[meteorite-list] Invisible Asteroids Might Endanger Earth

From: Matt <Matt_at_meteoritecentral.com>
Date: Thu Apr 22 09:44:38 2004
Message-ID: <002901c0ab1f$1aa17a60$c3dc7fa5_at_state.co.us>

Jeese, what's next!

I think there is sufficient evidence for a comet impacting at Tunguska. They
are grabbing straws here concerning impacts.

Matt
----- Original Message -----
From: "Ron Baalke" <baalke_at_zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list_at_meteoritecentral.com>
Sent: Monday, March 12, 2001 10:47 AM
Subject: [meteorite-list] Invisible Asteroids Might Endanger Earth


>
> http://www.vny.com/cf/News/upidetail.cfm?QID=166615
>
> Invisible asteroids might endanger Earth
>
> MELBOURNE, Australia, March 9 (UPI) -- Invisible asteroids and other
> cosmic bodies made of a new form of matter may pose a threat to Earth,
> asserts a noted Australian physicist.
>
> Robert Foot of the University of Melbourne claims a meteorite composed of
> mirror matter -- a form of the invisible dark matter that many say makes
up
> over 95 percent of the universe -- could impact the Earth without leaving
> any fragments.
>
> Indeed, he told United Press International, asteroids made of mirror
> matter may have been responsible for such cataclysmic events as the
> so-called Tunguska blast, which destroyed acres of Siberian forest in
1908.
>
> While scientists generally attribute this explosion to a meteorite, no
> traces of such an object have ever been found.
>
> However, "mirror matter would be undetectable in our ordinary matter
> surroundings," Foot told UPI in a telephone interview.
>
> Foot believes mirror-matter asteroids might be a greater danger than
> normal asteroids.
>
> "These objects may pose an overall greater risk than space bodies
composed
> of ordinary matter," Foot said. "An approaching space body made of pure
> mirror matter would not be detectable -- only after impact with the
> atmosphere would its effects be observable, but then it would probably be
to
> late to do anything."
>
> Mirror matter, Foot claims, arises naturally from two apparent symmetries
> of nature. One says matter is unchanged whether it moves forward or
backward
> in time; the other, that nature doesn't distinguish between right- and
> left-handed orientations.
>
> "These particles must exist if the symmetries exist," Foot said.
>
> In the invisible universe of mirror matter, Foot explained, space and
time
> are reversed. Time moves backward and right-handed spatial coordinates
have
> been interchanged with their left-handed counterparts.
>
> Something in the visible universe that is sitting at 50 degrees north and
> 20 degrees west as the clock ticks toward the future would have an
> invisible, identical counterpart at 50 degrees south and 20 degrees east
as
> the clock ticks toward the past, according to Foot's theory.
>
> Invisible forms of matter that preserve symmetries are nothing new to
> physicists. Nobel Laureate Paul Dirac predicted that anti-matter must
exist
> to preserve certain symmetries of matter. His prediction was borne out
with
> the discovery of positrons, the anti-matter form of electrons.
>
> Princeton physicist Howard Georgi is skeptical of Foot's claims, however.
>
> "Robert Foot's ideas are interesting," Georgi told UPI. "They are also,
of
> course, extremely speculative."
>
> Georgi also believes that invisible asteroids are not a top priority of
> physics research.
>
> "Foot's ideas have not attracted a huge following in the community that
> cares about these things, perhaps because the problems they solve, while
> interesting, are not the most critical puzzles that we are wrestling
with,"
> Georgi said.
>
> (Reported by UPI Science Writer Mike Martin from Columbia, Mo.)
>
>
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Received on Mon 12 Mar 2001 01:06:03 PM PST