Wisdom

Spiral galaxy...

Spiral galaxies take their name from the winding spiral shape they demonstrate. Most of the galaxies in the universe observed by scientists are spiral galaxies. These twisted collections of stars and gas often have beautiful shapes and are made up of hot young stars.

Most spiral galaxies contain a central bulge surrounded by a flat rotating disk of stars. Made up of older, dimmer stars, the bulge in the center is thought to contain a supermassive black hole, though observing it can be a challenge. The dim light from the older stars can make the bulge difficult to pinpoint, and there are some spirals that lack this characteristic. The supermassive black hole thought to exist at the center is often blocked by dust and gas surrounding it.

Orbiting the bulge, a rotating disk gives the galaxy its distinctive classification. The disk separates itself into arms that circle the galaxy. These spiral arms contain young stars that shine brightly before their quick demise, as well as a wealth of gas and dust. The brilliant stars are the reason the arms are so well defined.

The exact mechanism for the formation of the spiral arms continues to puzzle scientists. If they were permanent features of the galaxy, they would soon wind up tightly and disappear in less than a billion years. Scientists think they could be a result of density waves traveling through the outer disk. Encounters between galaxies could be a cause of these waves. As two galaxies come near collision, the mass of the one about to be consumed could affect the structure of larger. Another potential cause deals with how the galaxy was initially formed.

Approximately two-thirds of spiral galaxies contain a barred structure through their center, making unbarred spiral galaxies a minority. The Milky Way is one of these, though its bar is a challenge to see and was not suspected until the 1990s. Its barred structure was confirmed in 2005.

In 1926, Edwin Hubble devised a system to classify galaxies. Known as the Hubble sequence, or the "Hubble tuning-fork", it organizes galaxies based on their shape. Spiral galaxies are classified by how tightly wound their arms are, as well as by the presence or absence of a bar.

Spiral galaxies make up roughly 77 percent of the galaxies that scientists have observed. However, they are not thought to be the dominant galaxy type. That honor goes to elliptical galaxies, which spirals are thought to ultimately degrade into. Because elliptical galaxies are made up of older, dimmer stars, they are more challenging to spot. In large, in-depth surveys of patches of the sky, elliptical galaxies have dominated, leading scientists to conclude that they are prevalent throughout the rest of the universe.

Spiral galaxies are filled with gas and dust, which results in a wealth of star formation. They are considered to be younger than elliptical galaxies, which contain less dust and form fewer stars.

Spiral galaxies come in a wide variety of shapes. Roughly 60 percent of spiral galaxies contain multiple arms, while another 10 percent have only two. Approximately 30 percent of spiral galaxies lack well-defined arms, as their features have faded over time.

These twisted galaxies range from a billion to a trillion times as massive as the sun. The visible disk can be anywhere from 10 to 300 thousand light-years across. The largest known spiral galaxy is NGC 6872, which is 522,000 light-years across from the tips of its outstretched spiral arms, about 5 times the size of the Milky Way.

In the early universe, galaxies frequently collided and interacted with one another, so the spiral shape of these ancient giants would have been quickly disrupted. The oldest observed spiral galaxy, BX442, is approximately 10.7 billion years old. Because of the correlation between the distance and the amount of time it takes light to travel, scientists are able to see the galaxy only 3 billion years after the Big Bang formed the universe.

According to current scientific thought, as spirals burn through their gas and dust and star formation slows, they will lose their spiral shape and move on to the next stage of galactic evolution, elliptical galaxies.

IMAGE OF THE DAY - 28 OCTOBER 2013

Lattices of ultracold atoms, such as that depicted in this image, could soon be used to spot the elusive Hofstadter's butterfly - a phenomenon predicted by fractal mathematics. Read about the idea here: http://physicsworld.com/cws/article/news/2013/oct/28/ultracold-atoms-set-the-stage-for-hofstadters-butterfly

Image courtesy: MPQ, Immanuel Bloch

Cosmic Caterpillar

How beautiful is that?

This light-year-long knot of interstellar gas and dust resembles a caterpillar on its way to a feast. But the meat of the story is not only what this cosmic caterpillar eats for lunch, but also what's eating it. Harsh winds from extremely bright stars are blasting ultraviolet radiation at this "wanna-be" star and sculpting the gas and dust into its long shape.

The culprits are 65 of the hottest, brightest known stars, classified as O-type stars, located 15 light-years away from the knot, towards the right edge of the image. These stars, along with 500 less bright, but still highly luminous B-type stars make up what is called the Cygnus OB2 association. Collectively, the association is thought to have a mass more than 30,000 times that of our Sun.

The caterpillar-shaped knot, called IRAS 20324+4057, is a protostar in a very early evolutionary stage. It is still in the process of collecting material from an envelope of gas surrounding it. However, that envelope is being eroded by the radiation from Cygnus OB2. Protostars in this region should eventually become young stars with final masses about one to ten times that of our Sun, but if the eroding radiation from the nearby bright stars destroys the gas envelope before the protostars finish collecting mass, their final masses may be reduced.

Spectroscopic observations of the central star within IRAS 20324+4057 show that it is still collecting material quite heavily from its outer envelope, hoping to bulk up in mass. Only time will tell if the formed star will be a "heavy-weight" or a "light-weight" with respect to its mass.


Credits: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and IPHAS

Technical info: This image of IRAS 20324+4057 is a composite of Hubble Advanced Camera for Surveys data taken in green and infrared light in 2006, and ground-based hydrogen data from the Isaac Newton Telescope in 2003, as part of the IPHAS H-alpha survey. The object lies 4,500 light-years away in the constellation Cygnus.

An “Armstrong number” is an n-digit number that is equal to the sum of the nth powers of its individual digits.
For example, 371 is an Armstrong number since 3**3 + 7**3 + 1**3 = 371.
What is the digit k in the Armstrong number 16k4?
(A) 2 (B) 3 (C) 4 (D) 5 (E) 6
:
The example makes no sense as written, they mean 1^3 + 5^3 + 3^3 = 153
:
1^4 + 6^4 + k^4 + 4^4 = 1000 + 600 + 10k + 4
:
1 + 1296 + k^4 + 256 = 10k + 1604
:
1553 + k^4 = 10k + 1604
:


k^4 + 10k + 1553 - 1604 = 0
:
k^4 - 10k = 51
:
Since you only have 5 choices, just substitute until you have equality
k=3
3^4 - 10(3) =
81 - 30 = 51
:
The number 1634
:
CHeck 1^4 + 6^4 + 3^4 + 4^4 = 1634

European astronomers say they’ve obtained a three-dimensional view of an exploded star that confirms computer models of what happens in an exploding supernova. Furthermore, when this supernova was observed in 1987, it was the first naked-eye supernova seen for 383 years...

http://www.holoscience.com/wp/supernova-1987a-decoded-2/

IS THE UNIVERSE ALIVE?
As scientists peer across the galaxy, a new revelation emerges: The universe is shockingly organic. Are the secrets to the life and death of the universe hidden not in physics, but biology? Could it be that the universe is alive? - See more at: http://www.sciencegymnasium.com/2013/03/through-wormhole-is-universe-alive.html .DdkDe2iZ.dpuf

ScienceGymnasium: IS THE UNIVERSE ALIVE?

It's the birthday of Felix Bloch, who was born in 1905 in Zürich, Switzerland. Bloch did his PhD in Leipzig under Werner Heisenberg. His thesis introduced the concept of Bloch waves, which enabled the electronic properties of crystals to be understood in terms of quantum mechanics. Fearing N**i persecution, Bloch left Germany in 1934 for a position at Stanford University. There, he made his second great contribution to physics: The development of radio-based methods to study nuclear moments. He and Edward Purcell shared the 1952 physics Nobel for their work on NMR

We will end the day with a classic...

Jupiter's Great Red Spot from Voyager 1

It is a hurricane twice the size of the Earth. It has been raging at least as long as telescopes could see it, and shows no signs of slowing. It is Jupiter's Great Red Spot, the largest swirling storm system in the Solar System. Like most astronomical phenomena, the Great Red Spot was neither predicted nor immediately understood after its discovery. Still today, details of how and why the Great Red Spot changes its shape, size, and color remain mysterious. A better understanding of the weather on Jupiter may help contribute to the better understanding of weather here on Earth. The above image is a recently completed digital enhancement of an image of Jupiter taken in 1979 by the Voyager 1 spacecraft as it zoomed by the Solar System's largest planet. At about 117 AU from Earth, Voyager 1 is currently the most distant human made object in the universe.

Credit: NASA, JPL; Digital processing: Björn Jónsson (IAAA)
Posted by NASA APOD (credit caption). Wallpaper fanatics, for a full size image (22M), go to -http://apod.nasa.gov/apod/image/1105/redspot_voyager1_3072.jpg (double click on the image).

The Sky this Week: October 18–27, 2013 | Astronomy.com

Super-Earth Planet Is More Like Super-Venus, NASA Says

An alien planet declared a super-Earth by NASA might not be so habitable after all. New measurements flag the planet (called Kepler-69c) as more of a "super-Venus" that would likely be inhospitable to life.

The planetary status change is part of a larger struggle over how to define the habitable zone of a star. In recent years, scientists determined that the distance between a planet and its type of star is just one metric that hints at the likelihood of liquid water on its surface, which could fuel life. Other factors include the planet's atmosphere and even how the star behaves.

Read more: http://www.space.com/23209-super-earth-super-venus-nasa.html

Does Death Exist? New Theory Says ‘No’
Many of us fear death. We believe in death because we have been told we will die. We associate ourselves with the body, and we know that bodies die. But a new scientific theory suggests that death is not the terminal event we think. One well-known aspect of quantum physics is that certain observations cannot be predicted absolutely. Instead, there is a range of possible observations each with a different probability. One mainstream explanation, the “many-worlds” interpretation, states that each of these possible observations corresponds to a different universe (the ‘multiverse’). A new scientific theory – called biocentrism – refines these ideas. There are an infinite number of universes, and everything that could possibly happen occurs in some universe. Death does not exist in any real sense in these scenarios. All possible universes exist simultaneously, regardless of what happens in any of them. Although individual bodies are destined to self-destruct, the alive feeling – the ‘Who am I?’- is just a 20-watt fountain of energy operating in the brain. But this energy doesn’t go away at death. One of the surest axioms of science is that energy never dies; it can neither be created nor destroyed. But does this energy transcend from one world to the other? Consider an experiment that was recently published in the journal Scienceshowing that scientists could retroactively change something that had happened in the past. Particles had to decide how to behave when they hit a beam splitter. Later on, the experimenter could turn a second switch on or off. It turns out that what the observer decided at that point, determined what the particle did in the past. Regardless of the choice you, the observer, make, it is you who will experience the outcomes that will result. The linkages between these various histories and universes transcend our ordinary classical ideas of space and time. Think of the 20-watts of energy as simply holo-projecting either this or that result onto a screen. Whether you turn the second beam splitter on or off, it’s still the same battery or agent responsible for the projection. According to Biocentrism, space and time are not the hard objects we think. Wave your hand through the air – if you take everything away, what’s left? Nothing. The same thing applies for time. You can’t see anything through the bone that surrounds your brain. Everything you see and experience right now is a whirl of information occurring in your mind. Space and time are simply the tools for putting everything together. Death does not exist in a timeless, spaceless world. In the end, even Einstein admitted, “Now Besso” (an old friend) “has departed from this strange world a little ahead of me. That means nothing. People like us…know that the distinction between past, present, and future is only a stubbornly persistent illusion.” Immortality doesn’t mean a perpetual existence in time without end, but rather resides outside of time altogether. - See more at: http://www.sciencegymnasium.com/2013/04/does-death-exist-new-theory-says-no.html .Rjy4PLas.dpuf