Everest: how science conquered the world's highest mountain
Mount Everest was once the domain of elite mountaineers.
In the week of the 60th anniversary of the first ascent, the world's highest peak was climbed by 80 year old Yuichiro Miura of Japan.
The peak has also been climbed by a 13 year old and a blind athlete.
Technical advancements, increased safety and decreased cost have seen growing numbers attempt to scale the world's highest mountain.
How has science made Everest an easier mountain to climb?Summit made simpler
It was not known whether Everest could be climbed at all until 29 May, 1953 when Sherpa Tenzing Norgay and New Zealander Edmund Hillary were the first to reach the summit. Much of their gear was newly developed and experimental.
Since then, over 3,000 people have reached the summit and thousands more have tried.
Over three-quarters of all people who have climbed Mount Everest have done so since the year 2000.
Around 300 people have lost their lives on the mountain, though the death rate has dropped significantly in the last 20 years due to an increased understanding of how to safely climb Everest.
"Scientific and technological advancements have definitely made climbing Everest easier and safer," says Michael Kodas, author of High Crimes: The Fate of Everest in an Age of Greed.Safe and sound
Oxygen tanks are used by 95% of climbers. Two days before Hillary reached the top another team got within 100 metres of the summit before they had to turn back when their oxygen system failed.
Modern systems are designed to exclude moisture from the regulator and tubes to stop it freezing.
They are less than half the weight of the original systems, though the canisters needed for a summit bid still weigh over 10 kg and occasionally fail.
In 1953, the expedition set up radio masts between base camps. They were able to communicate over walkie talkies and even listen to a broadcast of the Queen's coronation.
Later, satellite phones allowed communication at any point on the mountain, and now 3G mobile phone coverage is available. This means climbers can be in constant contact with support teams or experts off the mountain.
Weather forecasting is more accurate and draws on satellite data to let climbers know when there is due to be a period of good weather to make a bid for the summit.
Modern climbing gear - ropes, crampons and ice axes - are lighter, stronger and now less likely to develop faults, and gloves and boots are electrically heated to reduce the chance of frostbite.
Alan Arnette, who has summited Everest seven times and runs a popular Everest blog, says improved material science makes individually small but welcome contributions, for example "Vibram on the soles of boots to increase grip, Goretex for lighter clothes and nylon for ropes."Ready to climb
Besides the improvements in gear, the mountain itself has been modified - ladders and ropes are installed on some sections, maintained by specialist Sherpa "icefall doctors".
This means ascents are quicker, safer and less fatiguing - making accidents less likely.
"There are a lot of resources and support available right on the mountain," says Kodas. The group sizes are larger than ever, which makes it easier to assist an injured or sick climber and help them back down the mountain.High altitude
- Everest (8848m) was named after Sir George Everest, the British Surveyor-General of India 1830-1843.
- It is known as Sagarmatha in Nepali and Chomolungma in Tibetan.
- Everest was confirmed as the world's highest mountain in 1852 by Indian surveyor Radhanath Sikdar.
"Many expeditions have medical equipment and monitors in their base camps to help athletes acclimatise and measure their progress," says Kodas.
Many climbers will develop altitude sickness, caused by lack of oxygen to the brain and lungs, which can be life-threatening. While effective drugs have been developed to reduce swelling and fluid retention, this can also pose problems, says Kodas.
"If a climber who is feeling weak uses Dexamethasone (an anti-inflammatory drug) to get to the summit and then the drug wears off, they are in worse shape and in a more dangerous place than they were when they initially used the drug."Death risk
In 1990, the death rate (fatalities compared to successful summits) was 37%. In 2012, it was under 2%, as 10 people lost their lives to the 548 who successfully summited. So have scientific, technological and medicinal advancements tamed Everest?
Alan Arnette does not think so: "While factors such as weather forecasting and better gear contribute in making Everest safer, it is still extremely dangerous, with deaths each year."
"Altitude sickness can strike anyone at any time," adds Arnette, "even those who had never had altitude issues and in spite of doing everything properly - including acclimatisation programmess and use of bottled oxygen."
"The best teams have Sherpas and guides who are trained to recognise these symptoms and turn the climber back, the only true response to any altitude-related incident."
Exhaustion, extreme weather and accidents also claim lives on the mountain. Even with modern medical treatments and gear, climbers will continue to die on Everest.Overcrowded
Because it has become safer and cheaper, more people attempt to climb Everest than ever before.
"The crowds can cause problems," says Michael Kodas.
"You're trying to get hundreds of people who speak different languages and have different values to cooperate in a hazardous and uncomfortable environment."
"Crowds mean more debris - snow, ice, rock, equipment - getting knocked down on other climbers, tent sites fill up and get overcrowded, and anyone who gets into trouble can draw many others into their rescue, thereby putting the other climbers at risk as well."
This caused tension in April 2013 when two climbers were involved in a fight with Sherpas.
The climbing season on Everest runs April through May, with only a few days every year offering a window in the weather to allow a bid for the summit.
"The more time you spend in the hazardous areas of the mountain, the more likely you are to have problems. So, a slow climber can put everyone else at risk," says Kodas.Climbing trend
"Scientific and technological advances have definitely made the act of climbing on Everest easier and safer for the individual," says Kodas. But this means inexperienced people can "crowd the peak, where they may find themselves in over their heads and endangering other climbers."
Similarly, Alan Arnette warns: "not everyone can climb Everest."
"It takes an uncommon dedication to physical training and mental toughness. Climbers need to have experience on other high altitude mountains so they are more self-sufficient and prepared if something goes wrong."
"Climbers who are accepted by guides without this experience are dramatically increasing the risk of a deadly incident."