Warmhole -Space Talks#7

A highly speculative idea of modern astrophysics, warmholes are theoretical possibilities allowed within the mathematical framework of Einstein's general theory of relativity. A warmhole is a short-lived portal, lasting only a brief moment, that joints two black holes in different locations.

Warmhole

Warmholes could connect two points in the present-day universe or, perhaps, in different times. In warmhole theory, matter falling into a black hole at one point should emerge through a proposed "White Hole"-- the reverse of a black hole-- at the other end (Travelers could go from point to point in time or space through warmholes, as imagined here in the picture).
Neither wormholes nor any evidence of them has yet observed. Scientists cannot determine how they would be created, although astrophysics such as Hawking continue to work on this intriguing notion.

The Zodiac -Space Talks#6

The Zodiac is a band of constellations that extends roughly nine degrees on each side of the ecliptic, the sun's apparent yearly path through our sky.

Constellations of the Zodiac

Ancient Greek astronomers divided the zodiac into 12 parts. Over time, Earth's slight rotational wobble has shifted the ecliptic by more than 30 degrees against the backdrop of stars. The 18-degree-wide now also includes parts of Cetus (the Whale) and Orion (the Hunter).
Constellations seen from the Northern Hemisphere became standardized through the observations of ancient Western and Middle Eastern cultures. Those of the Southern Sky were named mostly by European ocean voyagers.

Constellations -Space Talks#5

Stars seem to move across the sky through the night, but that movement is due to Earth's rotation. As Earth spins on its axis, objects appear to rise in the east and set in the west. In the Northern Hemisphere, some stars never appear to  set, called Circumpolar Stars, they circle at a point projected in the sky above the Northern Pole near Polaris, the Pole Star. A corresponding situation exists above the South Pole near the Star Sigma Octantis.

Constellations

In ancient cultures, sky-watching played an important role in navigation, agriculture, religion and even entertainment. Those who observed the heavens connected stars to form patterns that related to the heroes, gods and legends of their culture-- what we refer to today as Contellations.

Most cultures named constellations and attached cultural meaning to their patterns. Native American sky lore, for instance, often used constellations to teach moral lessons.

Today, the Western world acknowledges the constellations that originated in Mesopotamia more than 5,000 years ago. Babylonian, Egyptian, and Greek astronomers also made contributions during the classical ages of their cultures.

In 1928 the International Astronomical Union (IAU) determined which constellations would be officially recognized. Of the 88 constellations on the IAU list, 48 were identified in ancient times with just the naked eye. The remaining 40 were added in more recent centuries.

Discovery of Big Bang -Space Talks# 4

The first scientific evidence for the Big Bang was found in 1929, when astronomers discovered that light from distant galaxies is rendered. This color change happens when objects are moving away from us, making light waves stretch out and change color. The more distant the galaxies are, the faster they rushing away. This shows that the whole Universe is expanding.

No charge in starlight

Light waves stretched

Big Bang afterglow:-

More evidence of the Big Bang came in the 1960s, when astronomers detected faint microwave radiation coming from every point in the sky. This mysterious energy is the faded remains of the intense burst of energy released in the Big Bang.

Microwave map of whole sky

Changing elements:-

For hundreds of millions of years, the Universe consisted almost entirely of hydrogen and helium- the very simplest chemical elements.
After stars appeared, new elements began to be made in the cores of dying stars. All the complex elements in our bodies were forged in dying stars this way.

Big Bounce theory:-
What caused the Big Bang? We may never know for sure, but some scientists have suggested that there may have been lots of big bangs, with the Universe expanding after each one and then shrinking again. This theory is called the Big Bounce because the process repeats itself.
 

Star death- Space Talks# 3

All stars eventually run out of fuel and die. Most fade away quietly, but the most massive stars self-destruct in a huge explosion that can outshine an entire galaxy.

Like Earth, stars generate the force of gravity which squeezes their hot core. The more matter a star has, the greater the force of gravity and the hotter and denser the core becomes. The way a star dies depends on how powerfully its core is squeezed by gravity.

Stars make heat and light by the process of nuclear fusion: hydrogen atoms in the core crash together to form helium, releasing energy. In small stars, when hydrogen in the core runs out, the stars light slowly fades. But in more massive stars, the core is so hot and dense that fusion can spread beyond it, changing the star's appearance. The most massive stars are eventually overwhelmed by their own gravity, which crushes them so violently that they collapse into a pinprick to a create a black hole.

Ways to die:-
Stars can die in four different ways, all of which are shown on these pages. Our Sun, a typical star, will follow the central path, but not yet - it has enough fuel to keep shinning for 5 billion years. When larger stars die, they turn hydrogen into heavier chemical elements such as carbon and oxygen, which are later recycled to form new stars and planets. All the atoms in your body were created this way.

Seeing the invisible- Space Talks# 2

Professional astronomers don't just use visible light to see the night sky. Their telescopes can also create images from wavelengths of light that our eyes cannot see, such as X-rays, radio waves and infrared rays. The images below all show kepler's Supernova - the wreckage left by a giant star that exploded in 1604.

X-ray image:- 

    X-ray image of Kepler's Supernova

This image of Kepler's Supernova is from the orbiting Chandra X-ray Observatory. It shows a cloud of incredibility hot gas that emits high-energy X-rays. 

Visible light image:-

Visible light image of Kepler's image

Very little of the object can be seen in visible light, even in this image from the Hubble Space Telescope. The bright areas are clumps of gas.

Infrared image:-

Infrared image of Kepler's image

Taken by the Spitzer Space Telescope, this infrared image shows dust clouds that were heated by a shock wave from the exploding star.

Combined image of Kepler's image

 Combining all three sources produces a complete image: a shell of supernova debris expanding into space at 2,000 km (1,240 miles) per second.

Living in Space- Space Talks# 1

Astronauts must adapt to a zero-gravity environment when weightlessly can be fun, it can also cause medical problems.
Space stations are cramped places with few luxuries. Astronauts eat ready-made meals that are either freeze-dried or served in pouches.
All water is recycled, including the water vapour from human breath.
Astronauts clean themselves with special shampoos and soaps that don't need water, and they use space toilets that suck away waste rather than flushing with water.

Effects on the Body:-

Spaceman

When the human body spends a long time in space, it changes. Without gravity pulling on the spine, the body gets about 5 cm ( 2 in ) taller. Body fluids that flow downwards on Earth build up in the head. This gives astronauts swollen faces and blocked noses, making food seem tasteless. When astronauts come back to Earth, the return of full gravity can make them feel extremely weak.

Space stations:-  

A space station is a crewed satellite - a kind of orbiting laboratory in which astronauts and scientists live and work. The USSR launched the first station, Salyut 1, in 1971.

Salyut 1 (USSR)

  The USA soon followed with Skylab, in 1973. Russia's Mir, in use from 1986 to 2001, was the most successful station until the USA, Russia, and more than 10 other countries joined forces to build the International Space Station, in orbit since 1998. China's own space station prototype, Tiangong-1, was launched in 2011.

Skylab (USA)

Mir (USSR)

Tiangong -1 (China)

 

International Space Station