The Light Year: Part 3 Of 3 (Part 1, Part 2) Episode 5: A Sky Full Of Ghosts, Cosmos: A SpaceTime Odyssey

hubble’s panorama of the carina nebula, some 7500 light years away from earth, and about fifty light years in length here. stars old and new illuminate clouds of cosmic dust and gas, like the clumping hydrogen from which they were born. 

the top star seen at the bisection of the first two panels, part of the eta carinae binary star system (most stars are in binary systems), is estimated  to be more than a hundred times the mass of the sun - large enough to go supernoava in about a million years. 

it also produces four million times as much light as the sun, and was once the second brightest star in the night sky. but surrounding dust and gas has dimmed our view of the star, though it’s still visible in the night sky to all but those in the most light polluted cities.

the fifth panel shows ‘the mystic mountain,’ where nascent stars in the dust cloud are spewing hot ionized gas and dust at 850,000 miles an hour. eventually, the ultraviolet radiation from these stars will blow away the dust, leaving visible the stars, like the cluster seen at the top of the panel, which were formed only half a million years ago.

Guide to DIY Designing It Yourself  Wedding Dress from storymixmedia 

Writers continue to reblog these infographics for their useful terminology. 

If you’ve missed any infographics, here they are:

Know Your Shoes Part 1 Lobster Claws anyone? Know Your Shoes Part 2 Know You Heels Fashion Pattern Vocabulary Part 1 Fashion Pattern Vocabulary Part 2 Know Your Check Fabrics Know Your Animal Prints Know Your Hosiery Know Your Gloves History of Hairstyles Part 1 History of Hairstyles Part 2 Know Your Braids Know Your Scarves Know Your Belts Part 1 Know Your Belts Part 2 Know Your Sleeve Lengths Know Your jacket length Know Your Skirt Lengths Know Your Pant Lengths Know Your Front and Back Yokes Know Your Yokes and Hems  Know Your Pleats Know Your Darts Know Your Denim Pockets Part 1 Know Your Patch Pockets Part 2  Know Your Pockets Part 3 Know Your Sleeves Know Your Bras Know Your Collars Know Your Hair Buns Know Your Sunglasses Infographic Know Your Necklines Sleeves and Necklines Know Your Hats Know Your Collars and Cuffs Know Your Necklines Know Your Skirts Know Your Nail Shapes and What’s Popular on Instagram Know Your Eye Liners Know Your Wedding Dresses History of Swimwear Know Your Vintage Sleeves here  Know Your Vintage Collars and Necklines Know Your Zippers and Zipper Pulls

The maximum life span is a theoretical number whose exact value cannot be determined from existing knowledge about an organism; it is often given as a rough estimate based on the longest lived organism of its species known to date. A more meaningful measure is the average life span; this is a statistical concept that is derived by the analysis of mortality data for populations of each species. A related term is the expectation of life. Life expectancy represents the average number of years that a group of persons, all born at the same time, might be expected to live, and it is based on the changing death rate over many past years.

The concept of life span implies that there is an individual whose existence has a definite beginning and end. What constitutes the individual in most cases presents no problem: among organisms that reproduce sexually the individual is a certain amount of living substance capable of maintaining itself alive and endowed with hereditary features that are in some measure unique. In some organisms, however, extensive and apparently indefinite growth takes place and reproduction may occur by division of a single parent organism, as in many protists, including bacteria, algae, and protozoans. In order to consider life span in such organisms, the individual must be defined arbitrarily since the organisms are continually dividing. In a strict sense, the life spans in such instances are not comparable to those forms that are sexually produced.

There is a brief period during which it is impossible to say whether an organism is still alive, but this time is so short relative to the total length of life that it creates no great problem in determining life span.

Some organisms seem to be potentially immortal. Unless an accident puts an end to life, they appear to be fully capable of surviving indefinitely. This faculty has been attributed to certain fishes and reptiles, which appear to be capable of unlimited growth. Without examining the various causes of death in detail, a distinction can be made between death as a result of internal changes (i.e., aging) and death as a result of some purely external factor, such as an accident. It is notable that the absence of aging processes is correlated with the absence of individuality. In other words, organisms in which the individual is difficult to define, as in colonial forms, appear not to age.

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How do you observe that the Universe is expanding? 

In 2011, the Nobel Prize in Physics was awarded to Saul Perlmutter, Brian Schmidt and Adam Riess for discovering that the Universe is expanding at an accelerating rate. We’d known for a while that the Universe has been expanding ever since its birth - but we didn’t know whether the expansion was slowing down, staying the same, or speeding up. 

So, how exactly do you discover something like this? 

Perlmutter, Schmidt, and Riess did it by observing a special type of supernovae: Type Ia supernovae. Supernovae are the explosive deaths of large stars, and they usually occur when a star runs out of fuel and collapses under its own weight, generating a shockwave that blasts its material out into space. However, this only happens when a star is big enough - the initial star has to have a critical, threshold mass, called the Chandrasekhar limit. Our sun, for example, won’t go supernova because the Chandrasekhar limit happens to be around 1.4 solar masses. When it runs out of fuel, our sun will instead gently blow off its outer layers and quietly become a dense core of carbon and oxygen, called a white dwarf. 

But here’s the kicker: not all white dwarfs stay white dwarfs. 

Some white dwarfs exist as one half of a binary system, where two stars orbit each other in a perpetual celestial dance. In some situations, the white dwarfs can actually “steal” matter from their partner star, siphoning it off and guzzling it up to grow more and more massive. Eventually, when their mass hits the Chandrasekhar limit, the white dwarf is ripped apart in a supernova. 

Image Credit

This happens in binary systems all across the Universe, and because these white dwarfs all go supernova at exactly the same mass, this means we know exactly how bright the supernovae are. When they’re observed through telescopes, some look brighter and some look fainter depending on their distance - but because we know their actual intrinsic brightness, we can work out how far away they really are. (You could do this yourself using a more earthly standard candle.) For this reason, Type Ia supernovae are called “standard candles”. 

In their observations, Perlmutter, Schmidt, and Riess realised that far away supernovae were more redshifted than the supernovae close by. “Redshift” is essentially a measure of how much the Universe has expanded since the light left the supernovae, so by comparing the distance and the redshift of the supernovae, they could create an “expansion history” of the Universe. 

This showed pretty clearly that the universe isn’t just expanding, it’s accelerating - i..e, everything’s flying apart more quickly than it was yesterday, or a century, or a billion years ago. Why? Dark energy. 

Sleep is your superpower | Matt Walker

Sleep is your life-support system and Mother Nature’s best effort yet at immortality, says sleep scientist Matt Walker. In this deep dive into the science of slumber, Walker shares the wonderfully good things that happen when you get sleep – and the alarmingly bad things that happen when you don’t, for both your brain and body. Learn more about sleep’s impact on your learning, memory, immune system and even your genetic code – as well as some helpful tips for getting some shut-eye.

Largest Batch of Earth-size, Habitable Zone Planets

Our Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in an area called the habitable zone, where liquid water is most likely to exist on a rocky planet.

This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.

Assisted by several ground-based telescopes, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.

This is the FIRST time three terrestrial planets have been found in the habitable zone of a star, and this is the FIRST time we have been able to measure both the masses and the radius for habitable zone Earth-sized planets.

All of these seven planets could have liquid water, key to life as we know it, under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets. To clarify, exoplanets are planets outside our solar system that orbit a sun-like star.

In this animation, you can see the planets orbiting the star, with the green area representing the famous habitable zone, defined as the range of distance to the star for which an Earth-like planet is the most likely to harbor abundant liquid water on its surface. Planets e, f and g fall in the habitable zone of the star.

Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them. The mass of the seventh and farthest exoplanet has not yet been estimated.

For comparison…if our sun was the size of a basketball, the TRAPPIST-1 star would be the size of a golf ball.

Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces.

The sun at the center of this system is classified as an ultra-cool dwarf and is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.

 The planets also are very close to each other. How close? Well, if a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.

The planets may also be tidally-locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong wind blowing from the day side to the night side, and extreme temperature changes.

Because most TRAPPIST-1 planets are likely to be rocky, and they are very close to one another, scientists view the Galilean moons of Jupiter – lo, Europa, Callisto, Ganymede – as good comparisons in our solar system. All of these moons are also tidally locked to Jupiter. The TRAPPIST-1 star is only slightly wider than Jupiter, yet much warmer. 

How Did the Spitzer Space Telescope Detect this System?

Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. Spitzer is uniquely positioned in its orbit to observe enough crossing (aka transits) of the planets in front of the host star to reveal the complex architecture of the system. 

Every time a planet passes by, or transits, a star, it blocks out some light. Spitzer measured the dips in light and based on how big the dip, you can determine the size of the planet. The timing of the transits tells you how long it takes for the planet to orbit the star.

The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets. Spitzer, Hubble and Kepler will help astronomers plan for follow-up studies using our upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone and other components of a planet’s atmosphere.

At 40 light-years away, humans won’t be visiting this system in person anytime soon…that said…this poster can help us imagine what it would be like: 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

at what point in history do you think americans stopped having british accents

“Somewhere, something incredible is waiting to be known”

- Carl Sagan

How To Help Your Anxious Partner — And Yourself

Living with anxiety can be tough — your thoughts might race, you might dread tasks others find simple (like driving to work) and your worries might feel inescapable. But loving someone with anxiety can be hard too. You might feel powerless to help or overwhelmed by how your partner’s feelings affect your daily life.

If so, you’re not alone: Multiple studies have shown that anxiety disorders may contribute to marital dissatisfaction.

“We often find that our patients’ … partners are somehow intertwined in their anxiety,” says Sandy Capaldi, associate director at the Center for the Treatment and Study of Anxiety at the University of Pennsylvania.

Anxiety is experienced at many different levels and in different forms — from moderate to debilitating, from generalized anxiety to phobias — and its impacts can vary. But psychiatrists and therapists say there are ways to help your partner navigate challenges while you also take care of yourself.

Read the full story here

There’s a rare type of blood that’s shared by only 43 people in the entire world.

‘Rhnull’ blood doesn’t contain any of the Rh antigens that 99.9% of humans have. It’s often called ‘golden blood’ because it can be given to anyone who has a rare Rh blood type, but there are only 9 active donors, so it’s only used in extreme circumstances.

(Source, Source 2)