Physics
esiegel | June 8, 2009One of the simplest tricks you can use physics for is to figure out how high up you are. Either using a stopwatch or just by counting seconds, drop a dense object (e.g., not paper, a tissue, etc.) and figure out how long (in seconds) it takes from when you release the object to when it hits the ground. Take that number and square it. Multiply it by 16 to get your approximate height in feet, or multiply it by 5 to get your approximate height in meters.
What's remarkable is that all objects fall at the same rate. All of them. It doesn't matter what material they're made out of, how large or…
drorzel | June 8, 2009Tom at Swans On Tea comments on an article about meetings:
The most common meeting in my experience is the status meeting, where everyone gets together and reports on what they've accomplished. If it's a small group, these are usually fine because you already have familiarity with the tasks. But when you get a large group together, which has diverse tasks and goals, there is impending disaster. Bad meetings I've attended often involve people discussing details that nobody else at the table understands or possibly cares about -- the sort of thing that should happen one-on-one or in a small…
rallain | June 5, 2009Have you seen a cooler merrry-go-round than this?
Wow. A two-level huge merry-go-round with climbing ropes and everything. I didn't think you could have something like this in today's era of lawsuits. Man, the kids love this thing.
drorzel | June 5, 2009Physics World posted a somewhat puzzling story a few days back, headlined Ultra cold atoms help share quantum information:
Scientists in the US have demonstrated a novel "light-switch" in an optical fibre that could become a new tool in the communications industry. The device created by Michal Bajcsy at Harvard University and colleagues could be developed to share both classical and quantum information.
Quantum information systems could bring a revolution to global data-sharing, by encrypting, processing, and transmitting information using the properties of quantum mechanics. However, as…
drorzel | June 5, 2009Physics World reports on the awarding of a major French prize in science:
A physicist has been awarded France's top science prize for his work on atomic physics and quantum optics. Serge Haroche -- one of the founding fathers of cavity quantum electrodynamics (QED) -- was presented with this year's "gold medal" by the French national research council (CNRS) at a press conference in Paris yesterday. Haroche currently heads the electrodynamics and simple systems group at CNRS's Kastler Brossel Lab in Paris.
Previous physics recipients include the Nobel Prize winners Albert Fert and Claude Cohen…
esiegel | June 4, 2009Ever wonder how much daylight you can gain or lose just by getting in your car and driving either West or East?
Here's how to figure it out. The Earth's circumference is about 25,000 miles (40,000 km) at the equator. So if you start out at sunrise and drive 1,000 miles (1,600 km) Westward during the daylight hours, you'll get almost an extra hour of daylight. On the other hand, if you go East, you'll lose that much. 1,000 miles is pretty much the maximum you can go in about 12 hours, and that's going pretty fast (about 80 mph, or 130 kph).
But there's a trick to stealing extra daylight.
Get…
drorzel | June 4, 2009When this first came out, I didn't pick it up, despite a glowing recommendation from Jennifer Ouellette, because NASCAR is one of the few things on ESPN that interests me less than baseball. I didn't really think I'd be interested in reading a whole book on the subject.
I saw Jennifer and Diandra on Bloggingheads a little while back, and she made it sound pretty interesting. And then I saw that she was giving a public lecture at DAMOP, and figured it would be good for airplane reading on the way down and back.
The Preface gives a nice description of how she came to write the book:…
grrlscientist | June 3, 2009tags: NYC, Upper West Side, Manhattan, science, education
Nick with his potato gun,
on the downtown-bound A Train.
Image: GrrlScientist, 3 June 2009.
Today as I was riding the A Train to the library so I could use their free wifi, I ran into Nick and his friend who are high school students in NYC. Their hobby is science. Physics, to be precise. In the above picture (blurry -- the train provides a very bumpy ride), you can see Nick with one of his physics experiments, a potato gun that he designed and built using PVC pipe. Since I have designed and built a few items from PVC myself (mostly…
drorzel | June 3, 2009For reasons that don't really matter, I learned yesterday that there is a marathon in Antarctica:
On December 12th, 2009, the fifth Antarctic Ice Marathon will take place at 80 Degrees South, just a few hundred miles from the South Pole at the foot of the Ellsworth Mountains. This race presents a truly formidable and genuine Antarctic challenge with underfoot conditions comprising snow and ice throughout, an average windchill temperature of -20C, and the possibility of strong Katabatic winds to contend with. Furthermore, the event takes place at an altitude of 3,000 feet.
That's one of the…
rallain | June 3, 2009I haven't seen the Pixar Movie "Up" yet, so don't spoil it for me. I have, however, seen the trailer. In my usual fashion, I have to find something to complain about. There is this scene where the old man releases balloons out of the house.
What is wrong with this scene? Also, would that be enough balloons to make the house float? Here is a shot of the balloons coming out of the house.
Ok, I was already wrong. The first time I saw this trailer I thought the balloons were stored in his house. After re-watching in slow motion, it seems the balloons were maybe in the back yard held down…
drorzel | June 1, 2009Two noteworthy things in the meta-blog category:
1) The 3 Quarks Daily science blogging prize nominations are up, and it's a great list of sciencey bloggy goodness. If you're looking for a way to procrastinate, you could kill several days reading all 171 entries.
Once you're done reading them, go vote for your favorite. The top 20 vote-getters will be the shortlist given to Steven Pinker to choose the winners from.
2) Not on the list yet, but sure to provide some quality entries next year is the brand new X-Change Files blog from the Science and Entertainment Exchange. They're providing…
pontiff | June 1, 2009What in the world is a review for Star Trek doing in Nature Physics? (Thank to reader W for pointing this out.) I mean, at least the review of Angels and Demons has references to physics, but the review of Star Trek, is, well, just a review of Star Trek with no reference physics or science or, well, anything that I could see the audience of Nature Physics relating to.
I'm not saying I don't appreciate the review, or the book/art section of Nature Physics, but doesn't this seem a bit out of place. It is too bad, indeed, because the movie does contain time travel, and as Cosmic Sean…
drorzel | June 1, 2009Today is the first day of the last week of class, hallelujah. Unfortunately, it's also the first class on rotational motion and angular momentum. This is unfortunate because it's the hardest material in the course-- angular momentum doesn't behave in as intuitive a manner as linear momentum, and the math involved is the most complicated of anything we do in the course.
This mostly has to do with the vector product, or "cross product." Angular momentum can be written as the product between the position vector from the axis of rotation to the moving object and the linear momentum of the moving…
esiegel | May 31, 2009(It's just good, clean physics, I swear!) Last week, my buddy Lucas was watching a BBC documentary about petulant musician Mark Oliver Everett (of the Eels), and his quest to understand his father, the late physicist Hugh Everett.
Hugh Everett is famous as the discoverer of the many-worlds interpretation of quantum mechanics, which is a fascinating -- although speculative -- idea about how the Universe fundamentally works.
Imagine you have a wall with two slits -- very close together but distinct -- with a screen behind it. If I throw very small grains of sand at this wall, we can predict…
rallain | May 29, 2009My brother found this, but he is too afraid of the internet to post something in the comments on my previous post about acceleration and the iphone. It turns out that this too awesome to just be in a comment. It deserves its own note.
Anyway, I was looking for acceleration data from the iPhone and this guy put one in his model rocket.
iPhone Rocket Launch and Interview (from MobileOrchard.com) from Mobile Orchard on Vimeo.
Here is some more detail (with graphs!) about the iPhone model rocket.
rallain | May 29, 2009Here is another one from a great podcast - Buzz Out Loud. I totally can't remember which episode it was, I listened to a several in a row mowing the lawn and doing outside type work. Anyway, the discuss was along the lines of:
Could an iphone tell if your parachute didn't open with its accelerometer?
The first and simplest answer would be "no". When you are skydiving, you quickly reach terminal velocity such that you are no longer accelerating. Maybe the built in GPS could use elevation data, but it seems like that is rarely used (and not very accurate). There is perhaps a way that work…
pontiff | May 29, 2009Recently I finally got a chance to read the new preprint arXiv:0905.2292 "A new physical principle: Information Causality" by M. Pawlowski, T. Paterek, D. Kaszlikowski, V. Scarani, A. Winter, and M. Zukowski. It's been a long time since I spent more than a few spare hours thinking about foundational issues in quantum theory. Personally I am very fond of approaches to foundational questions which have a information theoretic or computational bent (on my desktop I have a pdf of William Wootter's thesis "The Acquisition of Information From Quantum Measurements" which I consider a classic in…
drorzel | May 29, 2009Why do we have two meter sticks taped together back to back?
What is the dark stain obscuring the markings between 30 and 70 cm on half of the meter sticks?
Where the hell are all the stopwatches?
Why are the demo magnets sticky?
Why do we still have six meters worth of a rusting, broken torsional wave demonstration?
Why are the springs sorted into drawers with color labels ("Springs-Red") when all the springs are the same color, and there's no particular correlation with the spring constant?
Why do we have five hundred yellowing sheets of newsprint?
Why are the metal projectiles stored in an…
drorzel | May 28, 2009We're having some technical difficulties on the ScienceBlogs back end, so this may be futile, but I've got a 9am lab class, so here's a Dorky Poll in hopes that the comments will work well enough to be entertaining. Today's lab is the "ballistic pendulum," in which students use conservation of energy and conservation of momentum to measure a projectile's velocity, and next week's lectures are on conservation of angular momentum, so the poll topic seems obvious:
What's your favorite conservation law?
Conservation of energy? Conservation of linear momentum? Conservation of angular momentum? If…
esiegel | May 26, 2009There are very few sources of truly clean energy out there. Coal, oil, natural gas, etc. all expel tremendous amounts of carbon dioxide into the atmosphere, something we know we need to stop doing very soon if we want our planet to be habitable to humans for very much longer. Biofuels, while not as harmful as fossil fuels, still emit tremendous amounts of carbon dioxide, and are not a long-term solution. Modern nuclear power produces low amounts of carbon dioxide, but significant amounts of radioactive waste, which isn't good for anybody! Even hydroelectric power has disastrous environmental…