The Guinness World Record for breath-holding belongs to Aleix Segura Vendrell, who managed 24 minutes and 3 seconds floating in a pool. How do Vendrell and others, like free divers and, er, David Blaine (see below) do it? Psychological training is obviously the first step, says Clayton Cowl, chair of preventive occupational and aerospace medicine at the Mayo Institute. But there's physiology at work too. From Smithsonian:
Olympic swimmers seem to be able to go great distances without breathing, but that is primarily due to aerobic conditioning, says Cowl. Those athletes are more efficient at getting oxygen into the tissue and extracting carbon dioxide. That allows them to breathe more effectively, and potentially, improve their breath holding.
Just being in the water may confer additional breath-holding ability. All mammals have what is known as a diving reflex. The involuntary reflex is most obvious—and pronounced—in aquatic mammals like whales and seals. But humans have this reflex, also. The purpose seems to be to conserve the oxygen that is naturally stored throughout the body, according to one study.
When a mammal dives into the water, the heart rate slows, and the capillaries of extremities like arms and legs—or flippers—constrict. Blood and oxygen is redirected towards the internal organs. The reflex helps diving animals override the need to breathe, which means they can stay underwater longer.
"What’s the Longest You Can Hold Your Breath?" (Smithsonian)
In Beijing, China banned 2.5 million cars from driving for 2 weeks to get this beautiful blue sky for a World War II commemorative parade. As soon as the parade was over, the ban was lifted, and the blue vanished within 24 hours. Read the rest
Reporting this week at the annual American Geophysical Union, scientists from UC Irvine discussed air quality results from samples taken during the 2012 and 2013 Hajj.
The annual pilgrimage brings between 3-4 million people to the holy city of Mecca. Isobel Simpson, the lead researcher on this project, stated that, "The problem is that this intensifies the pollution that already exists. We measured among the highest concentrations [of smog-forming pollutants] our group has ever measured in urban areas – and we’ve studied 75 cities around the world in the past two decades.”
The worst locations were tunnels leading into the Grande Mosque where carbon monoxide levels were up to 300 times higher than baseline measurements, and pedestrians were often walking in large numbers alongside idling motor vehicles. Increases in carbon monoxide are linked to increased numbers of hospitalizations and deaths from heart failure. In addition to carbon monoxide, the team found elevated levels of benzene, black carbon, and other fine particulates that can affect lung function.
The main culprit here that can be addressed by the Saudi government is a lack of regulation over automobiles, gasolines, and exhausts. Currently, there is a significant lack of public transportation in the area, and nearly everyone owns a car. Those cars don't have the devices that are currently required and built into vehicles in the Unites States to limit pollution.
The easiest thing to fix would be separating pedestrians from cars in the tunnels, or at least spreading vehicles out more evenly among the tunnels leading to the Mosque, so that pollutants don't build up as much and negatively affect those walking in. Read the rest
There are facts that just aren't apparent from our everyday perspective. Sometimes, in order to really get a scientific concept at the gut level, you have to seek out a different way to view the world. Do that, and you'll find yourself emotionally gobsmacked by well-known concepts you'd long ago accepted intellectually.
For instance, watching this video montage of 9 weeks worth of infrared images from NASA’s GOES-East satellite, the lizard-brain part of me was struck with a sudden realization, "Oh my god. Air really is a fluid, isn't it?"
Thanks to Patrick di Justo for making this and blowing my mind just a little.