It works.

Category: Uncategorized

Geogebra 2

For the second geogebra, I wanted to do something cool, but quickly found myself limited by my experience with the program. I wanted to create a situation where students could see how Fraunhofer Single Slit Diffraction depended on slit width, wavelength, and distance to the screen, but ended up with a raw simulation only dependent on wavelength and distance to the screen. Ideally I would have added a wave function for the intensity as well, but that was beyond the scope of my abilities given my time constraints this week.

Instead I used a ray model, with a slit width of one micrometer. The distance varies between 1 and 2 meters, and the wavelengths vary from either edge of the optical spectrum. It serves the purpose of allowing students to get a qualitative feel for how maxima and minima vary based on what kind of light is shining through and how far away the screen is, but I really would have liked to add intensity. 

I couldn’t figure out how to rotate the sine function (rotate object about point didn’t seem to work), but in the future I suppose I could feasibly just rotate my canvas and laser instead. 

Obviously this would work well for a class on optics, with the goal of having students feel their way through how light diffracts. PUM did not have a module laid out for optics, so this one was a bit of a solo project.

Here’s the link

Geogebra 1

It took me a while to think of something do simulate, and eventually I settled on making a variable force diagram for a pendulum. About 20 minutes into this, I decided that this was a terrible idea and set out to create a more interesting variable simulation. I stuck with the pendulum idea, but instead made a bar chart in geogebra.

This is modeled after the Energy Module in Pum, Lesson 3.4 specifically. Students are asked to reason as to how bar charts would change given different points in a bar charts motion. This simulation allows students to instantly check their reasoning.

Making the simulation was straightforward enough, from the get go I knew exactly what I wanted to accomplish. The hard part (unsurprisingly) was figuring out how to get geogebra to do what it was that I wanted it to do. You’ll have to forgive my work, as it is a bit messy, but lo and behold I accomplished my task.

A few notes: I made sure the pendulum bob was bound to the arc length cut out by my pivot point and two anchors, but for some reason it keeps going to a height of 1.01 instead of .98 on the right hand side. Because of this, the Kinetic Energy shows as (slightly) negative on that side. I’m not entirely sure why geogebra is allowing the bob to exceed it bounds on the right hand side, but seeing as this doesn’t really take away from the main point I’m not too worried about it. In addition, the simulation is not mobile, it is bound to the x-axis (technically it is mobile, but I wasn’t clever enough to design it such that all measurements are relative). For fun, I added two sliders: one for the mass of the bob and one for the value of the constant “g”. I imagine students will be able to have fun checking to see how messing with these values will affect the graphs.


Here’s the link.

ID Score Report

Student Percentage Grade
109 69% D
113 78% C
106 89% B
102 53% F
118 79% C
117 48% F
107 79% C
104 64% D
121 64% D
115 64% D
110 53% F
114 69% D
108 79% C
105 68% D
103 74% C
119 58% F
116 74% C
111 79% C
120 64% D
112 56% F
101 47% F
315 80% B
320 80% B
344 85% B
317 70% C
308 80% B
302 75% C
306 70% C
323 85% B
301 75% C
316 70% C
322 70% C
314 80% B
307 85% B
309 75% C
324 60% D
311 60% D
321 70% C
318 70% C
310 65% D
319 70% C
304 65% D
312 60% D
303 50% F
326 75% C
313 60% D
327 60% D
325 65% D
305 65% D
712 70% C
704 60% D
708 60% D
706 70% C
705 65% D
707 65% D
709 75% C
715 70% C
714 70% C
711 85% B
701 75% C
702 70% C
717 80% B
710 85% B
713 85% B
703 85% B
902 75% C
908 65% D
905 80% B
903 60% D
904 75% C
909 70% C
906 60% D
907 65% D
914 75% C
910 70% C
912 70% C
913 80% B
911 60% D
915 80% B
901 60% D



The condition, which was first discovered in the 1980s, is called inclusion body disease (IBD), and is known to affect pythons and boa constrictors.

Writing in National Geographic, Ker Than describes how IBD causes bizarre behavioral abnormalities in snakes, including an inability to flip over when turned on their backs, and a condition known as “stargazing,” which makes them stare off into space and weave their heads back and forth as if drunk. The virus also makes the snakes more susceptible to other diseases, such as bacterial infections in their mouths.

Via i09.

View original post



Neuroscientists who study consciousness have suggested that self-awareness depends on the presence of very specific “higher order” regions of the brain.

But now, a detailed analysis of a patient with a rare neurological condition has cast doubt on this assumption, indicating that self-awareness does not require a complex brain.


When it comes to the brain organs of self-awareness, neuroscientists have isolated the insular cortex, the anterior cingulate cortex (ACC), and the medial prefrontal cortex (mPFC). But in a recent paper published in PLOS, a research team tested this theory by studying a man with extensive bilateral brain damage that affected all three of these regions — and quite severely. After a severe bout of herpes simplex encephalitis (which causes inflammation of the brain), only 10% of the patient’s insula remained, along with only 1% of his ACC.

He suffers from extreme amnesia, a condition that has partially affected his “autobiographical…

View original post 33 more words

Dark Matter



Photographer Stephen Wilkes does something both jarring and beautiful with photographs: He merges images from different times of day together to show the passage of time.


Via Stephen Wilkes.

View original post


  • A Hangout is a web-based tool created by Google for communicating through video. Up to ten people can “hang out” at one time in a virtual “room.” A Hangout can be as simple or as complex as needed for the task at hand. It can be used simply to converse or, through the use of extra apps and add-ons that Google provides, a Hangout can become a robust, virtual meeting space.

View original post

The Extinction Protocol

   A giant gaseous cloud will collide with the black hole at the center of the Milky Way Galaxy sometime in the middle of 2013
February 3, 2013SPACE –A giant gas cloud is on collision course with the black hole in the center of our galaxy in 2013. This is a unique opportunity to observe how a super massive black hole sucks in material, in real time. The black hole at the centre of the galaxy, formally known as Sagittarius A*, fascinates scientists. By mid-2013 a gas cloud is expected to pass in its vicinity at a distance of only 36 light-hours (equivalent to km), which is extremely close in astronomical terms. So-called super massive black holes are the largest type of black holes. Their mass equals hundreds of thousands to a billion times the mass of our sun. The centre of all galaxies is…

View original post 373 more words



Researchers working at MIT have successfully manipulated the content of a rat’s dream by replaying an audio cue that was associated with the previous day’s events, namely running through a maze.

[W]hen the researchers played the audio cues from the experiment, they noticed a very interesting thing: the rats would dream about the section of the maze previously associated with the audio cue.

The experiment demonstrated that the content of a rat’s dream can be biased by re-activating certain memories while they’re asleep.

I am torn between making a snappy comment about potential supervillain origin stories or sly A Nightmare on Elm Street allusions.

Decisions, decisions.

Image via Fer Gregory at Shutterstock. via io9.

View original post