Punching out of wet paper bag, universal resources (03Oct08)

[neufer]

http://apod.nasa.gov/apod/ap081003.html
http://antwrp.gsfc.nasa.gov/apod/ap050811.html

http://antwrp.gsfc.nasa.gov/apod/ap031226.html
http://antwrp.gsfc.nasa.gov/apod/ap001016.html

http://antwrp.gsfc.nasa.gov/apod/ap070811.html
http://antwrp.gsfc.nasa.gov/apod/ap000321.html

http://antwrp.gsfc.nasa.gov/apod/ap970619.html
http://antwrp.gsfc.nasa.gov/apod/ap000313.html
http://antwrp.gsfc.nasa.gov/apod/ap080403.html
http://antwrp.gsfc.nasa.gov/apod/ap991129.html
-------------------------------------
http://antwrp.gsfc.nasa.gov/apod/ap070430.html

<<Explanation: Inside the head of this interstellar monster is a star that is slowly destroying it. The monster, actually an inanimate pillar of gas and dust, measures over a light year in length. The star, not itself visible through the opaque dust, is bursting out partly by ejecting energetic beams of particles. Similar epic battles are being waged all over the star-forming Carina Nebula. The stars will win in the end, destroying their pillars of creation over the next 100,000 years, and resulting in a new open cluster of stars. The pink dots are newly formed stars that have already been freed from their birth monster. The above image is only a small part of a highly detailed panoramic mosaic of the Carina Nebula taken by the Hubble Space Telescope and released last week. The technical name for the stellar jets are Herbig-Haro objects. How a star creates Herbig-Haro jets is an ongoing topic of research, but it likely involves an accretion disk swirling around a central star. A second impressive Herbig-Haro jet is visible across the bottom of a larger image.>>

[emc]

NASA unveils latest deep space probe designed to conciliate the NGC 7129 newly formed star groupin order to better understand newborn stellar evolution. This sleek Starcraft is quite a departure from their usual boxy shaped space probes.

One NASA official was overheard, “This baby will give us a new perspective on these stellar nurseries and should soothe our public relations to boot. We think this design will help placate the people that tend to whine about the astronomical cost of exploring outer space.”

(This post is a spoof and has nothing whatsoever to do with NASA… Ed of planet Earth just thought it might be a little bit humorous for folks looking for something silly to grin about in Asterisk)

[Arramon]

LOL


hehehehe...... thas funny. =b

[Eddie]

How much Hydrogen is there in the universe? As stars use up their fuel and new stars are born in the nebulae. Surely there will come a time when there is not enough Hydrogen to create more stars. This will mean that there is a time coming when all the stars have gone. The end of the universe. Hopefully, this won't happen for a few trillion years, but has anyone thought of this or am I just an idiot.

[Dr. Skeptic]

How much Hydrogen is there in the universe? As stars use up their fuel and new stars are born in the nebulae. Surely there will come a time when there is not enough Hydrogen to create more stars. This will mean that there is a time coming when all the stars have gone. The end of the universe. Hopefully, this won't happen for a few trillion years, but has anyone thought of this or am I just an idiot.

No you are not an idiot, these are insightful question proving otherwise.

The % of H in the universe (about 75% of normal matter) and concurs with the BB theory that the age of the universe is near 13.7 billion. Matter/Energy can be recycled back into H but not at a rate to sustain the 75% observable level, a "Steady-State" (infinite in age) universe would contain less than 5% H. There are lots of earlier threads here discussing the fate of the universe, feel free to drag them up if the dialog interests you.

[Qev]

Here's a Wikipedia article that summarizes the possible fates of an expanding universe:

http://en.wikipedia.org/wiki/Future_of_ ... g_universe

I've always been fond of the term "Stelliferous Era".

[neufer]

Here's a Wikipedia article that summarizes the possible fates of an expanding universe:

http://en.wikipedia.org/wiki/Future_of_ ... g_universe

I've always been fond of the term "Stelliferous Era".

So if it takes ~ ten trillion years to burn up all the hydrogen
and the universe is only ~ ten billion years old then:

1) there is no universal energy crisis and
2) the He/H ratio is what it was after the big bang.
----------------------------------------------------------
http://en.wikipedia.org/wiki/Big_Bang_nucleosynthesis
.
<<Big Bang nucleosynthesis predicts a primordial abundance of about 25% helium-4 by mass, irrespective of the initial conditions of the universe. As long as the universe was hot enough for protons and neutrons to transform into each other easily, their ratio, determined solely by their relative masses, was about 1 neutron to 7 protons (allowing for some decay of neutrons into protons). Once it was cool enough, the neutrons quickly bound with an equal number of protons to form helium-4. Helium-4 is very stable and neither decays nor combines easily to form heavier nuclei. So out of every 16 nucleons (2 neutrons and 14 protons), 4 of these (25%) combined into one helium-4 nucleus. One analogy is to think of helium-4 as ash, and the amount of ash that one forms when one completely burns a piece of wood is insensitive to how one burns it.
.
The helium-4 abundance is important because there is far more helium-4 in the universe than can be explained by stellar nucleosynthesis. In addition, it provides an important test for the Big Bang theory. If the observed helium abundance is much different from 25%, then this would pose a serious challenge to the theory. This would particularly be the case if the early helium-4 abundance was much smaller than 25% because it is hard to destroy helium-4. For a few years during the mid-1990s, observations suggested that this might be the case, causing astrophysicists to talk about a Big Bang nucleosynthetic crisis, but further observations were consistent with the Big Bang theory>>
-----------------------------------------------
http://en.wikipedia.org/wiki/CNO_cycle

<<The CNO cycle (for carbon-nitrogen-oxygen), or sometimes Bethe-Weizsäcker-cycle, is one of two sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton-proton chain. Theoretical models show that the CNO cycle is the dominant source of energy in stars heavier than the sun. The proton-proton chain is more important in stars the mass of the sun or less. This difference stems from temperature dependency differences between the two reactions; pp-chain reactions start occurring at temperatures around ~4×106 K, making it the dominant force in smaller stars. The CNO chain starts occurring at ~13×106 K, but its energy output rises much faster with increasing temperatures. At ~17×106 K, the CNO cycle start becoming the dominant source of energy. The sun has a temperature of around ~15.7×106 K and only 1.7% of 4He nuclei being produced in the Sun are born in the CNO cycle.

In the CNO cycle, four protons fuse using carbon, nitrogen and oxygen isotopes as a catalyst to produce one alpha particle, two positrons and two electron neutrinos . The positrons will almost instantly annihilate with electrons, releasing energy in the form of gamma rays. The neutrinos escape from the star carrying away some energy. The carbon, nitrogen, and oxygen isotopes are in effect one nucleus that goes through a number of transformations in an endless loop.>>
-----------------------------------------------