When a hitter makes solid contact with a baseball, the ball leaves the bat travelling very fast. The type of bat matters — ball speeds are higher with aluminum and newer composite bats than they are with wood bats. Why? Wood bats are solid. When one smacks a ball, the bat stays fairly rigid and the ball flattens out for a millisecond, absorbing some of the energy in the bat-ball collision. Aluminum and composite bats are hollow. When they strike a baseball, the bat gives. That means more of the energy of the bat-ball collision is transferred to the “bounce” of the ball off the bat. Harvard Health Letter editor Peter Wehrwein talks with experts in sports injury, the physics of baseball, and bat testing to explain connections between bat type and injury.
Archive for March, 2011
It can be hard to understand what the release of radiation from Japan’s earthquake-damaged Fukushima Daiichi nuclear power plant means in terms of human health. Are the radiation levels dangerous and, if so, how dangerous. Most reporters put the risk into perspective using words. Cartoonist Randall Munroe and nuclear reactor operator Ellen McManis have put together different ways of illustrating the risk visually, while radio producer Adam Ragusea offers an audio illustration of various radiation exposures.
A panel discussion at Harvard School of Public Health called “Boosting Vitamin D: Not Enough or Too Much?” highlights the current controversy over the once-overlooked sunshine vitamin. A panel of experts assembled by the Institute of Medicine recommends a daily dose of 600 IU per day for everyone from ages 1 to 70 and 800 IU for those over 70. Other experts think the IOM recommendation is too low. One way to get vitamin D is to spend a few minutes a day outside in the sun, but that’s a hot-button issue because sun exposure is a cause of skin cancer.
New government statistics show that there are nearly 12 million cancer survivors in the United States. In many ways this is terrific news, and a testament to improved diagnosis and treatment options. But there’s a flip side to surviving cancer, and many survivors are never totally “free” of the disease. The ongoing psychological and emotional issues can be almost as much a challenge as cancer treatment was. Harvard Health editor Ann MacDonald explores the ongoing fear of recurrence, survivor guilt, the “Damocles syndrome,” and more.
Minutes after I posted my article today about radiation from the damaged Fukushima Daiichi nuclear power plant not reaching the United States in harmful amounts, I heard a news report about iodine-131 from the plant being detected in rainwater in Massachusetts. Iodine-131 is a radioactive form of iodine. It’s a byproduct of the reaction that [...]
Even though the situation at the earthquake-damaged Fukushima Daiichi nuclear power plant in Japan remains unsettled, the likelihood that radiation released by the crippled power plant will reach the United States is slim. Harvard Health Letter editor Peter Wehrwein talks with Dr. Richard Zane, a disaster planning expert at Harvard-affiliated Brigham and Women’s Hospital, about potassium iodide pills: what they can—and can’t—do, their benefits and hazards, and why Americans should not be stockpiling or taking them.
• LINK TO VIDEO • In early March, I had the privilege of participating in a seminar on stress at Harvard Medical School. The talk was part of a free series called the Longwood Seminars which covers common medical topics. Although I was asked to talk about stress and the heart, I devoted most of [...]
Heart failure, the condition that took Elizabeth Taylor’s life, affects millions of Americans. The term “heart failure” is a scary one, conjuring up images of a heart that is suddenly unable to work. In truth, it represents a gradual decline in the heart’s ability to pump enough blood to meet the body’s needs. As the heart weakens, all parts of the body suffer the consequences. Harvard Heart Letter editor PJ Skerrett explains what heart failure is, how it affects the body, and what can be done to treat it.
Having sex (or performing any kind of physical activity) triples the risk of having a heart attack, according to a new study. But there’s more to the story. The odds of having a heart attack during sex are about 1 in one million; tripling the risk boosts it to 3 in one million. In other words, sex can cause a heart attack, but usually doesn’t. And the more a person exercises, or has sex, the lower the chances of having a heart attack during the activity.
Many suicides are impulsive, with just minutes or an hour elapsing between the time a person decides upon suicide and when he or she commits the act. Yet the stressful events that lead to suicidal thoughts are often temporary, such as losing a job or having a romantic relationship end.