Big Bang

[Bo]

in fact one can (under reasonable assumptions) calculate up to high Z if a nucleus is stable or not. and it appears (see basicly every image here: http://images.google.com/images?q=st...en&sa=N&tab=wi ) that there is a limit at about Z=80.
finding "elements that we know nothing about" would be very strange, since finding elements that don't fit in the scheme as we know it, would mean that some crucial parameters are different at other places (for example a small change in the fine structure constant would completely alter the pictures given in the link above)

Of course: nothing is impossible

Bo

[Turtle]

___Seems everyone danced around some on formation of the heavier elements. Yes they form from stars, but not until the star goes super nova or otherwise dies, not during their "regular" life.

[Erasmus00]

Originally Posted by Bo

in fact one can (under reasonable assumptions) calculate up to high Z if a nucleus is stable or not. and it appears (see basicly every image here: http://images.google.com/images?q=st...en&sa=N&tab=wi ) that there is a limit at about Z=80.

Most of those curves I believe are experimental. Doing QCD calculations is very difficult, I'm not sure if fundamental calculations have been carried out for very high Z numbers. Of course, using the semi-empircal mass formula, finding stable nuclei can be done with relative ease for quite high Z, but the formula is, of course, semi-empirical.
-Will

[Bo]

your absolutely right, our knowledge of nuclei is semi empirical, however that doesn't mean that we have good reasons to believe that the calculations are correct

(btw I doubt that you need QCD for these kinds of calculations)

Bo

[Qfwfq]

Originally Posted by Bo

(btw I doubt that you need QCD for these kinds of calculations)

Why not?

It is the strong and nuclear forces that determine the matter. I also believe straightforward calculations can't be done, just as for atomic orbitals. I do remember having read years and years ago, I can't remember where, that there may be an island of stability for Z above 120 or so.

[Jay-qu]

do you by any chance remember what it is that creates this 'island' to me it doesnt make sense to become more stable unless there are other forces at work that we dont know of

[Qfwfq]

I really don't know the details. However, it doesn't strike me so odd that there could be stability at larger Z values. QCD is definitly a complicated topic, let alone counting in the electro-weak forces too.

[Turtle]

___I confess I don't know a thing about this "Z" business, but when I hear structure I have to say Buckminster Fuller. You say how does an island of stability develop by a leap of degrees?; I say it takes a leap of degree to make a Fullerine. Too few or too many atoms of carbon & you have, well, another form of carbon.
___By Fuller's tetrahedral accounting, the internal structuring of atoms is self-similarly tetrahedral & synergetic (property of emergence). I encourage you guys to give Fuller's Synergetics a read.

[sergey500]

Most definatly. At the moment there is 118 elements, more gets discovered every year, it also depends on the enviroment they are discovered, remember that after 85 all elements are unstable, so there could be a source out there that provides much more elements.

[Jay-qu]

yeah and some of these unstable new elements that are been found last for fractions of a second - not enough time to determine simple properties like melting and boiling point! so what is the motivation - that they find one and they can then name it...