Date: Mon, 03 Jun 2013 00:41:27 -0400
From: "Mike B." <yahoo at omniphile.com>
To: WSFA members <WSFAlist at KeithLynch.net>
Subject: [WSFA] Re: negative gravity
Reply-To: WSFA members <WSFAlist at KeithLynch.net>

Dark energy is the name for the unknown cause of what appears to be a
repulsive force at very large scales (i.e. between galactic clusters).
Whether it is negative gravity, or something else, is as unknown as
whether it even exists as a force of any type (as opposed to say, a
side-effect of a non-uniform expansion of space).

I wouldn't refer to a gravitational reading that is less than a
reference level as "negative gravity"...since it is still a reading of
the usual attractive gravitational force, which has a positive value.
Referring to such a reading as being lower than a reference reading is
fine, and using negative numbers to record such a relative reading makes
sense, but "negative gravity"?  I don't think so.  I think that's an
invention of the reporter, stemming from lack of understanding of either
the subject matter, or English, or perhaps both.

-- Mike B.

On 6/1/2013 8:27 PM, Ron Kean wrote:
> In the case of a gravity map, negative and positive readings would
> probably be relative to a mean gravity reference strength.
>
> In a larger context, negative gravity can be a manifestation of dark
> energy.
>
> http://www.nytimes.com/2001/04/03/us/photo-gives-weight-to-einstein-s-the
> sis-of-negative-gravity.html
>
> Ron Kean
>
> On Sat, 01 Jun 2013 14:03:56 -0400 "Mike B." <yahoo at omniphile.com>
> writes:
>> On 5/31/2013 6:58 PM, mark wrote:
>>> Using high-resolution gravity data from NASA's Gravity Recovery
>> and
>>> Interior Laboratory (GRAIL) mission, researchers at MIT and
>> Purdue
>>> University have mapped the structure of several lunar mascons and
>> found
>>> that their gravitational fields resemble a bull's-eye pattern: a
>> center of
>>> strong, or positive, gravity surrounded by alternating rings of
>> negative
>>> and positive gravity.
>>
>> "Negative and positive gravity"????  What the hell is "negative
>> gravity"??  I'm surprised that got through in an MIT publication.
>>
>> I suspect that they meant increasing and decreasing levels of
>> attraction, not negative gravity.
>>
>> -- Mike B.
>>
>