Edwardo Crum's Official Blogging Page

The following was taken from Peter's Physics homework. I added two sets of parentheses to make the example more accurate...

Humans rarely survive long falls, but cats apparently have much better luck. A study published in 1987 considered 132 cats who had "accidentally" fallen from heights of two to 32 floors (6 to 98 meters), most of them landing on concrete. About 90% survived, and about 60% even escaped injury. Strangely, the extent of injury (such as the number of fractured bones or the certainty of death) decreased with height if the fall was more than seven or eight floors. (The cat that fell 32 floors had only slight damage to its thorax and one tooth and was released after 48 hours of observation.) Why might a cat have a better chance of survival in a longer fall? (The survival is by no means guaranteed, so if you live in a high-rise apartment, be sure to keep your cat away from any open window.)


Answer If a drowsy cat "accidentally" topples from a window sill, it quickly and instinctively reorients its body until its legs are underneath. The cat then uses the flexibility of its legs to absorb the shock of the landing: The flexibility lengthens the time of the landing and thereby reduces the force on the cat.


As a cat falls, the force of air drag that pushes upward on the cat increases. If the fall is from the sill onto the floor, the air drag is never very much. But if the fall is longer, then the air drag may become large enough to reduce the cat’s downward acceleration. In fact, if the fall is more than about six floors, the air drag can become large enough to match the gravitational force pulling downward on the cat. The cat then falls without acceleration and with a constant speed called terminal speed.


Unless terminal speed is reached, the cat is frightened by its acceleration and keeps its legs beneath its body, ready for the landing. (Your body is also sensitive to accelerations rather than speeds.) But if terminal speed is reached, the acceleration disappears, and the cat relaxes somewhat, instinctively spreading its legs outward (in order to increase the air drag on it) until it must finally get ready for the landing.


Once the cat spreads out, the air drag automatically increases, which reduces the speed of the cat. The longer the fall, the more the speed is reduced, until a new and reduced terminal speed of about 100 kilometers per hour is reached. Thus, a cat falling from, say, 10 floors will land with a speed that is less than that of a cat falling from five floors and will have a better chance of escaping serious injury.




Copyright © 2007 John Wiley & Sons, Inc. All rights reserved.

I am an introspective kind of guy, which is a good think to be when you've got so much valuable wisdom to share with the world. Today I'd like to talk about anger, specifically the manifestation of anger which often appears as losing one's temper. I have noticed that I have the tendency to get really angry at inanimate objects, which if you stop and think about it is really stupid. Just the other day I was emptying the trash can, taking the bag out of the can, when pieces of trash started falling out the top onto the floor. "Man!" "Don't do that!" "Stupid trash!" Of course my talking to the garbage was peppered with the appropriate descriptive adjectives and an occasional colorful noun. Finally I got all the trash back in the bag, and outside ready for collection. On may way back through the backyard, I had one of those moments, kind of a cross between an epiphany and an embarrassed thankfulness that no one had seen my behaviour. I realized that the individual pieces of trash could do nothing except obey the natural laws of physics. That trash can would have stayed undisturbed and peaceful for a millenia had not I shown up to take it away. It was I, no one and nothing else that had initiated the chain of events which caused some of the garbage to end up on the floor. This poses somewhat of a dilemma; if I shouldn't be angry at the trash, and I hadn't intentionally done anything wrong, logically there was no reason to be angry... But the fact remains that I had become angry; why had this happened? The simple fact of the matter is that the whole incident was a big misunderstanding. I at the time had felt that the trash was intentionally messing with me. Because the trash was unable to defend its actions I lashed out and took my frustration out verbally. Fortunately, because I am an introspective person, I was able to settle down, look at it from the trash's perspective, and recognize that it really wasn't the trash's fault. I walked away from this whole situation a better person, and now that I'm so humbly reporting it to you, I know that you'll be better people too.

Counting Crows; August and Everything After, King's X; Dogman, Neil Young; Mirrorball. These are just a few of the albums missing from Peter's collection.

I've been hanging out here at the Colorado Crum family abode for the past few days, and I've been keeping track of what my eyes have seen. Let me give you a brief glimpse into this strange world:

8:15 am Aravis is the last one up. She shuffles downstairs to find Peter and Jude on the couch playing "just one game" of Halo Reach. Peter shows enormous amounts of self-control when he actually puts down the controller (Jude scored 24, Peter a measly 8) and heads upstairs to do some homework.

9:00 am the dogs have been fed, the kids are eating breakfast, I'm laughing at the fact that Peter has his DVDs arranged in alphabetical order.

10:37 am I am tired of watching Phineas and Ferb, so I head upstairs to find Peter drawing birthday cards instead of doing homework. He apparently feels bad that he's missed so many birthdays, so he's in the process of "catching up".

12:00 pm grilled cheese (with mozzarella), macaroni and cheese (from a box), chips and salsa, and cherry-apple juice for lunch.

12:35 pm Ashley is watering the garden, Aravis is reading Charlie and the Chocolate Factory and Jude is doing something on Facebook. I head back downstairs to take a nap.

3:00 pm Peter is yelling something about getting shoes on and going to a park.

3:03 pm We are heading out to the car, the dogs go in the modified trunk and off we go.

3:10 pm Garter snakes seem to be the primary purpose for this excursion, we have such a weird family.

I could bore you with how the rest of the day went, not really much to say though.

I have become more and more frustrated in a Huckleberry Finn kind of way.

I am repressed.

The outlet of my expression has been stifled by an adherence to my beliefs. For example; I feel comfortable saying that someone can "go take a hike!" but more colorful destinations seem inappropriate to my sensibilities. Is it wrong that I desire to have a broader, more inclusive vocabulary? I am expected to clearly and concisely use the acceptable terms, grammar and cultural references in all my communication. I find this to be extremely inhibiting. Should I feel inhibited? Therefore, I have decided to start another blog, under a pseudonym which I will never reveal. On this other blog I will let me words flow, every which way they want to go.



P.S. I just did a little internet research, it seems like about 5 million people already had this idea, so it'll be a lot harder for you to find me...

It seems that the warnings are everywhere. Be careful what you post online, one day it will catch up with you. Obviously partying college students should be careful because very soon they will be looking for employment and that drunken trip to Burger King will exist on MySpace forever... Or will it? Are we so self-absorbed that we really believe that anything we do today will last forever? Sure, of course there are those blogs that rise above the rest, distinguishing themselves as something meaningful and worthwhile. I have little doubt that this blog for example will be studied and discussed in Ancient History classes 3000 years from now. As the Internet gets fuller and fuller of crap, each individual item becomes less and less important. Eventually the whole Internet will become a complete waste of time and will be abandoned. Of course some will continue to update their Profiles, completely out of habit of course, but this will be done without even looking at any given site. Monitors will become obsolete in about three or four years, because the only thing the Internet will be good for is dumping useless information. "Posting your status" will become analogous with "using the bathroom"... It's just something you do, but no one really wants to know about it.