Re: NYTimes.com Article: 10 Physics Questions to Ponder for

[David Bowman <David_Bowman@GEORGETOWNCOLLEGE.EDU>]

Regarding the NYTimes article Larry sent to the list concerning a top 10
list of open problems in fundamental physics (esp. problem # 6):

> ...
> 6. Why does the cosmological constant have the value that it has?
> Is it  zero and is it really constant?  Until recently cosmologists
> thought the universe was expanding  at a steady clip. But recent
> observations indicate that the expansion  may be getting faster and
> faster.  This slight acceleration is described  by a number called
> the cosmological  constant. Whether the constant turns  out to be
> zero, as earlier believed, or  some very tiny number, physicists
> are at a loss to explain why.
>
> According to some fundamental  calculations,  it should be huge --
> some 10 to 122 times as big as has  been observed.
      ^^^^^^^^^^^^^^^
I wonder if the error above was due to sloppiness on someone's part (maybe
a NYT reporter who was incredulous as to the correct value, or maybe just
a misunderstood orally given value.)  But the last statement in the quote
would be correct if it, instead, read:

     According to some fundamental  calculations,  it should be huge --
     some 10^122 times as big as has been observed.

This is quite a slip in a decimal point since the quoted value is at
least 120 orders of magnitude off.

Also cosmologists (other than maybe a couple of die hard steady state
theory supporters) previously did *not* think "the universe was expanding
at a steady clip" in the absence of a nonzero cosmological constant.
The usual Big Bang models without a cosmological constant have the
expansion of the universe's expansion rate decelerating with time.
(But the observations suggest that the expansion rate is accelerating,
and this is only compatible with a very small nonzero cosmological
constant within the current paradigm.)

David Bowman
David_Bowman@georgetowncollege.edu