φύσις
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About Me
Every time I look to the sky I acknowledge that I am part of this universe, but I also like to think that the universe is also within me..
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Summer is slowly coming to Saturn’s northern hemisphere. The north pole, which was in the midst of a 7-year-long winter when Cassini arrived in 2004, is now seen basking in the sunlight of mid-spring. Cassini is taking full advantage of the sunlight to capture these amazing views of the north polar hexagon and the myriad of storms, large and small, that comprise the weather systems in the polar region.
This view is centered on terrain at 75 degrees north latitude, 322 degrees west longitude. The image was taken with the Cassini spacecraft wide-angle camera on Feb. 26, 2013 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers.
The view was acquired at a distance of approximately 383,000 miles (616,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 48 degrees. Image scale is 21 miles (33 kilometers) per pixel.
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If you keep thinking you are going to fail….you are going to find a way to do it
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Barns Are Painted Red Because of the Physics of Dying Stars
Have you ever noticed that almost every barn you have ever seen is red? There’s a reason for that, and it has to do with the chemistry of dying stars. Seriously.
Yonatan Zunger is a Google employee who decided to explain this phenomenon on Google+ recently. The simple answer to why barns are painted red is because red paint is cheap. The cheapest paint there is, in fact. But the reason it’s so cheap? Well, that’s the interesting part.
Red ochre—Fe2O3—is a simple compound of iron and oxygen that absorbs yellow, green and blue light and appears red. It’s what makes red paint red. It’s really cheap because it’s really plentiful. And it’s really plentiful because of nuclear fusion in dying stars. Zunger explains:
The only thing holding the star up was the energy of the fusion reactions, so as power levels go down, the star starts to shrink. And as it shrinks, the pressure goes up, and the temperature goes up, until suddenly it hits a temperature where a new reaction can get started. These new reactions give it a big burst of energy, but start to form heavier elements still, and so the cycle gradually repeats, with the star reacting further and further up the periodic table, producing more and more heavy elements as it goes. Until it hits 56. At that point, the reactions simply stop producing energy at all; the star shuts down and collapses without stopping.
As soon as the star hits the 56 nucleon (total number of protons and neutrons in the nucleus) cutoff, it falls apart. It doesn’t make anything heavier than 56. What does this have to do with red paint? Because the star stops at 56, it winds up making a ton of things with 56 neucleons. It makes more 56 nucleon containing things than anything else (aside from the super light stuff in the star that is too light to fuse).
The element that has 56 protons and neutrons in its nucleus in its stable state? Iron. The stuff that makes red paint.
And that, Zunger explains, is how the death of a star determines what color barns are painted.
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10 Things You Didn’t Know About Space
There is still so little known about outer space by modern science, but of that little we do know, there are some extraordinarily amazing things. This is a list of the top 10 cool facts about Space.
10. Lightweight
Fact: If you put Saturn in water it would float
The density of Saturn is so low that if you were to put it in a giant glass of water it would float. The actual density of Saturn is 0.687 g/cm3 while the density of water is 0.998 g/cm3. At the equator Saturn has a radius of 60,268 ± 4 km – which means you would need an extremely large glass of water to test this out.
9. Constantly Moving
Fact: We are moving through space at the rate of 530km a second
Our Galaxy – the Milky Way is spinning at a rate of 225 kilometers per second. In addition, the galaxy is travelling through space at the rate of 305 kilometers per second. This means that we are traveling at a total speed of 530 kilometers (330 miles) per second. That means that in one minute you are about 19 thousand kilometers away from where you were. Scientists do not all agree on the speed with which the Milky Way is travelling – estimates range from 130 – 1,000 km/s. It should be said that Einstein’s theory of relativity, the velocity of any object through space is not meaningful.
8. Farewell old friend!
Fact: The moon is drifting away from Earth
Every year the moon moves about 3.8cm further away from the Earth. This is caused by tidal effects. Consequently, the earth is slowing in rotation by about 0.002 seconds per day per century. Scientists do not know how the moon was created, but the generally accepted theory suggests that a large Mars sized object hit the earth causing the Moon to splinter off.
7. Ancient Light
Fact: The light hitting the earth right now is 30 thousand years old
The energy in the sunlight we see today started out in the core of the Sun 30,000 years ago – it spent most of this time passing through the dense atoms that make the sun and just 8 minutes to reach us once it had left the Sun! The temperature at the core of the sun is 13,600,000 kelvins. All of the energy produced by fusion in the core must travel through many successive layers to the solar photosphere before it escapes into space as sunlight or kinetic energy of particles.
6. Solar Diet
Fact: The Sun loses up to a billion kilograms a second due to solar winds
Solar winds are charged particles that are ejected from the upper surface of the sun due to the high temperature of the corona and the high kinetic energy particles gain through a process that is not well understood at this time. Also, did you know that 1 pinhead of the sun’s energy is enough to kill a person at a distance of 160 kilometers? [Sourced from Planet Science]
5. The Big Dipper is not a constellation
Fact: The Big Dipper is not a constellation, it is an asterism
Many people consider the big dipper to be a constellation but, in fact, it is an asterism. An asterism is a pattern of stars in the sky which is not one of the official 88 constellations; they are also composed of stars which are not physically related to each other and can be vast distances apart. An asterism can be composed of stars from one or more constellations – in the case of the Big Dipper, it is composed entirely of the seven brightest stars in the Ursa Major (Great Bear) constellation.
4. George’s Star
Fact: Uranus was originally called George’s Star
When Sir William Herschel discovered Uranus in 1781, he was given the honor of naming it. He chose to name it Georgium Sidus (George’s Star) after his new patron, King George III (Mad King George). This is what he said:
In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities. In the present more philosophical era it would hardly be allowable to have recourse to the same method and call it Juno, Pallas, Apollo or Minerva, for a name to our new heavenly body. The first consideration of any particular event, or remarkable incident, seems to be its chronology: if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third.’
Uranus was also the first planet to be discovered with the use of a telescope.
3. Extra Moons
Fact: Earth has at least 4 moons
Okay – that is not actually true – but it is very close. In 1986, Duncan Waldron discovered a asteroid (5km across) that is in an elliptic orbit around the sun with a period of revolution virtually identical to that of Earth. For this reason the planetoid and earth appear to be following each other. The periodic planetoid is named Cruithne (pronounced krin-yə) after an ancient group of Scottish people (also known as the Picts). Because of its unusual relationship with Earth, it is sometimes referred to as Earth’s second moon. Cruithne, is fainter than Pluto and would require at least a 12.5 inch reflecting telescope to attempt to be seen. Since its discovery, at least three other similar asteroids have been discovered. These types of objects are also found in similar relationships to other planets in our Solar System. In the image above (courtesy of Paul Wiegert), the earth is the blue circle with a cross in it, and Cruithne’s orbit is shown in yellow.
2. Sunspot Music
Fact: Sunspot activity may be the primary reason for the beautiful sound of Stradivarius violins
Antonio Stradivari is considered to be the greatest violin maker ever. He lived in Italy in the 17th and 18th centuries. Scientists have been unable to work out what it is about his violins that makes them so incredible, but they do know that the timber used to make them is a very important contributing factor. From the 1500s to 1800s, the earth underwent a little ice age mostly due to increased volcanic activity and decreased solar activity (this is called the Maunder Minimum). As a result of this cooling, the types of trees that Stradivari used for his violins were particularly hard (due to slow growth). Hard timber is especially good when making violins. It is very probable that had Stradivari lived in a different age, his violins would not be prized as they are today. This picture above is made of three overlapping photos. It shows the rings in the spruce tree used to make the most famous Stradivarius violin, the “Messiah.” The first row of numbers gives the width of each ring in millimeters (one mm is about the thickness of a fingernail). The bottom row gives the years in which each ring grew.
1. Cold Welding
Fact: If two pieces of metal touch in space, they become permanently stuck together
This may sound unbelievable, but it is true. Two pieces of metal without any coating on them will form in to one piece in the vacuum of space. This doesn’t happen on earth because the atmosphere puts a layer of oxidized material between the surfaces. This might seem like it would be a big problem on the space station but as most tools used there have come from earth, they are already coated with material. In fact, the only evidence of this seen so far has been in experiments designed to provoke the reaction. This process is called cold welding. For those who still don’t believe it, here is the Wikipedia article on Cold Welding.
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Jupiter’s Great Red Spot is the largest known vortex in the Solar System. It’s big enough to engulf several Earths as shown in this artist’s rendition. — Michael Carroll
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"Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve."
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Follow this little Feynman Factoid up with TED Ed’s animated video about just how small an atom really is.
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Sun Lets Off First X-Class Flare of 2013
This week the sun emitted a significant solar flare. This flare is classified as an X1.7, making it the first X-class flare of 2013. The flare was also associated with another solar phenomenon, called a coronal mass ejection (CME) that can send solar material out into space. This CME was not Earth-directed.
The sun then emitted an X2.8-class flare. This is the the strongest X-class flare of 2013 so far, surpassing in strength the X1.7-class flare that occurred 14 hours earlier. It is the 16th X-class flare of the current solar cycle and the third-largest flare of that cycle.
Read more: http://www.laboratoryequipment.com/videos/2013/05/sun-lets-first-x-class-flare-2013 -
How do telescopes let us see so far into space?
Everything you need to know about how telescopes work.
Why is your eye so bad at seeing things far away?
Human eyes can see long distances. In fact the Andromeda Galaxy can be seen with the naked eye and that’s 2.5 million light-years away. But even a massive galaxy, like Andromeda, appears to us as a tiny point in the sky.
It makes sense that as an object gets further away it becomes harder to see. But why this happens helps us understand how vital telescopes have been in exploring the universe.
As an object gets further away less of its light will reach your eye. The image takes up less space on your retina (the light-sensitive tissue at the back of your eye), making the image smaller. This makes details of the image harder to see.
Do bigger lenses give us a bigger image?
To make a distant object appear brighter and larger, we effectively need a bigger eye to collect more light. With more light we can create a brighter image, we can then magnify the image so that it takes up more space on our retina.
The big lens in the telescope (objective lens) collects much more light than your eye can from a distant object and focuses the light to a point (the focal point) inside the telescope.
A smaller lens (eyepiece lens) takes the bright light from the focal point and magnifies it so that it uses more of your retina.
A telescope’s ability to collect light depends on the size of the objective lens, which is used to gather and focus light from a narrow region of sky.
The eye piece magnifies the light collected by the objective lens, like a magnifying glass magnifies words on a page. But the performance of a telescope depends almost entirely on the size of the objective lens, sometimes called the aperture.
What’s the big problem with refracting telescopes?
If you’ve ever seen light bend through a prism you probably have an idea of where the problem lies with a refracting telescope; it’s the lens.
When light travels through glass it slows down, that’s why it bends. Lenses are shaped perfectly to bend light in particular ways. But the amount light bends depends on the wavelength, or colour, of the light.
White light is a mixture of all colours, from red to violet. Red light bends the least and violet light bends the most.
When white light travels through the objective lens, the different colours bend at different angles and are focused at slightly different points. Different coloured images are misaligned creating a blurry image with fringes of colour along the boundaries that separate dark and bright parts.
Can telescopes with mirrors correct the problem?
Reflecting telescopes magnify distant objects using the same principle: more light is collected and focused to a point and this is magnified so that it fills your field of vision.
But instead of using a lens, a curved mirror (primary mirror) collects the light and reflects it to a focus. Because light doesn’t pass through the mirror, it doesn’t bend the different colours by different amounts, the way a refracting lens does.
A small mirror (secondary mirror) is placed in the path of light from the primary mirror to reflect the image towards the eyepiece. The secondary mirror must be very small so that it doesn’t block the light from the distant object as it travels to the primary mirror.
Another benefit of using mirrors instead of lenses is that big mirrors are easier and cheaper to make than big lenses. Reflecting telescopes can be much larger and therefore look deeper into space.
Are radio telescope like big reflecting telescopes?
Radio waves aren’t just for listening to your favourite songs, they occur naturally all over the universe. In fact, they are a special type of light that humans can’t see. They can be found emanating from clouds of gas where stars are born, as well as the centres of galaxies.
Many strong sources of radio waves are invisible in normal light, so looking at radio waves reveals a completely different picture of our universe. Even objects like the Sun and planets can reveal new features when viewed with radio telescopes, like Jodrell Bank.
Radio waves are also better at travelling long distances than shorter wavelengths, so we can get clearer signals from very distant objects in radio than we can in normal light.
The large dish acts like the primary mirror in a reflecting telescope, but it needs to be much larger to reflect the long wavelength radio waves. These are reflected up to a smaller mirror which reflects the images back to a receiver. The information from the receiver is then processed by computers to create colour images which we can see.
Source: BBC.co.uk
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thegirlwiththeredbow asked: AWESOME blog! :)
Thank you :) Im glad you like my super nerdy blog haha
You have a really cool blog yourself, sorry for the late reply but I always had the intention to answer you just kept putting it off
Anyways thanks again! You are too sweet!
And you have an amazing blog yourself :)
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