Paul A. Heckert's Blog
Posted by Paul A. Heckert
Santa Claus must be real. I know this because an eight year old girl named Virginia read it in the newspaper over 100 years ago. If you need more proof that Santa is real, don a red suit and walk into a roomful of three and four year old children.
Yet there are those who persist in trying to use physics to prove that Santa is impossible. They use arguments based on the distance Santa would have to travel, the time available on Christmas eve, and the speed his sleigh would have to travel. Other arguments include the fact that reindeer are somewhat less aerodynamic than an F16 and the size and weight of presents for all the good little boys and girls in the world.
Others use physics, and its resultant technology, to show how Santa can accomplish his annual deliveries. He might travel through a wormhole to get from place to place faster. Perhaps an anti-gravity device allows even non-aerodynamic reindeer and sleighs to fly. Rather than carrying all the gifts the entire way, nano-robots could manufacture them in flight as Santa approaches a house.
Perhaps it's not about physics and technology. It might be magic. But then Arthur C. Clarke says that sufficiently advanced technology is indistinguishable from magic.
Posted by Paul A. Heckert
Evel Knievel died last week. He first became famous in the 1960s as a daredevil jumping his motorcycle over cars, busses, and so forth. He wasn't always successful, breaking about 40 bones in his career.
Figuring out how fast Evel Knievel needed to launch his motorcycle to make a jump involves physics projectile motion problems. A projectile launches at some initial speed and angle. Once released, only gravitational forces act on it until it hits the ground.
How fast did Evel Knievel need to ride his motorcycle to complete his jumps? We need to know the distance of the jump, the height of the landing compared to takeoff, and the angle of the ramp propelling him upward. A 45 degree angle would give the greatest range but is unrealistic. A ramp at a 10% grade would be more realistic. Let's assume he lands at the same level he takes off from. Let's also neglect air friction, which means he would need to start a little faster to make a jump.
Doing the calculation, I get a minimum speed of a little over 100 miles per hour for one of his famous early jumps - 150 feet over 19 cars. That's not impossible, but missing the landing would result in broken bones or worse.
Evel Knievel's most famous attempt was the Snake River Canyon in 1974. Doing the same calculation, I find that jumping nearly 1600 feet requires a minimum projectile launch speed of over 330 miles per hour from a 10% slope. He attempted that jump on a rocket propelled motorcycle, so it was not a projectile in the physics sense. The rocket continued pushing him forward, eliminating the need for this impossibly high initial speed.
Posted by Paul A. Heckert
On a trip to the Dominican Republic I went for an early morning run along the beach. As the sun peeked over the eastern horizon and illuminated the clouds breaking up from the previous night's storm, a beautiful rainbow formed over the ocean.
A local woman also doing her morning workout was the only other person on the beach. Not knowing the Spanish word for rainbow, I just pointed, as I passed her. When she said, "Es muy bonito", I lacked the Spanish skills to do more than simply agree. Despite lacking a common language we were able to communicate our appreciation of nature's beauty.
The rainbow added to my enjoyment of my run. As a scientist, I can also explain what causes the rainbow. (Perhaps some day I'll even learn enough Spanish to explain it to the woman on the beach.) Some might argue that dissecting how the light reflects internally in the raindrops and disperses as it refracts on the raindrops' surfaces spoils the simple beauty of a rainbow.
Just as knowing it was composed by a man losing his hearing can increase the sense of awe from hearing the Ode to Joy, understanding the physics behind natural phenomena enhances their beauty and increases one's sense of wonder at them.
Upon returning to the hotel, I asked at the desk and learned that the Spanish word for rainbow is "arco iris", which literally means "arc color".
Nature's simple gift enhanced my morning run, transcended a language barrier, and helped me learn a new Spanish word. Knowing what causes rainbows increases their beauty.
Posted by Paul A. Heckert
One cold winter day over thirty years ago I tried running around the indoor track at a local YMCA. I thought it might be preferable to running outside in the cold. After about 5 miles at 10 laps to the mile, I decided that I hated indoor tracks. I would rather run outdoors in even the worst weather than run endless laps around an indoor track. I vowed to never run indoors again. I haven't.
No matter what the weather is, I always run outdoors. I have run in southwestern deserts with the hot sun beating down on me and vultures circling overhead thinking that dinner would soon be ready. At the other extreme, I have run in Nebraska blizzards with bone chilling winds penetrating what should have been enough clothing layers. Being too dark to see where I am putting my feet, deep snow, slippery ice, extremely humid heat, rain, and hail are all preferable to endless indoor laps. But outdoor running also offers many rewards.
Nature has treated me to rainbows and gentle waves caressing my feet during early morning runs on a beach. A beautiful mountain vista awaits after climbing a steep trail. Trails in the Grand Canyon, Bryce Canyon, and other national parks offer unparalleled scenery. Running in a cool gentle summer rain is its own reward as is making the first tracks in a fresh snowfall.
Daily outdoor runs allow me to experience all that nature has to offer.
Posted by Paul A. Heckert
I recently read a short news article about the dangers of walking while talking on a cell phone. We have heard about the possible dangers and distraction of trying to drive while talking on cell phone. This article was the first I had read about possible dangers of using cell phones when walking. Apparently pedestrians are just as likely to be distracted by cell phones as drivers. While distracted they can do dangerous things like walk into traffic. If a car and a pedestrian collide, it's not hard to figure out who gets hurt more.
In a half marathon I ran about a month ago, the race organizers outlawed the use of iPods during the race. It is a safety issue. They wanted runners to be able to hear as well as see traffic, and therefore reduce the chance of a runner being hit by a car in the race.
I have never had any desire for either of these devices while walking or running. I prefer to simply enjoy the outdoors without electronic distractions. I had never thought of the safety issue, but it makes sense.
In the winter months more people walk or run in the darkness. For safety if you walk or run after dark, do what you can to increase your visibility. For added safety, make sure that you don't decrease your ability to hear traffic. Also make sure that you are not distracted. Pay attention to what you are doing. Leave your cell phone and iPod at home when you walk or run after dark or near traffic.
