Daylight savings time (also known as DST) is a practice in many states in America, which encourages people to save energy by advancing their clocks an hour so that they will have more afternoon time. This practice started in the Second World War when America experienced a great need for saving energy. A law concerning the implementation of daylight savings time was approved at this time. However, several centuries after World War II, the national government decided to amend the law and let the local governments decide whether they need to practice the DST. To avoid confusions, it is important to know when people adjust the clocks. Read more

The time when fall starts is between summer and winter. As with the other seasons, its commencement differs and is based on the hemisphere you are in. Commencement Dates In astronomical terms the season begins on September 22 up to November 22 in the Northern Hemisphere. In the United States this would cover the months of September, October and November. In the United Kingdom and other European countries, the season covers the period from August, September and October. In the Southern Hemisphere the period is reversed. The season extends from March 22 to June 22. These dates are only approximates. For example, in Australia when fall starts it is on March 1. Falling Leaves The most conspicuous sign of the season are the changing color of tree leaves. This is most apparent in Canada and the US. The phenomenon is also observed in China, Korea and several countries in East Asia. The color shifting is also prevalent in other countries like Australia, Japan and Argentina. As the winter season...

The period when summer starts is June 20 or 21 in the Northern Hemisphere. It concludes on the 23rd of September. In the Southern Hemisphere it begins around December 22 and ends on March 23. Main Characteristic Its most conspicuous element is that days are longer and it is very warm. It is the hottest of all four seasons. The reason is that as the Earth tilts, one half (the Northern or Southern Hemisphere) is fully exposed to the sun. The result is the warm weather and climate. Depending on the region, the period may also reduce the moisture in the air. The end result is that when summer starts, the air will have a “dry” feel to it. Different Periods Because they are on opposite ends, the summer or hottest months in one hemisphere will be the coldest in the other. So the warm months of June, July and August in the United States are the coldest in lower South America and Australia. The metrological aspects of summer usually begin earlier than the astronomical one. It is also worth...

The time when each season begins depends on several factors. Some of the dates adopted are based on astronomical calculations, while others for convenience. Traditional Dates In the Northern Hemisphere, winter officially starts on December 21, followed by spring on the 20th of March. Summer follows starting on June 20 and autumn on September 22. The dates occur on the opposite months in the Southern Hemisphere. The abovementioned dating are widely followed. However they are not entirely accurate. While the dates given are specific, in actual fact it is not that simple. If you look at the meteorological and astronomical aspects, the seasonal periods will start and end quite differently. Meteorological Dates The times when each season begins are determined through changes in the weather. The earliest method was to divide the seasons according to temperature increases. The months when it started to get hot would be the start and end with the coldest. Based on the system used by the Romans,...

The Mars Spirit Rover descended on Mars on January 3rd in 2004. The time was between 7:00 PM and 8:35 PM PST. Together with the rover Opportunity, it has gone on to make several important findings. The Gusev Crater The craft settled on the Gusev crater. The site was chosen because it was believed to have been a lake sometime in the past. While no evidence of this has been discovered the site itself was important. It was able to provide scientists with the information they needed to setup additional target sites. Sleepy Hollow This area was part of the Mars Spirit Rover’s destination. It was primarily used as a base for taking shots of the sun. The name was derived from the fact that it sits on a depressed surface. It wasn’t too far from this site that a rock was grinded by the craft. The craft used a specially designed tool to carry out the task; the first in history. Other Discoveries and Target Sites Other sites that the craft visited and performed examinations on were Home...

Considered as one of the deadliest illnesses, skin cancer is characterized by a development of tumor and growth of cancer cells in the epidermis. The disease has different kinds such as squamous cell cancer, basal cell cancer and melanoma. Of all the types of cancer, skin cancer is the easiest to diagnose. To diagnose the illness, it is important that patients have a background on the causes as well as the symptoms. Below are important information and details that will help individuals who want to know when was the skin cancer first discovered. Discovery of the Disease There are no sufficient documents that can support the date or the year when was the skin cancer first discovered. However, to help researchers, there are documents that they can look at, which showed that the disease was first recognized by Rene Laennec, a French physician, in 1804. Even if the disease was discovered at this year, some medical professionals agree that skin cancer was identified in 1968 by a group of scientists...

Knowing when did the Vietnam War start is very important to enhance our understanding on world history. It is considered as one of the most popular wars of all times because many countries aside from North Vietnam and South Vietnam fought against each other at this war. The war started due to the interest of North Vietnam to have control over South Vietnam, Cambodia as well as Laos. Because of conflicting interests, many countries supported the resistance of South Vietnam such as the United States as well as some of the members of the Southeast Asia Treaty Organization. The war resulted to the communist’s control over the Laos, Cambodia and South Vietnam. When Did the Vietnam War Start? Vietnam War started in March 1959 and lasted for almost 26 years. The North Vietnamese Army used conventional military tactics and strategies in the war while the South Vietnamese Army and the U.S. Army implement air strikes as well as search and destroy operations. Even if a peace treaty was introduced...

An electronic device that people can use for data communication as well as telecommunication, a mobile phone has standard and special functions that are very helpful to connect with other individuals who use the device. Some of the special functions of mobile phones are text messaging, packet switching, email messaging as well as gaming. To attract consumers to purchase the device, mobile phone manufactures add other features like Bluetooth, music player, as well as a camera that can be used for taking pictures and videos. To learn when the first mobile phone was invented, it is significant to know the historical events that led to the development or creation of this telecommunication device. Background When was the first mobile phone invented? According to historians, the first mobile phone was invented and introduced by Ericsson in 1956 in Sweden. This device was known as the Mobile Telephone System A. The cellular phone is easy to use because it is automatic; however, the downside of...