Science and Technology

While science is driven by a desire to understand the world, technology is often driven by the desire to make the world safer, more convenient, and more fun for peo-ple.. The science was

WH I L E S C I E N C E I S the systematic study of the natural world, technology is the application of

sci-entific knowledge to create tools, equipment, and procedures that often simplify and improve our lives For every scientific discovery, there are dozens of potential applications of that knowl-edge Technological advances often lead to further advances in the sciences Therefore, science and technology are highly interdependent

 A b i l i t i e s o f Te c h n o l o g i c a l D e s i g n

Students tend to have a positive image of science They associate science with medicine and nature At the same time, students realize that technology plays multiple roles in our lives There are positive applications, including the use of technology for medical diagnosing, communication, transportation, and everyday chores However, technology often leads to pollution and problems While pollution and problems may unfortunately be a byprod-uct of certain technological processes, they are also the byprodbyprod-ucts of science In reality, science and technology are extremely interrelated and similar in many ways

One of the goals of technology is to apply the principles of science to make life more comfortable and work easier The aim of technology is not to create problems, but to solve them Technology is responsible for

deliver-C H A P T E R

Science and Technology

THIS CHAPTER discusses the aims of technology, the

relation-ship between science and technology, and the way in which needs and advances in one lead to needs and progress in the other You will also learn what drives technological progress and what is involved in technological design

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an ocean on a plane within hours, for the calculator, the

ATM, and our connection to the Internet Need we go

on? The printing press, toothpaste

Science-Technology-Science

Relationship

Technology is applied science—science put to use

While science is driven by a desire to understand the

world, technology is often driven by the desire to make

the world safer, more convenient, and more fun for

peo-ple Science research that has immediate and wide

appli-cations tends to receive funding from the government

and private companies more easily than very abstract

research Therefore, science that has technological

importance or potential is encouraged and driven by a

desire to produce and make a profit

Technology is also science on a large scale Running a

chemical reaction in a beaker in the lab is usually

classi-fied as science Running the same reaction in a huge

reac-tor in a chemical plant is classified as technology Science

and technology have a profound influence on each other,

and progress in one creates progress in the other

Consider this example Scientists figured out how

optical lenses work The science was used to make a

microscope (technology) The microscope was used to

observe a cell (science) In order to isolate the genetic

material from this cell, an instrument had to be used

(technology) But that instrument operates according to

the laws of science

Take another example Scientists figured out the laws

of fluid mechanics Engineers used these laws to design

airplanes And now both scientists and engineers can fly

to science conferences around the world

Optimization of Existing Products

and Processes

Technological inventions are often tools, instruments,

machines, or processes Engineers recognize a need for

an invention and see it as a design opportunity For

example, an engineer realizes that people are carrying

too many electronic devices—a telephone, a digital

plan-ner, a watch, a calculator, a laptop—so why not create

one device that can be used to accomplish what all of the

limited electronic devices do?

Consider how the need for computers arose

Scien-tists were tired of performing slow, repetitive

calcula-tions It took too long, and progress was limited So,

computers were designed to perform these long, repetitive

calculations The first computers were massive and required the use of special punch cards But with the advancement of technology, they became small enough to

be portable Improving existing designs or processes is another goal of technology

Alternative Solutions, Models, and Computer Design

Just as there are many ways to get from one place to another, there are sometimes many solutions to an engi-neering problem Because of that, engineers need to care-fully evaluate several different designs and choose between alternative solutions In addition to performing calculations, engineers build models of their designs or simulate a process using specialized computer programs For example, a program called CAD (Computer Aided Design) can be used to analyze harmful emissions into the atmosphere from vehicles (cars, trucks, and buses) Based on computer simulations, engineers are able to predict whether adding a lane of traffic would increase emissions above levels determined to be safe by environmental protection agencies

Chemical processes can also be simulated using com-puter programs Chemists discover new reactions or chemicals, but chemical engineers design a chemical plant that will run that reaction Designing chemi-cal plants involves sizing reactors and figuring out the amount of reactants needed, how quickly the reaction will proceed, how the product should be stored, how the waste should be managed, at what temperature the reac-tion should be run, and how to control different aspects

of the process It would be very time-consuming, expen-sive, and tedious to make a physical model for hundreds

of different conditions With computers, processes can

be simulated, and physical models can be built based on the computer simulations that work best

Design Considerations

Each technological design has to meet a number of design criteria The product or process should operate smoothly, without breaking down The demand for such

a product or process should be evaluated The product or process should be an improvement over other similar products and processes Improvement can be functional (working better), economic (more profitable), or aes-thetic (better looking, or taking up less space) Products and processes can also be made safer for people to use or run, and safer for the environment All of these design

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criteria need to be considered Economics often limit the

implementation of an otherwise best design For

exam-ple, the collection of solar energy is technologically

pos-sible and is good for the environment, but it is not widely

used because it is not economical yet Cars that run solely

on electric power have been designed and built, but

again, economics prevents their production Oil

compa-nies would lose profit if the use of electric cars became

widespread, and designs have been bought with the

pur-pose of preventing their manufacture

Evaluating the Consequences

The consequences of a technology product or process

need to be evaluated by scientists and engineers, but also

by public policy makers and consumers What kind of

short- and long-term effects does a technological

advance have on individuals, on the population, and on

the environment? You should be aware that

technologi-cal advances can have a variety of beneficial or harmful

consequences on the living standard, health,

environ-ment, and economy You should also be able to state the

tradeoffs often involved in choosing a particular design

or adopting a particular public policy For example, you

should be aware of the reasons for, and consequences of,

the one-child policy in China, and the different positions

in current debates such as the use of fetal tissue in stem

cell research, genetic engineering, recycling policy, and

other issues

Communication

Communication is another component of technological development Engineers often need to convince their superiors or the public of the advantages of their designs The communication involves stating the problem, describing the process or design, and presenting the solu-tion This is done through publishing or presenting reports, models, and diagrams and showing that a par-ticular design has advantages over alternative designs

 U n d e r s t a n d i n g s a b o u t S c i e n c e

a n d Te c h n o l o g y

Scientists in different disciplines ask different questions and sometimes use different methods of investigation Many science projects require the contributions of indi-viduals from different disciplines, including engineering The Human Genome Project, designed to map the human genome, involved thousands of researchers worldwide and was the largest, most expensive project in the history of biology New disciplines of science, such as geophysics and biochemistry, often emerge at the inter-face of two older disciplines

Technological knowledge is often not made public because of patents and the financial potential of the idea

or invention Similarly, it takes a while for a new drug to reach the public because extensive testing and legal issues are often involved

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SO M E P E O P L E M AY think that science is best left to the scientists But science is really every citizen’s

concern Individuals and communities must decide which new research proposals to fund and which new technologies to let into society These decisions involve understanding the alternatives, risks, costs, and benefits By being informed and educated regarding these issues, we can better decide what kind

of advances and projects are beneficial Students should understand the importance of asking:

■ What can happen?

■ What are the odds?

■ How do scientists and engineers know what will happen?

 P e r s o n a l a n d C o m m u n i t y H e a l t h

As human beings, we function better when we are healthy and well Malnutrition and poor hygiene are factors that can affect health and the body’s ability to function properly An unhealthy body is prone to diseases and other

hazards found in the environment There are two kinds of diseases: infectious and noninfectious.

C H A P T E R

Personal and Social Perspectives

in Science

SCIENCE DOES not happen in a vacuum Scientific advances

directly affect technology, which impacts politics and economics around the world This chapter will discuss current personal and social concerns in the sciences, including personal and public health, pop-ulation growth, use of natural resources, and environmental protection

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Infectious Disease

Diseases are caused by pathogens that invade a host body.

Pathogens need a host in order to survive and multiply

Some examples of pathogens are bacteria, viruses, and

fungi They can spread through direct body contact,

body fluids, and contact with an object that an infected

person has touched (some viruses, like the common cold

virus, can exist outside the body for a brief period before

they get passed on to another host) Tuberculosis is also

an infectious disease Victims of tuberculosis cough up

blood from their lungs Treatment and vaccines for

tuberculosis exist, and this disease has been almost

elim-inated in some parts of the world However, the total

number of people in the world infected with

tuberculo-sis keeps growing

Noninfectious Disease

If the disease cannot spread from person to person, then

it is considered noninfectious Two examples of

nonin-fectious diseases are cancer and heart disease Here are

some characteristics of noninfectious diseases:

■ They do not transfer from person to person

■ They are not caused by viruses, bacteria, or fungi

■ They are sometimes hereditary—meaning that

they are associated with genes and run in

families

Noninfectious diseases can be classified further:

■ Hereditary diseases Hereditary diseases are

caused by genetic disorders passed down from

previous generations Since they are inherited,

they are more difficult to treat because they are a

part of the body’s genetic makeup.

■ Age-related diseases Some diseases will start to

develop as the body gets older As the body grows

old, it does not work as efficiently to battle

rou-tine diseases and degenerative diseases such as

Alzheimer’s disease—which causes mild to severe

memory loss or distortion, forgetfulness, anxiety,

and aggressive behavior

■ Environmentally induced diseases An

environ-ment that has been polluted with toxins and

haz-ardous waste can affect the population living in

or around it Radiation from toxic waste can

cause cancer Exposure to asbestos can lead to

serious lung problems

Staying healthy by caring for the body is important in fighting and preventing disease Poor hygiene and unhealthy living conditions are invitations for disease Here are a few tips to stay healthy:

■ Eat a nutritious diet

■ Keep your hands and body clean

■ Exercise regularly

■ Reduce stress

■ Don’t smoke

■ Don’t drink excessively

It is also important to feel good about yourself A pos-itive view of who you are and what you look like can help reduce stress considerably

Looking for Symptoms

Before diagnosing a patient with a disease, a doctor looks for the telltale symptoms Every disease has specific symptoms that cause different reactions in the body Some of the more common symptoms are fever, nausea, and pain A doctor is trained to look for these symptoms

to give a correct diagnosis and issue proper treatment Blood tests and X-rays are special methods used to diag-nose some diseases

Epidemics

An epidemic is a disease that has infected a considerable portion of the population and that continues to spread rapidly Epidemics can occur when there is no medicine for the disease, when diseases develop a resistance to medicine and drugs, or when environmental conditions are favorable for a specific type of disease For example, cancer is rampant in areas with toxic chemicals and high levels of radiation Autoimmune deficiency syndrome, or AIDS, which is caused by the HIV virus, is an epidemic that is killing millions of people worldwide HIV is spread through sexual contact and through contact with the blood of an infected person

Natural and Medical Defenses

Humans and most other living beings have a natural built-in disease-fighting mechanism known as the

immune system The immune system is composed of

cells, molecules, and organs that defend the body against pathogens The immune system is responsible for find-ing the pathogen in the body and killfind-ing it, renderfind-ing it harmless, or expelling it from the body

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The development and use of vaccines and antibiotics

has added to our defenses against diseases Not only have

advances in medicine found ways to fight disease from

inside the body, but methods have also been developed

to prevent the onset of disease

A NTIBIOTICS

Antibiotics are chemicals that kill bacteria without

harming our own cells Some antibiotics, such as

peni-cillin, kill bacteria by preventing it from synthesizing a

cell wall Other antibiotics interfere with bacterial

growth by disrupting their genes or protein production

Bacteria can become resistant to antibiotics—there are

strands of bacteria that are resistant to every known

antibiotic

R ESISTANCE

In every population, a small number of bacteria

natu-rally have genes that make them resistant to antibiotics

With increased exposure to antibiotics, a normal

popu-lation of bacteria, having a few resistant individuals,

becomes resistant on average This is a result of natural

selection Those bacteria that survive are resistant Their

offspring is also resistant, and as a result, the whole

pop-ulation becomes resistant Some resistance enables

bac-teria to survive in the presence of an antibiotic Another

kind of resistance enables the bacteria to actually destroy

the antibiotic This kind of resistance is most dangerous

For example, someone who took antibiotics for treating

acne could accumulate bacteria capable of destroying the

antibiotic If that same person became infected with a

serious disease that is treated with the same antibiotic,

the resistant bacteria could destroy the antibiotic before

it was able to act on the disease

Community and Public Health

People are dying from diseases in many parts of the

world where clean water is scarce and living conditions

are poor Educating people on the importance of

per-sonal hygiene, cleanliness, and sanitation is the key to

preventing disease in these populations A clean, healthy

environment will ensure better health and safety

 P o p u l a t i o n G r o w t h a n d C o n t r o l

The human population growth rate was increasing rela-tively slowly up until 1,000 years ago Before the inven-tion of vaccines and antibiotics that prevented deadly infectious diseases, and before humans developed plumbing and sewage treatment plants to ensure safe, clean drinking water, factors such as the spread of dis-eases increased death rate Lack of food supply and intol-erance for living in extremely hot or extremely cold

environments are also examples of limiting factors that

control population growth

By the early 1800s, the world population reached 1 billion It took approximately 2.5 million years for humans to reach this mark But now, only 200 years later, the world population has reached 6 billion

From 1850 to 1930, a period of less than 100 years, the estimated world population doubled In 1975, less than

50 years later, the world population doubled again to reach 4 billion Then, only 12 years later, it reached 5 bil-lion It is estimated that by 2050, the world population will reach 10 billion

When a couple has two children, each child replaces one of the parents, and in theory, the population should stay the same However, due to increased life expectancy, several generations of people are alive at the same time

It is estimated that even if everyone from now on had only one or two children, the population would continue

to grow for about 50 years The reason for this is that most of the world population is young and has yet to reproduce In a way, the population has a momentum and its growth cannot stop immediately, in much the

Human Population Growth

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same way that you can’t instantaneously stop a car that

is running at 70 miles per hour Coming to a stop

takes time

Even if everyone in the world from this moment

on started having no more than two children,

the population would continue to grow for

about another 50 years

How Did This Happen?

So how did the human population grow so much and so

rapidly? One of the main reasons is that many limiting

factors to human population growth have been

elimi-nated Here are some explanations:

Advances in medicine and healthcare

enabled the development of:

■ vaccines to prevent the spread of infectious

diseases

■ antibiotics to cure common illnesses

■ therapies to treat patients with noninfectious

dis-eases such as cancer

Advances in technology enabled

humans to:

■ expand into new habitats

■ live in places with extreme climate conditions

■ develop sanitation and sewage-disposal systems

Advances in science enabled humans to:

■ increase food supply and improve living conditions

■ reduce deaths from natural disasters and other

hazards

■ use the Earth’s natural resources such as fossil fuels

Since people have learned to overcome some of the

limiting factors that prevented human growth and

sur-vival, the death rate has steadily decreased Because of the

increase in production of food supply and other

resources, the infant death rate has also decreased

What Does This Mean for

Our Future?

So what will happen if the human population continues

to grow at this rate? The result is overpopulation

Over-population occurs when there are too many individuals

in a given area, so that the resources are depleted faster than they can be replaced

Overpopulation is not the same as overcrowding,

which is another consequence of steady population growth Overcrowding occurs when there are too many individuals living in an area—to the point where most

of the individuals in the population live in substandard

or poor conditions because of lack of work and lack

of living space Mexico City, Istanbul, China, and India are some examples of places in the world experiencing overcrowding

How Will Overpopulation Affect Us?

Overpopulation can cause serious damage to our way of life as well as our environment Here are just some effects

of overpopulation

■ Hunger and starvation Technology has enabled

us to develop ways to improve food production and agriculture However, the rate of food pro-duction increase—at this moment—is not keep-ing up with the rate of population growth In other words, the amount of mouths to feed is increasing faster than our ability to feed them The uneven distribution of food, rather than the lack of food, however, is causing most of the hunger problems While huge amounts of food are being thrown away in some parts of the world, people in other parts of the world are starving to death

■ Depletion of our natural resources Some

resources are depleted faster than they are replen-ished Our oil and coal supplies, for example, take millions of years to replenish, and given the con-sumption rate, they will eventually run out

■ Ozone layer and global warming Ozone is a

very reactive molecule, made of three oxygen atoms At about ten to thirty miles above the Earth, a layer of ozone molecules absorbs ultravi-olet light (UV) emitted by the sun and shields liv-ing thliv-ings from potentially dangerous amounts of this radiation UV light can increase the amount

of mutations in DNA Some biologists believe that too much UV light has driven some species

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of frogs to extinction In humans, excess UV light

is a major cause of higher rates of skin cancer

About 20 years ago, scientists began to document

a thinning of the ozone layer, especially over

Antarctica, where the ozone hole is larger than

the size of North America The depletion of the

ozone layer is due largely to deforestation (to

make room for houses, roads, and buildings) and

chemicals, such as chlorofluorocarbons (CFCs),

that are being released into the atmosphere CFCs

are small molecules used as coolant in

refrigera-tors and air conditioners and as propellants in

some spray cans The evidence that CFCs are

destroying the ozone layer has become so clear

that CFC producers have agreed to replace these

compounds with others

■ Effect on biodiversity Overpopulation has a

pro-found effect on biodiversity In order to make

room for ourselves, our houses, factories, and

shopping centers, and to come by food and

energy sources, we have disrupted natural animal

and plant habitats One way in which humans

contribute to the extinction of species is by

frag-menting their habitats—splitting them into

sev-eral smaller habitats This decreases the genetic

diversity and structure of a habitat, which leads to

inbreeding, reduced reproduction, and small

population size A small, inbred population is

more likely to become extinct Extinction of one

species can lead to extinction of another that

depends on the first for food

■ Pollution Waste is produced faster than it can be

dispersed or biodegraded This causes the

buildup of contaminants that can affect our

water, soil, and air Noise can also contaminate

environments, especially in cities This

phenome-non is called noise pollution Light pollution is

another problem Very few stars are visible from

most cities, even on a clear night, because there is

too much artificial light around Images taken of

North America at night show a series of bright

spots throughout the continent Traveling by

plane at night makes the overwhelming amount

of artificial light produced by humans very

noticeable Research suggests that light at night

can affect the production of certain hormones

and, in return, increase some health risks In

addition, excess light may be harmful to animals

as well Much of the problem can be solved by turning on only the lights that are absolutely nec-essary for safety reasons; making them only as bright as they need to be; pointing them toward the ground, not the sky; and shielding them to prevent scattering Implementing these kinds of solutions will also help conserve resources by saving electricity

 N a t u r a l R e s o u r c e s

Humans depend on resources to sustain life A good part

of our everyday resources come directly from the

envi-ronment These are called natural resources—resources

provided by nature Air, water, sunlight, topsoil, and the

various plant and animal life known as biodiversity are

examples of Earth’s natural resources There are two

kinds of natural resources: renewable and nonrenewable.

1 Renewable resources are those that can be

replaced or replenished over a short period of time Plants and crops are examples of resources that, with proper agriculture, are replenishable

2 Nonrenewable resources are those that cannot

be replaced or that take many years to replenish Fossil fuels such as oil and coal are examples of nonrenewable resources

Depletion of Natural Resources

Currently, many of our nonrenewable resources are in danger of being depleted Water, topsoil, and energy are some of the essential resources that are in short supply

■ Water Water is necessary for agriculture, but it is

currently the resource in shortest supply Some parts of Africa and the Middle East are

experienc-ing mass starvation as a result of drought, or

water shortage Availability of drinking water, free

of chemical waste, is also decreasing

■ Topsoil Fertile topsoil takes hundreds, maybe

even thousands of years to replace Human activi-ties have already caused degradation of some of Earth’s fertile topsoil, and as a result, the degraded topsoil is no longer able to sustain agriculture

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■ Energy Most of our energy resources come from

fossil fuels such as oil and coal They are used for

heat, electricity, and gasoline Fossil fuels are

decreasing in supply worldwide because they are

being used faster than they are being produced

Reuse, Reduce, and Recycle:

Preserving Our Natural Resources

So how do we prevent our natural resources from

deplet-ing? There are several ways to help protect our natural

resources

C ONSERVE

It is important that we all learn to conserve our natural

resources To conserve is to limit or control the use of

natural resources, especially nonrenewable resources

While big industries are most responsible for energy use

and pollution, small consumers (like you), in the

com-pany of six billion other small consumers, can have a

notable effect on the use and preservation of natural

resources So:

■ If you are the last one to leave a room, turn off

the lights This will save electricity

■ When you brush your teeth, do you leave the

water running? If you shut the water off while

you brush, you are conserving water

■ Walking short distances instead of driving will

save fuel and limit air pollution

R ECYCLE

One way to protect our environment is by recycling—

reusing solid waste as is or breaking it down to make new

products

■ Old newspaper and cardboard can be shredded

up and recycled to make new paper

■ Glass bottles can be melted down and used to

make new bottles

These are examples of resource recovery, where the

raw materials are extracted to make new ones

Another form of recycling is reuse If you have an old

car, sell or donate it rather than discarding it In this way,

the car is recycled

Much of our solid waste can be recycled By recycling,

we are decreasing the demand for use of more natural

resources and decreasing the amount of space needed for

waste disposal Glass, paper, metal, and plastics are a few examples If we recycled all our paper garbage, it would save thousands of trees every year from being chopped down to make paper Recycling aluminum and other metals is more energy efficient than creating them from metal ores

P ROTECT B IODIVERSITY

Protecting biodiversity—the various plant and animal life

on Earth—means protecting our sources of food, water,

clean air, and fertile topsoil Extinction, or the dying off

of species of plants and animals, damages biodiversity Humans play a big part in causing the extinction of essential plant and animal life by:

■ interfering with and destroying natural habitats

■ polluting the air and water that feed plants and animals

■ using illegal methods (e.g., explosives) for fishing

■ killing already endangered species

C OME U P WITH B ETTER S OLUTIONS

Another option is to come up with better solutions— new ways of using or obtaining energy, developing more efficient processes, and better designs

For example, electric cars are beginning to show up in major cities like San Francisco and Los Angeles Usually available for rent to cruise the city in style, these little innovations are starting to make it to the consumer mar-ket If you have an AC power outlet in your garage, you are all set to own an electric car The benefits of owning

an electric car are easy to guess They are quiet and don’t emit toxic chemicals that deplete the ozone layer They also conserve natural resources needed to make gasoline

 S c i e n c e a n d Te c h n o l o g y i n

L o c a l , N a t i o n a l , a n d G l o b a l

C h a l l e n g e s

Science affects the way we live, work, act, and play Our technological abilities have also given us the ability to confront certain global challenges But we need to con-sider where our technological abilities lead us and make sure that our own might doesn’t destroy us By having a basic science education, we are taking the first step in preventing this from happening

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