Knowledge's port

5.                               Visible features on the sun's surface, sunspots are dark regions on the photosphere where a particularly strong portion of the sun's magnetic field has slowed the gas that is rising to the surface. The center of a sunspot, depressed a little below the level of the surrounding gas, exhibits a lower temperature SUNSPOT 536, just left of center, can flare and affect Earth. The spot itself is six times wider than our planet. than the surrounding photosphere, creating a visible spot. Sunspots can measure up to several times Earth's diameter. Their activity increases and decreases in an I -year cycle. Early in each cycle, most sunspots appear near the sun's 300 N and 300 S latitudes. Later in the cycle, they occur closer to its equator. During the low point in the cycle, called the solar minimum, the sun goes for days or even weeks without flaring. Photosphere : Visible surfa...

4.     A highly speculative idea of modern astrophysics, wormholes are theo-retical possibilities allowed within the mathematical framework of Einstein's general theory of relativity. A worm-hole is a short-lived portal, lasting only a brief moment, that joins two black holes in different locations. Wormholes could connect two points in the present-day universe or, perhaps, in different times. In worm-hole theory, matter failing into a blackhole at one point should emerge through a proposed "white hole" the reverse of a black hole at the other end. Neither wormholes nor any evi-dence of them has yet been observed. Scientists cannot determine how they would be created, although astro-physicists such as Hawking continue to work on this intriguing notion.  TRAVELERS COULD GO from point to point in time or space through wormholes, as imagined here in glowing purple. FAST FACT   The largest black hole on record weighs as much as 40 billion suns and is orbite...

3.                  A   black hole   is a region of   spacetime   exhibiting such strong   gravitational   effects that nothing—not even   particles   and   electromagnetic radiation   such as light—can escape from inside it.   The theory of   general relativity   predicts that a sufficiently compact   mass   can deform   spacetime   to form a black hole. The boundary of the region from which no escape is possible is called the   event horizon . Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed. In many ways a black hole acts like an ideal   black body , as it reflects no light.   Moreover,   quantum field theory in curved spacetime   predicts that event horizons emit   Hawking radiation , with   the same spect...

2.                                      Accepted astrophysical theories posit  that at one point there was nothing: no 0- 0- .., stars, planets, or galaxies not space itself. The matter that makes up  everything that now exists was centrated in a single, extremely dense point known as a singularity.  The force of gravity in a singulaity is so great that the fabric of space-time curves in on itself. In an instant known as the big bang, however, the contents of the primordial singularity escaped and formed the universe. The big bang is catchy shorthand for a complex astrophysical theory, backed up with sophisticated calcu-lations. The term was coined in the 1950s by British astronomer Fred Hoyle, a proponent of a theory of the universe as a steady state. In fact, Hoyle used the term derisively. Though the name stuck, it gives a false impression, making it seem as though the e...

1 .                                            Stars are born in an enormous cloud of interstellar dust and hydrogen gas called a nebula. Nebulae represent if the building blocks for stars, galaxies, and planets in the universe. Emission nebulae are hot, discrete clouds of primarily ionized hydrogen that glow with their own light. Reflec-tion nebulae emit a bluish glow by re-flecting the scattered light of nearby stars. Absorption nebulae, or dark nebulae, comprise dense clouds of gas and dust. They appear as silhouettes against the light f brighter objects.  Nebulae form when stars die. When the end comes for our sun, for example, its outer layers will heat, swell, and eventually flow off. The hot, dead core will create a glowing nebula, which will in turn become a nursery for new stars.