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SC300
Unit Two
Alissa Rennie
[email protected]
AIM: alissarennie1
Unit 2
Reading: Chapters 14 and 15
Discussion: Measurement
Seminar: Black Holes
Project: Public Health Investigation
SI base units
• Meter (m) – length
• Kilogram (kg) – mass
• Second (s) – time
• Ampere (A) – electric current
• Kelvin (K) – thermodynamic temperature
• Mole (mol) – amount of substance
• Candela (cd) – luminous intensity
Metric System
• Decimal based system of measurement
• Most common units: meter, sec, kg, liter, degree Celsius
• Where is it used?
Uncertainty (of measurement)
To know one’s ignorance is the best part of knowledge. ~Lao Tzu, The Tao, no. 71
Evaluating uncertainty
The Stars
• Astronomy: study of objects in the heavens.
• All stars send out energy, all are finite objects and
therefore have finite stores of energy.
• All stars have a beginning and an ending.
How we study stars and their energy
• 1. Their wavelength, which is measured by
spectroscopy
• 2. Their intensity, which is measured by a device like a
light meter
• 3. Their direction, which is measured by recording two
angles—one up from the horizon (called the altitude),
and the other around from north (called the azimuth)
• 4. The variations of these wavelengths, intensities, and
positions with time
A star’s wavelength
Why do stars have different
wavelengths?
• Field trip!!
• http://cas.sdss.org/dr6/en/proj/basic/color/physlet/blackb
ody.asp
Star Varieties
• Various colors
• Brightness: distance and energy output
- Luminosity – total energy emitted by a star
How do you figure out how far away they are?
Star Varieties
• Various colors
• Brightness: distance and energy output
- Luminosity – total energy emitted by a star
How do you figure out how far away they are?
Triangulation!
Birth of a Star
• Nebulae collapse on themselves
due to influence of gravity
Death of a star
• Size/mass dependent
• If large enough the star could go supernova and form
- Neutron Stars
- Pulsars
- Black holes
A Black Hole: No Escape
What is a Black Hole?
What is a Black Hole?
• A place where gravity is so extreme that it overwhelms
all forces and not even light can escape.
Black holes
Black Holes
What is the biggest obstacle
to proving that black holes
really do exist?
Black holes
Black Holes
What kinds of evidence are
there that they do?
M82: Middle mass black hole
M47: X-Ray Signal Presence
Elusive intermediate mass black hole
Black holes
Black holes
Black Holes
Given what you know about
scientific inquiry, why is the
lack of direct evidence for
black holes a problem for
scientists?
Black holes
Field trip!!!
• Lets make a black hole….
• http://hubblesite.org/explore_astronomy/black_holes/en
cyc_mod3_q12.html
Community health department
investigation
Community health department
investigation
Truman Middle School band director notes one-third
of his students are absent on Wed, May 20th.
Truman Middle School principal asks the health
department if the school should be concerned about
a health problem.
Image credit: William Harris,
http://science.howstuffworks
.com/scientific-method6.htm
Project Due by the End of Unit 2!!
• First task: Where are
absences taking place
• Is there is a common
reason for the absences?
Explain.
• Be sure to look at charts
and Health Department
info.
• Luckily, your team has already collected all the school
absences data and has put it on your Health
Department intranet site which includes things such as
the school event calendar, and interviews with the
students’ parents, among others
• Be sure to visit and analyze these links!!
From the rubric…
• · Student’s work demonstrates the ability to analyze the data such
that they can develop and defend two viable hypotheses for the
student absences based on the data and outside research.
• · Student’s work develops six testable questions that relate to their
investigation of the student absences. These questions clearly
demonstrate that the student understands what would or would not be
testable. These questions clearly relate to the investigation and
hypotheses outlined by the student.
• · Student’s work demonstrates an excellent knowledge of the
scientific method and what constitutes a good hypothesis.
• ·· Demonstrates a full and complete understanding of all questions.
• · Formatting guidelines are met, citations follow APA style
• ·
Unit 3 Discussion
Unit 3 Discussion
Reading – Chapter 6
• Waves and Electromagnetic Waves
- Nature of waves
- Properties
- Electromagnetic spectrum
Reading Chapter 8
• The Atom
- Elements and their pieces
- The Periodic Table
Questions?
Image credit: Microsoft Clip Art