Could collisions with Dark Matter explain the spacecraft fly-by anomalies?

Sounds like he's talking about the Aether Theory without actually
mentioning the Aether here.

Technology Review: Blogs: arXiv blog: The Clue That Could Explain The
Fly-By Anomalies
"Last year, we looked at an idea from Stephen Adler at Princeton
University, that suggested the change in velocity could caused by
collisions between the spacecraft and particles of dark matter. Adler
even calculated the kind of distribution of dark matter particles that
would explain the observed changes in velocity--a kind of halo of them
around Earth. "
http://www.technologyreview.com/blog/arxiv/24232/?a=f

Yousuf Khan

"Yousuf Khan" wrote in message
...
Sounds like he's talking about the Aether Theory without actually
mentioning the Aether here.


No, its got nothing whatsoever to do with that.


Technology Review: Blogs: arXiv blog: The Clue That Could Explain The
Fly-By Anomalies
"Last year, we looked at an idea from Stephen Adler at Princeton
University, that suggested the change in velocity could caused by
collisions between the spacecraft and particles of dark matter. Adler even
calculated the kind of distribution of dark matter particles that would
explain the observed changes in velocity--a kind of halo of them around
Earth. "
http://www.technologyreview.com/blog/arxiv/24232/?a=f

Yousuf Khan

Funny that the earth is surrounded by enough of these to noticeably slow a
spaceship, but none has even been observed on earth. I wonder if the paper
has an explanation of this curious fact ...

Yousuf Khan wrote:

Sounds like he's talking about the Aether Theory without actually
mentioning the Aether here.

Technology Review: Blogs: arXiv blog: The Clue That Could Explain The
Fly-By Anomalies
"Last year, we looked at an idea from Stephen Adler at Princeton
University, that suggested the change in velocity could caused by
ollisions between the spacecraft and particles of dark matter. Adler

Not even wrong.

Sorry.

even calculated the kind of distribution of dark matter particles that
would explain the observed changes in velocity--a kind of halo of them
around Earth. "
http://www.technologyreview.com/blog/arxiv/24232/?a=f

Yousuf Khan

Dear Yousuf Khan:

On Oct 13, 10:57*pm, Yousuf Khan wrote:
Sounds like he's talking about the Aether Theory
without actually mentioning the Aether here.

Technology Review: Blogs: arXiv blog: The Clue
That Could Explain The Fly-By Anomalies
"Last year, we looked at an idea from Stephen
Adler at Princeton University,

That there is a different kind of Dark Matter "in front" of a boosting
planet, than the kind "behind"... and that this Dark Matter isn't Dark
and actually must interact in ways that are obviated by other
observations. Including downing satellites anomalously.

that suggested the change in velocity could
caused by collisions between the spacecraft
and particles of dark matter. Adler even
calculated the kind of distribution of dark
matter particles that would explain the
observed changes in velocity--a kind of halo
of them around Earth.
"http://www.technologyreview.com/blog/arxiv/24232/?a=f

Don't waste another thought on this Rube Goldberg contraption.

David A. Smith

Yousuf Khan wrote:

Sounds like he's talking about the Aether Theory without actually
mentioning the Aether here.

Technology Review: Blogs: arXiv blog: The Clue That Could Explain The
Fly-By Anomalies
"Last year, we looked at an idea from Stephen Adler at Princeton
University, that suggested the change in velocity could caused by
collisions between the spacecraft and particles of dark matter. Adler
even calculated the kind of distribution of dark matter particles that
would explain the observed changes in velocity--a kind of halo of them
around Earth. "
http://www.technologyreview.com/blog/arxiv/24232/?a=f

Yousuf Khan

By hypothesis and definition dark matter does not interact except by
gravitation. Do neutrinos slow spacecraft?

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2

In sci.astro Yousuf Khan wrote:
Sounds like he's talking about the Aether Theory without actually
mentioning the Aether here.

Technology Review: Blogs: arXiv blog: The Clue That Could Explain The
Fly-By Anomalies
"Last year, we looked at an idea from Stephen Adler at Princeton
University, that suggested the change in velocity could caused by
collisions between the spacecraft and particles of dark matter. Adler
even calculated the kind of distribution of dark matter particles that
would explain the observed changes in velocity--a kind of halo of them
around Earth. "

No. Adler's papers investigate the possibility that the flyby anomalies
might be caused by drag as spacecraft pass through a cloud of dark
matter gravitationally bound to the Earth. In his most recent preprint
he suggests a specific experimental signature (collisions with dark
matter should slightly heat the spacecraft).

The relevant preprints are arXiv:0903.4879, arXiv:0908.2414, and
arXiv:0910.1564.

Steve Carlip

In sci.astro Uncle Al wrote:

By hypothesis and definition dark matter does not interact except by
gravitation.

Not true. By hypothesis, dark matter interacts weakly, but there is
certainly no requirement of no nongravitational interaction. In fact,
popular candidates (lightest supersymmetric particle, axions) certainly
do have nongravitational interactions. In fact, a major experimental
effort is going into searches for dark matter through such interactions.

Steve Carlip

On Oct 14, 8:27*am, wrote:
In sci.astro Uncle Al wrote:

By hypothesis and definition dark matter does not
interact except by gravitation. *

Not true. *By hypothesis, dark matter interacts weakly,
but there is certainly no requirement of no
nongravitational interaction.

For Dark Matter as WIMPs, this is true. But the Bullet Cluster
obviates such weakly interacting Dark Matter, doesn't it? The visible
matter is pretty hot, so maybe we cannot evaluate how much normal
matter is there...

*In fact, popular candidates (lightest supersymmetric
particle, axions) certainly do have nongravitational
interactions. *In fact, a major experimental effort is
going into searches for dark matter through such
interactions.

Isn't that a bit like searching for a lost item under a streetlight,
even if we did not lose the item there, because we can at least see?

David A. Smith

carlip-nospam wrote on Wed, 14 Oct 2009 15:27:19 +0000:

In sci.astro Uncle Al wrote:

By hypothesis and definition dark matter does not interact except by
gravitation.

Not true. By hypothesis, dark matter interacts weakly, but there is
certainly no requirement of no nongravitational interaction. In fact,
popular candidates (lightest supersymmetric particle, axions) certainly
do have nongravitational interactions. In fact, a major experimental
effort is going into searches for dark matter through such interactions.

What a waste of time and money!

Steve Carlip





--
http://www.canonicalscience.org/

BLOG:
http://www.canonicalscience.org/en/p...encetoday.html

wrote:

In sci.astro Uncle Al wrote:

By hypothesis and definition dark matter does not interact except by
gravitation.

Not true. By hypothesis, dark matter interacts weakly, but there is
certainly no requirement of no nongravitational interaction. In fact,
popular candidates (lightest supersymmetric particle, axions) certainly
do have nongravitational interactions. In fact, a major experimental
effort is going into searches for dark matter through such interactions.

Steve Carlip

CERN's axion telescope has proven to be cold manure. Collar's dark
matter detector Halon and perfluorocarbon bubble chambers are
brilliant but not implemented at scale. (If he wants to make a grant
funding splash he'll need a totally ridiculous, er, advanced working
fluid boiling around 0 C, like heptakis(trifluoromethyl)iodine. No
static molecular structure!) Ultracryogenic dark matter collision
phonon detectors are in place and working.

NO DETECTIONS. Gravity Probe B (such as it was) showed no anomaly.
Lunar laser ranging shows ZERO Nordtvedt effect.

Uncle Al calls "bull****" on undetected matter in space in sufficient
quantities to detectably alter local orbits, by collision
cross-section or by naked gravitation. If somebody comes up with a
reproducible lab signal (not the Italian stuff), Uncle Al will
apologize.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2