I am with you that generally Krauss does a good job of popularizations
of cosmology and so on. He is generally quite careful and accurate in
his book "A Universe from Nothing", except on page 166, where he says
"There is one universe in which the total energy is definitely and
precisely zero.... It is a closed universe..." This is just simply
incorrect. The total mass energy of a closed universe is not definable
because there is no reference point outside such a universe from which
one can measure the total enclosed energy. Krauss's argument by analogy
with the total charge in the universe fails because he appears to have
overlooked the simple fact that in a closed universe, light cannot go
right round and back to the starting point before the universe
re-contracts to zero size. This is a simple GR calculation in the
geometry of a closed universe. See the text by Misner, Thorne and
Wheeler (MTW, the 'Bible' of general relativists!)
Bruce
spudboy100 via Everything List wrote:
Sent from AOL Mobile Mail
I like Larry Krauss despite his attacks on Frank Tipler, because Larry
Krauss also concedes the possibility of faster than light travel. No
which among us, are going to turn down Star Trek?
From: meekerdb <meeke...@verizon.net>
Bruce is a very good physicist and he's right. John Baez has a good
discussion of the point on his blog.
Brent
On 10/25/2014 7:51 AM, Terren Suydam wrote:
I find this quite surprising too and wonder if Brent could weigh in
as I'm out of my league on that stuff.
Terren
On Oct 25, 2014 12:23 AM, "Peter Sas" < peterjacco...@gmail.com
<mailto:peterjacco...@gmail.com>> wrote:
Wow... That's quite shocking! I see I have to be much more
careful in taking over what the pop science writers say...
Unfortunately, physics is a subject where the text books tend to
carry
more weight than the popular presentations. The text books
show that the
claims about the zero net energy of the universe made by
people such as
Hawking and Krauss in popular presentations are wrong. The
interesting
question is why undoubtedly clever people such as Krauss and
Hawking
would make such fallacious claims. I suppose simplification can
sometimes be indistinguishable from over-simplification --
or else
people become more susceptible to brain farts as they get
older.....
Bruce
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