Satellite captures Earth 'rising' and 'setting'

Series of five images of the Earth 'setting' as seen from the Moon - taken by the Kaguya probe.

A Japanese satellite has captured the first high definition images of the Earth from the moon.

Footage taken from 62 miles above the lunar surface shows the most-detailed yet pictures of an "Earth-rise" and "Earth-set" above the moon's horizon.

Still photographs from the sequences show our planet in brilliant blue with Antarctica at the top, Australia in light brown on the left and the Middle East in the lower right section.

The images were taken last week using a high definition (HD) television camera, developed specially for use in space by the Japanese national broadcaster NHK.

This was mounted on Kaguya, a Japan Aerospace Exploration Agency (JAXA) probe which is carrying out the most extensive investigation of the moon since the Nasa Apollo missions.

Earth-rises and earth-sets can only be seen from satellites travelling in orbit around the moon as our planet is always seen in the same position from the lunar surface.

The Kaguya probe, named after a princess in a Japanese fairytale, was around 240,000 miles from Earth when it captured the footage.

The first ever image of the Earth was taken in 1959 by the US satellite Explorer VI while it was passing over the Pacific Ocean.

Kaguya, which launched in mid-September, will produce high resolution surface and gravity maps, observe lunar magnetic fields and search for water ice during its one-year mission.

Japan has been expanding its space operations, and has set a goal of sending an astronaut to the moon by 2020.


The onboard high definition camera of the moon explorer "KAGUYA," which is under initial functional verification, successfully acquired the world's first high definition images of an "Earth-rise" and "Earth-set." It was also the world's first HD images of the Earth from about 380,000 km away in space.

Indian man marries dog to beat 'curse'

An Indian farmer has married his dog in a bid to overcome what he believes is a curse caused by him having stoned to death two mating dogs in his rice field, press reports said.

Doctors were clueless, but an astrologer finally told him he was cursed by the spirits of the dogs he had killed. He could undo the curse only if he married a dog and live with it, the soothsayer said.

After a long search for a 'suitable bride', Selvakumar managed to get a four-year-old mongrel bitch from a friend and had a fully-fledged Hindu wedding in front of villagers and elders on Sunday, eyewitnesses said.

The canine bride, named Selvi, was adorned in a sari and flowers and brought to the temple by village women. A Hindu priest conducted the ceremony.

The reports, however, said Selvi the dog attempted to make a run for it -- apparently due to the large crowds -- but was eventually tracked down and returned to her new 'husband'.

"The dog is only for lifting the curse and after that, he plans to get a real bride," a friend of the groom said.

Six-legged frog is star attraction

A Chinese restaurant has found a six-legged frog - and is keeping it to attract diners.

The frog is on display in a glass tank at the restaurant in Quanzhou city, reports People's Daily.

"I bought more than 5 kilos of frogs from the market the other day, and upon coming back found that one of them has six legs," says chef Xiao Song.

The frog has two extra legs on the front left side which, according to waiters, means that it has a lopsided hop.

Experts at the local forestry department say the extra legs were most likely caused by genetic mutation.

Article~Time Dilation

The special theory of relativity describes how motion affects measurements of time and distance. Einstein concluded that these measurements must depend on how the person making the measurements is moving. The basis of this theory is that all people, whether moving or stationary, must agree on certain basic physical phenomena, especially those involving the behavior of light.

Imagine that you are standing on the Earth while our friend is traveling across our solar system at a high speed, as shown in the accompanying sketch. You set off a flashbulb that emits sudden bright flash of light. The radiation moves away from you at the same speed at all directions, and thus you see an expanding spherical shell of light. What does your high-speed friend see?

Einstein argued that this person must also see light moving away from her at the same speed in all directions, and thus she also sees an expanding spherical shell of light.By requiring that both people observe a spherical shell, Einstein derived a series of equations to relate specific measurements of time and distance between two people. These equations are named the Lorentz transformations, after the famous Dutch physicist Hendrik Antoon Lorentz (a contemporary of Einstein who developed these equations independently but did not grasp their true meaning.) These equations tell us exactly how a moving person's clock slow down and how rulers shrink.

To appreciate the Lorentz transformations, again imagine that you are on Earth while a friend is moving at a speed v with respect to you. Suppose that you both observe the same phenomenon on Earth - say, the beating of your heart or the ticking of your watch, which appears to occur over an interval of time. According to your clock (which is not moving relative to the phenomenon), the phenomenon lasts for T0 seconds. This is called the proper time of the phenomenon. But according to your friend's clock (which is moving relative to the phenomenon), the same phenomenon lasts for a different length of time, T seconds. The Lorentz transformation for time tells us that these two time intervals are related by:

Lorentz transformation for time





T = time interval measured by an observer moving relative to the phenomenon
T0 = time interval measured by an observer not moving relative to the phonomenon
v = speed of the moving observer
c = speed of light

EXAMPLE: Suppose that your friend is moving at 98% of the speed of light. Then, v/c = 0.98 so that

=> T = 5T0




The Lorentz transformation for time is plotted in the accompanying graph, which shows how 1 second measured on a stationary clock is stretched out when measured using a clock carried by a moving observer. Note that significant differencesEXAMPLE: Fast-moving protons from interstellar space frequently collide with atoms in the Earth's upper atmosphere. When they do, they can create unstable particles called muons (pronounced "mewons") that decay in an average time of 2.2 x 10 to power -6 seconds. Such muons typically move at 99.9% of the speed of light and are formed at an altitude of 10kn. As measured by an observer on the Earth, the time that a muon would take to reach the Earth's surface is




This is 15 times longer than the life expectancy of a muon, so it would seem that muon would never reach the Earth's surface before decaying. In fact, these muons are detected by experiments on the surface! The reason is that as seen by an Earth observer, the muon is a "moving clock", and hence its decay is slowed down by time dilation. To an Earth observer, the actual lifetime of a muon is



Thus, as measured by an Earth observer, muons live more than long enough for them to reach the surface. The detection at the Earth's surface of muons from the upper atmosphere is compelling evidence for the reality of the time dilation.