Science and TechnologyThe Nature and Development of Science

and Technology

Case 1: Science and Scientific investigation

Galileo Galilei, the Father of Experimentation, has explored the problem of ‘free falling motion’ when he was young. At the time of the 16th century, the theories of the famous ancient Greek philosopher Aristotle played an important role among scholars and were regarded as the classics by everybody. During that time, nobody has raised any questions on Aristotle’s theories.

The Father of Experimentation – Galileo Galilei (1564-1642)

Galileo Galilei : He believed that science must be originated from experiments.

Aristotle’s theories on motions of physical objects were ‘ the speed of an object falling from a higher position is directly proportional to its weight.’ It means the falling speed of a 10 lb object is faster than that of a 1 lb object. This theory seemed to be correct during that time and everybody believed it was unlikely for Aristotle to make a mistake with his wisdom.

However, Galileo discovered that Aristotle’s theory was incorrect and he started to carry out experiments for verifying his discovery.

50 kg

5 kg

Is the falling speed of a heavier object higher than a lighter one?

Galileo thought the science developed merely by thinking like what the Greeks had done was not progressive. He believed that science must be originated from experiments. An idea developed from inspiration would not be held true forever unless it has been proved by experiments.

The greatest contribution of Galileo was his suggestion on using experiment to test if the theories stand, which is so-called -‘scientific method’.

What is scientific method?

What is science?

Human have started to seek for deeper understanding to the natural environment since the ancient time. Science is thus the method and route for people to understand the natural environment.

Science is a process to search for the causal relationship ruling the universe.

Science is an area of study, a basic method for understanding the laws and facts of the nature, and also a process to establish, to test, to link up and to reject academic theories. These theories can describe, explain and predict some natural phenomenon.

Although the world we are living in seems to be very complicated and unpredictable, scientists believe there must be some regular patterns behind them and it is their work for discovering those regular patterns.

Scientists believe there must be some regular patterns behind them and it is their work for discovering those regular patterns.

Einstein's Theory of Relativity deduced that the trajectory of the planet Mercury would deviate from normal calculation when it is close to the Sun. A British scientist, Eddington, observed this phenomenon during the solar eclipse in 1919, and Einstein's theory was then verified.

Scientists need a method for conducting researches, this is the scientific method

The method often used by scientists (i.e. scientific method) can be divided into three parts:

1) Observation, 2) Hypothesizing and 3) Experimentation

If we want to know what science and scientific investigation are, we have to understand clearly the functions and the inter-relationship between each part.

Scientific method

1. Observation 2. Hypothesizing 3. Experimentation

Discover and identify the problem for conducting researches. A research must have a key point.

A main target is needed for acquiring scientific knowledge. As there are lots of things that we do not know, we must target on a problem at a particular area and solve it by carrying out investigation.

Summary of scientific method

Scientists can deduce some hypotheses through observation and logical deduction and hope it leads to the discovery of some natural laws.

The meaning of hypothesis is the scientists’ descriptions on some regular natural patterns. These descriptions are not general and they are confirmative and aimed for reflecting the truth. But these descriptions are regarded as hypotheses as they are not absolutely true and there may be wrong deductions.

Experiments must be conducted to verify whether the hypothesis holds or is rejected.

According to the differences of the hypotheses, the design of experiments would also be different. Scientists must be able to distinguish the hypothesized causes and results of the natural phenomenon when designing experiments to verify it. All experiments should be objective and a control experiment must be included for comparing and testing the results fairly.

4. Observing experimental results

5. Drawing conclusion

Summary of scientific method

All of the observed experimental result should be recorded accurately. It is because the conclusion made in the next step is based on the existing data. The accuracy of the conclusion is depended on the accuracy of the calculated and recorded data after observation.

To ensure the accuracy of measurement, nearly all of the science experiments are depended on science equipment. The reason of using science equipment is simply to minimize our subjective influence to the experiment. The objective data are obtained by using these equipments.

The recorded results from observations are compared with the hypotheses. If they are matched, the conclusion made can be verified. Otherwise, it is refuted.

However, scientific experiments are not purely for validating or rejecting hypotheses. As there are still some factors not being known by us, it is possible for the mismatch between the hypotheses and the recorded result being caused by the factors that have not been taken into account. A good conclusion can explain this type of discrepancy and give suggestions to the improvement of the experiment.

Carry out the scientific method Parachute design

We know that Galileo has proved the falling speed of ‘free-falling motion’ is not related to the

weight. However, we know that feather would fall slower onto the ground than the hammer from our daily observations.

How can we explain this natural phenomenon?

We know that feather would fall slower onto the ground than the hammer due to air resistance through experiment.

It is worthy for us to investigate further on the reasons causing difference in falling speeds for different objects, such as feather and iron hammer experienced different air resistance when falling down onto the ground.

According to Newton’s Second Law of motion ：F = m x a

If the air resistance increased, the accelerating speed of the object decreased; If the weight increased, the accelerating speed also increased.When there is no air resistance: accelerating speed = gravitational constant

This is Galileo’s description on ‘free-falling motion’, stating the accelerating speed (without air resistance) is unrelated to the weight of the falling object.

Please refer to <Extended readings> of Lesson 3, 4 for detailed information about Newton’s Second Law of motion

We now understand when an object is falling, If the air resistance increased, the accelerating speed of the object decreased; if only the weight increased, the accelerating speed also increased.

We can further investigate on the factors causing higher resistance produced when an object is falling, which reduced its falling speed.

The constraints of science and science investigation

Scientific researches can help people to know more about the myths of the natural world continuously. The achievements and application of scientific researches such as electricity, computers, etc. also improve human living unceasingly. Science seems to have unlimited power, but what are the constraints of science?

The scientific constraints canroughly be divided into two types:

The first type is the technical constraints.

The second constraint is related to the nature of scientific methods.

Typhoon attacks in summer would bring about a great destruction to economy and lives. If we can destroy the typhoon while it is forming or displace it from the original track to let it land at a less populated region, we can reduce the loss in economy and lives.

However, we cannot use the two ways mentioned above to reduce the damage caused by typhoon at the moment with the existing science and technology. Moreover, these methods are not economically applicable as the cost would be extremely high even though we have got the most advanced technology to do so.

1. Technical constraintsTyphoon

The influence of typhoon

FloodingTraffic

congestion

Buildingcollapse

Damagefarmlands

Powerfailure

ProductionstandstillCommercial

Activitiesimpeded

Loss of propertiesLoss of lives or

injuries

Classessuspension

Techniques of typhoon prediction

Modern techniques can monitor and predict typhoon

Use artificial satellites to take satellite images

Application of climatology, statistics and dynamics

Predict the position and the track of the typhoon

People need these typhoon information for arranging preventative measures

Constraints of predicting typhoon Applying satellite images and other data for prediction

still cannot reach 100% certainty about the initial position of the typhoon, its track and wind speed at present.

There are many factors influencing the typhoon track. There are some patterns still failed to be fully handled, which could only roughly be applied in the various predicting methods.

The capricious characteristic of tropical cyclone and their fluctuation characteristics of movement and wind intensity make the predicting work very difficult.

Researches to reduce the damagescaused by typhoon

Prevent the formation of typhoons

Alter the movement track of typhoons

The destructiveness of typhoons

Technically uncertain for success

Economic considerations

Resources needed for research

Economic benefits when putting into practice

Constraints in practice

Scientific methods can be applied widely and it can help us to justify lots of things. But when it is related to ethical, religious and political problems such as questions of ‘should’ or ‘should not be’, scientific method would fail to make justifications. Use abortion as an example, science supplies the technology for women to stop carrying a baby, but science fails to ethically justify whether abortion should be done.

2. Constraints on the nature of scientific methods

Moral constraint – abortion

The definition of abortion is spontaneous or induced termination of pregnancy before the foetus acquired viability

Modern technology allows women to choose artificial abortion–Abortion is completely illegal in some countries

–Abortion is conditionally legal in some countries

–Abortion is completely legal in some countries

NationsLife

safetyPhysiological

healthPsychological

healthRape

Congenital defect

Economy/Family

Demand

Vatican Illegal Illegal Illegal Illegal Illegal Illegal Illegal

Switzerland Legal Legal Legal Illegal Illegal Illegal Illegal

Britain Legal Legal Legal Illegal Legal Legal Illegal

The United States Legal Legal Legal Legal Legal Legal Legal

Laws about abortion in different nations

Life safety - Affecting the safety of mother’s lifePhysiological health - Affecting mother’s physiological health Psychological health - Affecting mother’s psychological health Rape - Mother becomes pregnant involuntarilyCongenital defect - The embryo has congenital defectEconomy/Family - Mother is not able to raise the babyDemand - Mother does not want to have a baby, without reasons

Women may become pregnant involuntarily or unexpectedly Pregnant women have the rights to choose if they would give birth to the

baby Consequences of keeping on pregnant and giving birth to the baby

involuntarily and unwillingly. – Psychological problems ： increase the chances of having prenatal

or postnatal depression– Economic problems ： the family may not be managed to raise

the baby– Family problems ： cause damage to relationship between

family members– Social problems ： an unhealthy family environment affects

children’s development of body and mind and

lead to series of social problems

Supporting viewpoints

Opposing viewpoints

Some people believed that embryo is viable and abortion is equal to murdering.

Religious organizations strongly oppose abortion and think it is immoral

Harmful to the health of pregnant women and abortion can lead to death

Moral constraints of science

Advanced science causes the techniques of abortion become more mature, but scientific

method fails to justify whether abortion is

moral.

1. Tsunami warning system 2. Technology for longevity3. Human cloning4. Solve the problem of energy shortage

Other topics about the constraints of science and scientific investigation

For the discussion questions and reference articles about the above topics,Please refer to Lesson 5.6 <Activity 4 worksheet>