Opinions differ among experts on what looks like a simple question. According to calculations that neglect the finite size of the nucleus, the maximum is atomic number 137. This approach is based on the magnitude of the “fine structure constant” which is 1/137.
The more recent and more fundamental approach predicts a value of 172 or even 173 for the maximum atomic number that can be achieved.
Please see my article in the July issue of Scientific American, titled, “Cracks in the Periodic Table.” Also see my website, www.ericscerri.com
for resources and information on the elements and the periodic table.
Ooooh. scerri, thanks for the reply and welcome to the Dope! I’m sure I can speak for everyone in saying we’d love to have you stick around–smart, knowledgeable folk are always in demand around here.
I think that particular issue slipped between when I was reading SciAm on planes a bunch and when I picked up an electronic subscription. Might pick up a back issue to check it out, though!
ETA: On the other hand, maybe it didn’t. I’ll have to go back and read it again.
I used to think this too, but apparently when the Quantum rears its head things get complicated. It is thought that the core of neutron stars consists mostly of a fluid of free neutrons, rather than superheavy nuclei:
Originally Posted by j_sum1 View Post
‘Of course one could argue that a neutron star is really one amazingly large collapsed nucleus with gabazillions of subnuclear particles.’
Now that is a concept to mull over…
Scerri, Kudos to you Sir, IQs measured in room temperature, in Kelvin are invaluable. Pity you’ve never thought of politics.
This thread reminds me of a school debating society notion of: ‘This house believes their is a finite amount of knowledge that can be gained from the physical universe.’
As I remember someone buggered up the debate by mentioning Og.
Thank you all for casting your knowledge into the platonic cave of my ignorance.
Peter
Missed the edit, Scerri, in broad terms what are the alternative concepts re:
Opinions differ among experts on what looks like a simple question. According to calculations that neglect the finite size of the nucleus, the maximum is atomic number 137. This approach is based on the magnitude of the “fine structure constant” which is 1/137.’
Long words and complex ideas appreciated, grist to the mill.
Peter
137 being the limit is flawed for two reasons. First, that’s just a limit on electrons orbiting the nucleus, not the nucleus itself. But we’ve already extended the table well beyond the point where the nuclei die too quickly to get a chance to attach electrons to them.
Secondly, though, the calculation which gives an electron’s speed as some multiple of alpha is a non-relativistic one. If you did somehow have a lump of stuff with a charge of +137 (there are ways to accomplish this), the speed of the electrons about it (to the extent such a thing can even be defined at all, which is already pretty murky in quantum mechanics) would be somewhere in the vicinity of 0.8, not 1, and no matter how high you made the central charge, it still wouldn’t be 1.
