Prove it!

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Prove it!

• What is proof?

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Sureness

• Certainty
• How sure can we be?

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Kinds of proof

• Mathematical
• Scientific

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Mathematical proof

• Prove that 7x321
• 333333321
• Proofs mean that you can make rules, so 7x3 is
  always 21

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Pythagorus theorum

• the square of the hypotenusesquares of other 2
  sides

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Pythagorus was right

• His logic was worked out step by step.
• It is completely correct because every step leads
  on from the last.
• Scientific proof is different.

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The Chocolate Conjecture

• Eating chocolate before you do sums will make you
  brainer. You will be able to get more sums right!
  
• PROVE IT.

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Design a good tests to investigate the chocolate
conjecture

• This is scientific proof.
• We need to do a test to find out.
• What would you do?
• How would you do it?

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Sums sheet

• 13
• 21
• 11
• 32
• 22

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Good tests

• Comparisons
• Equal comparisons control groups
• Before and after
• Useful measurements
• Logical reasons for changes
• Placebo effects

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why do we need fair tests?

• what happens when we dont do good tests?
• what could go wrong?

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Why do we need fair tests?
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how did we find out?

• science is about noticing things and thinking
  about WHY
• scientists can test ideas and find out if they
  are right or not
• this saves lives!

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people used to think smoking was good for you
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how did we find out that smoking harms us?

• science!

doctors who didnt smoke
doctors who smoked
50 years passed
scientists compared the two groups people who
smoked had more diseases and died younger
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this showed smoking harmed us

• lots of other studies in different places showed
  that smoking harmed us too
• we are very sure that smoking is bad for us

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scary statistics

• do you ever see scary statistics?
• would you like to help your mum and dad when they
  read newspapers?

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BROOMHILL NEWS science week 2013
Broomhill School Science Week 2013
cut risk of ATTACK by zombies by 50 !!!
ONLY 500! STOP ZOMBIES! NOW !
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• 500 to cut the risk of zombie attack by 50
• thats cutting the risk of attack in half!
• would you buy it?

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but...

• cutting the risk in half with a zombie kit sounds
  good
• but what was the risk to start with?
• whats it half of?

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• 100 RISK OF ZOMBIE ATTACK
• Means the Kit can cut the risk to 50

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But

• 1 risk of Zombie Attack
• HALF OF 1 means the kit reduces the risk of
  attack to 0.5
• DOESNT SOUND AS GOOD!

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• BUT zombies DONT EXIST
• there is NO CHANCE OF A ZOMBIE ATTACK
• The Zombie Kit cuts the risk by 50
• BUT HALF OF NOTHING IS NOTHING
• SO THE KIT IS RUBBISH

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STOP 90 OF ALL PAPERCUTS! GREAT NEW
INVENTION!ONLY 100!
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BUT!

• ONLY 10 out of 1000 of children get a papercut
  every year
• if we cut the risk of papercuts by 90
• instead of 10 out of 1000 children with papercuts
• its 1 in 1000
• but you have to wear gloves all the time!

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things that sound good might not be
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• Science is about looking, thinking and testing
• when we dont do fair tests, we make mistakes and
  harm people
• sometimes numbers can trick us - so we have to be
  careful

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