Eta Carinae Fatal pulse (APOD 26 Mar 2006)

[ta152h0]

Time has no mass, therefore cannot be treated in classical physics. The only quantification of time is that no two objects can occupy the same space at the same time.we don't have the smarts ( or the words in the english language ) to quantify time before the big Kaboom.

[astroton]

Time is a relative term. There is no absolute to measure it against. If you believe in big bang and want to consider t=0 at the moment of big bang, you still have no absolute. The next question is what happend before big bang.

[Martin]

I am not aware of any supported scientific evidence that suggest the entire universe is expanding. However, there is a large amount of evidence to support that observable matter is.

[Dave H]

I would like to start a movement to change the name Big bang to the Initial event and the name Dark energy to The Expansive Force. This expansive force is as I think we all know is the fifth discovered force following the 4 previous known, electro magnetism, gravity, the strong force and the weak force. All we understand about this force discovered about ten years ago is it dominates the universe comprising about 70% of everything and it seems to be increasing in a sort of feed back loop so that as space expands under its unrelenting force creating more space and the more space there is the more there is of this force. This is a run away process with nothing to slow it down the universe will expand forever and that is the mild scenario the harsh scenario finds this force so strong in the next couple billion years that even the atoms will not be able to hold themselves together under its ever increasing force. Yes the universe is expanding and it’s doing so at a ever increasing rate and there is nothing to slow it down or even hold it to a constant rate of expansion. We’re on a wild ride and there is no turning back.

[Qev]

Time has no mass, therefore cannot be treated in classical physics. The only quantification of time is that no two objects can occupy the same space at the same time.we don't have the smarts ( or the words in the english language ) to quantify time before the big Kaboom.

Actually, that rule really only applies to fermions (particles with spin 1/2). Any number of bosons can share the same quantum state, effectively being in the same place at the same time.

Really, the only 'definition of time' that I've ever encountered that makes sense is "Entropy increases".

Ah, the 'Big Rip' theory! That's kind of scary. I have to wonder if the 'force' being applied by dark energy is increasing, or is simply constant, but causing the expansion to accelerate because as objects move further apart, the gravitational attraction between them decreases, while the expansive 'force' remains the same. If this is the case, then the Big Rip is never going to happen. Should be interesting to see what we discover.

[astroton]

Dave H,

I neither am inclined nor against the idea of Big Bang. However, if my memory is not playing up, the name "Big Bang" was actually coined by Fred Hoyle, an opponent of big bang, to in fact ridicule the idea. However, the name stuck.

Probably, the unscientific name is also a reason why it is not popular.

Although theory is backed by equation based on Relativity, the first and foremost, people know it as "First there was nothing, then it exploded"

That's probably where half the problem lies.

[harry]

Hello all

Qev said

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.

Spacetime cannot expand. what is expanding. We need to prove actual expansion. Its only recently in the last couple of decades that all this is in question.
The redshift is now proven to be affected by the gravity of its object causing the redshift. if this is so where do we go, what can we assume.

Do not get me wrong, I just want to know what cards to play with. I feel sometimes that I'm going around in circles some scientists say this others say that. Its darn frustrating. I might as well look at porn and explain the Big Bang. What a blow to the model as so to speak.

[Dave H]

I think it is fairly well understood that space is not just a hollow empty place in which everything else plays around in. Space is it's own thing with dynamics of its own. We know intense gravity has an effect on space and that "empty space" can spawn virtual particles real things (Brief lived things) right out of thin” nothingness”. So then space is not the playground for all else rather it’s a playmate also. As for the playground we aren’t quite to that understanding yet.

[harry]

Hello DaveH

Dave there is no way matter or energy can come from nothing.

Space is nothing. It may contain gravity, energy, matter and what ever and these are the obeject we measure with time.


We need to get away from ideas of fantasy.

[Dave H]

Will someone please let Harry down nice and easy I'm afraid there is a "giant empty space" in his understanding

[starnut]

Hi, guys! I just read through this topic, and I can only shake my head at some of the posts here. A lot of misunderstandings and ignorance shown here could have been avoided if some of you took the trouble to use Google or some other search engine to research a lot of space facts. There are a wealth of information available on the WORLD WIDE WEB posted by universities and research labs. Please take the time to check them out.

Now about the sun's core becoming a neutron star. That is highly unlikely! The sun is just not massive enough for that to happen! It happens only to stars at least 8 times more massive than the sun and only when such a massive star goes supernova. Right now, the sun is slowing fusing hydrogen to helium and will continue to do so for another 5 billion years. Once most of the hydrogen is exhausted in the core, the heat output will decrease and gravity will squeeze the core until it comes hot enough for helium fusion to start. Then helium will be fusing to carbon for a few more million years, during which the sun will swell to a red giant. Earth will either end up being inside the red giant and vaporized, or be roasted to crisp. The sun's hydrogen envelope will eventually be blown off, creating a beautiful planetary nebula and leaving its core exposed as a very hot (100,000 degree or more) white dwarf. The white dwarf will slowly lose heat and go dark. It will NOT become a neutron star!

As for the expansion of space by dark energy, nobody knows yet what dark energy is, just as nobody knows what dark matter is. They have hypotheses, such as matter and anti-matter twin popping in and out of vacuum. Nobody knows if the expansion will continue to accelerate, leading to the "Big Rip" or slow down, leading to the "Big Crunch". We don't have to worry about it either way because the end of the universe isn't going to happen for another 100 billion years or more. And the "Big Bang" happened only 13.7 billion years ago!

I read not so long ago that the Sun is slowing becoming hotter and that in about 500 million years from now, it will be hot enough for water to evaporate from Earth, killing most life. And around the time the Sun becomes a red giant, our galaxy and the Andromeda Galaxy will begin to merge.

Eat, drink, and be merry, for tomorrow we die!

gary

[Dave H]

You are a peace maker Gary but I have to say nice try but no cigar you wrote "They have hypotheses, such as matter and anti-matter twin popping in and out of vacuum. "
Now that was very sweet and very gentle and for this I respect you but this is no hypotheses it's fact and you can verify this FACT by doin a little more of that Googlin you have so wisely reccommended

[Martin]

Again there seems to be a rather large misconception in this and other threads that the "universe is expanding, shrinking, exploding, crunching, appearing or disappearing. The FACT is none of these are true. The universe as a whole is not observable so any conjecture regarding what cannot be observed is simply imaginative speculation and it is not falsifiable.

Observable matter is all that we can observe. And all of what we can observe is contained within space-time which, in turn is at least 1 component of the entire universe. It is true that we can observe matter moving but this no way implies that the universe is.

Please stop equating observable matter as the “universe”, as if, it is its totality.

We can only guess what dark energy and dark matter is so don’t be offended by what they have named it. If it makes you feel better than you have our permission to call it unknown energy and unknown matter. You can argue its name but you cannot logically argue its existence.

The big bang is also just a simple phrase to explain an event. All you need to believe in an explosion and expansion of matter is to look at some old footage on nuclear weapons testing. Matter is turned into energy resulting in an explosive and expanding force so I think it is more than safe to say that the opposite is just as true. Where this energy came from is its greatest remaining mystery –I think.

“Discussions and questions are best shared however ignorance is best isolated in a small corner of one’s mind”.

[Dave H]

Don't be so stuffy it was simply a lighthearted suggestion for more descriptive name but as for what can be seen It was by observation of the seen that the revelation occurred. We can see type Io super nova what we can't see is what is driving them apart from us with unrelenting force thus the unseen is reveled by the seen and without ever having to see it we know that it’s there.( I still like the Expansive force but Dark energy has merit too)

[starnut]

You are a peace maker Gary but I have to say nice try but no cigar you wrote "They have hypotheses, such as matter and anti-matter twin popping in and out of vacuum. "
Now that was very sweet and very gentle and for this I respect you but this is no hypotheses it's fact and you can verify this FACT by doin a little more of that Googlin you have so wisely reccommended

I apologize. You are right! I assumed that because the virtual particle-antiparticle pairs exist so fleeting that they cannot be observed directly and so cannot be proved to exist. They can be observed when they indirectly affect the spectrum of hydrogen in a calculable way. (Source: Sept 2004 issue of Scientific American).

gary

[Dave H]

No need to apologize. Starnut and truly thanks are in order on my part for affirming my assertion and speaking up on behalf of scientific fact.

Dave

[harry]

Hello Starnut

Tell me what is a white dwarf core made from.
How come it has an extreme density.

What is a neutron star compared to a quark star and a Black Hole.

As for the sun becoming hotter, it maybe due to the increase in Iron.
But! I do not think that in 500 million years it will kill the earth.

As for a neutron star, they tell us you only need 1.4 sun mass to create a neutron star.

The problem is this we are estimating and that is a problem in itself.


There are many issues that need to be addressed.

The properties of the Core. The inner core to be more precise. The core in my opinion is already collapsed giving it enough gravity to hold the star and the heart at bay.

If the core was of less density than the heat would not be held and the sun would expand and explode.

Our sun was formed from a neutron star core, it may go through one more cycle leaving a ultra dense core being formed from neutrons, either way maybe small enough to be called a white dwarf that has a core made up of neutrons, this explains the ultra dense core.

there are many links that i can give you,,,,,,or just look up google
http://web.umr.edu/~om/report_to_fcr/report_to_fcr1.htm

The Sun’s radiant energy and protons in the solar wind (SW) come from the collapsed supernova core, a neutron star (NS), on which the Sun formed. The cradle (Figs. 9-12) indicates that the energy of each neutron in the Sun’s central NS exceeds that of a free neutron by @ 10-22 MeV (Figs. 13-15) Solar luminosity and the flux of solar-wind protons are generated by a series of reactions (Fig. 16): a) escape of neutrons from the central NS, b) decay of free neutrons or their capture by other nuclides, c) fusion and upward migration of H+ through material that accreted on the NS, and d) escape of H+ in the SW. An example might be:

a) The escape of neutrons from the NS, <1n> –> 1n + 10-22 MeV

b) The decay of free neutrons, 1n –> 1H+ + e- + nanti + 0.78 MeV

c) Fusion of hydrogen, 4 1H+ + 2 e- –> 4He++ + 2 n + 26.73 MeV

d) Some H+ reaches the surface and departs in the solar wind

Reactions like a) and b) produce part of the Sun’s radiant energy and perhaps the luminosity of isolated neutron stars25. Note that reaction a) alone may release more energy per nucleon than is released by the sum of reactions b) and c), the decay or capture of neutrons plus H-fusion. The well-established Solar Neutrino Puzzle26 confirms that reaction c) generates only part of the Sun’s total luminosity. Most 1H+ from b) is consumed by H-fusion, but the anomalous abundance of H (See Fig. 8) shows that 1H+ also leaks from the interior, selectively carrying lighter nuclides to the solar surface (See Fig. 6) before departing in the solar wind at an emission rate of about 2.7 x 1043 1H/yr. Homochirality in living creatures26 was likely initiated by circularly polarized light (CPL) from the Sun’s early NS. Their fate and climate changes of planets27 may depend on the half-life of this massive nucleus at the Sun’s core

[Qev]

Tell me what is a white dwarf core made from.
How come it has an extreme density.

A white dwarf star is composed of what's known as 'degenerate matter'. Basically, gravity has crushed the material of the star to such high density that the electrons are forced to fill all available quantum energy states. No two electrons can share the same quantum state, due to the Pauli Exclusion Principle, so once the material reaches this density, this resistance counteracts the pressure of gravity, preventing the material from collapsing any further. Of course, this resistance has its limits, known as the Chandrasekhar Limit. Once this is mass is exceeded, gravity overpowers electron degeneracy pressure, and you end up with a neutron star.

What is a neutron star compared to a quark star and a Black Hole.

A neutron star is formed by a non-fusing body who's mass exceeds the Chandrasekhar Limit of ~1.4 solar masses. This is too much mass for electron degeneracy pressure to maintain against the force of gravity; the electrons subsequently are forced into the nuclei of the atoms, converting protons to neutrons and releasing a great deal of neutrinos and energy. The core collaspes further, basically until it has the same density as an atomic nucleus. It is now supported by neutron degeneracy pressure, which operates very similar to the electron degeneracy pressure in a white dwarf star. This state also has its limit, known as the Tolman-Oppenheimer-Volkoff Limit, approximately 3-5 solar masses, beyond which neutron degeneracy pressure fails, and the object's collapse can no longer be halted. A black hole is the result.

Quark stars are a fairly recent discovery, a sort of mid-point between the neutron star and black hole states. According to theory, they form as the pressure increases within a neutron star to the point where neutrons disassociate into free quarks. These objects are not yet well understood.

As for the sun becoming hotter, it maybe due to the increase in Iron.

The Sun is too small a star to be producing iron; it is not accumulating in any significant quantities. I believe it's helium accumulation that's causing this effect, though I don't fully understand the process.

But! I do not think that in 500 million years it will kill the earth.

I'm a little dubious about that particular claim, also. It seems odd to me that the solar output is perfect for life here on Earth for four billion years, only to increase to untenable levels in such a recent and short span of time. But who knows, I guess we'll have to wait and see.

As for a neutron star, they tell us you only need 1.4 sun mass to create a neutron star.

Well, you need 1.4 solar masses of non-fusing material to form a neutron star. That is, 1.4 solar masses of matter that does not produce positive net energy through fusion. In stars, this means iron, so in order to form a neutron star, you need to have a progenitor star large enough to produce an iron core exceeding the Chandresekhar mass limit. That means a pretty hefty star.

The problem is this we are estimating and that is a problem in itself.

True, we can't actually get inside a star to look around, so there is some speculation at work, but it has its foundation solidly rooted in good science.

The properties of the Core. The inner core to be more precise. The core in my opinion is already collapsed giving it enough gravity to hold the star and the heart at bay.

If the core was of less density than the heat would not be held and the sun would expand and explode.

The Sun is a self-gravitating body; its entire mass is what's holding it together, in a balancing act between collapse under gravity, and the expansion caused by thermal energy produced in fusion reactions.

Our sun was formed from a neutron star core, it may go through one more cycle leaving a ultra dense core being formed from neutrons, either way maybe small enough to be called a white dwarf that has a core made up of neutrons, this explains the ultra dense core.

There's absolutely no way the Sun's core is degenerate neutron material. To start, the Sun would way more than twice what it does now. Fusion reactions at the surface of such a core would be impossibly intense, and likely blow the outer layers of the Sun completely off. And helioseismic holography would not work the way it does, as such intense fusion reactions would completely destroy convective motions in the outer parts of the Sun.

there are many links that i can give you,,,,,,or just look up google
http://web.umr.edu/~om/report_to_fcr/report_to_fcr1.htm

One of the key arguments this page uses to hold up their theory is the Solar Neutrino Problem, which has pretty much, at this point, been solved with the confirmed detections of neutrino mass and neutrino flavor oscillations. Our current theories of how fusion proceeds in the core of the Sun are very well established at this point.

[starnut]

Harry,

It seems to me that you and the authors in that link have a fundamental misunderstanding of what a neutron star is. I would be surprised if those authors' paper was accepted for publication as they simply didn't know what they were talking about! They are chemists, not astrophysicists!

What is a neutron star compared to a quark star and a Black Hole?

A neutron star is the less dense of the three. A black hole's singularity has the highest density which may well be infinite. A quark star is in-between. My guess is that a quark star is one where the gravitational collapse went past the neutron degeneracy point but did not go all the way to a black hole.

http://chandra.harvard.edu/photo/2002/0 ... 0interior)

As you know, a neutron star is produced when the core of a massive star (more than 8 solar masses) collapses catastrophically after the silicon in the inner core has been fused into iron, an element that is incapable of energy-generating fusion reactions. The iron breaks down into its component particles, protons, neutrons, and electrons (the constituents of atoms), and then protons and electrons get squashed together to become neutrons (and giving off neutrinos). Then the whole mass gets compressed into a tight ball of neutrons about the size of a city. The gravitational collapse stops only when the core reaches the maximum neutron degeneracy pressure. I won't go into details on what happens when the core reaches that point.

http://en.wikipedia.org/wiki/Degenerate_matter

A typical neutron star has a mass between 1.44 and about 3 to 5 solar masses, with a corresponding radius between 20 and 10 km (they shrink as their mass increases) — 30,000 to 70,000 times smaller than the Sun. Thus, neutron stars have densities of 8×10^13 to 2×10^15 g/cm³, about the density of an atomic nucleus. Compact stars of less than 1.44 solar mass, the Chandrasekhar limit, are white dwarfs; above 3 to5 solar masses, gravitational collapse does not stop, inevitably producing a black hole. So, when you are talking about the mass, you are talking about the mass of the core that becomes a neutron star, a white dwarf, or a black hole, not the mass of the precursor star.

Due to its small size and high density, a neutron star possesses a surface gravity 2×10^11 to 3×10^12 times stronger than that of Earth. One of the measures for the gravity is the escape velocity, the velocity needed for an object to escape from the gravitational field to infinite distance. For a neutron star, such velocities are typically 150,000 km/s, about 1/2 of the velocity of light. Conversely, an object falling onto the surface of a neutron star would strike the star also at 150,000 km/s. To put this in perspective, if an average human were to encounter a neutron star, he or she would impact with roughly the energy yield of a 100 megaton nuclear explosion. So, there is no way a neutron star could have formed the core of the sun. Any matter accreted onto the surface of the neutron star, usually from a companion star in a binary system, would form a thin, extremely dense layer on the surface. If enough accreted matter accumulates in this layer, the tremendous heat and pressure could trigger a thermonuclear explosion. It could not grow to the size of the sun, and there would be no further nuclear fusion to make it shine and give off heat.

http://www.astro.umd.edu/~miller/nstar. ... n%20Stars)

As for the white dwarf, it is nonsense that a white dwarf is made up of neutrons like a neutron star. A white dwarf and a neutron star are two different animals! One does not become the other! A white dwarf is formerly the dense core of a star up to 8 solar masses, one that wasn't massive enough to explode as a supernova. The core contracted while it was converting helium to carbon and oxygen during the precursor star's red giant phase. The core's collapse was halted only because of electron degeneracy, and its high temperature is due to the heat trapped inside. Its high density and small size (about the size of Earth) create a very strong gravity but it is not undergoing any more nuclear fusion in its interior, so as long as its mass is under the Chandrasekhar limit (1.44 solar masses), it will grow dimmer and cooler over billion more years. However, if the white dwarf is a part of a close binary system, and its companion has become a red giant whose surface closest to the white dwarf exceeds the companion's Roche lobe, the white dwarf's gravity will pull the red giant's envelope into an accretion disk around the white dwarf. Friction within the accretion disk will slow down the material closest to the white dwarf's surface, causing the material to fall onto it. If the infalling material causes the white dwarf's mass to reach 1.44 solar mass, the white dwarf will undergo a star-wide thermonuclear explosion, resulting in a Type 1a supernova that will destroy the white dwarf entirely, leaving no central remnant.

One last thing, the sun will never get to the stage where it will accumulate iron in its core. It is just not massive enough.

This is a bit long-winded and may not be 100% accurate, but I hope it will help you undertstand better the difference bewteen a neutron star and a white dwarf.

gary

[Dave H]

Thanks for expanding my understanding Starnut. So then nova explosions and 1a supernova explosion are very closely related and differ only in the way the in falling matter is layered down on the surface of the white dwarf. And thus determining if the white dwarf will be destroyed in the explosion (become part of the explosion) and this bring us back around to the issue of dark energy since these type 1a supernova are quite precise in their energy output and were the tool that determined that the expansion of the universe is speed up and overcoming gravitational attraction by a counter intuitive and previously unknown force that may be a attribute of space itself rather then some force moving through space. The bottom line is space may be expanding! This is the reason I prefer the name “expansive force”. Dark energy seem a little spooky to me plus gravity is a form of dark energy also

Dave

[harry]

Hello Qev and starnut

Thank you for the info,,,,,,,,,,,,,,,,,wow,,,good to hear from people who know a bit.

Your right about the Iron will not accumulate in the core. Unable.

As for the density within the core of a star.

Most stars go through many ejected Iron shells and still keep their ultra dense plasma core. This is different to a dust cloud collapsing matter to a core.
The other forms of core formation is from active black holes ejecting matter thousands of light years. The question is this. Is Ultra dense matter ejected or is the matter ejected collects and collapses to a star core.

I will come back to dwarf stars later.

Time to pick up the kids
Thanks again

[makc]

Time to pick up the kids

[Qev]

As for the density within the core of a star.

Most stars go through many ejected Iron shells and still keep their ultra dense plasma core. This is different to a dust cloud collapsing matter to a core.

You may perhaps be thinking of fusion shells forming around the core of a high-mass star, here? High-mass stars are able to drive fusion reactions well beyond the 'typical' hydrogen/helium fusion that powers average-sized stars like our Sun.

As time wears on, stars will exhaust the hydrogen supply available at their core, as it has been 'burned' into helium. This causes the core to collapse further until helium fusion ignites, restabilizing things. There's lot of hydrogen left outside the core, however, and a thin shell of hydrogen fusion starts up surrounding the core. This produces more helium 'ash' behind it. If the star is massive enough, this process repeats, helium runs out in the core, and carbon fusion begins, with a shell of helium fusion around it, and the hydrogen shell around that. This keeps going, to carbon, neon, oxygen, and finally silicon. Silicon fusion produces iron as its 'ash', which does not produce energy through fusion. So inert iron accumulates at the core of the star, and this is what leads to star death, supernovae, and the formation of neutron stars and black holes.

The other forms of core formation is from active black holes ejecting matter thousands of light years. The question is this. Is Ultra dense matter ejected or is the matter ejected collects and collapses to a star core.

I imagine black hole jets can trigger star formation, though not by 'seeding' stellar cores. The shockwave of the jet's passage through a molecular cloud can cause regions of higher density to form, which would then collapse under their own gravity to form new stars. Supernova shockwaves do the same sort of things.

[harry]

Hello Qev

Again thank you for the info,,,,,,,,,,


I am most impressed by your knowledge


At what stage does the star explode,,,,,,,,,,,,before He fusion or after or both.

[starnut]

Harry,

For a high-mass star (more than 8 solar masses), it will be after helium fusion...LONG after helium fusion. Before the star will explode (as a Type II supernova), the star's core will have to go through not only helium burning, but also in sequence, carbon-oxygen burning, neon burning, another oxygen burning, and finally silicon burning. Fusion and hence energy production cease when the core is full of iron. With no more thermal pressure in the core, gravity wins and crushes the core!

Here is a link that may help you see the whole picture of the process.

http://www-astronomy.mps.ohio-state.edu ... imass.html

gary