Secrets of Dark Matter

No wonder there is a rennaissance of anti-Darwin /
Intelligent Design with this sort of stuff coming from
a scientist. Belief in a big-G of the god/allah variety
seems more rational than this sort of thing.

http://education.guardian.co.uk/high...703204,00.html
Research into dwarf galaxies starts to unlock the deep secrets of dark
matter

· Mysterious substance described for first time
· 1,000-light-year-wide bricks make up universe

Alok Jha, science correspondent
Monday February 6, 2006
The Guardian

....
Cambridge University researchers have creaked open the door to one of the
greatest mysteries in science. For the first time they can describe some
physical properties of "dark matter", the mysterious substance that
outweighs all the stars and galaxies that can be seen in the universe.
Cosmologists know that the stars and planets we can see add up to only 4% of
the mass required to keep the universe in its ordered state. The rest is
made of a combination of unknown particles called dark matter and a source
of energy, which seems to push galaxies apart, called dark energy. Other
than knowing that both these things must exist, scientists have been at a
loss to describe anything about them.

But by studying the motion of dwarf galaxies orbiting the Milky Way, Gerry
Gilmore, the deputy director of the Institute of Astronomy at Cambridge
University, calculated that dark matter moved at 5.6 miles a second and that
the smallest chunks it could exist in measured 1,000 light years across and
had 30m times the mass of the Sun.

"This is the first time we've determined a property of the dark matter
robustly in a way that we expect will give us some real clues as to what the
real physics of this stuff is," said Professor Gilmore at a briefing in
London. He said the universe appeared to be built out of these invisible
1,000 light-year-wide bricks of dark matter.

"There must be some basic property of the dark matter that limits it in that
way," he said. "It's the basic unit from which bigger things are made up.
Some of these you put stars in and you call it a little galaxy; sometimes
you put several of these together and call it a bigger galaxy. But you never
get anything smaller."

The biggest surprise is that dark matter is not the cold cosmic sludge that
scientists once thought. Prof Gilmore calculated its temperature to be in
the tens of thousands of degrees, although this is not normal heat. "Normal
hot things glow and you can feel the infrared coming off," he said. "The
strange thing about dark matter is that it doesn't give off radiation." This
is because dark matter is not made of electrons and protons, the fundamental
particles that everything else consists of ....

"paul nutteing" wrote in message
...
No wonder there is a rennaissance of anti-Darwin /
Intelligent Design with this sort of stuff coming from
a scientist. Belief in a big-G of the god/allah variety
seems more rational than this sort of thing.

http://education.guardian.co.uk/high...703204,00.html
Research into dwarf galaxies starts to unlock the deep secrets of dark
matter

· Mysterious substance described for first time
· 1,000-light-year-wide bricks make up universe

Alok Jha, science correspondent
Monday February 6, 2006
The Guardian

...
Cambridge University researchers have creaked open the door to one of the
greatest mysteries in science. For the first time they can describe some
physical properties of "dark matter", the mysterious substance that
outweighs all the stars and galaxies that can be seen in the universe.
Cosmologists know that the stars and planets we can see add up to only 4%
of
the mass required to keep the universe in its ordered state. The rest is
made of a combination of unknown particles called dark matter and a source
of energy, which seems to push galaxies apart, called dark energy. Other
than knowing that both these things must exist, scientists have been at a
loss to describe anything about them.

But by studying the motion of dwarf galaxies orbiting the Milky Way, Gerry
Gilmore, the deputy director of the Institute of Astronomy at Cambridge
University, calculated that dark matter moved at 5.6 miles a second and
that
the smallest chunks it could exist in measured 1,000 light years across
and
had 30m times the mass of the Sun.

"This is the first time we've determined a property of the dark matter
robustly in a way that we expect will give us some real clues as to what
the
real physics of this stuff is," said Professor Gilmore at a briefing in
London. He said the universe appeared to be built out of these invisible
1,000 light-year-wide bricks of dark matter.

"There must be some basic property of the dark matter that limits it in
that
way," he said. "It's the basic unit from which bigger things are made up.
Some of these you put stars in and you call it a little galaxy; sometimes
you put several of these together and call it a bigger galaxy. But you
never
get anything smaller."

The biggest surprise is that dark matter is not the cold cosmic sludge
that
scientists once thought. Prof Gilmore calculated its temperature to be in
the tens of thousands of degrees, although this is not normal heat.
"Normal
hot things glow and you can feel the infrared coming off," he said. "The
strange thing about dark matter is that it doesn't give off radiation."
This
is because dark matter is not made of electrons and protons, the
fundamental
particles that everything else consists of ....

To a layman, the pronouncements of Prof. Gilmore, although no doubt well
intended, are as obscure and unlikely as any religious mantra. 1000 light
year chunks indeed!

My feeling is that dark matter is only there as a "balancing term" to make
observations fit predictions. What is actually the physical nature of dark
matter remains to be established and the whole theory could easily be
superceded as our knowledge advances.

Rodney Blackall wrote in message
...
In article , Max Turner
wrote:

To a layman, the pronouncements of Prof. Gilmore, although no doubt
well intended, are as obscure and unlikely as any religious mantra.
1000 light year chunks indeed!

My feeling is that dark matter is only there as a "balancing term" to
make observations fit predictions. What is actually the physical
nature of dark matter remains to be established and the whole theory
could easily be superceded as our knowledge advances.

To me it seems increasingly likely that Fred Hoyle was right (continuous
creation) and the microwave background is caused by something other than
the Big Bang.

--
Rodney Blackall (retired meteorologist)(BSc, FRMetS, MRI)
Buckingham, ENGLAND
Using Acorn SA-RPC, OS 4.02 with ANT INS and Pluto 3.03j



That sounds far more rational

My feeling is that dark matter is only there as a "balancing term" to make
*observations fit predictions*.

Wasn't it Einstein who *predicted* the cosmological constant and then
rejected it (on arguably theological grounds)? Don't these
*observations* vindicate the truth of those first equations...?

What is actually the physical nature of dark
matter remains to be established and the whole theory could easily be
superceded as our knowledge advances

Total agreement there!

"justbeats" wrote in message
oups.com...
My feeling is that dark matter is only there as a "balancing term" to
make
*observations fit predictions*.

Wasn't it Einstein who *predicted* the cosmological constant and then
rejected it (on arguably theological grounds)? Don't these
*observations* vindicate the truth of those first equations...?

What is actually the physical nature of dark
matter remains to be established and the whole theory could easily be
superceded as our knowledge advances

Total agreement there!

Is there any possibility that we are trying to measure the total mass of the
universe in too few dimensions (i.e 4 instead of 10,11, 26 or whatever is in
vogue these days) and that the "dark" matter is just matter that resides in
different dimensions ? (Curled up at sub Planck lengths or whatever....)

Rodney Blackall wrote:

In article , Max Turner
wrote:

To a layman, the pronouncements of Prof. Gilmore, although no doubt
well intended, are as obscure and unlikely as any religious mantra.
1000 light year chunks indeed!

Not his fault. He is merely describing what properties their
observations and/or numerical simulations are consistent with.

My feeling is that dark matter is only there as a "balancing term" to
make observations fit predictions. What is actually the physical
nature of dark matter remains to be established and the whole theory
could easily be superceded as our knowledge advances.

It is quite likely that we will revise and refine things in time. What
is not in doubt is that there is a lot of non-luminous gravitating
matter that we cannot see or detect at present. We can see its indirect
effects in the rotation curves of galaxies. In the 80's it was still
just possible to hide enough ordinary matter as chair legs, rhubarb, or
old biros but modern observations rule this possibility out.

To me it seems increasingly likely that Fred Hoyle was right (continuous
creation) and the microwave background is caused by something other than
the Big Bang.

Not a chance. Even in the 1960's it was apparent that the Steady State
Universe was totally inconsistent with the surveys of radio galaxies
(and now also with the Hubble deep field). The universe was different
when it was younger. It led to the Hoyle vs Ryle feud in Cambridge.

Add to that the recent gamma ray bursts seen from Z=6 replete with time
dilation and there is essentially no doubt that remotest parts of the
universe are receeding from us at speeds close to c.

Regards,
Martin Brown

To Rodney

You may guess to your heart's content and will never come any closer to
a resolution insofar as between optical astronomy,theorists and the
ill-suited empirical doctrine,real astronomy as Kepler and Copernicus
knew it is screened out.

"To set down in books the apparent paths of the planets [vias
planetarum apparentes] and the record of their motions is especially
the task of the practical and mechanical part of astronomy; to discover

their true and genuine path [vias vero veras et genuinas] is . . .the
task of contemplative astronomy; while to say by what circle and lines
correct images of those true motions may be depicted on paper is the
concern of the inferior tribunal of geometers"


Kepler 'Mysterium Cosmographicum'

Newton's quasi-geocentric resolution for heliocentricity, which also
suits the calendrically driven Ra/Dec system of optical astronomers,
squeezed out what Kepler called 'contemplative astronomy' or the
ability to distinguish true motions from locally observed motions .

Humanity has moved on from the exotic novelties that were spawned by
17th century misjudgements yet because optically driven astronomy has
no roots beyond Newton and Flamsteed,it can guess all it likes as one
opinion or theory is no better or worse than the next.Such is the
absurd 'joy' of Newtonian quasi-geocentricity and relativistic
homocentricity.

To Rodney

You may guess to your heart's content and will never come any closer to
a resolution insofar as between optical astronomy,theorists and the
ill-suited empirical doctrine,real astronomy as Kepler and Copernicus
knew it is squeezed out.

"To set down in books the apparent paths of the planets [vias
planetarum apparentes] and the record of their motions is especially
the task of the practical and mechanical part of astronomy; to discover

their true and genuine path [vias vero veras et genuinas] is . . .the
task of contemplative astronomy; while to say by what circle and lines
correct images of those true motions may be depicted on paper is the
concern of the inferior tribunal of geometers"


Kepler 'Mysterium Cosmographicum'

Newton's quasi-geocentric resolution for heliocentricity, which also
suits the calendrically driven Ra/Dec system of optical astronomers,
squeezed out what Kepler called 'contemplative astronomy' or the
ability to distinguish true motions from locally observed motions .

Humanity has moved on from the exotic novelties that were spawned by
17th century misjudgements yet because optically driven astronomy has
no roots beyond Newton and Flamsteed,it can guess all it likes as one
opinion or theory is no better or worse than the next.Such is the
absurd 'joy' of Newtonian quasi-geocentricity and relativistic
homocentricity.

Martin Brown wrote:

[...]

I tend to agree. Despite its many problems, BBT is the best theory we've
got.

[...]
What is not in doubt is that there is a lot of non-luminous gravitating
matter that we cannot see or detect at present.

Actually, AIUI there is some doubt in some quarters. IIRC there is a
hypothesis that does away with the need for dark matter by postulating a
mean path length -- the figure 17kpc lurches to mind, but is probably
wrong -- for gravitons. I have no more problem accepting a mean path
length we cannot measure for a particle that we cannot detect than I do
accepting the existence of matter that we cannot detect.

To me it seems increasingly likely that Fred Hoyle was right
(continuous
creation) and the microwave background is caused by something other than
the Big Bang.

Not a chance. Even in the 1960's it was apparent that the Steady State
Universe was totally inconsistent
[...]
there is essentially no doubt that remotest parts of the universe are
receeding from us at speeds close to c.

AIUI Hoyle and Wickramasinghe postulated a Continuous Creation that is
not Steady State and which is consistent with the recession speed
observations.

Best,
Stephen

Remove footfrommouth to reply

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"oriel36" wrote in message
ups.com...
To Rodney

You may guess to your heart's content and will never come any closer to
a resolution insofar as between optical astronomy,theorists and the
ill-suited empirical doctrine,real astronomy as Kepler and Copernicus
knew it is screened out.

"To set down in books the apparent paths of the planets [vias
planetarum apparentes] and the record of their motions is especially
the task of the practical and mechanical part of astronomy; to discover

their true and genuine path [vias vero veras et genuinas] is . . .the
task of contemplative astronomy; while to say by what circle and lines
correct images of those true motions may be depicted on paper is the
concern of the inferior tribunal of geometers"


Kepler 'Mysterium Cosmographicum'

Newton's quasi-geocentric resolution for heliocentricity, which also
suits the calendrically driven Ra/Dec system of optical astronomers,
squeezed out what Kepler called 'contemplative astronomy' or the
ability to distinguish true motions from locally observed motions .

Humanity has moved on from the exotic novelties that were spawned by
17th century misjudgements yet because optically driven astronomy has
no roots beyond Newton and Flamsteed,it can guess all it likes as one
opinion or theory is no better or worse than the next.Such is the
absurd 'joy' of Newtonian quasi-geocentricity and relativistic
homocentricity.

Eh?