Hi Tom,
The way the proton comes in, is to replace m_e, the rest mass of the
electron, with its reduced rest mass, which does involve the rest mass of
the proton. If that is done, values different than 13.5056923 eV and its
corresponding R_infinity are obtained. You have confirmed that the value
13.6056923 does not give R_H, but R_infinity. It sure looks hard to find
an
accurate, "purely experimentally determined" (i.e., not derived by an
equation) Rydberg constant for hydrogen (R_H) on the net. I find that
rather
surprising. The Wikipedia site presents a value:
http://en.wikipedia.org/wiki/Rydberg_constant
But it's from an equation. Perhaps there is no way to actually directly
measure either hydrogen's Rydberg constant or its ground state binding
energy. Once again, I would find that surprising. I tried looking at the
link you've given, but couldn't find the 13.6056923 number, but that is
exactly the number for R_infinity quoted at the above Wikipedia site. The
number 10967758.341 m^-1 is given for R_H. I wonder if physicists would
say
that if indeed, R_H were determined directly from experimentation, this is
what would be obtained (with some slight difference, due to the particular
experimental error that occurred).
Thanks for the information,
Steve
"Tom Roberts" <tjroberts137@sbcglobal.net> wrote in message
news:JQIOj.1422$26.1327@newssvr23.news.prodigy.net...
Steve Bell wrote:
Thanks for the information. This value, when converted to a Rydberg
constant, looks like it gives R_inf. I'm looking for R_H, specifically
an
accurate experimentally determined value for R_H. I don't think the
13.6056923 could be an true, "uncorrupted by theory" experimental
value,
since an experimental value should show only real world effects, that
is, it
should have "in it" the effect of finite nuclear mass. R_inf and its
associated binding energy does not, so it's difficult for me to accept
the
13.6056923 value as truthfully what hydrogen itself "presents" to the
outside world.
The booklet calls this "Rydberg energy" and has a formula
h*c*R_\infinity = m_e*c^2*alpha^2/2. That clearly has nothing related to
the nucleus or proton in it, and it looks like a theoretical formula
based on experimental measurements of the constants involved rather than
direct measurements on hydrogen (though I believe those are involved in
measurements of \alpha). I am not familiar with the distinction you
make, I'm just reading the booklet and passing on its contents.
But look it up, as the PDG usually provides references for their data.
Tom Roberts
Steve
"Tom Roberts" <tjroberts137@sbcglobal.net> wrote in message
news:7byOj.2318$I55.2066@newssvr22.news.prodigy.net...
The Particle Data Group's "Particle Physics Booklet" gives a value
13.6056923(12) eV (the digits in parens are the uncertainty in the
last
2 digits given). They usually give experimental references -- look in
http://pdg.lbl.gov
Tom Roberts
Steve Bell wrote:
Since there is a one-to-one relationship between hydrogen's Rydberg
constant
and its ground state binding energy, an accurate, experimentally
determined
value of hydrogen's ground state binding energy would also be of
interest to
me.
Steve Bell
"Steve Bell" <sb635@starband.net> wrote in message
news:3922d$480a9cd0$943f641c$15830@STARBAND.NET...
Does anyone know where I can find the value of an accurate,
experimentally
determined Rydberg constant for hydrogen?
Thanks,
Steve Bell
