Professor Dame Jocelyn Bell-Burnell FRS, centre in the photograph, spoke on the above topic at our London Centre on 15 February.
Imagine ten months from now, it is the morning of the 21st
December the last Friday before Christmas, schools are breaking up and
people are frantically doing their last minute shopping.
The
clock turns to 11:11 it does not turn to 11:12 because the World has
been destroyed and we are all dead! Many people believe this will
actually happen, in fact an industry has sprung up publishing books and
releasing a blockbuster film to cash in on this ‘prophesy’.
If
there is the remotest chance that such a catastrophe could occur then
why are crisis meetings not being held at the UN? Why are underground
shelters not being excavated under mountain ranges?
Why are food,
fuel and medicines not being stockpiled? Why are survival colonies not
being constructed in orbit or on the Moon? The answer is simple: It is
all complete nonsense!
On 15 February the branch was fortunate
enough to have Professor Dame Jocelyn Bell-Burnell speak to a packed
Rutherford lecture theatre about this so-called prophesy of doom.
Her
lecture came about because while lecturing in the United States
somebody would always ask her ‘Is the World going to end in 2012?’ Being
a responsible scientist she decided to research the subject.
It
all has to do with an ancient civilisation called the Maya that
flourished in what is now Mexico in the two millennia before Christ.
They were accomplished mathematicians and astronomers. They produced
calendars that spanned long periods of time.
Their last calendar
which started on 11 August 3114 BC will end on 21 December 2012 AD. Some
people have speculated that the Maya did not extend their calendar
beyond this date because they somehow ‘knew’ the World would end on that
day - that’s it!
Dame Jocelyn made it very clear that there is no
historical or archaeological evidence that the Maya intended the end of
their calendar to mark the end of the world.
She believes the
Maya would have treated it in the same way we celebrated Millennium
Night - with a party and a day off! She believes 11:11 AM 21st December
2012 was chosen because it is the northern hemisphere winter solstice
when the Earth is at full tilt and the Sun is at its lowest point in the
sky.
This makes sense, a precise astronomical event that you can
use to start the next calendar. The Mayan calendars were also inscribed
in stone, they may simply have not had a rock big enough to go further
into the future!
As the calendar ends with an astronomical event
Dame Jocelyn decided to survey geophysical and astronomical threats that
could befall the Earth. These include:
- Geomagnetic Field Reversals
- Solar Storms
- Asteroid Impact
- The planet Nibiru
- Planetary alignments perturbing the Earth’s orbit
There
is evidence that in the past the direction of the Earth’s magnetic
field has changed direction - flipped. Towing a magnetometer across the
Atlantic sea floor has revealed mirror images of alternating directions
of magnetisation either side of the mid-Atlantic ridge. A crustal
construction zone, magma swells up and spreads creating new sea floor.
As the magma cools and solidifies it is magnetised by the geomagnetic
field leaving a record in the rock of the direction of the Earth’s
magnetic field.
From this we see that the geomagnetic field
reverses on average every 300,000 years (the last was 750,000 years ago
so we are well overdue). Many living things, including birds, can sense
the geomagnetic field and use it for navigation.
They would
obviously be affected by a reversal but a flip does not occur overnight,
it takes about 5,000 years to complete, giving animals time to adapt.
As Dame Jocelyn points out, there have been eleven reversals since our
tool making ancestors H.habilis evolved two and a half million years ago
- and we are still here!
Our Sun also has a magnetic field which
periodically reverses but despite being a much more massive body a solar
field reversal occurs in much less time.
The interval between
maxima (when the Sun’s magnetic field is at full strength) is
approximately eleven years. Maxima are also when sunspots and solar
storms are most numerous. A solar storm is a jet of protons and
electrons emitted from the Sun.
When these particles strike the
upper atmosphere they give rise to beautiful auroras. The last maxima
was in the year 2000 the next will be in 2013 (not 2012). Dame Jocelyn
reminded us that a solar storm has never killed anybody or caused a
building to collapse although they can disable satellites and we are now
more dependant on satellite services such as GPS. She produced a chart
of number of sunspots against date.
The peaks corresponding to
maxima were very clear but also noticeable was that the peaks were in
groups of lower and higher amplitude. It is predicted the 2013 maxima
will be the lowest in a hundred years.
A threat we are very
familiar with is asteroid impact. A massive impact 65 million years ago
is believed to have caused an extinction event that wiped out the
dinosaurs. Dame Jocelyn produced an image of Barringer crater in
Arizona.
This mile wide crater is believed to have been made by
an object 50 metres in diameter. The object that exterminated the
dinosaurs is believed to have been a kilometre across. The Earth is
struck by an asteroid this size every 50 to 100 million years so again
we are due for another impact.
Last October a small asteroid
passed between the Earth and the Moon. Around the globe several
telescopes are dedicated to Near Earth Object Monitoring.
The
speaker showed a photograph of the Pan Starrs telescopes under
construction in Hawaii which will scan the night sky for objects under
200m in diameter that come close to the Earth.
Interestingly Dame
Jocelyn stated that the technology to deflect an asteroid is already
available. She said the worst thing we could do is to try and blow it up
using a nuclear weapon - a la Bruce Willis - this would create millions
of objects to track.
A better way is to coat the object with a
white deposit or erect a solar sail on it and use the radiation pressure
of sunlight to push it out of harm’s way. The only NEO astronomers are
concerned about is an asteroid called 1950DA which will come
uncomfortably close to the Earth in 2880. Nibiru is a planet that
was supposed to have been discovered by the ancient Sumerians about 2500
BC. The pseudo-science community have suggested this planet will
collide with the Earth in December. There are many problems with
Nibiru: Why did not other stargazing civilisations such as the
Mesopotamians, Babylonians and the Chinese also discover it? Nibiru is
said to have an orbital period of 3600 years (Pluto 248 years) this
means it has a very large orbit but to collide with the Earth its
perihelion point must lie inside the Earth’s orbit. This can only come
about if Nibiru’s orbit is unbelievably eccentric. At the time of ‘discovery’ Nibiru would have been ten times the distance to Pluto against a very crowded starfield background.
Assuming
the Sumerians had not discovered the telescope then to be a naked eye
object at that distance Nibiru would have to be 150 times the size of
the Sun and have a mass of 3.3 million Solar masses - we are not taking
about a planet! Dame Jocelyn did mention the possibility that Nibiru
could be a brown dwarf - a star that did not quite make it.
The
Sun is unusual in that it is solitary, most stars are in multiple
star-systems. Our nearest stellar neighbour, proxima centauri, is part
of a trinary star system. However a brown dwarf would be a daylight
object even at four astronomical units.
Occasionally the planets
line up in what is called a conjunction where they can all be seen in a
small area of sky. Venus and Jupiter will be in conjunction on the 13th
of March.
Could the combined gravitational pull of the other
planets pull the Earth into a different orbit? The speaker produced a
pie chart showing the relative gravitational influence of the other
bodies on the Earth. Nearly all the chart was due to the Sun with a thin
sector representing the Moon.
The combined contribution of the
other planets is one two hundredths of the Moon and could not be seen on
this scale. In 2000 five planets and the Sun where in conjunction with
the Earth. In 1962 five planets, the Sun and the Moon were in
conjunction. There are no major conjunctions in 2012. At the
centre of all galaxies lies a monster - a supermassive black hole. The
speaker showed a clip of stars orbiting an invisible object at the
centre of our galaxy. It can be viewed below:
One
star can be seen to describe a complete orbit. Another star, designated
SO-45, moves in a straight line. When asked about this Dame Jocelyn
suggested its orbital plane is edge-on to our line of sight. Could
an alignment of the Sun and the black hole at the centre of the Milky
Way throw the Earth out of the Solar System? Coincidentally the Sun and
Black Hole are in conjunction on the 21st December. As supermassive
black holes go the one at the centre of our galaxy is a tiddler,
weighing in at a mere four million solar masses.
The galactic
centre is also 26000 light years away. In short the gravitational pull
of the Sun on the Earth is one hundred billion times stronger than the
black hole.
Surprisingly the one threat the discoverer of pulsars
did not discuss was supernovae. The red supergiant Betelgeuse is
regarded as a potential supernova and astronomers have recently noticed
an unusual variation in its light curve indicating it is becoming
unstable. Fortunately it is 640 light years away so when it does go off we will get an impressive light show but no damage.
Dame
Jocelyn concluded her lecture by asking what was going on? Why do so
many people choose to believe in the most fantastic, unsubstantiated
theories? As she says we are not rational beings.
She showed us
one of her favourite websites www.manyendings.com. This site lists doom
prophecies that were going around in various years and there are a
surprising number of them. In 1954 a cult predicted the end of the
World.
The American psychologist Leon Festinger used his graduate students to infiltrate the cult in order to study them. They
patiently waited for the appointed hour and waited and waited and
waited until at two in the morning the cult leader announced he had
received a revelation that God was so happy with the devotion of the
group he had decided to postpone the apocalypse! To the psychologists surprise this did not undermine the faith of the cultists, the opposite happened, it reinforced it!
This
was a laughable example of cults others have been very tragic. In 1997
comet Hale-Bopp was visible from Earth, a UFO cult in California
believed a spacecraft was in the tail that would take them to a new
planet but they would first have to surrender all their worldly
possessions including their bodies. Police later found the remains of 39
cult members. Dame Jocelyn reminded us the Internet can be used
to disseminate misinformation. One site, belonging to the ‘Institute of
Human Continuity’ makes several references to the Columbia Pictures film
‘2012’ and is believed to be a subtle form of advertising for the
film.
The speaker said one way you could recognise it was not an academic site is that it is too professional!
She
recommended people should receive their information from real academic
sites such as iop.org and look for sites ending in .ac.uk and .edu.
Finally Dame Jocelyn said that to stop people believing in doom
prophesies we must improve our teaching and communication of science. So don’t use the Maya as an excuse for not doing Christmas this year, get the turkey on order!
