Top 10 Science and Technology Events since WWII

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Transcript Top 10 Science and Technology Events since WWII

Presenter: Dr. Pat Stephens
Department of Physics, UWImona
[email protected]
[email protected]
Course Text: Prescribed Manual
pages 5 - 16
Help you to understand why science and
technology are important to the Caribbean
 Stimulate your interest in matters scientific
 Prompt you to spot in the media, science
related stories/events of immediate interest
to you and your wider community
 Encourage you to attempt to make
connections between scientific
developments and their likely social and
economic consequences
Exam considerations
October 19, 2006; 4:00- 6:00 pm
Unit I’s contribution to overall exam
10 Multiple choice questions (compulsory)
 1 essay type question
Overall Module I exam
 Students will have 1 hour to answer 50
MCQ and 1 hour to answer one of five
essay questions, based on the course
material covered in the manual and lectures.
 IS
Why Science is important
– Because the output of scientific
activity has the potential to
affect the life of every single
individual human being on this
Stephens’ Top 10 Science and
Technology Events since WWII*
1945 – A-Bomb
1948 – The Transistor
1952 – Polio vaccine
1953 – Structure of
1957 - Sputnik, 1st
man made satellite
1967 – First heart
1975 – First PC
1984 – AIDS virus
1986 – Chernobyl
2000 - Human
genome mapped
Recent important “sciencebased” news stories
The fight against
 The containment of
the SARS epidemic
 The sequencing of the
human genome
 Cloning
Climate change
Mad cow and foot and
mouth disease
Stem cell research
 Genetically modified
Introduction – whetting your appetites
 The story of Global Warming
 Resource security
 The story of unleaded gas
 The “Mad Cow” story
A treat - A Jamaican scientific detective
story---Snails, rats, worms and
Dr John Lindo
Global Warming
Definition of Global Warming
Evidence of global warming
Some possible consequences of global warming
How does it happen? (Greenhouse gases)
Society’s response
Global warming
Global Warming: The Evidence*
Record of average
global temperatures
over the last
[Mote, Philip, The evidence for
climate change; Senate
Workshop on Climate change
approx 15C (59F) -->
Global Warming: The Evidence
Record of average global
temperatures over the
last century
[This image shows the
instrumental record of global
average temperatures as compiled
by the Climatic Research Unit of
the University of East Anglia and
the Hadley Centre of the UK
Meteorological Office. 2001".
Journal of Climate, 16, 206-223.]
Global Warming: The Evidence
(from Wikepedia the free Encyclopaedia)
Global warming: the evidence (contd.)*
More frequent extreme weather
 Disappearing glaciers
 Melting polar sea ice
 Melting Greenland ice sheet
 Tropical diseases spreading
 Bleaching of coral
Global warming: The evidence(contd.)
More frequent extreme weather
Global warming: The evidence(contd.)
more frequent extreme weather
Global warming - consequences
Climate change
 Melting of polar ice caps
 Rise in sea level
 Disappearance of low lying islands and
coastal cities
 Drastic changes in crop distribution
Global warming – the mechanism*
Question: Why is the earth warming up?
Ans: “Because of a change in the normally
beneficial greenhouse effect”
Question: What is the greenhouse effect?
Glasshouse/Greenhouse - a heat trapping enclosure
How a greenhouse works
Radiation from the sun (mainly light and
ultraviolet) passes through the glass and warms up
the interior and its contents
Warm interior “re-radiates” but this radiation is
mainly infrared which cannot easily pass through
the glass so the heat carrying rays are trapped
inside the enclosure
Result is that the interior maintains a higher
temperature than the surroundings
Earth is a greenhouse*
Certain gases in the atmosphere form a
blanket around the earth which acts like the
glass in a greenhouse
These gases are called greenhouse gases
The “greenhouse gas blanket” helps regulate
the temperature of the earth within a range
in which humans and other animals can live
Earth is a greenhouse (contd.)
If the “blanket” were to stop functioning properly
then the average temperature of the earth would
Such a change could threaten the very existence of
life on our planet.
This is what is currently happening.
The concentration of “natural” greenhouse gases is
increasing and other “industry” derived gases are
being added to the atmosphere.
Earth is a greenhouse (contd.)*
There are several “greenhouse gases”
The most important ones are:
Carbon dioxide (CO2)
Methane (CH4)
Water vapour (H2O)
These gases occur naturally but are also
generated as a result of human activity
Earth is a greenhouse (contd.)
Other greenhouse gases are:
Nitrous oxide
Global warming and the greenhouse gases
Average levels of CO2 in the atmosphere
have risen by more than 30% since 1750.
Average levels of nitrous oxide, with 300
times the heat trapping power of CO2, have
risen by 17% since 1750.
These factors along with other evidence
have led some influential scientists to
conclude that:
Global warming and the greenhouse gases
There is still some debate about the validity
of this conclusion
Global warming – the international community’s
Series of international conferences involving more than
160 countries – starting in 1992
Conference convened in Kyoto, Japan-1997
Protocol and time schedule developed for reductions in
emission of greenhouse gases.
Time schedule required the emission of green house gases
to be reduced to 5% below 1990 levels.
Emission levels would be averaged over the five-year
period 2008 -2012.
Global warming – the international community’s
The treaty would come into force when countries accounting for more
than 55% of worldwide emissions had acceded or ratified the protocol.
Up to January 2006 more than 154 countries had either ratified,
accepted, approved or acceded to the protocol.
The US, arguably the main polluter, accounting for 35 % of worldwide
emission, does not support the protocol.
With the ratification of the treaty by the Soviet Federation, the 55%
threshold was passed and the treaty came into force on February 16,
Public opinion in the US seems to be changing gradually. Several
states have adopted policies of reducing greenhouse gas emission.
Global warming
- discussion
Should we in the Caribbean be concerned? Why?
Would you expect China (a prodigious coal
burner) to be concerned? If they are not
concerned how can they be persuaded?
Resource security
 Major
• Water
• Energy
• Food
Resource security (region of interest)
Resource security (contd.)
Requires that the particular resource be
When needed
– In sufficient quantities
– With satisfactory quality
– With guaranteed continuity
– At an affordable price
Food security concerns
Large proportion of the food consumed in
the Caribbean is imported
Imported food can act as a vehicle for the
introduction of harmful organisms and pests
Food security concerns – society’s response
 Local
scientists and other interests
must cooperate in managing
distribution chain to ensure:
Integrity of supply
 Proper inspection to prevent the entry of
harmful pests and microorganisms.
Energy security concerns
Most of the energy used in Caribbean
comes ultimately from imported (except
T&T) fossil fuel.
By burning these fuels we may be damaging
our own environment.
Our islands lie close to the transport route
for spent radioactive fuel rods
Energy security concerns – society’s response
Scientists and wider society must plan
together to rationalize the national fuel mix
(coal, oil, gas, refined fuels etc) to satisfy
security and other concerns
Public education must be widened so that as
wide a cross section of society, as possible,
can take part in the discussion
Water security concerns
Most Caribbean countries have adequate
water supply
Many different types of water sources
Water is life
Water security concerns – society’s response
“governments will wish to ensure that
they have control of water resources
sufficient to meet the present and likely
future needs of their peoples”
 Accepting for the moment that:
– Science, technology and medicine have
had and will continue to have a
profound effect on our every day lives
– Some of the results of scientific activity
might threaten our very existence
– We need to be able to understand
scientific problems in order to make
rational choices about the kind of
world we wish to live in
If scientific issues are so important
shouldn’t “scientific literacy” be as
important a part of the curriculum as Math
and English?
Science is sometimes seen to be “hard”.
Should we not just leave science up to the
Unleaded gas*
Widespread alarm about air quality in US
cities prompted President Nixon in 1970 to
amend the Clean Air Act
 The amendments targeted emissions from
motor cars.
 They enjoined the auto industry to produce
a pollution free car by 1975
 One of the most noxious of these emissions
was lead.
 The President ordered that lead-free
gasoline be used in all government vehicles
Unleaded gas story (contd.)
Emission control devices were placed in
exhaust systems of all new cars by 1975
These devices could not tolerate lead in the
emissions so use of unleaded fuel grew
rapidly in the States
Unleaded gas story (contd.)*
Research begins to emerge that lead is a
very dangerous atmospheric pollutant
Many countries stop the sale of leaded
Countries in the Caribbean follow suit
“Mad Cow disease”*
The problem
The “science” behind the problem
Decision > Action > Social and economic
“Mad Cow Disease”
“Mad cow disease” - the problem
1985 – unamed British vet encounters
disease characterized by odd symptoms:
infected cattle lose control of their muscles
and stagger about in an uncoordinated way.
Infected animals eventually die.
Behaviour of infected animals reminiscent
of sheep infected with “scrapie”
Informs the Central Veterinary Laboratory
“Mad cow disease” and the scientists
Scientists investigate and find evidence of a
new cattle disease.
The brains of the affected cattle were full of
holes, similar to Swiss cheese or a sponge
They name it Bovine Spongiform
Encephalopathy (BSE)
Also theorized that BSE had crossed over
from sheep via cattle feed containing parts
of “scrapie” infected animals
BSE – spread and development
By 2003 more than 185,000 infected cattle
found in Britain.
BSE found in native born cattle in more
than 16 European countries.
Also in Canada, Israel, Japan, Oman, and
Las Malvinas ( Falklands)
“Mad cow disease” – Decision and action
Slaughter all infected cattle
By 1988 - Compulsory destruction of all suspect animals and the
burning of their carcasses
Discontinue the feeding of rendered remains as protein supplement
Ban human consumption of high risk offal
Brain, spinal cord, spleen
Establish a monitoring unit
Reassure the public. BSE is an animal disease and will not affect
humans. Prevent panic.
“Mad cow disease” - consequences
1995 several farmers who owned herds with
BSE infected cattle become sick and die.
Their cause of death is a variant of CreuzfeldJakob disease, (vCJD)
vCJD causes very similar brain destruction in
humans as BSE does in cattle
British government forced to admit that BSE
had crossed over from cattle to humans via
consumption of contaminated beef
Discoverer of the cause of BSE
Stanley B. Prusiner
Discovered prions –
infectious particles
Nobel Prize for
physiology (1997)
The cause of BSE*
Cows fed animal feed containing the rendered
remains of sheep and goats infected with
The abnormal protein (prion) in the animal food
is able to trigger normal protein into switching to
an abnormal form.
Abnormal protein destroys the brain and other
nerve cells in animals
“Mad cow disease” - consequences
2000 - more than 100 people die from the human
variant of BSE
Britain culls infected herds. All high risk cattle,
including animals over 30 months, destroyed
More than half the cattle population of Britain is
Rate of infection decreasing rapidly