period of pendulum (equation)
motion of the pendulum, in general
SI units - what are the standards based on
Study the first submitted homework assignment.
Monday, September 29, 2014
Wednesday, September 24, 2014
HW
Come to class with a definition of these things:
- wave
- amplitude
- frequency
- sine wave - this may be beyond where you are mathematically at the moment, so don't panic if you don't get it.
What do you see as the connection between the motion of a pendulum - what we call "simple harmonic motion" - and the motion of a wave?
- wave
- amplitude
- frequency
- sine wave - this may be beyond where you are mathematically at the moment, so don't panic if you don't get it.
What do you see as the connection between the motion of a pendulum - what we call "simple harmonic motion" - and the motion of a wave?
Monday, September 22, 2014
HW for Wednesday
Check out the list of humorous units (for fun!):
http://en.wikipedia.org/wiki/List_of_humorous_units_of_measurement
In this spirit, create your own unit(s).
Also - we didn't chat about the blog postings. Sorry about that! Bring thoughts or questions you may have (if any).
You may want to see the list of SI prefixes:
http://en.wikipedia.org/wiki/Metric_prefix
Finally. Determine the length of a milliday (in units that make sense). How does a milliyear compare to normal class period?
http://en.wikipedia.org/wiki/List_of_humorous_units_of_measurement
In this spirit, create your own unit(s).
Also - we didn't chat about the blog postings. Sorry about that! Bring thoughts or questions you may have (if any).
You may want to see the list of SI prefixes:
http://en.wikipedia.org/wiki/Metric_prefix
Finally. Determine the length of a milliday (in units that make sense). How does a milliyear compare to normal class period?
Thursday, September 18, 2014
Read for HW
Read my old blog posts for homework. Write down anything you find interesting, or any questions you may have.
http://howdoweknowthat.blogspot.com/2009/07/how-do-we-know-that-earth-is-spherical.html
http://howdoweknowthat.blogspot.com/2009/07/so-how-big-is-earth.html
And if you have time:
http://howdoweknowthat.blogspot.com/2009/07/how-far-away-is-that.html
http://howdoweknowthat.blogspot.com/2009/07/how-do-we-know-that-earth-is-spherical.html
http://howdoweknowthat.blogspot.com/2009/07/so-how-big-is-earth.html
And if you have time:
http://howdoweknowthat.blogspot.com/2009/07/how-far-away-is-that.html
Tuesday, September 16, 2014
Homework questions to turn in Thursday
Please finish these questions/problems - try them all - and be prepared to turn this in to me in class on Thursday.
1. What is a "simple pendulum"? What makes a simple pendulum "simple" or why do we call it simple?
2. Calculate the period of a simple pendulum with a 0.5-m long length:
a. on Earth
b. on the Moon, where g = 1.7 m/s/s
3. The acceleration due to gravity on Jupiter is about 2.5 times greater than that of Earth. Without calculating, how would the period of a pendulum be different on Jupiter (compared to Earth)?
4. Draw the approximate shape of the graph for period vs. length of a pendulum.
5. A little bit of algebra may be required - try this, even if algebra isn't your strongest skill. You want a pendulum to swing with a period of 2 seconds. How long must it be?
6. What is the current standard of the meter based on?
1. What is a "simple pendulum"? What makes a simple pendulum "simple" or why do we call it simple?
2. Calculate the period of a simple pendulum with a 0.5-m long length:
a. on Earth
b. on the Moon, where g = 1.7 m/s/s
3. The acceleration due to gravity on Jupiter is about 2.5 times greater than that of Earth. Without calculating, how would the period of a pendulum be different on Jupiter (compared to Earth)?
4. Draw the approximate shape of the graph for period vs. length of a pendulum.
5. A little bit of algebra may be required - try this, even if algebra isn't your strongest skill. You want a pendulum to swing with a period of 2 seconds. How long must it be?
6. What is the current standard of the meter based on?
Monday, September 15, 2014
HW
Yikes - forgot to update this with the homework for tomorrow:
Look up the equation/relationship for the period of a simple pendulum.
Describe how the equation works; the variables involved, etc.
Look up the equation/relationship for the period of a simple pendulum.
Describe how the equation works; the variables involved, etc.
Thursday, September 11, 2014
Try this instead...
There is some problem downloading Logger Pro. I guess the password has been changed and I'm not sure what the new one is.
Try the demo version for now:
http://www.vernier.com/downloads/logger-pro-demo/
Try the demo version for now:
http://www.vernier.com/downloads/logger-pro-demo/
Wednesday, September 10, 2014
HW for Friday
If you have a computer at home, please download LoggerPro - a software package site-licensed to Park School:
https://parkscience.pbworks.com/w/page/351271/LoggerPro
Run the installer. When prompted for a password, type: ecosystem
Open the software and play around with it. Using your data for period (in seconds) vs. length (in cm, or whatever unit you used), plot it.
You may need to "autoscale" the graph -- to make it fit nicely. Do this by right-clicking and choosing autoscale (twice). On a Mac, right click is a two-finger tap on the keypad or CTRL-click.
If you are feeling ambitious, try a "curve fit" under the analyze heading.
Print out your period vs. length graph.
https://parkscience.pbworks.com/w/page/351271/LoggerPro
Run the installer. When prompted for a password, type: ecosystem
Open the software and play around with it. Using your data for period (in seconds) vs. length (in cm, or whatever unit you used), plot it.
You may need to "autoscale" the graph -- to make it fit nicely. Do this by right-clicking and choosing autoscale (twice). On a Mac, right click is a two-finger tap on the keypad or CTRL-click.
If you are feeling ambitious, try a "curve fit" under the analyze heading.
Print out your period vs. length graph.
Tuesday, September 9, 2014
Set up for lab
In our laboratory experiment, we will determine a physical relationship: what factors affect the motion/time of a pendulum.
We determined in class that the length of a pendulum seems to matter most - it seemed to have the greatest effect on the time for one complete swing of a pendulum (also known as the period). Angle mattered a little, but mostly if you were at an angle greater than 15 degrees (with respect to vertical).
For next class, prepare a data table for many trials. You'll be measuring time/period vs. length. In your data table, decide: the units for each column, whether or not you're timing one swing or multiple swings (and have a separate column for a single swing), enough space for 20 different lengths (and maybe multiple trials of each), etc. Also, prepare a short statement that describes your technique for measuring the time of swing (period).
Ultimately, you will produce a graph that suggests the relationship (if there is one to be found).
For next class, prepare a data table for many trials. You'll be measuring time/period vs. length. In your data table, decide: the units for each column, whether or not you're timing one swing or multiple swings (and have a separate column for a single swing), enough space for 20 different lengths (and maybe multiple trials of each), etc. Also, prepare a short statement that describes your technique for measuring the time of swing (period).
Ultimately, you will produce a graph that suggests the relationship (if there is one to be found).
Friday, September 5, 2014
Pseudoscience reading
What Is Pseudoscience?
Distinguishing between science and pseudoscience is problematic
By Michael Shermer
Climate deniers are accused of practicing pseudoscience, as are intelligent design creationists, astrologers, UFOlogists, parapsychologists, practitioners of alternative medicine, and often anyone who strays far from the scientific mainstream. The boundary problem between science and pseudoscience, in fact, is notoriously fraught with definitional disagreements because the categories are too broad and fuzzy on the edges, and the term “pseudoscience” is subject to adjectival abuse against any claim one happens to dislike for any reason. In his 2010 book Nonsense on Stilts (University of Chicago Press), philosopher of science Massimo Pigliucci concedes that there is “no litmus test,” because “the boundaries separating science, nonscience, and pseudoscience are much fuzzier and more permeable than Popper (or, for that matter, most scientists) would have us believe.”
It was Karl Popper who first identified what he called “the demarcation problem” of finding a criterion to distinguish between empirical science, such as the successful 1919 test of Einstein’s general theory of relativity, and pseudoscience, such as Freud’s theories, whose adherents sought only confirming evidence while ignoring disconfirming cases. Einstein’s theory might have been falsified had solar-eclipse data not shown the requisite deflection of starlight bent by the sun’s gravitational field. Freud’s theories, however, could never be disproved, because there was no testable hypothesis open to refutability. Thus, Popper famously declared “falsifiability” as the ultimate criterion of demarcation.
The problem is that many sciences are nonfalsifiable, such as string theory, the neuroscience surrounding consciousness, grand economic models and the extraterrestrial hypothesis. On the last, short of searching every planet around every star in every galaxy in the cosmos, can we ever say with certainty that E.T.s do not exist?
Princeton University historian of science Michael D. Gordin adds in his forthcoming book The Pseudoscience Wars (University of Chicago Press, 2012), “No one in the history of the world has ever self-identified as a pseudoscientist. There is no person who wakes up in the morning and thinks to himself, ‘I’ll just head into my pseudolaboratory and perform some pseudoexperiments to try to confirm my pseudotheories with pseudofacts.’” As Gordin documents with detailed examples, “individual scientists (as distinct from the monolithic ‘scientific community’) designate a doctrine a ‘pseudoscience’ only when they perceive themselves to be threatened—not necessarily by the new ideas themselves, but by what those ideas represent about the authority of science, science’s access to resources, or some other broader social trend. If one is not threatened, there is no need to lash out at the perceived pseudoscience; instead, one continues with one’s work and happily ignores the cranks.”
I call creationism “pseudoscience” not because its proponents are doing bad science—they are not doing science at all—but because they threaten science education in America, they breach the wall separating church and state, and they confuse the public about the nature of evolutionary theory and how science is conducted.
Here, perhaps, is a practical criterion for resolving the demarcation problem: the conduct of scientists as reflected in the pragmatic usefulness of an idea. That is, does the revolutionary new idea generate any interest on the part of working scientists for adoption in their research programs, produce any new lines of research, lead to any new discoveries, or influence any existing hypotheses, models, paradigms or worldviews? If not, chances are it is pseudoscience.
We can demarcate science from pseudoscience less by what science is and more by what scientists do. Science is a set of methods aimed at testing hypotheses and building theories. If a community of scientists actively adopts a new idea and if that idea then spreads through the field and is incorporated into research that produces useful knowledge reflected in presentations, publications, and especially new lines of inquiry and research, chances are it is science.
>
http://www.randi.org/site/index.php/encyclopedia.html
http://www.quackwatch.com/01QuackeryRelatedTopics/pseudo.html
http://en.wikipedia.org/wiki/Pseudoscience
http://www.skepdic.com/pseudosc.html
>
Also keep in mind sites like:
snopes.com
http://www.straightdope.com/
>
Distinguishing between science and pseudoscience is problematic
By Michael Shermer
Climate deniers are accused of practicing pseudoscience, as are intelligent design creationists, astrologers, UFOlogists, parapsychologists, practitioners of alternative medicine, and often anyone who strays far from the scientific mainstream. The boundary problem between science and pseudoscience, in fact, is notoriously fraught with definitional disagreements because the categories are too broad and fuzzy on the edges, and the term “pseudoscience” is subject to adjectival abuse against any claim one happens to dislike for any reason. In his 2010 book Nonsense on Stilts (University of Chicago Press), philosopher of science Massimo Pigliucci concedes that there is “no litmus test,” because “the boundaries separating science, nonscience, and pseudoscience are much fuzzier and more permeable than Popper (or, for that matter, most scientists) would have us believe.”
It was Karl Popper who first identified what he called “the demarcation problem” of finding a criterion to distinguish between empirical science, such as the successful 1919 test of Einstein’s general theory of relativity, and pseudoscience, such as Freud’s theories, whose adherents sought only confirming evidence while ignoring disconfirming cases. Einstein’s theory might have been falsified had solar-eclipse data not shown the requisite deflection of starlight bent by the sun’s gravitational field. Freud’s theories, however, could never be disproved, because there was no testable hypothesis open to refutability. Thus, Popper famously declared “falsifiability” as the ultimate criterion of demarcation.
The problem is that many sciences are nonfalsifiable, such as string theory, the neuroscience surrounding consciousness, grand economic models and the extraterrestrial hypothesis. On the last, short of searching every planet around every star in every galaxy in the cosmos, can we ever say with certainty that E.T.s do not exist?
Princeton University historian of science Michael D. Gordin adds in his forthcoming book The Pseudoscience Wars (University of Chicago Press, 2012), “No one in the history of the world has ever self-identified as a pseudoscientist. There is no person who wakes up in the morning and thinks to himself, ‘I’ll just head into my pseudolaboratory and perform some pseudoexperiments to try to confirm my pseudotheories with pseudofacts.’” As Gordin documents with detailed examples, “individual scientists (as distinct from the monolithic ‘scientific community’) designate a doctrine a ‘pseudoscience’ only when they perceive themselves to be threatened—not necessarily by the new ideas themselves, but by what those ideas represent about the authority of science, science’s access to resources, or some other broader social trend. If one is not threatened, there is no need to lash out at the perceived pseudoscience; instead, one continues with one’s work and happily ignores the cranks.”
I call creationism “pseudoscience” not because its proponents are doing bad science—they are not doing science at all—but because they threaten science education in America, they breach the wall separating church and state, and they confuse the public about the nature of evolutionary theory and how science is conducted.
Here, perhaps, is a practical criterion for resolving the demarcation problem: the conduct of scientists as reflected in the pragmatic usefulness of an idea. That is, does the revolutionary new idea generate any interest on the part of working scientists for adoption in their research programs, produce any new lines of research, lead to any new discoveries, or influence any existing hypotheses, models, paradigms or worldviews? If not, chances are it is pseudoscience.
We can demarcate science from pseudoscience less by what science is and more by what scientists do. Science is a set of methods aimed at testing hypotheses and building theories. If a community of scientists actively adopts a new idea and if that idea then spreads through the field and is incorporated into research that produces useful knowledge reflected in presentations, publications, and especially new lines of inquiry and research, chances are it is science.
>
http://www.randi.org/site/index.php/encyclopedia.html
http://www.quackwatch.com/01QuackeryRelatedTopics/pseudo.html
http://en.wikipedia.org/wiki/Pseudoscience
http://www.skepdic.com/pseudosc.html
>
Also keep in mind sites like:
snopes.com
http://www.straightdope.com/
>
Alien Autopsy film - when you watch it, consider what makes it believable or NOT believable.
If you ever have an hour to kill - the definitive documentary on pseudoscience and psychic stuff, in general.
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