Maharashtra Board Class 12 Logic Chapter 7 Hypothesis PDF Download

Hypothesis

7.1 Introduction

In scientific method, one of the important step is formulation of a hypothesis when scientists are faced with a situation or a problem which they are not able to understand and explain then the scientific inquiry begins.

Scientific investigation may be either in the field of natural sciences like physics, chemistry or social sciences like Sociology, Anthropology etc., when scientist observe nature they come across certain facts, events or situations which they are not able to explain. These are problems faced by scientist. Feeling of a problem is the starting point of scientific investigation. Next important step is to formulate a hypothesis.

Unless a hypothesis is formed scientific investigation cannot proceed further. Thus, hypothesis gives a direction to scientific investigation and is an important step in scientific investigation.

It is therefore necessary to know what hypothesis is and how it is established in science.

7.2 Definition And Nature Of Hypothesis

Scientist's investigation begins with the formation of hypothesis. The word hypothesis is derived from the Greek word 'hypo' which means 'under' and 'thithenai' means 'to place'.

Coffey defines hypothesis as "An attempt at explanation, a provisional supposition made in order to explain scientifically some facts or phenomenon".

In simple words hypothesis is defined as a tentative solution given to the problem.

For e.g - Since childhood, Edward Jenner had heard that in spite of getting cow pox blisters on their hands, milkmaids did not develop small pox. To explain this situation, he formulated a hypothesis that 'the pus in the blisters might have protected the milkmaids from small pox'. This was a provisional supposition. Thus hypothesis is a guess work as to how facts are connected.

Teacher's Note

A hypothesis is like a smart guess. When a student wonders why their plant dies even with water, they make a guess that the soil is not good. That guess is a hypothesis.

Exam Trick

Remember: Hypothesis = Smart Guess. It is not a wild guess. It is based on facts you already know. Like a detective making a guess about who did a crime.

Points to Remember

Hypothesis is a tentative solution to a problem.
It gives direction to scientific investigation.
It is based on facts and observation.
It must be testable to check if it is right or wrong.

7.3 Characteristics Of Hypothesis

(1) It Is An Important Stage In Scientific Investigation

Every scientific investigation starts with the problem for which scientist intends to find solution. He begins by assuming a possible explanation on the basis of which he starts investigation. Hypothesis is like guiding post which gives direction to scientific investigation. No scientific investigation is possible without hypothesis. Unless a hypothesis is formed scientists would not know what facts to observe and what experiments to conduct in order to find the solution to the problem.

For example: Discovery of Neptune.

Astronomers had calculated the orbit of planet Uranus, on the basis of the gravitational pull of then known planets. But, in 1820, scientists Bouvard observed that there was a deviation in this calculated orbit. Astronomers advanced the hypothesis that there is a planet beyond Uranus which is disturbing the gravitational force of Uranus.

The great Berlin telescope was turned towards that direction and they found the planet. This planet was named Neptune. Hence the hypothesis was verified to be true.

(2) Attempts At Explanation

Hypothesis is an attempt at explaining observed facts which scientist are unable to explain. Hypothesis does not explain the fact unless it is verified to be true. On the basis of this possible explanation the investigator proceeds to collect data through observation and may use the experiment to verify it. Once the hypothesis is verified it becomes the explanation of the problem.

(3) Provisional

Every hypothesis is always provisional in character. It is suggested as a likely solution. It is merely a tentative supposition or suggestion or simply a claim to explain the fact. It may turn out to be a right explanation or may turn out to be a wrong one. There is no finality about the solution provided by it.

Teacher's Note

Provisional means it can change. If your hypothesis is wrong, scientists change it and try again. Like when you guess the answer wrong in a test, you can write a new answer.

Exam Trick

Provisional = Can Change. A hypothesis is not final. It is just a guess that can be proven wrong. Remember: Provisional = Temporary = Can Change.

Points to Remember

Hypothesis is not the final answer.
It is a temporary guess or supposition.
It can be right or wrong.
It must be tested to find the truth.

(4) It Is An Organising Principle

The aim of science is to understand and explain facts. This is done by introducing order in facts.

In fact there is an order in nature but this order cannot be perceived the way in which one can perceive facts. One has to find out this order. This is what science attempts to do. At initial stage of scientific inquiry one fails to understand the connection between innumerable facts and events in nature. Facts appear to be scattered, isolated and unrelated to each other. But once the hypothesis is verified to be true, the order among the facts is revealed. Therefore, it is an organising principle.

For example: Before Newton discovered the theory of gravitation, there appeared to be no connection between facts like - freely falling objects, movements of planets, phenomena of tides. His theory of gravitation revealed the connection between these apparently unrelated facts and showed that they were all due to gravitation.

(5) Result Of Rational Activity

In order to solve the problem, hypothesis is suggested but no problem can be solved without rational thinking. So, hypothesis is said to be the result of rational activity.

(6) Result Of Keen And Creative Imagination

Every hypothesis originates out of a problematic situation. However, to perceive and solve the problem is not easy. Hypothesis is the result of the scientist's keen and creative imagination.

For example: In the year 1795, Nicolas Appert observed that Napoleon Bonaparte regularly shipped food for his military. But the food would spoil by the time it reached its destination. Nicolas wondered about the why and how of this event. A thought came to his mind that if the food is boiled and sealed in a glass jar with a cork then it may not get spoilt. He conducted an experiment to test this hypothesis and found that the food did not get spoilt, as the germs in the food were killed by boiling the food and also outside germs could not enter the food as the glass jar was sealed with the cork.

This hypothesis which resulted from Nicolas Appert's creative imagination lead to the invention of canned food.

Teacher's Note

Creative imagination means thinking of new ideas. Nicolas Appert thought of a new way to keep food fresh. That creative idea gave us canned food that we eat today.

Exam Trick

Remember: Great discoveries need creative thinking. Newton saw an apple fall and thought of gravity. Edison imagined the light bulb in his mind before making it.

Points to Remember

Hypothesis comes from creative thinking of scientists.
Hard work and imagination together create good hypotheses.
Many scientists failed before finding the right hypothesis.
Creative ideas come from observing everyday things carefully.

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