View Full Version : a question on alternative to inflation as discussed in astro-ph/0308325
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>I asked this question on sci.astro.research but got no replies. Maybe\nsome\nexperts here can\nprovide more explanation for Penrose pov as pointed out in the review\narticle below by Freedman and Turner.\nThanks\n\n\n\nOn pg 18 (2nd para) of the preprint mentioned above, Turner and\nFreedman remark: "apparently a special beginning is required. There\nare two ways to read this: The first is that the state of the universe\naccurately pins down the initial conditions, a point of view advocated\nby few and they cite a reference to a paper by Penrose in 1979.\n\nAnyhow can someone explain to me more about Penrose point of view as\nan alternative to inflation? also is his idea relevant today or was\nruled out many years ago? Thanks Melroy\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>I asked this question on sci.astro.research but got no replies. Maybe
some
experts here can
provide more explanation for Penrose pov as pointed out in the review
article below by Freedman and Turner.
Thanks
On pg 18 (2nd para) of the preprint mentioned above, Turner and
Freedman remark: "apparently a special beginning is required. There
are two ways to read this: The first is that the state of the universe
accurately pins down the initial conditions, a point of view advocated
by few and they cite a reference to a paper by Penrose in 1979.
Anyhow can someone explain to me more about Penrose point of view as
an alternative to inflation? also is his idea relevant today or was
ruled out many years ago? Thanks Melroy
Phillip Helbig---remove CLOTHES to reply
Dec4-04, 03:13 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In article <1b7c3dda.0412021542.3944b42f@posting.google.com>, \nmelroysoares@hotmail.com (Melroy) writes:\n\n> I asked this question on sci.astro.research but got no replies. Maybe\n> some\n> experts here can\n> provide more explanation for Penrose pov as pointed out in the review\n> article below by Freedman and Turner.\n> Thanks\n>\n>\n>\n> On pg 18 (2nd para) of the preprint mentioned above, Turner and\n> Freedman remark: "apparently a special beginning is required. There\n> are two ways to read this: The first is that the state of the universe\n> accurately pins down the initial conditions, a point of view advocated\n> by few and they cite a reference to a paper by Penrose in 1979.\n>\n> Anyhow can someone explain to me more about Penrose point of view as\n> an alternative to inflation? also is his idea relevant today or was\n> ruled out many years ago? Thanks Melroy\n\nCheck out Penrose\'s contribution to one of the Texas Symposia (might\nhave been 1978, with the proceedings appearing in 1979) as well as his\nsemi-popular books.\n\nPenrose is thinking in much bigger terms, with rather unorthodox ideas\nabout quantum gravity. Many things hang together, in his view. The\nlast I heard (when I saw him in Groningen a few years ago) was that he\nwas discussing an experiment with Anton Zeilinger (the "quantum\nteleportation" guy from Austria whose experiments in quantum optics have\ngotten a lot of press recently) which would be able to disprove his\nideas (a hypothesis which doesn\'t make testable predictions isn\'t near\nas interesting as one which does).\n\nI definitely wouldn\'t write off Penrose.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>In article <1b7c3dda.0412021542.3944b42f@posting.google.com>,
melroysoares@hotmail.com (Melroy) writes:
> I asked this question on sci.astro.research but got no replies. Maybe
> some
> experts here can
> provide more explanation for Penrose pov as pointed out in the review
> article below by Freedman and Turner.
> Thanks
>
>
>
> On pg 18 (2nd para) of the preprint mentioned above, Turner and
> Freedman remark: "apparently a special beginning is required. There
> are two ways to read this: The first is that the state of the universe
> accurately pins down the initial conditions, a point of view advocated
> by few and they cite a reference to a paper by Penrose in 1979.
>
> Anyhow can someone explain to me more about Penrose point of view as
> an alternative to inflation? also is his idea relevant today or was
> ruled out many years ago? Thanks Melroy
Check out Penrose's contribution to one of the Texas Symposia (might
have been 1978, with the proceedings appearing in 1979) as well as his
semi-popular books.
Penrose is thinking in much bigger terms, with rather unorthodox ideas
about quantum gravity. Many things hang together, in his view. The
last I heard (when I saw him in Groningen a few years ago) was that he
was discussing an experiment with Anton Zeilinger (the "quantum
teleportation" guy from Austria whose experiments in quantum optics have
gotten a lot of press recently) which would be able to disprove his
ideas (a hypothesis which doesn't make testable predictions isn't near
as interesting as one which does).
I definitely wouldn't write off Penrose.
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Melroy wrote:\n....\n>\n> Anyhow can someone explain to me more about Penrose point of view as\n> an alternative to inflation? also is his idea relevant today or was\n> ruled out many years ago? Thanks Melroy\n\nPenrose cosmological pov is juxtapposed to Hawking\'s in "The Nature of\nSpace and Time", which makes for great reading and is even cheap.\n\n"Stephen Hawking and Roger Penrose gave a series of 3 lectures each at\nthe Isaac Newton Institute in Cambridge. The full series is available\nin a book of the same name. Here we have compiled Stephen\'s\ncontribution to the series, as well as the final debate.\nThis is available for download as pdf format or 4 postscript files or\n(penrose1.ps penrose2.ps penrose3.ps penrose4.ps)." ([1])\n\nImo Hawking\'s contribution is by far the deeper one, although\ninterestingly Penrose regards the measurement problem as fundamental,\nwhile Hawking appears to wave it away.\nPenrose states that we "need to have one (or both) of the following:\n(A) A theory of experience\n(B) A theory of real physical behaviour\n....\nI [that\'s Penrose] believe that Stephen must be an A-supporter [SWH:\nNo] because he isn\'t a B-supporter. I am a strong B-supporter , as I\nbelieve that (A) is a dangerous view to adopt, which leads to all sort\nof trouble" ([2]).\n\nAs you may know, Penrose supports Diosi\'s idea that state vector\nreduction is induced by gravity.\nBulky stuff collapses right away, lighter stuff takes its time.\n\nBelieve that and stay out of trouble.\n\nCheers,\n\nIV\n\n\n\n[1] http://www.hawking.org.uk/text/public/public.html\n[2] in Ch. 7 of S. Hawking, R. Penrose "The Nature of Space and Time" .\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Melroy wrote:
....
>
> Anyhow can someone explain to me more about Penrose point of view as
> an alternative to inflation? also is his idea relevant today or was
> ruled out many years ago? Thanks Melroy
Penrose cosmological pov is juxtapposed to Hawking's in "The Nature of
Space and Time", which makes for great reading and is even cheap.
"Stephen Hawking and Roger Penrose gave a series of 3 lectures each at
the Isaac Newton Institute in Cambridge. The full series is available
in a book of the same name. Here we have compiled Stephen's
contribution to the series, as well as the final debate.
This is available for download as pdf format or 4 postscript files or
(penrose1.ps penrose2.ps penrose3.ps penrose4.ps)." ([1])
Imo Hawking's contribution is by far the deeper one, although
interestingly Penrose regards the measurement problem as fundamental,
while Hawking appears to wave it away.
Penrose states that we "need to have one (or both) of the following:
(A) A theory of experience
(B) A theory of real physical behaviour
....
I [that's Penrose] believe that Stephen must be an A-supporter [SWH:
No] because he isn't a B-supporter. I am a strong B-supporter , as I
believe that (A) is a dangerous view to adopt, which leads to all sort
of trouble" ([2]).
As you may know, Penrose supports Diosi's idea that state vector
reduction is induced by gravity.
Bulky stuff collapses right away, lighter stuff takes its time.
Believe that and stay out of trouble.
Cheers,
IV
[1] http://www.hawking.org.uk/text/public/public.html
[2] in Ch. 7 of S. Hawking, R. Penrose "The Nature of Space and Time" .
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