Web link of the week: http://climate.nasa.gov/evidence
Sorry - still caught up in busi-ness... no photos this week
This great old planet of ours continues silently on its way around the sun. We all know about gravity pulling us inward but what keeps us from being pulled into the sun? It isn't centripetal force as old textbooks used to say – (such a force does exist). Instead its Newton’s first law of motion in action. (Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.) So here we go - pulled in toward the sun by gravity, but also tending to continue in outward travel away from our orbit – and equilibrium has been maintained between the two processes over the millennia.
Two things that bother me:
1) People who say - "Oh thats just a theory!" - like that somehow discredits the idea. Theories are all we have in explaining conceptual models to explain how our known world 'works'. A bad theory os based on bad evidence... and needs to be discredited!
2. People who say - " Oh I saw that 'scientists' found evidence to support that___ is true." First who are the 'scientists'?, what are their "qualifications"? And most important - good science is never based on the results of one experiment - but on the sum total of all reasonable scientists working on that problem. If there is a landmark discovery it must be replicatable by other scientists in the field. Remember the guys who claimed to have created 'cold fusion' - creating H power release at room temps. Others tried to repeat their experiment and it worked for no one... Bad science.
Sorry - still caught up in busi-ness... no photos this week
This great old planet of ours continues silently on its way around the sun. We all know about gravity pulling us inward but what keeps us from being pulled into the sun? It isn't centripetal force as old textbooks used to say – (such a force does exist). Instead its Newton’s first law of motion in action. (Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.) So here we go - pulled in toward the sun by gravity, but also tending to continue in outward travel away from our orbit – and equilibrium has been maintained between the two processes over the millennia.
Our
great old planet, with its axis tilted at 21° is now moving us in the Northern Hemisphere into the
season where the sun appears higher in our sky, which causes more hours of
sunlight each day until June 21. (We were once in Riga Latvia for mid summer’s
day - people of the Northern Lands have
a special appreciation for the return of warmth and light). The people there still enact an ancient
custom on that night. The have grand
outdoor picnics with a bonfire and then jump over the flames of the bonfire to
burn all their bad luck from the previous year.
After a glass (or two) of the local vodka I jumped too... Sure its a superstition - but people still take satisfaction doing it...
For me living in Northern
California, this time of year, It puts things into perspective to walk through the hills and
valleys of Garin Park ( one of our local regional “wild” parks) … The plant life there is
settling in to its summer time of hibernation – oak trees send roots deep into
the soil to seek out enough water for survival; herbaceous plants survive by
forming seeds to live until the rain next winter. It is not a time of deprivation – just a
normal part of their annual cycle of existence in any Mediterranean ecosystem. Not everything hibernates – Ground birds and
mice are in a season of riches as they harvest dry grass seeds. Gopher snakes seek out the mice; lizards are
on the look out for insects…
So the great food web passes the energy of the sun
from plant to mouse to snake to hawk…. with a lot of alternate pathways in the
mix as well. Energy transfer is not very
efficient – when an animal is eaten only about 1/10 of the energy in that
animal is incorporated in the body tissue of the next trophic level of life… so
it takes 1000 units of stored plant energy to provide 100 units of energy in
the mouse’s body – and only 10 of those energy units are passed to the snakes
body. When the hawk eats the snake it
receives only 1 unit of the original energy. The lost energy dissipates as radiant
energy and returns to the blackness of space.
Sunlight energy – plants – animals – back to space. From space back to space.
One miracle enacted before us is
that of plants that adapt their body forms to the season of the year. The chromosomes in an original chard or kale
seed are replicated into every cell of that plant’s “body”. Chromosomes contain
many segments called genes. Genes carry
the genetic code in the form of molecules of DNA. Now the amazing thing is that almost all the
genes are inactivated until their products are needed. Individual genes are
activated by environmental conditions – such as day length, the changing hue of
sunlight, drought, contact with a surface, etc. This time of year conditions
are right to activate the sudden growth of a large central stem and the
production of flowers and seeds... this is called “bolting”. The intermediates in this story are special
proteins – plant hormones – coded for by part of the DNA itself – but they in
turn respond to environmental changes and stimulate the various growth
structures and processes... Imagine this the next time you are enjoying some
sautéed kale with garlic and chicken!
Almost everything I describe here today falls into the category of Scientific Conceptual Models - These ideas are based on the best current research evidence available today. Are these ideas likely to be replaced? Very unlikely that will be drastically changed - undoubtedly as new evidence becomes available our understanding will be further refined - But our theory of planetary motion is here to stay - Also the theory of energy flow within a food web, and the functioning of DNA to control the development of plant structures.
Side Note: Two things that bother me:
1) People who say - "Oh thats just a theory!" - like that somehow discredits the idea. Theories are all we have in explaining conceptual models to explain how our known world 'works'. A bad theory os based on bad evidence... and needs to be discredited!
2. People who say - " Oh I saw that 'scientists' found evidence to support that___ is true." First who are the 'scientists'?, what are their "qualifications"? And most important - good science is never based on the results of one experiment - but on the sum total of all reasonable scientists working on that problem. If there is a landmark discovery it must be replicatable by other scientists in the field. Remember the guys who claimed to have created 'cold fusion' - creating H power release at room temps. Others tried to repeat their experiment and it worked for no one... Bad science.
