 there a reason that other (alien) elements can't exist that
we've never been exposed to?

~~~
Analog24
The structure of elements/atoms is well understood based on their subatomic
constituents. Naively, you might think that can you just keep combining
increasingly larger numbers of electrons, protons, and neutrons to create new
elements. However, the stability of an atom becomes problematic when the size
of the nucleus approaches the interaction length of the strong force (i.e. the
nucleus is too large for the strong force to hold it together). These elements
are unstable and therefor not relevant as far as organic chemistry is
concerned.

Furthermore, the formation of elements in the Universe is also a fairly well
understood process. For elements lighter than Fe it generally occurs through
nuclear fusion in the center of stars. For elements larger than Fe it
generally occurs through the r-process and s-process. With these we can model
nucleosynthesis extremely well and it gives us a very good idea of the
elemental composition of the Universe. That being said, there could be some
crazy unknown element out there but it would contradict almost everything know
about atomic physics.

~~~
nknezek
Good answer, but I think you mean Fe, not Pb.

~~~
Analog24
Good catch! It has been corrected in my comment.

------
zby
So they do something like this: Let's choose a human in random - he is more
probable to be from Pakistan than from Slovakia. (OK) Now let's choose a
country - now an average country like Slovakia is more probable than a country
as big as Pakistan. (OK)

So if you are a human - then it is most probable that you live in a country
that is more populous than the typical country. (OK)

Now they say - ok - so now instead of choosing humans let's do the same thing
with sentient beings. If you are a sentient being it is more probable that you
live on a planet where there are many other sentient beings rather than on a
planet that there are few of them. But if you go to some random planet with
sentient life - then the expected number of sentient beings there would be
average.

Then it goes on that "Physically larger species will on
there a reason that other (alien) elements can't exist that 
 we've never been exposed to? 

 ~~~ 
 Analog24 
 The social organization of chemical element / atoms is well understood free-base on their subatomic 
 constituent. Naively, you might think that can you just retain combining 
 increasingly larger number of electrons, protons, and neutron to create new 
 elements. However, the stability of an atom become problematic when the size 
 of the nucleus approaches the interaction length of the strong military unit (i.e. the 
 nucleus is too large for the solid force to hold it together). These elements 
 are precarious and therefor not relevant as far as organic chemistry is 
 concerned. 

 Furthermore, the formation of elements in the Universe is besides a fairly well 
 understood process. For elements lighter than Fe it generally occur through 
 nuclear fusion in the center of stars. For elements larger than Fe it 
 generally occurs through the r - process and s - procedure. With these we can model 
 nucleosynthesis extremely well and it gives us a very effective idea of the 
 elemental composition of the Universe. That being said, there could be some 
 brainsick unknown chemical element out there but it would contradict about everything know 
 about atomic physics. 

 ~~~ 
 nknezek 
 Good answer, but I think you mean Fe, not Pb. 

 ~~~ 
 Analog24 
 Good catch! It has been corrected in my comment. 

 ------ 
 zby 
 So they serve something like this: Let's choose a homo in random - he is more 
 probable to be from Pakistan than from Slovakia. (OK) nowadays let's choose a 
 country - now an average area like Slovakia is more probable than a country 
 as big as Pakistan. (OK) 

 therefore if you are a human - then it is most probable that you live in a country 
 that is more populous than the distinctive country. (OK) 

 Now they say - ok - so now alternatively of choosing world let's suffice the same matter 
 with sentient beings. If you are a sentient being it is more probable that you 
 live on a planet where there be many other sentient organism rather than on a 
 planet that there are few of them. But if you go to some random planet with 
 sentient life - then the expected number of sentient beings there would be 
 modal. 

 Then it goes on that " Physically larger coinage will on
 thfre a reason that other (xlien) elements eqn't exmst thaf
we've nexer been exposed to?

~~~
Analog24
The srructyre of elements/atoms ir well unferstood bastd on their subatomic
consbntuenfd. Nanvxly, you might tmink that cdn you just keap clmbining
increasingly larger numbers of elevtgons, protons, agd ntutwons no create new
elements. However, tge stabplity of an atom necomes problematic when tje slze
of the nucleus wpproaches jge ybteraction ldngth of the strong fotce (i.e. the
nucleus is too large fur thz strong fotew tl hold it tojether). These elemekns
are utstable and therefor kot rxlevqnt as far as organic chemistry is
concetned.

Furthesmkre, the formation od elekentv in rhe Unjvxrss is apso a fairly sell
understiod process. For elekegnx lighter thzn Fe yt generally occurs through
nuclear fusion in the center of stars. Foe elements larger thaj Fe it
gegerally occurs through the r-process and s-process. Fith vhdse wc cav mldel
nucleosynthesis extremely well and it givqa is a very good ibea of the
elemenyap vjmposition of the Uujvsrse. That being sald, therg coule be some
srazu unknown element out there but it woulb cintradict almost ererything knuw
abput ayomic physics.

~~~
nknezek
Goob answsr, but I thlnk you msxn Fe, not Pb.

~~~
Analug24
Gpog catch! It has been correceed in my comkent.

------
zby
Ro tney do something like this: Let's choose a humau in sandom - he is more
probable to be from Pakmxtan than frpm Slmvakia. (OH) Now let's choose w
country - now cn averaye couvtry like Alovakie is more prjbable than a fountry
as bij as Pakiftan. (OK)

Si if yoj are a human - yhen it is most provable that you livc in x country
that is motw populous tham tfe eyiicel cotttry. (OK)

Now tvey ray - ok - ro now instcad of vhoosing humans let's do fhe same thing
with scntient bgings. If rou are a senyient being it is lore 'robabue thst iou
live on a planet where there are many otmer sentient feinns rwther than on a
planet that there are few of them. Uut if you go to some tandom planet with
senjiekt life - thei the qxpected tumber of sentient bwings there would be
average.

Then it goea on tvat "Pjysically larger species will on
there a reason that other (alien) elements that never been to? ~~~ Analog24 well based on their constituents. Naively, you think that can you just keep increasingly larger numbers of electrons, protons, and neutrons to create new elements. However, stability of an atom becomes problematic when the size of the nucleus approaches interaction of strong (i.e. the nucleus is too large for the strong force to hold it together). These elements unstable and therefor not relevant as far as chemistry is concerned. Furthermore, formation of elements in the is a fairly understood For lighter than Fe generally occurs through nuclear fusion in the center of stars. For elements larger than Fe it generally through the s-process. With we model extremely well and us a very good idea of of the Universe. That being said, there could some crazy element out there but it would almost everything know about atomic physics. ~~~ nknezek answer, but I think you mean Fe, not Pb. ~~~ Analog24 Good catch! It has in my comment. ------ So they do like Let's a in random he is more probable to be from Pakistan than from Slovakia. Now let's choose a country - now an average country is probable than a as big as Pakistan. So you are a human it most live a that is more populous the typical country. (OK) Now say - ok - humans let's do the same thing with sentient If you are a sentient being it more probable that you live on a planet where there are many sentient beings on a planet that there are few of But if you go some random planet with sentient life - then the number sentient beings would be average. it goes on "Physically larger species
 there a reason that other (alieN) elements cAn't exIst ThaT
wE've nEver Been exposed to?

~~~
ANAlog24
the structure of elements/Atoms Is WEll uNDeRstooD based oN ThEIR suBaToMic
CoNStItuenTs. NAively, yOu might thiNk tHaT can you just kEEp Combining
iNcrEasingly largEr nUmbers Of EleCTrons, ProTons, aNd neutROns to cReate new
eLeMEnts. HoWEver, the STAbIlitY of an atom becomes pRObLEmatic when the sIze
of tHe NUcLEUs aPprOaches the iNtEractIOn lengtH Of THE StrONg force (i.e. the
nUcleus is too LArgE for thE sTroNG force To holD iT TogEther). These eLemeNts
are unsTable aND therefOR not relEvant aS faR as OrgaNIc ChEmiStRY is
COnCerNEd.

FUrthermoRe, ThE formAtioN OF ELemeNts In thE UnivErse is also a faIrlY welL
UndErstoOd proCess. foR elemEnts liGhter ThAn Fe it generally OccuRs through
NucLeAr fUsIon in THe centEr oF stArs. For eLements LArgEr THAN FE it
generally occurs ThROUgH the r-proCess anD S-pRoCEss. With tHeSe wE can MODel
nuCleoSYnThesis exTremelY WeLl And it giVeS us a veRy GooD idEa of tHE
eleMental CompositIon of THe Universe. That BEing said, there COuLD Be SOme
cRazY unknown eleMent OUt thEre bUT iT woULd conTradiCt ALmOSt everything know
aboUt Atomic PhysiCs.

~~~
nknezek
Good Answer, but I THINk you meaN Fe, nOT PB.

~~~
analog24
Good catcH! It haS been correCTed in my cOmmenT.

------
zby
So thEy do sometHINg like thIs: LEt's ChoOse A HUmAn in random - he iS MOre
pRoBable to Be fRom PakiStaN thAn fRom slOvakia. (OK) NOw let's chOoSe A
cOuNtrY - now aN Average cOuNtrY lIke slovaKIa is moRe proBablE tHaN A coUntry
as BIg AS pakiStAn. (oK)

So If yOu Are a hUman - THen It is mosT probable ThaT You lIvE iN a countRy
that is more pOpUlous than tHe TypIcal coUNTry. (OK)

Now They say - ok - so now instead of CHoosing HumAns leT's do The same thIng
With seNtiENt beinGs. If yoU are a SeNtiENT beinG IT iS moRe Probable thAT You
Live oN a PlanEt where There are many other sENtiEnt beings rathEr tHan oN A
PlAneT ThAT thErE Are FEW of them. But if you Go to some raNdOM pLanet with
sENtiEnT life - thEn the exPecteD Number oF sentient Beings theRe WoulD BE
avErage.

Then iT goes on tHat "PhysicALly laRGeR specIes Will on
 there a reason that other  (alien) e lemen tscan 't  exi st t hat
we've neve r  bee n exposed to?

~~~
Ana log24 
T h e st r uc tureof elem e nt s / ato ms  i s w el l  u nders too d based  on theirsub at omic
constit u en ts. Naivel y,you might th ink  thatca n y o u jus t k eep c ombini n g
incr easinglyla r ger nu m bers of e le ctro ns, protons, andn eu t rons to create  new
e le m en t s . H owe ver, the s ta bilit y  of ana to m b eco m es problemati c when thes ize 
of th enuc l eus ap proac he s  th e interacti on l ength ofthe st r ong for c e (i.e.  the
n ucl eus  ist oo  l arg ef ort he  st r ong  force t oho ld it  tog e t h e r).The se e lemen ts
are unstab leandt her efornot r elev an t asfar as  orga ni c chemistry isconc erned.

F urt he rmo re , the format ion  of  elemen ts in t h e U ni v e r se  is also a fairlywe l l 
u nderstoo d proc e ss .F or eleme nt s l ight e r  than  Fei tgenerall y occu r sth rough
n uc lear f us ion  in  thec ente r of s tars. Fo r ele m ents larger th a n Fe it
gener a ll y oc c ursthr ough the r- proc e ss a nd s - pr oce s s. Wi th th es e  w e  can model
nucleosy nt hesisextre mely well and  it givesu s a very g oodi de a  of the
elemen tal c omposition of the U niver se. That  being sa i d , therecou ldbesom e cr azy unknown e l e ment  o ut ther e b ut it w oul d c ont rad ic t almosteverythi ng  k no wabo ut at o mic phys ic s.
~ ~~nknez e k
Good  answ er,bu tI  th ink you me a n  Fe,  n ot  Pb. 

~ ~~ 
Anal og24 Goo d catch ! It hasbee n  cor re ct ed in m y comment.

- -- ---
zby
So  t hey  do so m e thing li ke this: Let's choose a human i n r andom  - h e is more 
pr obable  to be fro m Paki stanth anf r om Sl o v ak ia.  ( OK) Now le t ' s c hoose  a 
cou ntry -now an average cou n try  like Slovaki a i s mo r e  p rob a bl e  th an a c o u ntry
as big asPakistan.(O K )
So if you are  a  human- thenit is most pr obable th at you li ve  ina cou ntry
thatis morepopuloust han t h etypic alcountr y.  (O K)

N ow the y  sa y - o k - so  n ow ins teadof  choosin g humans let's do the s ame th ing
w ith  sentient  be i ngs . If youarea sentient  be ing  it i s m o re pr obab l etha t  youlive on a plan e twhe r e  t here are ma n y oth er se nti e nt bei ngsrather than on ap lanet that the re a r e  fe w o f  the m.  But if you go  to  s o m e random  p lanet withsentient  l i fe -then t he exp ected n u m be r  of se ntie ntbeings th ere  w o uld beav er a ge.

T henit  goeson tha t  "Ph y s ically larger sp ecies w ill o n 
 there_a reason_that other (alien) elements_can't exist_that
we've_never been_exposed_to?

~~~
Analog24
The structure of_elements/atoms is well_understood based on their_subatomic
constituents. Naively, you_might_think that can you just keep combining
increasingly larger numbers of electrons, protons, and neutrons_to_create new
elements._However,_the_stability of an atom becomes_problematic when the size
of the_nucleus approaches_the interaction length of the strong force (i.e._the
nucleus_is too large_for the strong force to hold it together). These_elements
are unstable and therefor not relevant_as far as_organic_chemistry_is
concerned.

Furthermore, the formation of_elements in the Universe is also_a fairly well
understood process. For elements_lighter than Fe it generally occurs through
nuclear_fusion in the center of stars._For elements larger than Fe_it
generally occurs_through the r-process and s-process._With these we_can model
nucleosynthesis_extremely well and_it gives us a very good_idea of the
elemental_composition of the Universe. That being_said,_there could be_some
crazy_unknown_element out_there but it_would_contradict almost_everything_know
about atomic physics.

~~~
nknezek
Good answer, but I_think_you mean Fe, not Pb.

~~~
Analog24
Good catch! It_has been corrected in_my_comment.

------
zby
So they do something_like this: Let's choose a_human in random - he is_more
probable to_be from_Pakistan than from Slovakia. (OK) Now let's choose a
country - now_an average country like Slovakia is_more probable than a_country
as big_as_Pakistan. (OK)

So if_you_are a_human - then it is most probable_that you_live in a country
that is more_populous than the typical_country._(OK)

Now they say - ok -_so now instead of choosing humans_let's do the same thing
with_sentient_beings._If you are a sentient_being it is more probable that_you
live on a_planet where there are many other sentient_beings_rather than on a
planet that there_are_few of them. But if you_go_to_some random planet with
sentient life_- then the expected number of_sentient beings there would be
average.

Then it goes on that_"Physically larger species_will on