how old is the sun? is there definitive proof?

[copperie]

Hi everyone,<br /><br />by all accounts the sun is about 4.5 billion years old and should live about another 4-5 billion. can someone direct me to where I might find a scientific study which proves this or at least point me in the right direction? how have scientists come to this conclusion of it's age?<br /><br />thanks for the help. this is my first post so try be gentle ;-)<br /><br />copperie

 

[3488]

Hi Copperie.<br /><br />Welcome to SDC. Great first post.<br /><br />I think the age of our Sun, has been determined from radioactive decay (Uranium, Thorium & Cesium & other natural radioactive materials) in meteorites, which are thought to havve formed in the circum solar disk, that went on to form the planets. <br /><br />I think the sun too in its own chemistry as deduced through spectroscopy also holds answers.<br /><br />I think also studies of other solar type stars, such as 18 Scorpii, Delta Pavonis, Eta Cassiopei, Alpha Centauri A & B, Delta Trianguli, etc have also helped regarging their 'metallic' properties (elements heavier than Helium, so the abundance Litium & heavier & how our own sun compares).<br /><br />I hope this helps. I expect others on SDC will find other reasons too.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[copperie]

Thanks for the warm welcome Andrew, <br /><br />some good info there. does anyone have a link to one or more studies mentioned below or a study on the age of the sun in general?

 

[MeteorWayne]

Try looking here <br /><br />Pretty good quick summary.<br /><br />Welcome to SDC! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[3488]

Hi Meteorwayne & copperie, it pretty well backs up what I said.<br /><br />The Sun in its infancy, is thought to have only been about 70% as powerful as now. Also the Sun is thought to have been very active with a much shorter 'solar cycle' & rotate much more quickly on its axis, as is with Epsilon Eridani. <br /><br />Epsilon Eridani is thought to be about only 800 million years old or about 18% of the sun's age. <br /><br />The 'sun spot' cycle of Epsilon Eridani is only about 5.5 years, as against our sun's average of 11 years. <br /><br />Also Epsilon Eridani, rotates on its axis about once every 8 days, as against our sun's 25 days at the equator & about 35 days at the poles.<br /><br />Epsilon Eridani has star spots that make the sun's look like little spots (despite the fact that Epsilon Eridani has only about 70% of the sun's diameter).<br /><br />Sirius / Alpha Canis Majoris rotates once evey 5.5 days & appears to have a star spot cycle lasting only three years (although the companion star the white dwarf Sirius B must affect this).<br /><br />These are all clues to the sun's age.<br /><br />Some older stars, or those approaching the end of their lives have slower rotation. Aldebaran / Alpha Tauri spins once every two years, & Betelgeuse / Alpha Orionis is thought to spin once every 17 years (yes, once every seventeen years).<br /><br />Hope you find the above interesting!!<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[vogon13]

Composition of the sun is known to high accuracy thanks to over a century of spectroscopy.<br /><br />The nuclear reactions that power the sun are also known to such precision that men can reproduce the reactions on earth with amazing fidelity in atomic weapons and Tokamak style fusion power experiments.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[3488]

Hi vogon13.<br /><br />Do we know how Tokamak is going?<br /><br />Also nuclear fusion could power spacecraft, extracting hydrogen from Jupiter & Saturn's atmospheres???<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[search]

Hello copperie<br />In addition to the method mentioned above there is another one derived from the Theory of stellar structure and evolution.<br /><br /> Stellar Age Determination <br /><br /> The Standard Sun Model

 

[Boris_Badenov]

Vogon has a nuclear fusion powered spacecraft in the bunker garage, so he can get home on weekends<img src="/images/icons/cool.gif" /> <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[newtonian]

Search - Thank you for the good links.<br /><br />Note that standard models can be wrong, for various reasons.<br /><br />Your last link notes two of those reasons, and I quote:<br /> <br />[concerning how the standard model is mathematically derived]<br /><br />"The symmetry breaking physics of magnetic fields and rotation are neglected because they increase the complexity of the problem enormously and are generally not believed to affect the structure and evolution of the model by very much. We note that the energy arguments used to prove the unimportance of magnetic fields and rotation are based on the surface values of these quantities. It is possible that magnetic fields and rotation in the interior are orders of magnitude stronger."<br /><br />Indeed. "Star differs from Star in glory" - my favorite source states.<br /><br />The link notes minor variations between our sun and the standard sun model.<br /><br />However, recent studies have shown how different similar mass stars can be. For example, there are the newly discovered variety of stars called "magnetars." Search Scientific American for an excellent article on magnetars. These are stars with unusually strong magnetic fields.<br /><br />It is also now known that our sun's corona is very hot, much hotter than the surface of the sun.<br /><br />The cause of this heating is magnetism - specifically, very powerful magnetic fields in motion coming from magnetic dynamoes deep within our sun.<br /><br />The sources of these (there are many) magnetic fields are in motion - one group of researchers have found evidence of floating magnetic fields from near the core to the surface.<br /><br />This all effects the age of the sun very much.<br /><br />How so?<br /><br />Well, the standard model of stellar evolution assumes zero mixing of core gas with outer layers of gas.<br /><br />As a result, the standard model has our sun going to red giant phase when there actually is much hydrogen not yet fused into Helium (nuclear fusion).<br /><br></br>

 

[doubletruncation]

<font color="yellow">Composition of the sun is known to high accuracy thanks to over a century of spectroscopy.</font><br /><br />Actually, believe it or not, there is currently a big crisis in solar physics regarding the metallicity of the Sun. In the last five years, a lot of work done by Martin Asplund in Australia and others have actually shown the metallicity of the solar convection zone is about half of what had been thought for a long time. They got this result by actually using detailed time-dependent, 3-dimensional hydrodynamic model of the solar atmosphere to match with the observed spectrum of the sun (previously people had only been able to use 1-d hydrostatic models - you can get very very nice spectra for the Sun, but pulling abundances out of a spectrum is a very difficult modeling problem). You can see for example, http://lanl.arxiv.org/abs/astro-ph/0410214<br /><br />This has, needless to say, thrown a monkey wrench into solar models based on helioseismology, the solar models constructed using the new composition are substantially out of agreement with helioseismology compared to the incredible match that had been achieved in the late nineties. Unfortunately it doesn't seem like the revised metallicities are wrong - a lot of people have been working on double checking and so on. There has been a suggestion that perhaps if the Neon abundance of the sun is quite a bit higher, then the models would be in better agreement with the helioseismology data. Neon is a particularly tricky element to measure in the Sun, and it turns out that a lot of the stars in the neighborhood have much higher Neon abundance than has been measured for the Sun. If the Ne abundance for the Sun is off (which is entirely possible), then the models are in better agreement with the data, but they are still quite a bit off compared to the models calculated using the old solar abundances. (See for <div class="Discussion_UserSignature"> </div>

 

[doubletruncation]

Not to say that this changes the prediction for the age of the Sun appreciably, the discrepancy is only a percent at worst (whereas it been 0.3% before the composition revision). <div class="Discussion_UserSignature"> </div>

 

[09de0]

They are all theories , and no theory as you know have the 'definitivity' you could want. Because the minor boundary of the sun's age is stated by the age of Earth&nbsp;&nbsp;they could calculate , and the age of the fossils they've found, does any one not thought yet that Earth , Moon and may all be planets in our solar system could have been burnt above a threshold that no age-calculation can be made , to be&nbsp;stated roughly. Sun can have 20 billions of age , be cause&nbsp;the proofs that it is thought to be proven by is not adequate.&nbsp; This turned out to be a theory not pure physics, but rather including SETI.<br />

 

[qso1]

<p><font color="#800080">They are all theories , and no theory as you know have the 'definitivity' you could want.</font></p><p>This the scientific community and even a layman like me already knows. And I would agree that the age of the sun and planets is not able to be verified 100% fact. Few things in science are this clear cut. But in view of that situation, one goes with the best data available. </p><p><font color="#800080">Because the minor boundary of the sun's age is stated by the age of Earth&nbsp;&nbsp;they could calculate , and the age of the fossils they've found,</font></p><p>The earth and sun are thought to be about 5 billion years old. One of the best supportive data that I have seen is the equation for nuclear fusion which in effect, gauges how long fusion would go on in the sun based on the suns size temperature and probably other factors.</p><p>The way I see it, if man figured out nuclear fusion, as clearly demonstrated by the H-bomb. Man is probably not too far off on the estimated age of the sun.&nbsp;</p><p><font color="#800080">does any one not thought yet that Earth , Moon and may all be planets in our solar system could have been burnt above a threshold that no age-calculation can be made , to be&nbsp;stated roughly.</font></p><p>The whole idea behind science is to think of every plausible scenario and test it as best can be done. There have been several different theories as to what the sun actually is. But as more reseacrh is done and our instruments become more advanced, theories that simply do not work are discarded.</p><p>This burning you mention, I suspect if we had evidence for that, it would be similar to the evidence gathered for the meteor impact dinosaur extinction theory. Some boundry layer on earth, Like the Kt layer and the mass extinction associated with it...would probably show evidence of any sustained major burning event.</p><p>I know of no data in existence that would show the earth or other planets have been burnt. </p><p><font color="#800080">Sun can have 20 billions of age , be cause&nbsp;the proofs that it is thought to be proven by is not adequate.</font></p><p>The difference between simply stating the sun can have 20 billions of years of age and the sun is 5 billion years old based on the rate of nuclear fusion and the mass of the object fusing is that the latter is supportable by data while the former isn't. That is, unless you can show where and why you got the idea the sun could be 20 billion years old.</p><p>No serious scientist I'm aware of ever said the sun is proven to be 5 billion years old.</p><p><font color="#800080">This turned out to be a theory not pure physics, but rather including SETI. Posted by 09de0</font></p><p>I'm not clear on what you mean in this statement. Theory and not pure physics? Whats SETI got to do with it?&nbsp;</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>