The earth is less active and its spin is controlled by the sun and its change of spin is extra slow, snail speed.
White Dwarfs
http://antwrp.gsfc.nasa.gov/apod/ap031110.html
http://antwrp.gsfc.nasa.gov/apod/ap050123.html
http://antwrp.gsfc.nasa.gov/apod/ap951130.html
http://antwrp.gsfc.nasa.gov/apod/ap950910.html
http://www.spacetelescope.org/news/html/heic0516.html
The sun
http://fusedweb.pppl.gov/CPEP/Chart_Pag ... ayers.html
http://antwrp.gsfc.nasa.gov/apod/ap950813.html
http://antwrp.gsfc.nasa.gov/apod/ap960521.html
Darn thing I get carried away with links,,,,,,,,,,I better take up smoking or drinking or wild ladies to break my habit.
Posted: Sat Apr 01, 2006 3:57 pm
by Martin
Another theory actually paints gamma-ray bursts in a positive light. University College Dublin researchers Brian McBreen and Lorraine Hanlon recently estimated the effects of a nearby gamma-ray burst on the preplanetary solar nebula, the cloud of condensing star stuff that formed our solar system some 4.5 billion years ago. They calculated that iron in the nebula would have been the major absorber of the high-energy X-rays and gamma rays from such a burst, causing the nebula's dust to become molten in seconds and then cooling slowly to form millimeter-sized chondrules, round granules of cosmic origin. Chondrules, they note, combined to form meteorites and possibly the rocky terrestrial planets, including Earth.
Posted: Sat Apr 01, 2006 8:47 pm
by Qev
harry wrote:The sun's core is very active, and it does have a spin. When our sun sheds its skin it will be left with a neutron core. Possibly a white dwarf.The earth is less active and its spin is controlled by the sun and its change of spin is extra slow, snail speed.
A quick note, the Sun is too small to actually form a neutron star upon its demise; it's destined to shed it's outer layers in a planetary nebula, and quietly fade away as a small white dwarf star.
Earth's spin is actually dominated more heavily by the presence of the Moon. Tidal effects between the two bodies are causing the Earth's rotation to slow, while simultaneously widening the Moon's orbit. Some day, we'll no longer be able to see total solar eclipses like the one we just had; the Moon will be too far away to completely cover the Sun.
White dwarf verses Neutron star
Posted: Sat Apr 01, 2006 9:59 pm
by Dave H
I know that in both cases the matter is very dense in fact neutron star matter (a teaspoon worth) weighs about mountian worth here and in fact thats all it is is just neutrons packed together but to what point is the matter packed in white dwarf matter?I know it is very dense and should a white dwarf colide with our sun it would pass through the sun unscathed exploding the Sun. Or so I read in a great articule that was suggesting this actually happens from time to time mainly in dense star communities such as globular clusters.
Posted: Sat Apr 01, 2006 11:32 pm
by astroton
Dave H,
Have you looked at the Sirius A & B? Sirius B is tiny dwarf and A is a giant compared to the Sun. B is chewing matter from A and will make it eveolve faster than normal. So I read a few years back. Hubble recently took a snap of these companions. The tiny one determines how the giant goes through its orbit. Here is the link,
http://hubblesite.org/gallery/album/sta ... r2005036a/
Posted: Sat Apr 01, 2006 11:36 pm
by harry
Hello All
Our sun will become a white dwarf,,,,,,,,,a very dense core,,,,this ultra dense matter may become a neutron star
http://imagine.gsfc.nasa.gov/docs/scien ... warfs.html
http://imagine.gsfc.nasa.gov/docs/scien ... warfs.html
http://www.spacetelescope.org/news/html/heic0516.html
Posted: Sat Apr 01, 2006 11:50 pm
by astroton
Harry,
I thought for a star to become neutorn star, its mass has to be over Chndrasekar limit. Chandra's limt postulate states that a star above 1.44 times the mass of the sun goes to form Neutron Star and Blackhole. Below this limit they become Dwarfs.
Unless a dwarf has other source of matter, they eventully cool down and become a dead star of very dense matter but not as dense as a neutron star.
Posted: Sun Apr 02, 2006 2:13 am
by Dave H
When other matter is added to White dwarfs it does not become a part of the cinder core proper the incoming material forms a sort of surface crust and at a critical lmass it explodes in a nova ( non super type). The white dwarf lives on to "nova " over and over.
Posted: Sun Apr 02, 2006 3:26 am
by harry
Hello Astroton
You are right in what you say. But there are some who say that our sun will become a neutron star. I'm looking for that info and the reasons why.
as for collapsing matter.
The Stability of Matter
http://www.sciencenews.org/pages/sn_edpik/ps_3.htm
Their report proved that with Pauli's exclusion principle, matter is stable; without it, matter collapses into a dense state, creating a situation in which "the assembly of any two macroscopic objects would release energy comparable to that of an atomic bomb
Working in concert with many collaborators, Lieb then turned his attention to examining more carefully those situations in which matter does, in fact, collapse. For example, under the influence of gravitational forces, which only attract and never repel, matter will collapse despite the effects of the Pauli exclusion principle--a situation that presents a problem only for an object as massive as a star.
In 1931, the late Nobel laureate Subrahmanyan Chandrasekhar predicted that stars with more than about 1.4 times the sun's mass would, on running out of nuclear fuel, collapse under their own gravity. More than half a century later, Lieb and H.-T. Yau, a mathematical physicist now at New York University's Courant Institute, proved that, starting from the basic principles of quantum mechanics, Chandrasekhar had indeed been correct.
A neutron star, the result of a massive star's collapse, generates crushing magnetic and gravitational fields. Such stars have the power, for example, to squeeze Earth into an object the size of a marble. But such large fields simply do not exist on Earth. Moreover, to create fields of such intensity requires a huge amount of energy.
"There are two issues here, one weak, one strong," Lieb says.
"The weaker issue is that matter is stable because there's a limit to the amount of energy that each atom can have.
"The stronger issue is that the energy of matter remains strictly proportional to the number of particles." In other words, the amount of energy and the number of atomic particles increase at the same rate. This phenomenon of nature is rooted in certain immutable physical constants.
"We have proved that under these conditions, the energy is not only finite but also proportional to the number of particles," Lieb says, "as it should be in order to have the strong kind of stability."
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going back a bit to expoding star
http://hyperphysics.phy-astr.gsu.edu/hb ... cn.html#c2
either the fission or fusion of iron group elements will absorb a dramatic amount of energy - like the film of a nuclear explosion run in reverse. If the temperature increase from gravitational collapse rises high enough to fuse iron, the almost instantaneous absorption of energy will cause a rapid collapse to reheat and restart the process. Out of control, the process can apparently occur on the order of seconds after a star lifetime of millions of years. Electrons and protons fuse into neutrons, sending out huge numbers of neutrinos. The outer layers will be opaque to neutrinos, so the neutrino shock wave will carry matter with it in a cataclysmic explosion
Eta Carinae
Posted: Fri Apr 07, 2006 2:37 am
by ta152h0
c'mon Eta baby..........do it .................throw us the Periodic table in its entirety..............
Posted: Fri Apr 07, 2006 6:37 am
by Dave H
10 billion light years away and these events come in clear and crisp.
8 thousand light years away and crisp becomes crispy.
which by the way rasies the one of the greatest mystery questions of all "whats crispy about krispy creme dounuts ?"
Posted: Fri Apr 07, 2006 7:50 pm
by Qev
The density of white dwarf material is something on the order of one million times the average density of the Sun, which puts it at about one-and-a-half billion kilograms per cubic meter. Or put another way, 71 cubic centimeters of white dwarf material would mass as much as the USS Nimitz aircraft carrier.
A neutron star, on the other hand, has a truly ridiculous density, on the order of three hundred quadrillion kilograms per cubic meter (3x10^17kg/m^3). Put in terms of aircraft carriers, that would be three Nimitz aircraft carriers packed into one cubic millimeter.
Posted: Fri Apr 07, 2006 11:06 pm
by astroton
It's said that if Rigel were located where the Sirius is, it would have cast shadows on earth in the nighttime. I wonder what would have happened, had Eta been at the place of Sirius.
She's so Heavy;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Posted: Fri Apr 07, 2006 11:14 pm
by kovil
Qev,
John Dobson like to say it as for a neutron stars density; it is equal to
100,000 US Aircraft Carriers
all covered in aeroplanes and sailors on parade,
in a one pint jar !
I am assuming the Nimitz is one million tons displacement ?
On the MARKARIAN 205 posting, the jets are not coming at us or going away from us, they are going at somekind of oblique to perpendicular direction, across to us. Would this make for the kind of time slowing we are seeing in their redshift? Do you have any of Arp's books? "Seeing Red" or "Catalogue of Discordant Redshift Associations" ? The Latter is the newer book. Arp has deduced the flanking objects are close to the central galaxy, and not being lensed by it. Most mainstream astrophysicists think he's nuts, and it is being lensed. Arp believes he finds connecting trails of material being siphoned from, or jetting from, one to the other, and that causes him to conclude they are all in adjacant propinquity.
There are quite a number of them. He thinks the large number of them is a probability reason to think they are not being lensed.
I haven't finished either book yet, they are both a good read so far.
Posted: Sat Apr 08, 2006 9:39 am
by Qev
I believe the USS Nimitz is around 102,000 tonnes displacement or so. That's the figure I grabbed from the web, anyway.
As for Arp and his theories... I've tried reading a few webpages on it, but they kept spiralling into really awful and obvious misinterpretations of various theories. I've seen some of the photographic evidence Arp's supporters claim 'prove' connection between high and low redshift objects, and it just doesn't seem too likely to me. And the constant linking of his ideas to 'electric universe' theories... ugh.
Arp has interesting ideas, but there's this tool called Occam's Razor that kinda leads me to believe his ideas are flawed. Given the choice between universal expansion, and a quantized, time-dependant change in the fundamental laws of physics that
only seems to affect redshift observations and nothing else, I'll stick with the universal expansion, thanks.
Posted: Sat Apr 08, 2006 10:46 am
by harry
Hello Qev
How can the universe expand?
What is expanding?
Is it the local galaxies or cluster of galaxies?
It cannot be the universe because the universe is all, and all cannot expand.
Maybe I'm wrong, but! the wave of information against the Big Bang is so great that we cannot put it aside.
Posted: Sat Apr 08, 2006 5:34 pm
by Qev
harry wrote:Hello Qev
How can the universe expand?
What is expanding?
Is it the local galaxies or cluster of galaxies?
It cannot be the universe because the universe is all, and all cannot expand.
Maybe I'm wrong, but! the wave of information against the Big Bang is so great that we cannot put it aside.
The metric we call spacetime itself is expanding. If there were no forces counteracting it (ie. if you eliminated gravity), everything would be moving away from everything else, because there would constantly be
more space stretching out between them.
If you want to think of space as composed to discrete units (which it may very well be), it's like new 'pieces' of space are constantly being inserted in between existing ones, pushing them farther apart. It doesn't matter that the total amount of space is infinite, you can still keep adding to it.
As it stands now, there's far more evidence for the Big Bang theory than against. It's going to take some pretty extraordinary and well-backed-up evidence to deal it a serious blow. Which in a way I kind of hope for; not because I don't like inflationary Big Bang theory, but because it would be terribly, terribly exciting; it would be a revolution.
expanding Universe
Posted: Sat Apr 08, 2006 5:47 pm
by ta152h0
Newton and I had an ice cold one years ago and he convinced me that objects maintain velocity and direction until acted upon by a Force.
Force
Posted: Sat Apr 08, 2006 6:01 pm
by ta152h0
External force, that is ...................
Posted: Sat Apr 08, 2006 7:41 pm
by BMAONE23
If time is fluid and therefore keeps progressing, it would progress in every direction. Time therefore is expanding. And as goes time, so with it goes everything else.