|
QuickSearch
Welcome! You are not logged in. [ Login ] |
EvC Forum active members: 62 (9024 total) |
| |
Moe's URL Addresss | |
Total: 882,850 Year: 496/14,102 Month: 496/294 Week: 252/136 Day: 28/32 Hour: 2/3 |
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: Question About the Universe | ||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 155 days) Posts: 20714 From: the other end of the sidewalk Joined: |
No, just in the area where Baumgardner gathered his samples. Which is what leads me to the conclusion that it was intentional. Enjoy. by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
|
||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 155 days) Posts: 20714 From: the other end of the sidewalk Joined: |
So they have been phased out ... From google scholar quote: The paper cited is from 1977, so they were used. Enjoy. by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
|
||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 155 days) Posts: 20714 From: the other end of the sidewalk Joined: |
AND, getting back to the subtitle ... SN1987A demonstrates that radioactive rates have not varied significantly in the last 168,000 years. Enjoy by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
|
||||||||||||||||||||||||||||||||||||||||||
Astrophile Member Posts: 89 From: United Kingdom Joined: |
A search for 'Population III stars' turned up some interesting information. Observations (R.A.E. Fosbury et al., 2003) of a gravitationally lensed galaxy (z = 3.36) a show anomalous emission-line intensities in the Si III doublet at 188.3 nm and 189.2 nm; this over-abundance of Si may be a nucleosynthetic signature of past pair-instability supernovae in a Population III cluster. T.H. Puzia et al., 2006; (Astrophys. J., 248, 383-388) also find evidence for pair-instability supernovae in the metal abundances of globular clusters in elliptical galaxies. The metal abundances in SDSS J0018-0939 also appear to show the signature of pair-instability supernovae. Kashlinsky et al. (Nature, 2005) attribute the angular power spectrum and amplitude of large-scale fluctuations in the (IR) background to light from the Population III era. One of your own sources said that the distribution of metal abundances in stars is consistent with nucleosynthesis in supernovae with typical masses of 16 to 33 solar masses, and another source says that metal abundances in extremely metal-poor Population II stars implies that their metal-free progenitors had masses of 20-130 solar masses. There have been various hypotheses for the failure to find Population III stars.
Age estimates from the oldest globular cluster range from 12.6 to 13.4 Gyr. Extremely metal-poor stars, such as HD 140283, SDSS J102915+172927 (Caffau’s star) and SMSS J031300.36-670839.3 have ages of 13 Gyr or more. Studies of white dwarfs show that the Galactic halo is about 11.4 Gyr. The age of the Galactic disc is 8.8±1.7 Gyr. Let's get to the point. There is compelling evidence that the universe began in a high-density high-temperature state 13.8 Gyr ago, and that hydrogen, helium and lithium were formed in this initial state, about three minutes after time zero. There is also compelling evidence that we can now observe stars that contain small quantities of 'metals' that were formed more than 13 Gyr ago. Nobody has found a way of producing elements heavier than lithium in the 'Big Bang', but these elements are present in the oldest stars that we can see. You say that these 'metals' were not produced in a first generation of metal-free stars. Very well, then; what is your hypothesis for the origin of these 'metals'?
|
||||||||||||||||||||||||||||||||||||||||||
jar Member Posts: 33119 From: Texas!! Joined: Member Rating: 4.4 |
Doesn't Oklo show that rates have not changed for at least two billion years?
Anyone so limited that they can only spell a word one way is severely handicapped!
|
||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 155 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Indeed, so there are multiple lines of information with consilient results ... ... and any theory of changing radioactive must be able to account for all of them having similar results. Enjoy by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
|
||||||||||||||||||||||||||||||||||||||||||
Pressie Member (Idle past 9 days) Posts: 2087 From: Pretoria, SA Joined: |
It is very, very basic. High school level stuff. Or were you home-schooled?
|
||||||||||||||||||||||||||||||||||||||||||
Pressie Member (Idle past 9 days) Posts: 2087 From: Pretoria, SA Joined:
|
Edited by Pressie, : Changed sentence Edited by Pressie, : Added link
|
||||||||||||||||||||||||||||||||||||||||||
zaius137 Member (Idle past 2159 days) Posts: 407 Joined: |
quote: The best observational evidence is still lacking for population III stars. There is no way the Big Bang can continue as a viable theory without population III stars (if it is even a viable theory now). quote: I agree. quote: I only implied that since population III stars are not observed there is no reason to believe the current explication of stellar existence.
|
||||||||||||||||||||||||||||||||||||||||||
zaius137 Member (Idle past 2159 days) Posts: 407 Joined: |
quote: Since you research coal (probably not your dream job) you might just check it for C-14.
|
||||||||||||||||||||||||||||||||||||||||||
zaius137 Member (Idle past 2159 days) Posts: 407 Joined: |
quote: C-14 does not form from a radioactive decay of N-14. It is a slow neutron being absorbed by stable nitrogen (N-14).
I guess you did go to school in the United States.
|
||||||||||||||||||||||||||||||||||||||||||
zaius137 Member (Idle past 2159 days) Posts: 407 Joined: |
This brings up a good point… What are good sources for slow or thermal neutrons. Not just any radioactive source can convert Nitrogen into C-14. Only sources that produce neutrons directly or threw a simple chain of low weight elements.
The mechanism for creating C-14 in diamonds just got more complicated.
|
||||||||||||||||||||||||||||||||||||||||||
zaius137 Member (Idle past 2159 days) Posts: 407 Joined: |
quote: That is another bad assumption. It is clear that delta’s in decay rates are not the same across the board. Why some isotopes are affected in different ways by time of year or sun distance is unknown. The mechanism is still uncertain. But the data is clear, Atomic decay rates are not as stable as once thought.
|
||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 155 days) Posts: 20714 From: the other end of the sidewalk Joined: |
It's not an assumption, it's an observation that similar results are seen from different sources.
Yet we still know that the decay rates are stable for extended periods of time -- over 168,000 years in the case of observed decay from SN1987A. All the differences found to date are still insignificant in affecting the measurements for the age of the universe. Enjoy Edited by RAZD, : .. by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
|
||||||||||||||||||||||||||||||||||||||||||
zaius137 Member (Idle past 2159 days) Posts: 407 Joined: |
quote: Did that distance of 168,000 light years include the co-moving inflation distance (it is outside our galaxy). Even if it does, you expect me to believe that the decay deviation is outside the standard deviation for these elements. What I have said, over and over, is that the variance seems to be dependent on the element, distance from sun or solar flare (mechanisms are not yet known). How are these elements in proximity of influence of a nearby star? They are in free space, so how can you say they are even relevant to our argument? Edited by zaius137, : No reason given. Edited by zaius137, : No reason given. Edited by zaius137, : No reason given.
|
|
|
Do Nothing Button
Copyright 2001-2018 by EvC Forum, All Rights Reserved
Version 4.0 Beta
Innovative software from Qwixotic © 2021