Galaksi

dune1989

aku setuju dgn pendapat awak ...... cuma halangan2 dalam pergerakan yang menambahkan masa .... ...
mencacus Post at 26-5-2011 01:01 AM

yup, but it's ok..
someone will clear it..
aku pun berminat nak tahu..
dulu aku mmg minat giler astronomi.. buku rujukan sains pasal astronomi mmg aku hafal..
tapi bila dah besar ni..
dah hilang minat but still it capture the moment that once a time i was love the subject..

mencacus

Reply 41# dune1989


ok lah tu ..... aku pun sama macam awak sampai lukis gambar sistem suria pastu tepek kat dinding bilik ..... bab2 astronomi nie yang aku kurang tentang buruj sebab susunan kawanan bintang nie buat aku pening kepala .....

bayangkan macam mana kaum mayan boleh gunakan kedudukan bintang itu sebagai kaedah pembangunan tamadun mereka .....sekarang aku terbuka nak belajar pasal buruj .......

mk-sabio

Reply  dune1989


ok lah tu ..... aku pun sama macam awak sampai lukis gambar sistem suria pastu ...
mencacus Post at 26-5-2011 01:30

tu la..so impressed with the mayans and sumerians..gak2 nyer diorang ni kaum nabi ape ek?

mencacus

tu la..so impressed with the mayans and sumerians..gak2 nyer diorang ni kaum nabi ape ek?
mk-sabio Post at 26-5-2011 06:06

kaum mayan aku x pasti tapi sumerians ada kaitan dengan nabi ibrahim as (zaman namrud)...... kebanyakkan ahli2 astronomi dunia islam kebanyakan dari keturunan sumerians ( bangsa parsi ) .....so , dah ada contoh terdekat kat situ .....jangan lupa jugak tamadun mesir pun berpaksikan bintang2 sebagai contoh , 3 piramid dibina selari dengan kedudukan gugusan orion ......

tawaf mengelilingi ka'abah seolah2 menyerupai galaksi membuatkan aku ingin mencari sumber yang menyatakan kawasan ka'abah mempunyai punca tenaga yang tinggi di bumi ......

HaMiZiE

cube kita drive keta tercium bontot bas, gerenti tak jimat duit poket ehehhee
dune1989 Post at 25-5-2011 02:32

sama ler jugak flock yang terbang kat langit dalam shape V...
biler mereka terbang dalam kondisi sebegini... they can save they energy travelling for longer distance...  

same goes to female whale yang berenang ngan anak dia dor longer distance...
si anak akan berenang rapat dibahagian atas belakang ibunya...  
aliran yang dihasilkan oleh ibu tadi akan menolong si anak berenang menyaingi si ibu

HaMiZiE

takpe lah hamizie , aku pun bukan study bidang nie jugak tapi minat tu ada ..... kadang2 aku p ...
mencacus Post at 25-5-2011 23:39

kan....
make sense gak
tah tah kaum bunian ni merupakan makhluk daripada universe yang lain ...
dan mereka yang sesat masuk ke alam bunian ni tah tah termasuk dalam 'wormhole' ni secara tak sengaja :re:

mencacus

kan....
make sense gak
tah tah kaum bunian ni merupakan makhluk daripada universe yang lain .. ...
HaMiZiE Post at 26-5-2011 07:15

setahu aku ..... kaum bunian nie memang berada bersama dengan kita , xde universe lain sebab budaya mereka sama dengan kita , bahasa pun sama .....cuma berada di alam makhluk halus .....dia nampak kita , kita x nampak dia ..... yang membezakan faktor masa yang berlainan (dia dari api , kita dari tanah) .....

aku buat masa nie keliru worm hole tu black hole ke atau memang worm hole ( pintu gerbang ) ........kalau black hole yg aku tengok kat dokumentari tu ......belum masuk lagi , jasad dah hancur diratah graviti black hole ......

HaMiZiE

setahu aku ..... kaum bunian nie memang berada bersama dengan kita , xde universe lain sebab b ...
mencacus Post at 26-5-2011 15:14

hurm .. susah nak dijelaskan ar...
sebab kengkadang ... biler melibatkan teori parralel life, ni yang dimaksudkan terdapat mahluk lain yang hidup dalam dimensi lain (or other universe)... yang sama sama menjalani kehidupan tapi tak menyedari kewujudan kehidupan lain selain daripada mereka...

Wormhole tu... short cut kalo nak travel dari satu point ke another point kat ruang angkasa... kalo ikut jalan biasa, may takes years... tapi kalo pakai wormhole, leh sampai cepat (macam star gate ar ... huhuhu)

black hole... tu yang menyedut segala gala kat angkasa lepas

mk-sabio

hurm .. susah nak dijelaskan ar...
sebab kengkadang ... biler melibatkan teori parralel life, n ...
HaMiZiE Post at 26-5-2011 16:19

bg aku, mengikut kajian n teori aku sendiri, sangatlah mustahil kalo kita kata bumi je yg ada hidupan, takkan la seluas2 alam semesta ni Tuhan cipta bumi je yg ada hidupan. so aku sgt yakin kt planet lain samada dlm galaksi kita atau galaksi lain, ada byk planet yg ada hidupan mcm di bumi..cuma mungkin cara kehidupan mereka berbeza..gas yg diorang hirup pun berbeza..kalau nak jumpa semua, kena tgu kiamat dlu la..tgu semua dibangkitkan di pdg mahsyar..my teori la..

mk-sabio

kaum mayan aku x pasti tapi sumerians ada kaitan dengan nabi ibrahim as (zaman namrud)...... k ...
mencacus Post at 26-5-2011 06:33

terfikir jugak, kalaulah kaum2 terdahulu tak kena bala, betapa majunya teknologi kita hari ni..gi keje teleport je kot..hehe

mencacus

hurm .. susah nak dijelaskan ar...
sebab kengkadang ... biler melibatkan teori parralel life, n ...
HaMiZiE Post at 26-5-2011 16:19

selagi kita masih berada di alam bumi nie , selagi itu kita dilanda pertanyaan ataupun suasana misteri alam ......banyak betul teori tentang ya'juj dan ma'juj nie ...... ada teori yang mengatakan pintu worm hole itu ditutup oleh zulkarnain.... yang biasa kita dengar ya'juj  ma'juj terperangkap di kawasan caucasus ( kawasan russia ) .....kita pun tahu al-qur'an ada yang jelas dan ada yang tersirat .....

wallahualam .....

mencacus

bg aku, mengikut kajian n teori aku sendiri, sangatlah mustahil kalo kita kata bumi je yg ada  ...
mk-sabio Post at 26-5-2011 23:53

tentang kehidupan lain di lain planet , maybe ada ......

mencacus

terfikir jugak, kalaulah kaum2 terdahulu tak kena bala, betapa majunya teknologi kita hari ni..g ...
mk-sabio Post at 26-5-2011 23:58

peradaban yang tertinggi yang pernah wujud ialah zaman nabi sulaiman .....tak macam sekarang nie ..... sebab tu dekat baitul muqadis , palestin ada banyak buku2 catatan yang tertanam di bawah masjid al-aqsa ( buku2 sihir pun ada ).....

testas

benda paling senang nak test.. kalau tak silap aku..

kepada org yg selalu travel naik kapal terbang.. travel overseas ke..

sediakan 2 jam, set kan jam hour, minit and saat. 2 2 jam tadi sama.

then 1 jam simpan kat rumah. and 1 lagi pakai.

after some times , banyak kali travel naik kapal terbang. jam saat mesti dah tak sama, ada sedikit beza.

mencacus

Reply 54# testas


adakah menaiki kapal terbang itu , masa bertambah laju ataupun bertambah perlahan ?

testas

tak pasti la.. rasa laju...

ada tgk dalam discovery channel...

u all jugak boleh test kalau drive kereta..

mana yg selalu bawak laju.. try tgk la ada effect or not..

mencacus

tak pasti la.. rasa laju...

ada tgk dalam discovery channel...

u all jugak boleh test kalau dr ...
testas Post at 27-5-2011 10:59

kalau kereta biasa x boleh kot walaupun selaju lebih 200 km/h ..... aku setuju dengan kapal terbang sebab suasana kat atas jadi lain seperti tekanan udara + kurang graviti + kuasa enjin pesawat .....i think masa bertambah laju , my opinion

mencacus

sambungan ......

Unusual dynamics and activities

Interacting

The average separation between galaxies within a cluster is a little over an order of magnitude larger than their diameter. Hence interactions between these galaxies are relatively frequent, and play an important role in their evolution. Near misses between galaxies result in warping distortions due to tidal interactions, and may cause some exchange of gas and dust.

Collisions occur when two galaxies pass directly through each other and have sufficient relative momentum not to merge. The stars within these interacting galaxies will typically pass straight through without colliding. However, the gas and dust within the two forms will interact. This can trigger bursts of star formation as the interstellar medium becomes disrupted and compressed. A collision can severely distort the shape of one or both galaxies, forming bars, rings or tail-like structures.

At the extreme of interactions are galactic mergers. In this case the relative momentum of the two galaxies is insufficient to allow the galaxies to pass through each other. Instead, they gradually merge together to form a single, larger galaxy. Mergers can result in significant changes to morphology, as compared to the original galaxies. In the case where one of the galaxies is much more massive, however, the result is known as cannibalism. In this case the larger galaxy will remain relatively undisturbed by the merger, while the smaller galaxy is torn apart. The Milky Way galaxy is currently in the process of cannibalizing the Sagittarius Dwarf Elliptical Galaxy and the Canis Major Dwarf Galaxy.


The Antennae Galaxies are undergoing a collision that will result in their eventual merger.

Starburst

Stars are created within galaxies from a reserve of cold gas that forms into giant molecular clouds. Some galaxies have been observed to form stars at an exceptional rate, known as a starburst. Should they continue to do so, however, they would consume their reserve of gas in a time frame lower than the lifespan of the galaxy. Hence starburst activity usually lasts for only about ten million years, a relatively brief period in the history of a galaxy. Starburst galaxies were more common during the early history of the universe, and, at present, still contribute an estimated 15% to the total star production rate.

Starburst galaxies are characterized by dusty concentrations of gas and the appearance of newly formed stars, including massive stars that ionize the surrounding clouds to create H II regions.These massive stars produce supernova explosions, resulting in expanding remnants that interact powerfully with the surrounding gas. These outbursts trigger a chain reaction of star building that spreads throughout the gaseous region. Only when the available gas is nearly consumed or dispersed does the starburst activity come to an end.

Starbursts are often associated with merging or interacting galaxies. The prototype example of such a starburst-forming interaction is M82, which experienced a close encounter with the larger M81. Irregular galaxies often exhibit spaced knots of starburst activity.


M82, the archetype starburst galaxy, has experienced a 10-fold increase in star formation rate as compared to a "normal" galaxy.


Sumber : wikipedia

mencacus

Active nucleus

A portion of the galaxies we can observe are classified as active. That is, a significant portion of the total energy output from the galaxy is emitted by a source other than the stars, dust and interstellar medium.


A jet of particles is being emitted from the core of the elliptical radio galaxy M87.

The standard model for an active galactic nucleus is based upon an accretion disc that forms around a supermassive black hole (SMBH) at the core region. The radiation from an active galactic nucleus results from the gravitational energy of matter as it falls toward the black hole from the disc.In about 10% of these objects, a diametrically opposed pair of energetic jets ejects particles from the core at velocities close to the speed of light. The mechanism for producing these jets is still not well understood.

Active galaxies that emit high-energy radiation in the form of x-rays are classified as Seyfert galaxies or quasars, depending on the luminosity. Blazars are believed to be an active galaxy with a relativistic jet that is pointed in the direction of the Earth. A radio galaxy emits radio frequencies from relativistic jets. A unified model of these types of active galaxies explains their differences based on the viewing angle of the observer.

Possibly related to active galactic nuclei (as well as starburst regions) are low-ionization nuclear emission-line regions (LINERs). The emission from LINER-type galaxies is dominated by weakly ionized elements.Approximately one-third of nearby galaxies are classified as containing LINER nuclei


Sumber : wikipedia

mencacus

Formation and evolution

The study of galactic formation and evolution attempts to answer questions regarding how galaxies formed and their evolutionary path over the history of the universe. Some theories in this field have now become widely accepted, but it is still an active area in astrophysics.

Formation

Current cosmological models of the early Universe are based on the Big Bang theory. About 300,000 years after this event, atoms of hydrogen and helium began to form, in an event called recombination. Nearly all the hydrogen was neutral (non-ionized) and readily absorbed light, and no stars had yet formed. As a result this period has been called the "Dark Ages". It was from density fluctuations (or anisotropic irregularities) in this primordial matter that larger structures began to appear. As a result, masses of baryonic matter started to condense within cold dark matter halos. These primordial structures would eventually become the galaxies we see today.

Evidence for the early appearance of galaxies was found in 2006, when it was discovered that the galaxy IOK-1 has an unusually high redshift of 6.96, corresponding to just 750 million years after the Big Bang and making it the most distant and primordial galaxy yet seen. While some scientists have claimed other objects (such as Abell 1835 IR1916) have higher redshifts (and therefore are seen in an earlier stage of the Universe's evolution), IOK-1's age and composition have been more reliably established. The existence of such early protogalaxies suggests that they must have grown in the so-called "Dark Ages".


Artist's impression of a young galaxy accreting material.

The detailed process by which such early galaxy formation occurred is a major open question in astronomy. Theories could be divided into two categories: top-down and bottom-up. In top-down theories (such as the Eggen–Lynden-Bell–Sandage [ELS] model), protogalaxies form in a large-scale simultaneous collapse lasting about one hundred million years. In bottom-up theories (such as the Searle-Zinn [SZ] model), small structures such as globular clusters form first, and then a number of such bodies accrete to form a larger galaxy.

Once protogalaxies began to form and contract, the first halo stars (called Population III stars) appeared within them. These were composed almost entirely of hydrogen and helium, and may have been massive. If so, these huge stars would have quickly consumed their supply of fuel and became supernovae, releasing heavy elements into the interstellar medium. This first generation of stars re-ionized the surrounding neutral hydrogen, creating expanding bubbles of space through which light could readily travel

Evolution

Within a billion years of a galaxy's formation, key structures begin to appear. Globular clusters, the central supermassive black hole, and a galactic bulge of metal-poor Population II stars form. The creation of a supermassive black hole appears to play a key role in actively regulating the growth of galaxies by limiting the total amount of additional matter added. During this early epoch, galaxies undergo a major burst of star formation.

During the following two billion years, the accumulated matter settles into a galactic disc. A galaxy will continue to absorb infalling material from high velocity clouds and dwarf galaxies throughout its life. This matter is mostly hydrogen and helium. The cycle of stellar birth and death slowly increases the abundance of heavy elements, eventually allowing the formation of planets.

The evolution of galaxies can be significantly affected by interactions and collisions. Mergers of galaxies were common during the early epoch, and the majority of galaxies were peculiar in morphology. Given the distances between the stars, the great majority of stellar systems in colliding galaxies will be unaffected. However, gravitational stripping of the interstellar gas and dust that makes up the spiral arms produces a long train of stars known as tidal tails. Examples of these formations can be seen in NGC 4676 or the Antennae Galaxies.

As an example of such an interaction, the Milky Way galaxy and the nearby Andromeda Galaxy are moving toward each other at about 130 km/s, and—depending upon the lateral movements—the two may collide in about five to six billion years. Although the Milky Way has never collided with a galaxy as large as Andromeda before, evidence of past collisions of the Milky Way with smaller dwarf galaxies is increasing.


I Zwicky 18 (lower left) resembles a newly formed galaxy.

Such large-scale interactions are rare. As time passes, mergers of two systems of equal size become less common. Most bright galaxies have remained fundamentally unchanged for the last few billion years, and the net rate of star formation probably also peaked approximately ten billion years ago.

Future trends

At present, most star formation occurs in smaller galaxies where cool gas is not so depleted. Spiral galaxies, like the Milky Way, only produce new generations of stars as long as they have dense molecular clouds of interstellar hydrogen in their spiral arms. Elliptical galaxies are already largely devoid of this gas, and so form no new stars. The supply of star-forming material is finite; once stars have converted the available supply of hydrogen into heavier elements, new star formation will come to an end.

The current era of star formation is expected to continue for up to one hundred billion years, and then the "stellar age" will wind down after about ten trillion to one hundred trillion years (1013–1014 years), as the smallest, longest-lived stars in our astrosphere, tiny red dwarfs, begin to fade. At the end of the stellar age, galaxies will be composed of compact objects: brown dwarfs, white dwarfs that are cooling or cold ("black dwarfs"), neutron stars, and black holes. Eventually, as a result of gravitational relaxation, all stars will either fall into central supermassive black holes or be flung into intergalactic space as a result of collisions


Sumber : wikipedia