Chapter 1 WHAT IS SCIENCE · 2018-09-06 · Free distribution by A.P. Government 1 experimentation. Science is a tool for searching truths of nature. Science is the way of exploring

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experimentation. Science is a tool forsearching truths of nature. Science is theway of exploring the world.

Questioning is the primary orfundamental step in scientific thinking.There are so many things around us whichsprout doubts in our minds. Ofcourse theymay be problems. Let us observe thefollowing experiences, you too add yourobservations to enrich the list.

1. Why leaves fall from the tree whenthey turn in yellow?

2. How ants identify sweets kept in a tin?3. Why can not we see stars during day

time?4. Pickles do not spoil but sambar gets

spoilt, why?5. Farmers are afraid of unseasonal

rains and uncontrolled pests. How tosolve these problems?

6. Why diseases occur and how toprevent and cure?

Consider some examples. An ecologistobserving the territorial behaviors of bluebirds and a geologist examining the

I t is amazing to think of thefacilities available today when

compare with primitive man. Computers,mobile phones, internet, space shuttles,robotics, hybrid food grains, medicines, etcare all the results of ideas which originatedin some human brains. They are all thepeople who think differently to observe andunderstand the nature in a specific way. Letus understand how they think and what theydo.

What is science?Science is the concerted human effort

to understand or to understand better, thehistory of the natural world and how thenatural world works, with observablephysical evidence as the basis of thatunderstanding.It is done throughobservation of natural phenomena, and/orthrough experimentation that tries tosimulate natural processes undercontrolled conditions. Science is a processof thinking.

Science is an organized study ofknowledge which is based on

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What does that really mean? Sciencerefers to a system of acquiring knowledge.This system uses observation andexperimentation to describe and explainnatural phenomena. The term science alsorefers to the organized body of knowledgepeople have gained using that system. Lessformally, the word science often describesany systematic field of study or theknowledge gained from it.

Why do science?

The individual perspectiveWhy are all these people described

above doing? what they are doing? In mostcases, they’re collecting information totest new ideas or to disprove old ones.Scientists become famous for discoveringnew things that change how we think aboutnature, whether the discovery is a newspecies of dinosaur or a new way in whichatoms bond. Many scientists find theirgreatest joy in a previously unknown fact(a discovery) that explains some problemspreviously not explained, or that overturnssome previously accepted idea.The Societal Perspective

If the ideas above said, explain whyindividuals do science, one might stillwonder why societies and nations pay thoseindividuals to do science. Why does asociety devote some of its resources tothis business of developing new knowledgeabout the natural world, or what hasmotivated these scientists to devote theirlives to develop this new knowledge?

distribution of fossils in an outcrop areboth scientists making observations inorder to find patterns in natural phenomena.They just do it outdoors and thus enlightenthe general public. An astrophysicistphotographing distant galaxies and aclimatologist shifting data from weatherballoons similarly are also scientistsmaking observations, but in more discretesettings.

The examples above are of observationalscience. There is also experimentalscience. A chemist observing the rates ofone chemical reaction at a variety oftemperatures and a nuclear physicistrecording the results of angular momentumof a particular particle in the circular pathare both scientists performing experimentsto discover consistent patterns emerge. Abiologist observing the reaction of aparticular tissue to various stimulants islikewise experimenting to find patterns ofbehavior. These folks usually do their workin labs and wear impressive white lab coats.

The critical commonality is that allthese people are making and recordingobservations of nature, or of simulationsof nature, in order to learn more about hownature, in the broadest sense, works. We’llsee below that one of their main goals is toshow that old ideas (the ideas of scientistsa century ago or perhaps just a year ago)are wrong and that, instead, new ideas toexplain nature in a better way.

The word science comes from the Latinword “scientia”, meaning knowledge.

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One realm of answers lies in the desireto improve people’s lives. Geneticiststrying to understand how certain conditionsare passed from generation to generationand biologists tracing the pathways bywhich diseases are transmitted are clearlyseeking information improve the lives ofordinary people. Earth scientistsdeveloping better models for the predictionof weather or for the prediction ofearthquakes, landslides, and volcaniceruptions etc are likewise seekingknowledge that can help avoid the hardshipsthat have plagued humanity for centuries.Any society concerned about the welfareof its people, which is at the least anydemocratic society should do, will supportefforts like these to better people’s lives.

Another realm of answers lies in asociety’s desires for economicdevelopment. Many earth scientists devotetheir work to finding more efficient ormore effective ways to discover or recovernatural resources like petroleum and ores.Plant scientists seeking strains or speciesof fruiting plants for crops are ultimatelyworking to increase the agricultural outputthat nutritionally and literally enrichesnations. Chemists developing newchemical substances with potentialtechnological applications and physicistsdeveloping new phenomena likesuperconductivity are likewise developingknowledge that may spur economicdevelopment. In a world where nationsincreasingly view themselves as caught upin economic competition, support of suchscience is nothing less than an investmentin the economic future.

Lastly, societies support sciencebecause of simple curiosity and because ofthe satisfaction and enlightenment thatcome from knowledge of the worldaround us.

Science and ChangeIf scientists are constantly trying to

make new discoveries or to develop newconcepts and theories, then the body ofknowledge produced by science shouldundergo constant change. Such changeprogress towards a better understanding ofnature. It is achieved by constantlyquestioning whether our current ideas arecorrect or not

The result is that theories come and go,or atleast modified through time, as oldideas are questioned and new evidence isdiscovered. In the words of Karl Popper,“Science is a history of correctedmistakes”, and even Albert Einsteinremarked of himself “That fellow Einstein. . . every year retracts what he wrote theyear before”. Many scientists haveremarked that they would like to return tolife in a few centuries to see what newknowledge and new ideas have beendeveloped by then - and to see which oftheir own century’s ideas have beendiscarded.

Scientists observe the nature and itslaws. They discover the secrets of nature.Based on these discoveries and inventionsdifferent innovations take place. Scientistsfollow a specific way for their innovations.The way that they follow is called'scientific method'. Let us find out how theyfollow

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Aravind is using this scientific methodfor experimenting to find an answer to hisquestion. You can use these steps, too.

Step 1 Observe, and ask questions.

• Use your senses to make observations.

• Record one question that you wouldlike to answer.

• Write down what you already knowabout the topic of your question.

• Decide what other information youneed.

• Do research to find more informationabout your topic.

Step 2 Form a Hypothesis.

• Write a possible answer, or hypothesis,to your question.

A hypothesis is a possible answer thatcan be tested.

• Write your hypothesis in a completesentence.

What soil works best forplanting bean seeds ?

I need to find out moreabout the different

My hypothesisis bean seedssprout best in

How scientists work - Scientific Method

Planning an investigationHow do scientists answer a question or solve a problem they have identified? They use

organized ways called scientific methods to plan and conduct a study. They use scienceprocess skills to help them gather, organize, analyze, and present their information.

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Step 3 Plan an experiment.• Decide how to conduct a fair test of

your hypothesis by controllingvariables.

Variables are factors that can affect theoutcome of the investigation.

• Write down the steps you will followto do your test.

• List the equipment you will need.• Decide how you will gather and record

your data

I'll put identicalseeds in three different

kinds of soil. Each flowerpotwill get the same amountof water and light. So, I'll

be controlling the variablesof water and light.

I'll measure each plantevery 3 days. I'll record the

results in a table and thenmake a bar graph to showthe height of each plant 21

days after I planted theseeds.

Step 4 Conduct the experiment.

• Follow the steps you have written.

• Observe and measure carefully.

• Record everything that happens.

• Organize your data so that you can studyit carefully.

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Step 5 Draw conclusions and communicateresults.

• Analyze the data you gathered.• Make charts, tables, or graphs to show

your data.• Write a conclusion. Describe the

evidence you used to determinewhether your test supported yourhypothesis.

• Decide whether your hypothesis iscorrect or not.

I'll test this newhypothesis : Marigold

seeds sprout best in a combination of clay, sandy, and potting soil. I

will plan and conduct a test usingpotting soil, sandy soil, and acombination of clay, sandy,

Hmmm... My hypothesis is not

correct. The seeds sproutedequally well in potting soiland sandy soil. They did not

sprout at all in clay soil.

Investigate FurtherIf your hypothesis is correct…

You may want to pose another questionabout your topic that you can test.

If your hypothesis is incorrect…

You may want to form anotherhypothesis and do a test of a differentvariable.Do you think Aravind’s new hypothesisis correct? Plan and conduct a test to findout!

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Using science process skillsWhen scientists try to find an answer to aquestion or do an experiment, they usethinking tools called process skills. You usemany of the process skills whenever youspeak, listen, read, write, or think.Think about how these students use processskills to help them answer questions, doexperiments, and investigate the worldaround them.

What Saketh plans to investigate? Saketh collects seashells on his visit to

the beach. He wants to make collectionsof shells that are alike in some way. Helooks for shells of different sizes andshapes.

How Saketh uses process skillsHe observes the shells and compares

their sizes, shapes, and colours. Heclassifies the shells first into groups basedon their sizes and then into groups basedon their shapes.

Process SkillsObserve – use the senses to learn

about objects and events.

Compare – identify characteristicsof things or events to find out how theyare alike and different.

Classify – group or organize objectsor events in categories base on specificcharacteristics.

What Charitha plans to investigateCharitha is interested in learning what

makes the size and shape of a rock change.She plans an experiment to find out whethersand rubbing against a rock will causepieces of the rock to flake off and changethe size or shape of the rock.

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How Charitha uses process skillsShe collects three rocks, measures their

masses, and puts the rocks in a jar with sandand water. She shakes the rocks every dayfor a week.

Then he measures and records the massof the rocks, the sand, and the container.She interprets her data and concludes thatrocks are broken down when sand rubsagainst them.

How Aravind uses process skillsHe decides to use a model of the switch

and the wires in the wall.

He predicts that the bulb that the bulb,wires, and batteries have to be connectedto make the bulb light.

He infers that moving paper clipinterrupts the flow of electricity and turnsoff the light. Aravind’s model verifies hisprediction and inference.

Process SkillsUse a Model : make a representation tohelp you understand an idea, an object,or an event, such as how somethingworks.Predict : form an idea of an expectedoutcome, based on observations orexperience.Infer : use logical reasoning to explainevents and draw conclusions based onobservations.

What Aravind plans to investigateAravind wants to find out how the light

switch in his bedroom works. He usesbatteries, a flashlight bulb, a bulb holder,thumbtacks, and a paper clip to help him.

Process SkillsMeasure – Compare and attribute of

an object, such as mass, length, orcapacity to a unit of measure, such asgram, centimetre, or litre. Gather,Record, Display, and Interpret Data

• Gather data by making observationsthat will be useful for inferences orpredictions.

• Record data by writing down theobservations in a table, graph, ornotebook.

• Display data by making tables, charts,or graphs.

• Interpret data by drawing conclusionsabout what the data shows.

What Swetha plans to investigate

Swetha wants to know what brand ofpaper towel absorbs the most water. She

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plans a test to find out how much waterdifferent brands of paper towels absorb.She can then tell her father which brand isthe best one to buy.

How Swetha uses process skillsShe chooses three brands of paper

towels. She hypothesizes that one brandwill absorb more water than the others. Sheplans and conducts an experiment to testher hypothesis, using the following steps:• Pour 1 litre of water into each of three

beakers.• Put a towel from each of the three

brands into a different beaker for 10seconds.

• Pull the towel out of the water, and letit drain back into the beaker for 5seconds.

• Measure the amount of water left ineach beaker.

Swetha controls variables by makingsure each beaker contains exactly the sameamount of water and by timing each step inher experiment exactly.

Process Skills

Hypothesize – make a statementabout an expected outcome.

Plan and Conduct Experiment –identify and perform the steps necessaryto test a hypothesis, using appropriatetools, recording and analyzing the datacollected.

Control Variables – identify andcontrol factors that affect the outcomeof an experiment so that only onevariable in a test.

Reading to learnScientists use reading, writing, and numbers in their work. They read to find out everything

about a topic they are investigating. So it is important that scientists know the meaning ofscience vocabulary and that they understand what they read. Use the following strategies tohelp you become a good science readers.

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