Comments on: A Busy Couple of Weeks

By: shantanu

shantanu — Wed, 03 May 2006 03:37:25 +0000

Thanks, Sean for the answer . I find it difficult to intute stuff from Lagrangians, (but that’s just me.)
Also one more general quesion about all these modifed gravity
theories used to explain dark energy such
as DGP, CDTT and even those which are used to explain away dark matter
such as MOND/TeVss . Won’t these theories also affect physics of compact
objects such as neutron stars , black holes with possibly
some observable consequences which could be tested? (or the physics for such compact objects same as GR for thse modified gravity theories.) I haven’t seen any of these theories address physics of compact objects. But perhaps you or others could clarify.
Thanks

By: Sean

Sean — Tue, 18 Apr 2006 01:43:33 +0000

Sorry, Shantanu, I missed your question earlier. No, these theories generally do not obey the strong equivalence principle, since the behavior of gravity depends on the background; they are much like Brans-Dicke theories that way. But really it’s better to forget about the equivalence principle and think about Lagrangians.

By: Shantanu

Shantanu — Tue, 18 Apr 2006 01:37:20 +0000

Mark or Sean, could you tell me what is the answer to question # 10?
Thanks

By: Shantanu

Shantanu — Sat, 15 Apr 2006 08:00:45 +0000

Hi
I went through the transparencies of your talk at FNAL . I have a naive question.
(which I am sure is discussed in some of your papers) you cited.
the class of modified gravity models which you are considering
to account for Dark energy(eg CDTT) and that in astro-ph/0410031 , do these models obey strong equivalence principle?

By: Jim Graber

Jim Graber — Mon, 06 Mar 2006 22:15:37 +0000

Hopefully some ppt or pdf of your talk will soon be available on this website
http://www-ppd.fnal.gov/EPPOffice-w/colloq/colloq.html
or elsewhere?
Congratulations to your friends on their weddings etc. but I would really like to see some physics after this tantalizing hint.
Best,
Jim

By: Life is LIke a Box of

Life is LIke a Box of — Mon, 06 Mar 2006 21:27:34 +0000

Pick one. Sure. It doesn’t matter.

Nothing emotional about the future of cosmology and of physics of reductionism together?

Okay. So you don’t get emotionally involved.

It’s still science.

And that’s all I got to say about that.

By: Science

Science — Mon, 06 Mar 2006 21:04:34 +0000

I just mean LQG. Greene is prejudiced in favour of string theory, which is fine if he keeps scientific, but we don’t need emotional brainwashing to spread prejudice in science.

By: Plato

Plato — Mon, 06 Mar 2006 18:32:44 +0000

I wasn’t talking about all your other ideas:)

By: Science

Science — Mon, 06 Mar 2006 18:28:51 +0000

Plato: I disagree! If nature was inherently poetic and graceful, there would hardly be wars, starvation, disease, etc. People who write novels and film scripts are full of beautiful ideas and happy endings. The world simply isn’t like that. Don’t try to force your poetry on to natural science. High expectations create prejudices, and scientists have to be prepared to accept the most simple theory that explains the facts, even if it looks vulgar.

By: Plato

Plato — Mon, 06 Mar 2006 18:11:38 +0000

“Nothing to me would be more poetic; no outcome would be more graceful … than for us to confirm our theories of the ultramicroscopic makeup of spacetime and matter by turning our giant telescopes skyward and gazing at the stars,” Greene said.

You don’t have to be from any particluar “camp” to understand the implications of these words, without assigning them to some agenda?