graph
rallain | March 19, 2009I just got back from judging elementary level science fair (this is like kids in 6th grade or something). Here are some quick notes in no particular order.
Please, please do not have a 20 item list of supplies that you used on your board including things like thumb tacks, tape, paper and poster board. And then please do not read this list aloud during your presentation. I know you are nervous, I feel for you. Maybe you are trying to fill up time - maybe you think a long presentation is a good one. However, don't do it. Stick to the important stuff. If you need to fill up space on your…
rallain | February 28, 2009This idea comes from my friend Thomas. His son is like mine in that they both think LEGO are awesome, and they are correct. For some reason, Thomas decided to calculate the price per piece of LEGO in each set. To promote repeatability, I decided to do this also. Looking at the catalog at LEGO.com, I can get both the price of each set and how many pieces it has. Just a note, I looked at almost all of the Star Wars LEGO series and some other select themes. I didn't include any sets that had been marked down in price. I will put the first plot on down below, maybe this would be a good…
rallain | January 29, 2009I really didn't want to post this, but I am going to anyway. I used ScreenToaster.com to make a screen capture movie (with audio) of a tutorial on spreadsheets.
This should accompany my previous post on numerical calculations.
Free online screen recorder
rallain | January 25, 2009When you pour a beer, there is this foamy top called the head. The size of the head decreases over time. What is this process dependent on? Clearly, little bubbles of beer are popping. Does each bubble have an equal probability of popping? Do only the bubbles on the top (or bottom) pop? I became aware of this idea from a colleague. Maybe he was going to do an analysis, but I haven't seen it yet. If you do (Gerard), I am sorry for doing this before you. This may have been investigated before, but in the spirit of re-doing everything I have not searched for previous beer head studies.…
rallain | January 12, 2009I am not going to try and even surprise you with this. Notice the "tools:". This post is not about physics really, but something used in physics. When I get enough of these, I will put them together in a "tools" page - or you can just use the tools-tag.
Suppose you have some data. You want to plot that data and turn it in with your lab report. Your instructor (me) told you to be sure and include error bars on your graph.
What are error bars?
How do you add error bars - whatever they are?
Error bars are a way to graphically represent the uncertainty in a data point. Every time you take a…
rallain | September 21, 2008**pre-reqs**: [kinematics](http://scienceblogs.com/dotphysics/2008/09/basics-kinematics.php) *I don't think you need [part I of this](http://scienceblogs.com/dotphysics/2008/09/basics-making-graphs-with-ki…) if you don't want*
So, you still want to make a graph with that kinematics data? You think that graphs on paper are too barbaric? Well, if you are ready, you can use a spreadsheet. But be careful. If you don't know what you are doing, you can cause some damage (much like flying a 747 after reading a blog about it). Spreadsheets allow you to do a couple of things.
make pretty graphs…
rallain | September 18, 2008**pre reqs:** [kinematics](http://scienceblogs.com/dotphysics/2008/09/basics-kinematics.php)
Suppose there is some experiment in which you throw a ball up and collect position and time data (with video analysis). What do you do with this data? Your instructor told you to make a graph, but how do you do that?
Here is the fictional data you (or I) collected:
Here is the text file with the data if you want to reproduce the graphs I make here [kinematics data](http://scienceblogs.com/dotphysics/kinematics_data.…
rallain | September 6, 2008So, I am still in Alabama because of lack of electricity in Louisiana (although we got power back last night - YAY!). My wife convinced me to go out and hear this band since we are staying at my parents and they said they would watch the kids. In general, I am way too old and crotchety to go out - but it appears I had no choice. Overall, it was not too bad except for staying out too late. (the band was actually pretty good - I think they were called [Fly By Radio](http://www.fly-byradio.com/) and they played 80s musics) The one thing I thought about while in the bar was the long line of…
esiegel | May 14, 2008When I think of molecules, I think of Conan O'Brien doing his skit where he plays Moleculo...
the molecular man! I don't think of astronomy, and I certainly don't think of the leftover radiation from the big bang (known as the cosmic microwave background)! But somebody over at the European Southern Observatory put these two together and made an incredibly tasty science sandwich.
See, we can measure the cosmic microwave background today, because we have photons (particles of light) coming at us in all directions at all locations, with a temperature of 2.725 Kelvin. Theoretical cosmology…