La Casa en el Aire (literally “The House in the Air” in Spanish) is a unique hostel located on a cliff face, about 30 meters above the ground, in the Colombian mountains.

Built primarily out of wood and featuring a tin roof, the cheap hotel is attached to a bridge that rises up among the area. It is held in place by several steel wires connected to the cliff and supported by a long wooden pole also placed against the cliff. It stands about 20 meters above the ground, at an altitude of about 2,500 meters above sea level.

La Casa en el Aire is the brainchild of Colombian mountain climber Nilton Lopez, who recently said that building this unusual hostel meant realizing an old dream of his. He is most proud of the fact that his creation is practical, with electricity being produced by solar panels, and all rubbish being collected and transported to Medellin.

Apart from staying and sleeping in a cabin hung on the side of a huge rock, visitors of La Casa en el Aire can also involve in a variety of exciting activities, such as bungee jumping out of the house or spending the night in hammocks(吊床)hung on steel wires above the house.

Because the hostel is located in a faraway area of Abejorral, with no easy access to food and water, visitors are encouraged to bring long-lasting foods (dry bread, cookies, etc.), as well as five-liter bottle of water with them.

There are several changes in the procedure for employees who wish to apply for vacant positions within the company. These changes make it much easier for in-house employees to fill vacancies that occur.

First, the most important difference is that employees will now be notified of all available positions before the positions are advertised for the general public. Accordingly, all in-house candidates will be interviewed before we see any outside candidates, and we will offer the job to outside candidates only if no current employees are able to fill the position.

Second, under the new procedure, in-house employees can be hired even if they don’t meet all job requirements. Under our old policy, in-house employees had to meet all job qualifications in order to obtain the vacant position. Now, however, employees who have proven themselves dedicated to the company will be hired for a vacant position even if they are lacking in some minor qualifications; training will be provided.

A third change involves recommendations. From now on, employees do not need to be recommended for an in-house position before they apply. Instead, employees may apply as soon as they are aware of the vacancy. The remaining procedures and policies (those regarding increase in pay, interview procedure, and hiring approval) remain the same.

It had always been assumed that the rarity of lightning in ocean storms was due to cleaner air over the vast seas, but keen observations have shown that even highly polluted air is associated with reduced lightning at sea when sea spray aerosols (气溶胶) are abundant. In their paper published in the journal Nature Communications, an international team of researchers describes their multi-year study of atmospheric conditions over the oceans bordering Africa and what it showed about salt in sea spray aerosols and its impact on lightning.

The researchers obtained atmospheric data on Africa and the oceans around it for the period 2013 to 2017. The data included numbers of lightning flashes, rainfall, temperatures and cloud representations. They looked for differences in atmospheric conditions in storms that occurred over land versus those that occurred over the sea and found one main difference: the amount of salt in the air.

Lightning is produced when upwardly moving air in clouds forms ice crystals (冰晶) — aerosol particles then begin to bump into one another, creating an electrical charge. Lightning happens when the electrical field in one part of the cloud becomes positively charged (usually at the top of the cloud) and another negatively charged (usually at the bottom of the cloud). And clouds form, of course, when vapor evaporates (蒸发) from the surface of the Earth and the water drops bond with aerosols.

The researchers found that things are slightly different over the ocean. When water evaporates from the sea, it bears a load of salt. When the salt water bonds with aerosols to form water droplets, they tend to be bigger and heavier than those that form over land due to the salt — and that results in more of the water in the clouds falling as rain before it can rise up and form ice crystals. The result is far fewer lightning discharges.

The researchers suggest their findings could be useful in improving the accuracy of both climate models and meteorological reports. It could also possibly lead some to attempt to seed storm clouds with salt to reduce their severity.