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Dr Bill Napier continued his research into the origin and evolution of
interplanetary dust, the effects of dust and small-body impacts on the
Earth, and the analysis of extragalactic redshifts.
- 1.
- A variable zodiacal cloud model was developed in order to
investigate the variable accretion rate of extraterrestrial dust on
the Earth. The model considers a population of comets, injected at
random into short-period, Earth crossing orbits, where they
disintegrate, producing dust. The dust particles so produced undergo
mutual collisions as well as spiralling into the Sun under the
influence of radiation pressure. Preliminary results show that large
fluctuations in the dust population are likely to result.
- 2.
- An analysis of the recession velocities of nearby galaxies (103 with
velocities less than 500km s-1, out to a distance of
10Mpc) was carried out with a view to checking whether a
redshift periodicity of 37.5km s-1 exists in this dataset, as
had been found in other extragalactic datasets. The new analysis
yielded a local cosmological expansion of
km s-1
Mpc-1, closely similar to the corresponding values
and
found by the two groups studying Type Ia supernovae. However,
the most significant (and extraordinary) result to emerge from this
study was the confirmation that there is indeed a periodicity of
37.5km s-1 in the recession velocity of these nearby galaxies,
a result previously found by Napier and a co-author in a more accurate
dataset extending to 2600km s-1.
- 3.
- Reviews of the small-body impact hazard, and the dust hazard,
on timescales relevant to civilization, were prepared and published.
- 4.
- Miscellaneous activities: student supervision at various
levels (e.g. two QUB undergraduates, one school work experience
student), and acting as external examiner to a Ph.D. student at the
University of Wales at Cardiff. The alleged meteorite crater near
Belleek was investigated early in the year with Mark Bailey and Tom
Mason and shown not to be meteoritic.
- 5.
- PUS: five presentations were made, ranging from IAU Symposium 194
(Armenia) to colloquia and popular talks. In addition, a popular
review (`Comets, Dragons and Prophets of Doom') was published in the
PPARC journal Frontiers, and a novel (`Nemesis'), a thriller
with a science base exploring the issue of the asteroid impact hazard
to civilization, was written and published by Hodder Headline plc.
These outreach activities resulted in wide media coverage, including
interviews for television documentaries, full-page reports in the
national press as well as interviews on national BBC radio. The book
`Nemesis' has currently sold more than 15,000 hardback copies. The
PPARC-funded STEM course on scientists and the media was found to
provide a useful introduction to dealing with the various mass media.
Next: C.J. Butler, Research Astronomer
Up: Research
Previous: M. de Groot, Senior
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ARM Starlink Manager Martin Murphy
1999-12-14