Sunday, 15 December 2013
China successfully landed an unmanned vehicle on the Moon.
The Chang'e-3 mission is named after the goddess of the Moon in Chinese mythology and the rover vehicle is called Yutu (Jade Rabbit) after her pet.
Chang'e-3 landed on a volcanic site Sinus Iridum which is part of Mare Imbrium.
This landing makes China the third country after USA and Soviet Union to have landed unmanned spacecrafts to the Moon.
Good luck to them...
Tuesday, 10 December 2013
sense is what we humans live by – it is kind of wisdom gained from experience
over many generations. Humans experience the world through the
five senses, but importantly we also use our intelligence to perform cause and effect
analysis of what has been happening around us to understand how the world behaves.
Common sense has worked very
well and has ensured the survival of the human race; particularly, in the
avoidance of dangerous and harmful situations.
Human societies evolved to preserve and enhance the species. Shared knowledge and effort proved useful in
meeting adverse situations and quality of life improved rapidly as humans
started to live together in social groups.
Survival of human societies is a multifaceted situation;
they not only have to guard against the hostile physical environment around
them but also against other fellow humans who are driven by greed, violence and
other undesirable traits. Humans have
always enjoyed exercising power and control over others around them. This is a
classic example of conflicting requirements – living in societies is beneficial
but at the same time exposes one to potentially dangerous elements of oppression
and exploitation. How humans dealt with
this is fascinating and will be discussed in a future blog.
does our common sense relate to the laws of nature is what we wish to look at
first. The difference is in the scope of
the evidence available.
Laws of nature are
deduced from experimental observations at all possible levels of space and
time. As human ability improves to
expand such observations to wider regions of space and time, laws of nature are
modified or even replaced by a different set of laws. Fine-tuning of the laws is fundamental to
their authenticity and acceptance. The
current set is the best available to make sense of what the empirical evidence
sense is much more restricted in terms of empirical evidence at its disposal. Without technological aids - and most human
experiences have been in such conditions - humans really occupy a small region
roughly in the middle of space-time expanse.
Their experiences are limited in size, speed, time, colour, frequency
etc. Quantitatively: We experience
Physical dimensions from ~0.01 mm to a few hundred km.
vary from rest to a few tens of km/hour.
is restricted to our reaction time of the order of 10 ms to a few hundred
Colour is perceived in the narrow wavelength range of 0.4 to 0.8 micron (1 micron = 0.001 mm)
Perception of sound is limited to frequencies less than about 20 kHz.
species do better in colour and sound perception due to the evolutionary need
to protect themselves against predators etc.
mainly perceive the world around them through light which travels at the
fantastic speed of 300,000 km per second; this gives the feeling of
instantaneous communication – things are happening as we see them.
phenomena like rain, thunder, lightening, tides, storms, earthquakes, motion of
heavenly bodies, infectious/mental and other diseases etc. were mediated by
causes outside the range of human perception.
Theories and explanations were put forward – of course different in
different societies – to make sense of such events. This can give rise to beliefs, customs, rituals, superstitions etc.
We shall return to this later.
scope of human experience, nevertheless, provided some quite sensible and
workable theories about the way the world operates – kind of ‘limited’ laws of
nature. In good true scientific spirit a
law would get modified when the evidence against it became overwhelming. Sometimes it would require great sacrifices as
changing a law might encumber on the interests/dogma of the
powerful in the society.
started to improve about 500 years ago with the acceptance that experiment
based evidence could not be ignored and must be taken into account in
formulating so called laws of nature.
Technological advances helped in removing many of the limits to
observations – in space, time and other areas.
Common sense inspired laws of nature started to be replaced by the new
physics at the turn of the 20th century and in the short span of 25
years the acceptance of the new laws of relativistic and quantum physics was
common sense laws are arrived at through observations, mostly visual, and rely
on the behaviour of matter around us at the macroscopic scale of dimensions
greater than about 1 micron (0.001 mm), laws of nature (physics) are determined
in the way elementary particles, typically of dimensions less than 0.001 micron,
interact with each other. These
interactions are of four types:
strong nuclear (SN) and
weak nuclear (WN).
and EM are long range and affect matter at all distances. SN and WN are relevant only at nuclear
dimensions with distances of the order of a billionth of a micron or less!
Chemical and biological properties are determined by EM forces acting between atoms and molecules at distances of the order of 0.001 microns and may not be properly understood
through evidence from everyday experience. Old theories based on human experiences have been unable to make good sense of chemistry and life sciences.
of heavenly bodies is governed by gravitational forces but mostly involves
distances far greater than our senses can be sensitive to. That is why there has been so much confusion
about this subject in historical accounts. Newton's laws of gravitational attraction
explained the way heavenly bodies are organised in the
sky but a proper understanding of the Universe had to wait for the theories of relativity and the development of nuclear sciences.
The world of atoms and nuclei was latent to our ancestors as the distances involved
were unimaginably small and even their existence could not be contemplated. Understanding
the true nature of atoms and nuclei only started at the turn of the 20th
century and this has created the atmosphere in which modern industry could start. Nuclear energy, Nanotechnology, Computers,
Biotechnology, Space Exploration all owe their success to the laws of nature
enunciated through empirical evidence acquired through development in
technology in the 19th and 20th centuries.
Without this mind-set, modern industry would not even be science fiction.
interesting aspect of this discussion is the emergence of paradoxes. A language that is weakly developed will be
unable to describe a situation that is highly complex – the vocabulary is just
not there. A good example of a paradox
is the wave-particle duality in classical physics (mostly based on common sense
observations). In our daily lives we see
objects behave like material particles or as undulating waves in motion. We do not have objects that switch between
being waves and particles at different times.
This was the situation until the end of the 19th century when light was
observed to exhibit properties akin to waves in some experiments but behaved
exactly like a stream of particles in others.
The situation was resolved and explained by quantum description of light
in 1925. Now, we know that everything in
the universe shows wave-particle duality and it is just our attempt to
classify things as either waves or particles that is flawed. We are using the wrong language for our
is not that there are no paradoxes in the modern theories. There are many and this simply points to the
fact that, while we have a much better understanding of the world we live in,
we have more to learn and the laws of nature will be rewritten differently
in the future.
Thursday, 14 November 2013
It has been a long holiday; not in the normal sense but happenings in my life have kept cropping up leaving little or no time to sit down and write something down.
A year ago, Gerry Peterson introduced me to the idea of harnessing nuclear energy from Thorium. It looked interesting and I presented a seminar at Glasgow University in January 2013 about the promise of Th as an energy source. There are aspects in Th energy that are very attractive but the way I see nuclear energy is a stop-gap measure until we have sufficient renewable energy available - optimistically by 2075. Uranium technology is much more firmly established and that is the way most new nuclear plants will be built over the next 30 years to fill in the energy gap being created by forsaking fossil fuels and waiting for ample supply of renewable energy.
Sometimes the pessimist in me gets the upper hand and the feeling that we won't actually reduce our use of fossil fuels ignoring all warnings about climate change issues. The task of achieving a harmonious world order will get more difficult with misery for billions of people. The rich countries will probably suffer much less and majority of pain will fall on the poorer populations of Africa and Asia.
Other exciting developments that I struggle to keep up with are in Nanotechnology, Artificial Intelligence and Biotechnology (NAIB). Research is moving too rapidly there and while I thought many times of preparing a series of talk on these subjects, a feeling of being not quite ready always dominates. It is nevertheless good to read with excitement what is happening in these fields and feel thankful that retirement has given me the opportunity to enjoy the fruits of labour of so many researchers throughout the world.
I feel much more at home now looking back towards the history of science and have started on the preparation of a series of talks on the life and work of some of our great scientists. The Curies are fascinating for the sheer determination and hard work that they showed over two generations and as a result dominated the field of nuclear physics for more than quarter of a century. Five Nobel Prizes are apt proof of how significant their contribution was. Something that I did not appreciate until recently was the wisdom of hoarding Polonium and Radium by Marie Curie in her institute. This gave her the most powerful radiation source for nuclear research only bettered after particle accelerators appeared on the scene.
I hope to use the blog to comment on some of the current scientific news about Climate Change, NAIB and whatever else looks interesting.