Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 87 (8993 total)
73 online now:
nwr, Pollux (2 members, 71 visitors)
Newest Member: Juvenissun
Post Volume: Total: 879,210 Year: 10,958/23,288 Month: 210/1,763 Week: 177/390 Day: 66/32 Hour: 0/2

Announcements: Topic abandonment warning (read and/or suffer the consequences)


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Oklo reactor
judge
Member (Idle past 5024 days)
Posts: 216
From: australia
Joined: 11-11-2002


Message 1 of 6 (71518)
12-08-2003 3:42 AM


As I understand it the uranium from the oklo reactor showed us that decay rates have been constant over billions of years.
This is because if decay rates had changed then alpha the fine structure constant which measures electromagnetic force would have had to have changed as well.
If alpha had changed then the point at which critical mass was reached to enable fusion to occur would have been different , but indications from Oklo are that fusion was reached at the same point as today, therefore alpha was the same?

Is this correct....anyone know?

[This message has been edited by judge, 12-08-2003]


Replies to this message:
 Message 2 by Minnemooseus, posted 12-08-2003 3:50 AM judge has not yet responded
 Message 3 by JonF, posted 12-08-2003 10:01 AM judge has not yet responded

  
Minnemooseus
Member
Posts: 3824
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001


Message 2 of 6 (71519)
12-08-2003 3:50 AM
Reply to: Message 1 by judge
12-08-2003 3:42 AM


quote:
... to enable fusion ...

Your message leaves me a little confised.

Moose


This message is a reply to:
 Message 1 by judge, posted 12-08-2003 3:42 AM judge has not yet responded

  
JonF
Member
Posts: 6158
Joined: 06-23-2003
Member Rating: 1.7


Message 3 of 6 (71555)
12-08-2003 10:01 AM
Reply to: Message 1 by judge
12-08-2003 3:42 AM


Pretty much true, except for the fusion-fission confusion..

Claim CF210 (note that one of the relevant references is available online). Or The Oklo bound on the time variation of the fine-structure constant revisited or Alpha: a constant that is not a constant? (both PDF and pretty technical).


This message is a reply to:
 Message 1 by judge, posted 12-08-2003 3:42 AM judge has not yet responded

  
Turtle
Inactive Member


Message 4 of 6 (72394)
12-11-2003 9:33 PM


Judge,

It is usually claimed that Oklo sets limits on how much the fine
structure constant - designated as the symbol alpha (and which is itself a mathematical combination of other constants) - could have been different than its present value, at the time the Oklo reactors were reacting.

The argument goes something like this: Samarium-149 is produced by fission. It has a neutron absorption resonance that is close to the thermal energy of the neutrons in the reactors. It is theorized that a change in the fine structure constant (alpha) would cause a shift in the resonance energy level of Sm-149 which would be detectable by the isotopic content that we can measure today. It’s not really related to critical mass (only distantly, if at all). If I run across a reference that explains it more clearly, I’ll post it (I think I've seen one). By the way, the spectra of quasars is
currently thought to show that the fine structure constant has changed, this may or may not contradict the Oklo results – this is covered in one of the links above.

Interestingly, there is a paper in the Proceedings of the Fifth
International Conference on Creationism, that makes the case that Oklo
seems to be indicating that one or more nuclear constants must have been fairly drastically different when Oklo was reacting. The argument goes like this: Some (most?) of the reactors at Oklo were too thin, by a long shot, to go critical (oddly, this problem is something you don’t see mentioned in the popular literature on Oklo, nor in most all of the technical literature). Yet there is evidence of criticality. How can this be? The only way some of the reactors at Oklo could have been reactors is if some of the nuclear properties of some, or all, of the isotopes involved were different when the reactors were critical.

[This message has been edited by Turtle, 12-11-2003]


Replies to this message:
 Message 5 by Eta_Carinae, posted 12-11-2003 10:54 PM Turtle has not yet responded
 Message 6 by judge, posted 12-22-2003 5:03 PM Turtle has not yet responded

  
Eta_Carinae
Member (Idle past 2955 days)
Posts: 547
From: US
Joined: 11-15-2003


Message 5 of 6 (72418)
12-11-2003 10:54 PM
Reply to: Message 4 by Turtle
12-11-2003 9:33 PM


The quasar results are currently hotly debated in the astrophysics community. Most astrophysicists are doubtful of the claims. The experimental technique being used is extremely difficult to perform and very susceptible to errors.

I know in my department the observational guys think it's a false result.


This message is a reply to:
 Message 4 by Turtle, posted 12-11-2003 9:33 PM Turtle has not yet responded

  
judge
Member (Idle past 5024 days)
Posts: 216
From: australia
Joined: 11-11-2002


Message 6 of 6 (74698)
12-22-2003 5:03 PM
Reply to: Message 4 by Turtle
12-11-2003 9:33 PM


Thank for all the replies.
Is this link taliking about the same thing?http://www.photonics.com/spectra/tech/XQ/ASP/techid.1200/QX/read.htm

This message is a reply to:
 Message 4 by Turtle, posted 12-11-2003 9:33 PM Turtle has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2020