Planetary line-up and the sunspot cycle
Enjoyed browsing through some of your efforts on the Web. I am hoping
you could help settle some of my thoughts before I make a fool of
In your experience, has anyone tried to correlate lineups of the sun,
earth and major planets' magnetospheres with the sunspot cycles? My
spare-time effort found some correlation between lineups and cycles in a
number of years. My wonderment centers around the possibility that
some forces of the planets when lined up, possibly relating to their
magnetospheres, impact the suns magnetosphere causing a solar max. I've
also considered the possibility that related magnetosphere effects could
be the cause of previous polar reversals on the earth. Additionally,
ringing of our magnetosphere might impact charged tectonic plates...but
that is again another direction. Only if you have time, please comment.
There exists a tempting closeness between the length of the solar
cycle and the orbital period of Jupiter, but I don't think the two
are related. I cannot imagine any mechanism coupling the two--
especially since the Sun rotates in about 27 days, so the relative
period of Jupiter going around the Sun is of that order. Furthermore,
the solar wind moves with supersonic speed, which means that solar
disturbances can (and do) travel downstream with it, but disturbances
from a planetary magnetosphere (whatever they might be) don't easily
Above and beyond all these, there is always the question of energy--
the currency in which the price of any physical process must be paid.
The energy required in the solar cycle is much bigger than anything
planetary magnetospheres can supply.
So what causes the cycle? The Sun rotates unevenly, slower near the
poles, faster near the equator, probably because of the way gas flows
in it (Jupiter also has such a difference). In a magnetized hot gas,
this difference deforms and amplifies the magnetic field, and there
exist some general theories of the sunspot cycle based on this, although
many details remain unclear. The general idea is that as the magnetic
field gets amplified, it forms concentrated "ropes" which push out
the hot gas, and when they reach a certain strength, enough gas is
displaced that the ropes are light enough to float to the surface,
where they are seen as sunspots.
Again, the magnetosphere is a relatively weak influence on the Earth's
internal magnetism--even a big magnetic storm only reduces the surface
equatorial field by 1%. Furthermore, the time scale differs--reversals
happen on time scales of 0.5-1 million years, while magnetic storms
have a 1-day scale or faster.
What seems to be involved are the currents which circulate in the Earth's
core, presumably driven by flows there, which (like flows on the Sun) get
their energy from heat. The magnetic field is fairly complicated--the
2-pole structure we see (north-south) is dominant, but not by as much as
it seems, because more complicated modes get filtered away faster by
distance. Right now the 2-pole field is declining at about 5-7% per
century, but the late Ed Benton has shown that the more complex parts
are gaining energy, and the total sum is fairly constant. Maybe, when a
reversal occurs, for a while the 2-pole part gets small and the total
field is rather complex (4, 8 poles..), and when the simple pattern
re-emerges, it is reversed.
Anyway--keep studying, keep up your sense of wonderment
What are comet tails made of?
Are comet tails the reult of melting and evaporation of ices from
the comet core or are they dust collected by the comet as it moves
in its orbit?
Comet tails contain both evaporated ices and dust, as explained in the
section "Comet Tails and the Solar Probe" near the end of the file
The dust however is not collected by the comet in its orbit, but is part of its make up, probably dating back to the beginning of the solar system. Comets
may have two tails, and sometimes these are well separated, as in the recent
Comet Hale Bopp: they differ in color, composition, and direction,
and are pushed away from the Sun by different forces.
Dust tails are pushed by light pressure, and their colors are those
of sunlight, scattered by them the way clouds on Earth also scatter sunlight.
The other tails contain plasma--free electrons and ions, that is, atoms
from which sunlight has removed one or more electrons, leaving a positive
charge. They glow in the colors characteristic of their material (a bit like the
way streetlights produce the characteristic glow of sodium), and are pushed back by the solar wind. As explained on the above web page, the velocity of the solar wind is not too many times larger than that of the comet, and that
causes them to point not straight away from the Sun but at a small
angle to that direction.
See also htpp://www.phy6.org/Education/wsolwind.html
If light speed sets the limit, why fly into space?
I have a question as to space travel. What is the point in
exploring space? Is it just for achievment purposes or in the future
will man discover LIGHTSPEED? Because otherwise, the whole thing seem
rather pointless. It is rather like asking a garden snail to tour America
in it`s own lifetime. Can you put any light on this question?.
From all we know, achieving lightspeed or anything close to it
is well beyond today's technology, and I suspect, tomorrow's as well.
The purpose of exploring space is different--to expand humanity's reach,
and to understand the universe in which we live. Ancient humans may
have been content to see the sun, moon and stars rise and set without
caring what they were, or how distant. We have come a long way from
then--to electricity, cars, airplanes and the internet--essentially,
because humans want to understand more. Most Americans would probably
feel rather stale if no progress happened over their lifetimes--just
different teams making it to the superbowl, different wars being fought
overseas. I for one felt excited by the landing on the moon, by the first
pictures from Jupiter and Neptune, and of the sun in X-rays (quite
different from the bland disk we see). I also feel excited by evidence
of distant planets and giant black holes at the center of galaxies.
No, I don't think we'll get there in my lifetime or in the next
1000 years--but humanity has a longer timetable, much longer than
that of any individual.