force
dr. dolittle | November 17, 2015 Testing the bite force of American cockroaches. Image from: Tom Weihmann | University of Cambridge
I'll admit I get a bit squeamish when I see a cockroach. However, after reading new research about the "ew" inspiring creatures, I have a bit more respect for them.
Not only can these bugs run vertically up walls, survive nuclear war and live without their head for weeks (thus I suggest squishing the whole body), new research published in PLOS ONE shows they have super-biting powers. The research team measured bite force using a sensor (shown in the image above).
The reason for doing the…
dr. dolittle | August 21, 2014 Image of a green tree python from www.kids.britannica.com J.H. Pete Carmichael—The Image Bank/Getty Images
Dr. Greg Byrnes (Siena College, Loudonville, NY) and Dr. Bruce Jayne (University of Cincinnati, OH) discovered that snakes use more force than is necessary to support their weight when climbing. To climb, snakes rely on friction and repeatedly contract and extend their bodies, a process called concertina locomotion. To study the forces generated by snakes during this type of locomotion, the researchers constructed a vertical cylinder that was covered with textured tennis racket tape…
esiegel | October 4, 2013"Time is a sort of river of passing events, and strong is its current; no sooner is a thing brought to sight than it is swept by and another takes its place, and this too will be swept away." -Marcus Aurelius
Every one of us does our best to come up with an accurate picture of reality, and that includes the Universe, from the smallest subatomic particles to the largest scales fathomable. But given how bizarre and counterintuitive some of our physical laws are -- even at a fundamental level -- this can be a daunting task for even those of us who are professional theoretical physicists.
Image…
esiegel | June 27, 2012"I found I could say things with color and shapes that I couldn't say any other way -- things I had no words for." -Georgia O'Keeffe
When it comes to the Universe, it isn't just the stuff that's in it that's important.
Image credit: 2MASS Extended Source Catalog (XSC).
It's also how all that stuff interacts with itself and everything else. To the best of our knowledge, there are four fundamental forces in the Universe, and they're all essential to our existence.
Image credit: Stichting Maharishi University of Management, the Netherlands.
Some of them are familiar, like gravitation. On the…
drorzel | August 27, 2010I'm pretty sure I've used this topic before, but not with PollDaddy. And while I really ought to do a ResearchBlogging post today to make it a clean sweep for the week, I just don't have the energy.
So here's a poll: what's your favorite fundamental force?
What's your favorite fundamental force?online surveys
Those of us with corporeal existence should restrict our answers to the low-energy condition of the present material universe, not any of the higher energy unification scales.
rallain | August 7, 2010I have seen several videos similar to this.
Real? Fake? How many tries did this take? Let the analysis begin. Before I do any analysis, let me state that I think this is not fake. I do not know that for sure, just my first guess.
How would I tell if it is real or fake? This is tricky. I can't really get a good trajectory of the ball to make some measurements on it because of the camera angle (next time people, make sure you set the camera up perpendicular to the plane of motion and far enough away to avoid perspective problems - thanks!) Really, the best I can do is to look at the…
rallain | June 4, 2010I got tired of attacking ESPN Sport Science. Well, tired of attacking might not be the best term. How about, attack in a new way (here are my older Sport Science attacks).
Check out episode 1 of Spoof Science:
A couple of notes:
Watch it youtube if you want the HD version
Making videos takes WAY longer than a blog post
If you hate hearing your own voice, you will really hate hearing your own voice AND seeing yourself while you are editing
rallain | May 17, 2010Grades are in. So, let me just say a couple of trends that I saw on the physical science final exam.
Gravity on the moon
I asked the question: "why is the gravitational force on an astronaut less on the moon than on Earth?"
The simplest answer is that the gravitational field on the moon is smaller than on Earth (I would accept that answer). Why is this? It is because the moon as a much smaller mass even though it also has a smaller radius (that idea is rather complicated for this class - that gravitational force depends on both mass and radius). I would also take "the mass is smaller" as…
rallain | April 19, 2010You probably already know how I feel about the "media" and their physics explanations (see attacks). Let me summarize the problem. There are a whole bunch of cool shows on tv that deal with sciency stuff - that is good. These shows then try to teach some science along with their demos and explosions and stuff. This is also good. However, they usually butcher the explanation part. Some of them (ESPN's Sport Science) must just literally make stuff up that sounds cool.
I understand that in common usage, things like "force" can be used lots of different ways. I am ok with that. Also,…
rallain | April 16, 2010If you have been on the internet, you surely have seen this website showing the sizes of different starships. Way cool. Here is a small sample - but it doesn't do the site justice. You really need to go browse around.
Of course, I can't let something like this just go. One of the things I always think is interesting is to consider objects of different size. Perhaps the general idea is that you can just scale stuff up or down as you like. But, it doesn't work this way. Let me start with my own spaceship. It is a sphere with a thruster on the back. It just holds one person.
Now, what…
rallain | February 14, 2010I was thinking about some experiments that deal with friction and I wanted to show something with a force probe. The problem is that most people don't have one of these. So, I decided to try and make one out of simple things. In this case, I am using some straws, a rubber band and some paper clips. Let me draw a little sketch of how this thing works.
The basic idea is to use the rubber band to measure the force (by measuring the amount the rubber band stretches). The two paper clips do two things. First, it allows you to hook up the device to something (like hanging some Lego bricks on…
rallain | December 18, 2009Fight Science is an entertaining show. Great graphics. The basic idea is to look at the science in different fighting styles. They had a clip-style commercial on it during a MythBusters episode I was watching. And from that, I can say that the kicking looked cool, but the science needs some work.
The Setup
The basic idea is that they wanted to compare kicks from different fighting styles. From what I can gather, they collected data by having some dudes kick this "kicking bag". During the kick, they measured the force exerted on the bag and they had a sensor on the kicker's leg - I…
rallain | November 20, 2009In my previous post on launching a pumpkin (punkin chunkin) I essentially just looked at what happens to the pumpkin after it is launched. How fast would you have to shoot it to go 1 mile? The answer seems to be around 1000 mph and they are currently shooting them around 600 mph.
The question for this post, how fast can you launch a pumpkin so that it does not smash into smithereens? First, why would it smash at all? Here is a diagram of a pumpkin being launched while still in the tube.
The pumpkin launcher works by releasing compressed air inside the tube. This means that the force…
rallain | February 3, 2009People say I am picky. Ok, sometimes I am. But somebody has to stand up for what is right and just. Maybe I am that person.
Please stop using the word force if you don't know what it is.
There. I said it. You can attack me now.
It wasn't just one thing that got me fired up. It was two things. First, I read this article on physics and football (Physics of 'The Hit' from the NY Times). If it was just this article, I would have let it go and moved on. But no. One of my kids just happened to be watching MythBusters (We all love MythBusters) and there was a discussion that used the term…
rallain | January 30, 2009I said I would come back to this, and I am. I am a man of my word. Yesterday, I posted a link to a video of this really cool water rocket thingy.
How does this work? What is the physics going on here? I think this can be best explained with the momentum principle.
Let me start by pretending like I have some object that shoots out a piece of water (or really it could be anything). Also, let me pretend like this is in space ore something where there are no external forces.
Above is a before and after picture. Initially, there is something (the box) with water inside. Through some process…
rallain | January 10, 2009So, here is a video (from break.com - so you know it is likely fake).
null - Watch more free videos
If for some reason, you can not view this video, here is the plot.
Guy wears parachute and brings a portable thing like a see-saw.
Guy approaches large crane dropping a large mass repeatedly (I assume to flatten a dirt road)
Guy sneaks up an puts the see-saw under the area that the mass drops on and then stands on the other end of the see-saw.
Mass drops, guy shoots up and parachutes down.
So, why is it fake? I think the best thing is to give an analysis of the see-saw. To start this…
rallain | December 30, 2008Just to be clear, Newton probably didn't have a portable video camera. I do. I have one of these Flip Mino pocket cameras. Very nice. You can put it in your pocket. However, there is a problem with cameras like these (think of video from camera phones). The problem is the mass, it is too small.
Video from a camera phone or small portable camera looks too jerky (unless you are careful). Sometimes it is jerky to the point that it makes me feel barfy. The reason this happens is that with a small mass, a force can cause a significant acceleration. Let me draw a picture (you know I like…
rallain | December 23, 2008Clearly, I am not a professional blogger. I am an amateur. This is because I was under the impression that only amateur bloggers could compete in the blogging olympics. When did they change these rules? Anyway, Adam Weiner did a physics-based analysis of the latest Star Trek movie trailer. Here is the trailer:
In the trailer (oh, spoiler alert) a young Kirk jumps out of a car before it goes over a cliff. It does look odd, and that is why I had intended to analyze it. In Adam's analysis, at PopSci.com the basic approach was:
Take the initial velocity of the car (from the clip)
Assume…
rallain | December 19, 2008I am sure I have mentioned the Discovery show Time Warp before. The basic idea of the show is to find how many cool things they can look at with an ultra slow motion video camera (btw - this is on my christmas list).
So, I have seen this Samurai guy on the show twice. Yes, he has a big sword. Yes, he could utterly destroy me if he wished. However, I can not handle him talking about physics. Mr. Samurai guy, please stop using the words "kinetic energy" until you know what they mean (I said please). Here is my first problem. Samurai guy is showing how to chop people down. He plans to…
rallain | December 1, 2008This is something I have thought about for some time. It is also something I (as a father of 4) have a lot of experience with. The problem is these infant car carriers. In the car they are not a problem. The problem is out of the car. Not sure what I am talking about? Here is a picture:
I don't mean to attack the infant carrier industry. I am sure some people really like these things. For me, there is only two situations that are good for taking the seat out of the car.
In a restaurant. The infant seat works well with those toddler high chairs. Most of the current infant seat…