I am a fish
undersea enforcer
Posts: 600
Registered: 16-1-2003
Location: Bath, United Kingdom
Member Is Offline
Mood: Ichthyoidal
|
|
Bismuth dethroned as heaviest stable element.
Bismuth 209 – the only naturally occuring isotope of the element – has been found to be an alpha emitter. It's half-life is
by far the longest known – (1.9 +/- 0.2) x 10^19 years. This leaves lead as the heaviest stable element.
1f `/0u (4|\\| |234d 7|-|15, `/0u |234||`/ |\\|33d 70 937 0u7 /\\/\\0|23.
|
|
|
Nick F
Hazard to Others
Posts: 439
Registered: 7-9-2002
Member Is Offline
Mood: No Mood
|
|
LOADS of things are long half-life alpha emitters. A few that spring to mind are (IIRC, I can't find the website) tungsten, germanium, neodymium
(about half the lanthanides, actually), zinc too I think, a goodly portion of d-block metals....
It just depends on where you draw the line between stable and instable. Just because you might not detect a single decay from a ton of material over a
billion years, does not mean that it never decays but I think we would call it stable!
|
|
|
Microtek
National Hazard
Posts: 883
Registered: 23-9-2002
Member Is Offline
Mood: No Mood
|
|
In fact, even protons ( and thus all matter ) decays with a half life of 10^32 years.
|
|
|
Blind Angel
National Hazard
Posts: 845
Registered: 24-11-2002
Location: Québec
Member Is Offline
Mood: Meh!
|
|
if all decay to the simpliest form, does they regenerate also?
/}/_//|//) /-\\/|//¬/=/_
My PGP Key Fingerprint: D4EA A609 55E4 7ADD 8529 359D D6E2 33F6 4C76 78ED |
|
|
Nick F
Hazard to Others
Posts: 439
Registered: 7-9-2002
Member Is Offline
Mood: No Mood
|
|
Microtek, I think protons would be like neutrons in that they decay only outside the nucleus, due to quarks moving and swapping around and this keeps
them stable (another concise explanation there  ).
I haven't been keeping up-to-date on my physics, last time I checked the proton was still stable. Just like benzene used to be safe.
|
|
|
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
Posts: 1986
Registered: 2-3-2011
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Nick F  | LOADS of things are long half-life alpha emitters. tungsten, germanium, neodymium (about half the lanthanides, actually), zinc too I think, a goodly
portion of d-block metals....
It just depends on where you draw the line between stable and instable. Just because you might not detect a single decay from a ton of material over a
billion years, does not mean that it never decays but I think we would call it stable! |
Is this really true?! Not all of the naturally occuring isotopes of tungsten and germanium actually radioactive. wikipedia says that 70Ge, 72Ge, 73Ge,
74Ge are all stable.
[Edited on 20-9-2011 by AndersHoveland]
|
|
|
phlogiston
International Hazard
Posts: 1379
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline
Mood: pyrophoric
|
|
Microtek, protons are not unstable.
In fact, this is an important issue in particle physics. Observing proton decay would provide clues to 'new' physics beyond the standard model, and
has therefore been rigorously investigated. So far, no observationsof proton decay have been made. The half life you mention (10^32) is actually the
-lower limit- of proton half life determined from the experiments so far. (i.e. nobody observed any proton decay events in a volume of such and such,
over a time span of ..., etc).
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by phlogiston | Microtek, protons are not unstable.
In fact, this is an important issue in particle physics. Observing proton decay would provide clues to 'new' physics beyond the standard model, and
has therefore been rigorously investigated. So far, no observationsof proton decay have been made. The half life you mention (10^32) is actually the
-lower limit- of proton half life determined from the experiments so far. (i.e. nobody observed any proton decay events in a volume of such and such,
over a time span of ..., etc). |
Cosmologists accept the universe will eventually decay to radiation soup. We just haven't up to now been able to observe a single proton decay, at
least as far as I know...
|
|
|
dann2
International Hazard
Posts: 1523
Registered: 31-1-2007
Member Is Offline
Mood: No Mood
|
|
Three cheers for LEAD.
All together now, hip hip...........
Dann2
|
|
|
simba
Hazard to Others
Posts: 175
Registered: 20-5-2011
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by blogfast25 |
Cosmologists accept the universe will eventually decay to radiation soup. We just haven't up to now been able to observe a single proton decay, at
least as far as I know... |
I think the topic's name should be changed to 'How the universe will end?' or 'How do you picture the apocalypse'. 
[Edited on 21-9-2011 by shivas]
|
|
|
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
Posts: 1986
Registered: 2-3-2011
Member Is Offline
Mood: No Mood
|
|
I see the universe as cyclical, everything is headed towards how it was before.
I am not sure if everything will be swallowed up by a super-massive black hole, but if it is, I think this would warp space-time enough that the black
hole would be able to explode, starting the next "big bang".
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
