nature of science l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Nature of Science PowerPoint Presentation
Download Presentation
Nature of Science

Loading in 2 Seconds...

play fullscreen
1 / 14

Nature of Science - PowerPoint PPT Presentation


  • 269 Views
  • Uploaded on

Nature of Science Scientific Measurements “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.” ~Albert Einstein Size of Earth Eratosthenes measured the size of the earth in 235 BC

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Nature of Science' - libitha


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
scientific measurements

Scientific Measurements

“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”

~Albert Einstein

size of earth
Size of Earth
  • Eratosthenes measured the size of the earth in 235 BC
  • Calculated the circumference of earth by comparing shadows at local noon
eratosthenes method
Eratosthenes’ Method
  • Determine angle between sun’s rays and vertical
  • This angle is equal to the angle between the two radius vectors
  • 7.1o/360o = 1/50
  • Distance between Syene and Alexandria known to be 800 km
  • 50*800 km = 40,000 km
size of the moon
Size of the Moon
  • Aristarchus determined the size of the moon in 240 BC
  • Eclipse of moon
  • Shadow of earth at moon’s distance has tapered by 1 moon diameter
  • Shadow was 2.5 X the moon’s diameter
  • Earth’s diameter is therefore 3.5 X moon’s diameter
  • Moon diameter = 2*6,370 km/3.5 =
  • 3640 km
distance to moon
Distance to Moon
  • Once Aristarchus had estimated the diameter of the moon (to within 5% of the present accepted value)
  • the above technique was used to calculate the distance to the moon
  • 110*3640 km = 400,400 km
distance to sun
Distance to Sun
  • Once earth-moon distance is known
  • Right triangle trigonometry allows the determination of the earth-sun distance
  • Aristarchus measured the angle X to be 87o
  • Actual value is 89.8o (difficult to measure)
  • Sun is 400 X farther than moon
  • Aristarchus estimated 20 X earth-moon distance
size of the sun
Size of the Sun
  • Pinhole camera
  • Sun’s diameter is
  • 150,000,000 km/110
  • = 1,360,000 km
pinhole camera
Pinhole Camera
  • Pinhole camera can be used to safely view a partial eclipse
  • Spaces between leaves act as pinholes during eclipse
science terms
Science Terms
  • Fact – a close agreement by competent observers – facts can change
  • Hypothesis – must be stated in a way that it can be disproved
  • Theory – a synthesis of a large body of information encompassing well-tested and verified hypotheses
scientific hypotheses
Scientific Hypotheses
  • Scientific Hypothesis
    • Must be testable
    • Must be falsifiable
  • Our universe is surrounded by another, larger universe, with which we can have absolutely no contact.
    • Not testable
  • There are other inhabited planets in the universe.
    • Not falsifiable
  • The moon is made of green cheese.
    • Testable & Falsifiable
check yourself
Check Yourself
  • Which of these is a scientific hypothesis?
    • Atoms are the smallest particles of matter that exist.
    • Space is permeated with an essence that is undetectable.
    • Albert Einstein was the greatest physicist of the twentieth century.
check yourself13
Check Yourself
  • Which of these is a scientific hypothesis?
    • Atoms are the smallest particles of matter that exist.
    • Space is permeated with an essence that is undetectable.
    • Albert Einstein was the greatest physicist of the twentieth century.
scientific method
Scientific Method
  • There are many scientific methods – but generally
    • Recognize a question
    • Form a testable hypothesis
    • Make predictions
    • Test predictions
    • Formulate simplest general rule