We Know The Speed of Light But What Is The Speed of Dark ?

This question, like many others, centers on a negative concept. There are a few of these running around and it is fairly common to get tripped up by them, but part of the fun in science is when you can apply negative concepts to positive ones, helping us better understand how each facet of the universe work together AND independently. One such negative concept asks: “What is darkness?” “And is there such a thing as the speed of darkness?”

In order to know what the speed of darkness is, or anything else about it, we would have to quantify it. What is it? Well darkness is the absence of light. So darkness isn’t a thing, it is instead a lack of a thing. Therefore questions about characteristic of darkness, which is an absence instead of a presence, become hard to define.

The most correct answer to the question would be that darkness has no speed. In order for something to have speed, it must be able to move relative to other bodies. Since darkness doesn’t actually exist, it cannot move and therefore cannot have a speed. However, since the level of illumination of a given area cannot change at a different rate than the speed of light, you could also equate it as having the speed of light, though less correctly.

I’ll use an example to make my point. Lets say you are in a room which is completely sealed off from the outside world, and nothing can enter it (particularly light). In this room you have a perfect light bulb. It has no warm up or cool down time, when you flip the switch, it instantly starts or stops producing a steady stream of light. In addition to this, let’s say that the walls do not reflect light, but instead completely absorb it. For convenience, let’s make the room round and have the light bulb at the center. Most of this can’t actually be done, but this is still a helpful thought experiment.

Now lets say we suddenly turn off the light bulb. The light will travel at a predictable speed from the bulb, and as it does, it will leave behind it an area without any light at all (meaning the light in the room is receding at the speed of light. Note that the darkness isn’t advancing, but the light is receding. As I’ve said earlier, darkness isn’t actually a thing; therefore, it cannot have a speed.

However the lack of light in our hypothetical room is spreading at the speed of light. Colloquially, this is a minor point. It is however a very important distinction. Darkness doesn’t exist, and therefore cannot spread or move, but light (which obviously does exist) can. And in doing so it can also leave an absence of light, and this absence will grow or shrink at the speed of light.

Since darkness isn’t a tangible thing, it is hard to properly quantify its characteristics. It doesn’t have a speed, but light will always advance or recede at the universal speed limit (186,000 miles per second, or 299,792,458 meters per second).

Source:- http://futurism.com/the-milky-way-lyrids-by-mike-taylor/

NASA probe shows PLUTO has blue skies

Nothing Is Solid ; Everything Is Energy

Scientists Explain The World of Quantum Physics

It has been written about before, over and over again, but cannot be emphasized enough. The world of quantum physics is an eerie one, one that sheds light on the truth about our world in ways that challenge the existing framework of accepted knowledge.

What we perceive as our physical material world, is really not physical or material at all, in fact, it is far from it. This has been
proven time and time again by multiple Nobel Prize (among many other scientists around the world) winning physicists, one of them being Niels Bohr, a Danish Physicist who made significant contributions to
understanding atomic structure and quantum theory.

“If quantum mechanics hasn’t profoundly shocked you, you haven’t
understood it yet. Everything we call real is made of things that
cannot be regarded as real.” – Niels Bohr

 At the turn of the nineteenth century, physicists started to explore the relationship between energy and the structure of matter. In doing so, the belief that a physical, Newtonian material universe that was at the very heart of scientific knowing was dropped, and the
realization that matter is nothing but an illusion replaced it.

Scientists began to recognize that everything in the Universe is made
out of energy.

“Despite the unrivaled empirical success of quantum theory, the very
suggestion that it may be literally true as a description of nature is
still greeted with cynicism, incomprehension and even anger.” (T.
Folger, “Quantum Shmantum”; Discover 22:37-43, 2001)

Quantum physicists discovered that physical atoms are made up of vortices of energy that are constantly spinning and vibrating, each one radiating its own unique energy signature. Therefore, if we really want to observe ourselves and find out what we are, we are really beings of energy and vibration, radiating our own unique energy signature -this is fact and is what quantum physics has shown us time
and time again. We are much more than what we perceive ourselves to be, and it’s time we begin to see ourselves in that light. If you observed the composition of an atom with a microscope you would see a small, invisible tornado-like vortex, with a number of infinitely small energy vortices called quarks and photons. These are what make up the structure of the atom. As you focused in closer and closer on the structure of the atom, you would see nothing, you would observe a physical void. The atom has no physical structure, we have no physical structure, physical things really don’t have any physical structure!
Atoms are made out of invisible energy, not tangible matter.

“Get over it, and accept the inarguable conclusion. The universe is
immaterial-mental and spiritual” – Richard Conn Henry, Professor
of Physics and Astronomy at Johns Hopkins University (quote taken from
“the mental universe)

It’s quite the conundrum, isn’t it? Our experience tells us that our reality is made up of physical material things, and that our world is an independently existing objective one. The revelation that the
universe is not an assembly of physical parts, suggested by Newtonian physics, and instead comes from a holistic entanglement of immaterial energy waves stems from the work of Albert Einstein, Max Planck and
Werner Heisenberg, among others.

The Role of Consciousness in Quantum Mechanics 

What does it mean that our physical material reality isn’t really
physical at all? It could mean a number of things, and concepts such
as this cannot be explored if scientists remain within the boundaries
of the only perceived world existing, the world we see. As Nikola Tesla supposedly said:

“The day science begins to study non-physical phenomena, it will make more progress in one decade than in all the previous centuries of its existence.”

Fortunately, many scientists have already taken the leap, and have already questioned the meaning and implications of what we’ve discovered with quantum physics. One of these potential revelations is that “the observer creates the reality.”

A fundamental conclusion of the new physics also acknowledges that the
observer creates the reality. As observers, we are personally involved with the creation of our own reality. Physicists are being forced to admit that the universe is a “mental” construction.

Pioneering physicist Sir James Jeans wrote: “The stream of knowledge is heading toward a non-mechanical reality; the universe begins to look more like a great thought than like a great machine. Mind no longer appears to be an accidental intruder into the realm of matter, we ought rather hail it as the creator and governor of the realm of matter. (R. C. Henry, “The Mental Universe”; Nature 436:29, 2005)

One great example that illustrates the role of consciousness within the physical material world (which we know not to be so physical) is the double slit experiment. This experiment has been used multiple times to explore the role of consciousness in shaping the nature of physical reality.

A double-slit optical system was used to test the possible role of consciousness in the collapse of the quantum wave-function. The ratio of the interference pattern’s double-slit spectral power to its single-slit spectral power was predicted to decrease when attention was focused toward the double-slit as compared to away from it. The study found that factors associated with consciousness, such as meditation, experience, electrocortical markers of focused attention and psychological factors such as openness and absorption, significantly correlated in predicted ways with perturbations in the double-slit interference pattern.

This is just the beginning. I wrote another article earlier this year that has much more, sourced information with regards to the role of consciousness and our physical material world:

http://www.collective-evolution.com/2014/03/08/10-scientific-studies-that-prove-consciousness-can-alter-our-physical-material-world/

What’s The Significance?

The significance of this information is for us to wake up, and realize that we are all energy, radiating our own unique energy signature. Feelings, thoughts and emotions play a vital role, quantum physics helps us see the significance of how we all feel. If all of us are in a peaceful loving state inside, it will no doubt impact the external
world around us, and influence how others feel as well.

“If you want to know the secrets of the universe, think in terms of energy, frequency and vibration.” – Nikola Tesla.

Studies have shown that positive emotions and operating from a place of peace within oneself can lead to a very different experience for the person emitting those emotions and for those around them. At our subatomic level, does the vibrational frequency change the manifestation of physical reality? If so, in what way? We know that when an atom changes its state, it absorbs or emits electromagnetic
frequencies, which are responsible for changing its state.  Do different states of emotion, perception and feelings result in
different electromagnetic frequencies? Yes! This has been proven.

source:- http://www.collective-evolution.com/2014/09/27/this-is-the-world-of-quantum-physics-nothing-is-solid-and-everything-is-energy/

Leidenfrost effect

The Leidenfrost effect is a phenomenon in which a liquid, in near contact with a mass significantly hotter than the liquid's boiling point, produces an insulating vapor layer keeping that liquid from boiling rapidly. 

This is most commonly seen when cooking; one sprinkles drops of water in a pan to gauge its temperature: if the pan's temperature is at or above the Leidenfrost point, the water skitters across the pan and takes longer to evaporate than in a pan below the temperature of the Leidenfrost point (but still above boiling temperature).

The effect is also responsible for the ability of liquid nitrogen to skitter across floors. It has also been used in some potentially dangerous demonstrations, such as dipping a wet finger in molten lead or blowing out a mouthful of liquid nitrogen, both enacted without injury to the demonstrator. The latter is potentially lethal, particularly should one accidentally swallow the liquid nitrogen.

The effect can be seen as drops of water are sprinkled onto a pan at various times as it heats up. Initially, as the temperature of the pan is below 100 °C (212 °F), the water just flattens out and slowly evaporates. As the temperature of the pan goes above 100 °C (212 °F), the water drops hiss when touching the pan and evaporate quickly. Later, as the temperature exceeds the Leidenfrost point, the Leidenfrost effect comes into play. On contact with the pan, the water droplets bunch up into small balls of water and skitter around, lasting much longer than when the temperature of the pan was lower. This effect works until a much higher temperature causes any further drops of water to evaporate too quickly to cause this effect.

This is because at temperatures above the Leidenfrost point, the bottom part of the water droplet vaporizes immediately on contact with the hot plate. The resulting gas suspends the rest of the water droplet just above it, preventing any further direct contact between the liquid water and the hot plate. As steam has much poorer thermal conductivity, further heat transfer between the pan and the droplet is slowed down dramatically. This also results in the drop being able to skid around the pan on the layer of gas just under it.

The temperature at which the Leidenfrost effect begins to occur is not easy to predict. Even if the volume of the drop of liquid stays the same, the Leidenfrost point may be quite different, with a complicated dependence on the properties of the surface, as well as any impurities in the liquid. Some research has been conducted into a theoretical model of the system, but it is quite complicated. As a very rough estimate, the Leidenfrost point for a drop of water on a frying pan might occur at 193 °C (379 °F).[citation needed]

The effect was also described by the eminent Victorian steam boiler designer, Sir William Fairbairn, in reference to its effect on massively reducing heat transfer from a hot iron surface to water, such as within a boiler. In a pair of lectures on boiler design, he cited the work of one M. Boutigny & Professor Bowman of King's College, London in studying this. A drop of water that was vaporized almost immediately at 334 °F (168 °C) persisted for 152 seconds at 395 °F (202 °C). Lower temperatures in a boiler firebox might evaporate water more quickly as a result; compare Mpemba effect. An alternative approach was to increase the temperature beyond the Leidenfrost point. Fairbairn considered this too, and may have been contemplating the flash steam boiler, but considered the technical aspects insurmountable for the time.

The Leidenfrost point may also be taken to be the temperature for which the hovering droplet lasts longest.

It has been demonstrated that it is possible to stabilize the Leidenfrost vapour layer of water by exploiting superhydrophobic surfaces. In this case, once the vapour layer is established, cooling never collapses the layer, and no nucleate boiling occurs; the layer instead slowly relaxes until the surface is cooled.

Leidenfrost point

 A water droplet experiencing Leidenfrost effect on a hot stove hot plate

The Leidenfrost point signifies the onset of stable film boiling. It represents the point on the boiling curve where the heat flux is at the minimum and the surface is completely covered by a vapor blanket. Heat transfer from the surface to the liquid occurs by conduction and radiation through the vapor. In 1756, Leidenfrost observed that water droplets supported by the vapor film slowly evaporate as they move about on the hot surface. As the surface temperature is increased, radiation through the vapor film becomes more significant and the heat flux increases with increasing excess temperature..

The minimum heat flux for a large horizontal plate can be derived from Zuber's equation,

where the properties are evaluated at saturation temperature. Zuber's constant, C is approximately 0.09 for most fluids at moderate pressures.

Source:- https://www.engineersedge.com/physics/leidenfrost_effect_13089.htm

Wireless Electricity Transmission

Wireless Electricity Transmission

Magnetic induction is a technology that you will probably remember from your physics classes at high school.

The magnetic fields used to transfer energy are "perfectly safe" -- in fact, they are the same kind of fields used in Wi-Fi routers.

In the house of the future, wire-free energy transfer could be as easy as wireless internet.

If all goes to WiTricity's plans, smartphones will charge in your pocket as you wander around, televisions will flicker with no wires attached, and electric cars will refuel while sitting on the driveway.

WiTricity has already demonstrated the ability to power laptops, cell-phones, and TVs by attaching resonator coils to batteries -- and an electric car refueler is reportedly in the works.

Introduction
Wireless Power transfer was first demonstrated by Nikola Tesla in the 1890s, however it is only really in the last decade that the technology has been harnessed to the point where it offers real, tangible benefits to real world applications.  Applications using resonant wireless power technology have been most noticeable in the Consumer Electronics market where wireless charging promises to deliver new levels of convenience for the charging of millions of everyday devices.

(Wireless) Inductive Power Transfer or IPT involves the transmission of energy from a power source to an electrical load, without connectors, across an air gap.  The basis of a wireless power system involves essentially two coils – a transmitter and receiver coil.  The transmitter coil is energized by alternating current to generate a magnetic field, which in turn induces a current in the receiver coil.

How does Wireless Power work?
The basics of wireless power involves the transmission of energy from a transmitter to a receiver via an oscillating magnetic field.

To achieve this, Direct Current (DC) supplied by a power source, is converted into high frequency Alternating Current (AC) by specially designed electronics built into the transmitter.

The alternating current energizes a copper wire coil in the transmitter, which generates a magnetic field.  Once a second (receiver) coil is placed within proximity of the magnetic field, the field can induce an alternating current in the receiving coil.

Electronics in the receiving device then converts the alternating current back into direct current, which becomes usable power.

The diagram below simplifies this process into four key steps.

1. The ‘mains’ voltage is converted in to an AC signal (Alternating Current), which is then sent to the transmitter coil via the electronic transmitter circuit.
2. The AC current flowing through the transmitter coil induces a magnetic field which can extends to the receiver coil (which lies in relative proximity)
3. The magnetic field then generates a current which flows through the coil of the receiving device. The process whereby energy is transmitted between the transmitter and receiver coil is also referred to as magnetic or resonant coupling and is achieved by both coils resonating at the same frequency. Current flowing within the receiver coil is converted into direct current (DC) by the receiver circuit, which can then be used to power the device.


What is meant by “Resonance”?
The distance at which the energy can be transferred is increased if the transmitter and receiver coils are resonating at the same frequency.

This resonant frequency refers to the frequency at which an object naturally vibrates or rings – much like the way a tuning fork rings at a particular frequency and can achieve their maximum amplitude.

A Brief History

The idea of inductive power was made possible in 1888 when German physicist Heinrich Hertz proved the existence of electromagnetic waves by creating a spark gap transmitter and receiver.

A spark generated by the transmitter also created a small spark in the receiver, which could be seen with a microscope. Serbian American inventor and engineer Nikola Tesla learned of Hertz’s work by the following year and began duplicating his experiments.

By 1891, Tesla had developed a high-tension induction coil, which he used to demonstrate wireless energy transmission. He successfully presented his technique to the American Institute of Electrical Engineers and the National Electric Light Association. By 1894 Tesla had developed the equipment to wirelessly light incandescent lamps at his New York laboratory. This method used resonant inductive coupling, which involves tuning two nearby coils to resonate at the same frequency.

By 1896 he had increased the range of transmission to 30 miles (48 km). Tesla began construction on his Wardenclyffe Tower, designed for wireless broadcasting and power generation, in 1901. After several construction delays and technical setbacks, the project ran out of funds a few years later and was eventually demolished. After this, no significant advances were made for more than 50 years.

In the early 1970s, experiments with RFID tags began and by the early 2000’s Professor She Yuen (Ron) Hui and S.C. Tang developed a charger to provide resonant power transfer for small electronics. Today wireless power is used for everything from industrial motors to charging smartphones and tablets.

Researchers predict that wireless power will be making a significant contribution to energy supplies by the end of this decade.

Benefits of Wireless Power

1. Reduce costs associated with maintaining direct connectors
2. Greater convenience for ​the charging of everyday electronic devices
3. Safe​ power transfer to applications that need to remain sterile or hermetically sealed
4. Electronics can be fully enclosed, reducing the risk of corrosion due to elements such as oxygen and water.
​Robust and consistent power delivery to rotating, highly mobile industrial equipment​
5. ​Delivers reliable power transfer to mission critical systems in wet, dirty and moving environments.
6. Whatever the application, the removal of the physical connection delivers a number of benefits over traditional cable connectors, some of which aren’t always obvious.  The video below highlights just some of the benefits and advantages of wireless power and offers an insight into a world where wireless power is widely integrated into industrial and mission critical environments.

http://www.youtube.com/embed/tKJGpXIu8s0


Source:-http://powerbyproxi.com/wireless-power/

Why does water rise in the burning candle experiment?

Objective: 
To study the rise of water in the inverted glass which covers a burning candle placed in water. 

Equipment:
three plates, four similar candles, three drinking glasses of same size.

Introduction:
The experiment described in the first part is very famous and is used by many teachers and students to show that there is 21% oxygen in air. In this demo experiment I will show that the real physics of rising water is very different.

Procedure:
Put a candle vertically in a plate. Light the candle. Put some water in the plate so that a small lower portion of the candle is in water. The candle keeps on burning. Cover  the burning candle by an inverted glass. The candle goes off and water rises in the glass. How much water will rise in glass depends on the thickness of the candle and how much time you allowed the candle to burn before you covered it.
Use a candle and cover it quickly after burning. As the candle goes off, very small amount of water rises in the glass. It could be hardly 5% of the volume of the glass. Leave this set up as it is and take another plate, put a similar candle, pour water, light the candle and wait for some time. If a fan is running nearby put it off. Now cover it with a glass of the same size. This time water rise will be much more. 
Now take the third plate and put two candles in it. Pour water in the plate and light all the candles. Wait for some time and then cover both by a glass of the same size as used in the previous trials. This time the water rise will be very high, may be 40-50%.
What is the Physics of this rising water? When candle burns the air surrounding the flame becomes hot. The flame itself is very hot gases. The pressure of this surrounding air is the same as the atmospheric pressure as all air is connected. As pressure remains the same and the temperature rises the density goes down from the gas law
PV = nRT. For a given volume n will decrease if T increases.  When you cover the candle(s) you trap this less dense air. As the oxygen is consumed and the candle goes off, the air (gases in fact) inside the glass cools down. As the number of moles n is now fixed, decreasing the temperature will decrease the pressure and this will suck water in the glass. In equilibrium the temperature in the glass will be the same as the room temperature, the pressure will be P= P0-hrg, where P0 is the atmospheric pressure and h is the height water rises.
If you cover the candle just after the burning, the air trapped is not that hot. The density is thus not much lowered and hence on candle going off the water rise is not much. On the other hand if you burn two candles together the surrounding air becomes much more hotter and hence the water rise is high.

Discussion:
The experiment described clearly shows that the rise of water has no relation with the oxygen content in air. In fact for each oxygen molecule consumed, you produce a molecule of CO2 among other products. Also the solubility of CO2 is lower than that of O2. So there is no question of decrease in pressure inside due to consuming oxygen.
There is another factor that contributes in rising water in the glass. At higher temperature the saturation vapour pressure of water is also high. As the air in the inverted glass is in contact with water, it will contain saturated vapour. When the candle goes off and the temperature falls, saturation vapour pressure also decreases and some of the vapour condenses. This also decreases pressure inside and helps in rise of water.
Please note that water starts rising only after the candle goes off.

Even When You’re Standing Still, You’re Still Moving

Even When You’re Standing Still, You’re Still Moving

A human body, or any object on the Earth, is never at rest. Even when you’re asleep in bed, you’re moving pretty fast. Our Milky Way Galaxy is rotating at 225 kilometers per second, and hurling through the cosmos at an estimated 305 kilometers per second. Add those figures together, and we’re racing through space at around 530 kilometers, or 330 miles per second. So in one minute’s time, you’ve  traveled almost 20,000 kilometers, or more than 12,000 miles. And your friends always complain that you never go anywhere.

Newtons Experiments - rolling cone and catenoid

Newtons Experiments - rolling cone and catenoid

Here we have a simple triangular ramp made out of two pieces of long straight metal with adjustable screws at the three ends. The screws can be adjusted so that ramp slopes. We have three things to put on the ramp: a cylindrical rod, a double cone and a shape called a catenoid. The cylinder is simply a piece of painted broom pole which is uniform along its length. The double cone (or spindle) is made out of two wooden christmas cone decorations glued back-to-back at the wide ends to make something that is thicker in the middle than it is at the ends. This was smoothed and painted. Finally the catenoid, believe it or not, is the body of a loo brush holder. It has the 'opposite sort' of shape to the double cone in that the metal body is wider at the ends and tappers in smaller at the middle.

Experiment 1 - cylinder
First we set up the screws so that the ramp just slopes. That is we adjust the two screws at the ends of the metal bars to be slightly higher than the screw located at the meeting point of the two metal bars. What will happen if we put the cylindrical rod onto the middle of the ramp? Well no prizes for guessing that it will roll down hill - correct!

Experiment 2 - double cone

However if we put the double cone in the middle what will happen? - it apparently defies gravity and rolls up hill! What's going on?? The explanation is something like this. As the double cone rolls along the sloping ramp it only ever makes contact at two points. Because of the ramp shape these points of contact change (move out from near the center of the double cone) as it moves along. At first the ramp may contact the double cone near to the center where it is quite thick and so the center point of the double cone is quite high above the ramp. As it rolls up the ramp the point of contact changes and this center points drops down toward the level of the ramp. Now as long as this drop is greater than the apparent rise up the sloping ramp, the center of mass of the double cone is always falling even if it looks like its actually going up hill ! The crucial point here is that the center of mass is actually always falling down hill as it apparently looks like its going uphill - its a sort of optical illusion (also see the diagram below). If the ramp gets too steep the center of mass of the double cone will not be able to move downhill enough to compensate for the rise and the illusion will not work.

Experiment 3 - catenoid

If the ramp is now turned over (so that it slopes the other way) its now at the correct angle for the catanoid to apparently roll up-hill. Newton didnt have such high tech loo-brush holders, although he would have probably known of the shape - the catenoid !

There is no magic here (apart from the magic of physics) its just depends on the relationship between the ramp slope angle (A), the angle / width of the ramp
(B) and the way the double cone or catanode shapes change over its length
(C) that makes for this very interesting illusion of apparently defying gravity - see the diagram below.

Source:-http://www.creative-science.org.uk/rolling_cone.html

NASA Spent Millions to Develop a Pen that Would Write in Space, whereas the Soviet Cosmonauts Used a Pencil

NASA Spent Millions to Develop a Pen that Would Write in Space, whereas the Soviet Cosmonauts Used a Pencil.

An AG-7 Astronaut Space Pen in presentation case.

1960s, legend has it, NASA scientists realized that pens could not function in space. They needed to figure out another way for the astronauts to write things down. So they spent years and millions of taxpayer dollars to develop a pen that could put ink to paper without gravity. But their crafty Soviet counterparts, so the story goes, simply handed their cosmonauts pencils.

Originally, NASA astronauts, like the Soviet cosmonauts, used pencils, according to NASA historians. In fact, NASA ordered 34 mechanical pencils from Houston's Tycam Engineering Manufacturing, Inc., in 1965. They paid $4,382.50 or $128.89 per pencil. When these prices became public, there was an outcry and NASA scrambled to find something cheaper for the astronauts to use.

Pencils may not have been the best choice anyway. The tips flaked and broke off, drifting in microgravity where they could potentially harm an astronaut or equipment. And pencils are flammable--a quality NASA wanted to avoid in onboard objects after the Apollo 1 fire.

Paul C. Fisher and his company, the Fisher Pen Company, reportedly invested $1 million to create what is now commonly known as the space pen.

In 1965 Fisher patented a pen that could write upside-down, in frigid or roasting conditions (down to minus 50 degrees Fahrenheit or up to 400 degrees F), and even underwater or in other liquids. If too hot, though, the ink turned green instead of its normal blue.

That same year, Fisher offered the AG-7 "Anti-Gravity" Space Pen to NASA. Because of the earlier mechanical pencil fiasco, NASA was hesitant. But, after testing the space pen intensively, the agency decided to use it on spaceflights beginning in 1967.

Unlike most ballpoint pens, Fisher's pen does not rely on gravity to get the ink flowing. The cartridge is instead pressurized with nitrogen at 35 pounds per square inch. This pressure pushes the ink toward the tungsten carbide ball at the pen's tip.

The ink, too, differs from that of other pens. Fisher used ink that stays a gellike solid until the movement of the ballpoint turns it into a fluid. The pressurized nitrogen also prevents air from mixing with the ink so it cannot evaporate or oxidize.

How space pen was made?

The ballpoint is made from tungsten carbide and is precisely fitted in order to avoid leaks. A sliding float separates the ink from the pressurized gas. The thixotropic ink in the hermetically sealed and pressurized reservoir is able to write for three times longer than a standard ballpoint pen. The pen can write at altitudes up to 12,500 feet (3800 m). 

The ink is forced out by compressed nitrogen at a pressure of nearly 35 psi (240 kPa). Operating temperatures range from −30 to 250 °F (−35 to 120 °C). The pen has an estimated shelf life of 100 years.

Source:- http://www.scientificamerican.com/article/fact-or-fiction-nasa-spen/

And

Wikipedia

Aurora -A natural light display in the sky.

An aurora is a natural light display in the sky, predominantly seen in the high latitude (Arctic and Antarctic) regions.

If you're camping near the United States/Canada border or points farther north, you might see an eerie glow in the night sky. Sometimes it can look like twilight. At other times it can look like a glowing, dancing ribbon of light. The light may be green, red, blue or a combination of these colors. What you are seeing is called the aurora borealis, or simply an aurora.

Because auroras are caused by the interaction of solar winds with the Earth's magnetic field, you can see them most often near the poles, both north and south. In the north, they're called aurora borealis, or Northern Lights. Aurora is the name of the Roman goddess of the dawn, and "boreal" means "north" in Latin. In the southern hemisphere, auroras are called aurora australis (Latin for "south").

What causes auroras?

Auroras are indicators of the connection between the Earth and the sun. The frequency of auroras correlates to the frequency of solar activity and the sun's 11-year cycle of activity.

As the process of fusion occurs inside the sun, it spews high-energy particles (ions, electrons, protons, neutrinos) and radiation in the solar wind. When the sun's activity is high, you'll also see large eruptions called solar flares and coronal mass ejections. These high-energy particles and radiations get released into space and travel throughout the solar system. When they hit the Earth, they encounter its magnetic field.

The poles of the Earth's magnetic field lie near, but not exactly on, its geographic poles (where the planet spins on its axis). Scientists believe that the Earth's liquid iron outer core spins and makes the magnetic field. The field is distorted by the solar wind, getting compressed on the side facing the sun (bow shock) and drawn out on the opposite side (magnetotail). The solar winds create an opening in the magnetic field at the polar cusps. Polar cusps are found on the solar side of the magnetosphere (the area around the Earth that's influenced by the magnetic field).

Let's look at how this leads to an aurora.

1) As the charged particles of solar winds and flares hit the Earth's magnetic field, they travel along the field lines.
2) Some particles get deflected around the Earth, while others interact with the magnetic field lines, causing currents of charged particles within the magnetic fields to travel toward both poles -- this is why there are simultaneous auroras in both hemispheres. These currents are called Birkeland currents after Kristian Birkeland, the Norwegian physicist who discovered them.
3) When an electric charge cuts across a magnetic field it generates an electric current. As these currents descend into the atmosphere along the field lines, they pick up more energy.
4) When they hit the ionosphere region of the Earth's upper atmosphere, they collide with ions of oxygen and nitrogen.
The particles impact the oxygen and nitrogen ions and transfer their energy to these ions.
5) The absorption of energy by oxygen and nitrogen ions causes electrons within them to become "excited" and move from low-energy to high-energy orbitals.
6) When the excited ions relax, the electrons in the oxygen and nitrogen atoms return to their original orbitals. In the process, they re-radiate the energy in the form of light. This light makes up the aurora, and the different colors come from light radiated from different ions.

As we mentioned, auroras take on different appearances. They can look like an orange or red glow on the horizon -- like a sunrise or sunset. Sometimes they may be mistaken for fires in the distance, like the American Indians thought. They can look like curtains or ribbons and move and undulate during the night.

Auroras can be green, red or blue. Often they will be a combination of colors, with each color visible at a different altitude in the atmosphere.

Note: The particles that interact with the oxygen and nitrogen ions in the atmosphere don't come from the sun, but rather were already trapped by the Earth's magnetic field. The solar winds and flares perturb the magnetic field and set these particles within the magnetosphere in motion.

How do we know what causes auroras?

In 1895, a Norwegian physicist named Kristian Birkeland addressed the queston of what causes auroras. Birkeland believed that auroras were caused by electrons from the sun that interacted with the Earth's magnetic field. To test this, he placed a spherical magnet called a terrella inside a vacuum chamber. He also had an electron gun inside the chamber. When he turned on the gun, electrons interacted with the magnet's field and produced an artificial aurora, supporting his hypothesis.

Birkeland's artificial aurora didn't show the characteristic oval ring. The auroral ring was actually predicted by a Japanese graduate student named Shun-ichi Akasofu in 1964. He examined photographs of auroras and concluded that auroras were rings. So, why weren't Birkeland's auroras oval? Birkeland thought the electrons that excited the oxygen and nitrogen ions came directly from the sun. Only when satellites began to study auroras and measure the magnetosphere did scientists figure out that the electrons came from the magnetosphere itself. When this idea was placed in mathematical models, auroral rings could be explained.

Do auroras occur only on Earth?

Because auroras are caused by the interactions of solar winds and solar flares with the magnetic fields of a planet, you'd think they'd happen on other planets as well. What you need is:
Solar flares and winds that provide the charged particles and energy to interact with a planet’s magnetic field
A planetary magnetic field (probably of some strength) that traps electrons from space
A planetary atmosphere that contains ionic gases that interact with energetic electrons from the magnetic field and produce light through excitation and relaxation of their electrons
So, with these conditions, we have observed auroras on Jupiter and Saturn. Both planets have powerful magnetic fields and atmospheres with ionized gases, mainly hydrogen and helium.

The Hubble Space Telescope caught images of auroras on Jupiter, and the Cassini probe orbiting Saturn has photographed auroras there. ­

Source:-

http://science.howstuffworks.com/nature/climate-weather/atmospheric/aurora2.htm

How pressure cooker works?

What is a pressure cooker, and what does it do?
A pressure cooker works on a simple principle: Steam pressure. A sealed pot, with a lot of steam inside, builds up high pressure, which helps food cook faster.

When was the pressure cooker invented?
It was invented in the 1600s by a Frenchman by Denis Papin, who wanted to translate new discoveries in physics about pressure and steam into cooking. He called his pot the "Digester" but it took quite a while before better manufacturing standards and technology could make these high pressure pots safe.

How does a pressure cooker work?
A pressure cooker is a sealed pot with a valve that controls the steam pressure inside. As the pot heats up, the liquid inside forms steam, which raises the pressure in the pot. This high pressure steam has two major effects:

Raises the boiling point of the water in the pot. When cooking something wet, like a stew or steamed vegetables, the heat of your cooking is limited to the boiling point of water (100°C). But with the steam's pressure now the boiling point can get as high as 138°C. This higher heat helps the food to cook faster.
Raises the pressure, forcing liquid into the food. The high pressure also helps force liquid and moisture into the food quickly, which helps it cook faster and also helps certain foods, like tough meat, get very tender very quickly.

The extra-high heat of the pressure cooker also promotes caramelization and browning in a surprising way — we're not used to food caramelizing when it is cooking in liquid. But the flavors created in a pressure cooker can be really deep and complex — unlike regular steamed foods.

What can you cook in the pressure cooker?
Almost anything! It cooks rice in just a few minutes, and it cooks tougher things like beans and chickpeas in much less than an hour. It is very good for foods that need to be tenderized like braised meats and roasts. But people have cooked all kinds of other things in it too. Laura at Hip Pressure Cooking even made hard-boiled eggs (apparently the shells pop right off). But it is used most frequently around the world for beans and pulses, stews, and vegetables.

This is a link to see the working of pressure cooker at youtube.

http://m.youtube.com/watch?v=TWV3FbgPPXo

Death of a Star.

Several billion years after its life starts, a star will die. How the star dies, however, depends on what type of star it is.

Stars Like the Sun

When the core runs out of hydrogen fuel, it will contract under the weight of gravity. However, some hydrogen fusion will occur in the upper layers. As the core contracts, it heats up. This heats the upper layers, causing them to expand. As the outer layers expand, the radius of the star will increase and it will become a red giant. The radius of the red giant sun will be just beyond the Earth's orbit. At some point after this, the core will become hot enough to cause the helium to fuse into carbon. When the helium fuel runs out, the core will expand and cool. The upper layers will expand and eject material that will collect around the dying star to form a planetary nebula. Finally, the core will cool into a white dwarf and then eventually into a black dwarf. This entire process will take a few billion years.

Stars More Massive Than the Sun

When the core runs out of hydrogen, these stars fuse helium into carbon just like the Sun. However, after the helium is gone, their mass is enough to fuse carbon into heavier elements such as oxygen, neon, silicon, magnesium, sulfur and iron. Once the core has turned to iron, it can burn no longer. The star collapses by its own gravity and the iron core heats up. The core becomes so tightly packed that protons and electrons merge to form neutrons. In less than a second, the iron core, which is about the size of the Earth, shrinks to a neutron core with a radius of about 6 miles (10 kilometers). The outer layers of the star fall inward on the neutron core, thereby crushing it further. The core heats to billions of degrees and explodes (supernova), thereby releasing large amounts of energy and material into space. The shock wave from the supernova can initiate star formation in other interstellar clouds. The remains of the core can form a neutron star or a black hole depending upon the mass of the original star.

How aeroplane fly?

Flight requires two things: thrust and lift.

Thrust

Thrust is the forward motion provided by a propeller or jet engine.

Lift on an aeroplane wing

The shape of the aeroplane wing is peculiar. Its upper surface is
more curved than its lower surface and its leading edge is thicker than its trailing edge. As an aeroplane moves forward, the air blown in the form of stream lines over the wings of aeroplane is shown below.
As the upper surface of wing is more curved than its lower surface, therefore, the speed of air above the wings two is larger than the speed of the air below the wings. According to Bernoulli’s theorem, the pressure above the wings becomes less than that the pressure
below the wings. Due to this difference of pressure on the two sides of the wings, a vertical lift acts on the aeroplane. When this lift is sufficient to overcome the gravity pull on the aeroplane, the aeroplane is lifted up.

Drag

Two forces work against flight: drag and gravity.
A wing has to be designed not only to produce lift, but also to minimize the friction with passing air, which causes drag.
Every airplane has a specific takeoff speed, where lift overcomes gravity. That critical speed changes based on how much weight a particular flight packs. The planes propeller or jet engine, meanwhile, has to work to provide enough thrust to overcome drag.

Pilots can make minor adjustments to the wing flaps, effectively changing the wing's angle into the wind. A more tilted wing allows more lift to be created at a lower speed.

THE EARTH DOESN’T ACTUALLY ORBIT THE SUN?

You were taught that Earth and other planets in our solar system orbit the sun, and that our solar system orbits the center of the Milky Way. Is it possible that your science teacher had it wrong? Is everything you’ve learned about physics and gravity incorrect?

THE EARTH DOESN’T ACTUALLY ORBIT THE SUN?

Let us first start by saying that for all practical purposes, what you were taught isn’t entirely wrong. The Earth does in fact orbit the sun. In the strictest sense, however, it doesn’t.

“But how can this be?”, you might ask. It’s been tested, verified and is common knowledge. It’s one of the first science lessons taught to kids in in grade school. How can our fundamental understanding of the solar system be wrong? Well, it’s actually due to a technicality.

Everything that has mass has gravity. The more massive something is, the more gravity it has.

The sun and other planets all each have their own “gravity well” which interact and pull on one another. Because there are several different gravity wells interacting with each other, it means that everything in an orbital system (like our solar system) orbit the center of mass of the system. This center of mass of the system is called the barycenter.

The Earth, the sun and everything else in our solar system actually orbit this barycenter – not the sun.

"The center of mass of our solar system very close to the Sun itself, but not exactly at the Sun's center."

Right now, the barycenter is just outside the Sun's surface. But it's constantly changing depending upon where the planets are in their orbital paths.

Source:-

http://zidbits.com/2011/09/the-earth-doesnt-actually-orbit-the-sun/

Why the humid climate is unbearable?

Because our bodies need to disperse heat, and they can’t do that effectively when the air temperature is close to our body temperature or air is humid. Our muscles and metabolism generate heat continuously.

We transfer that heat into our surroundings by sweating, exhaling warm air, and circulating blood near the surface of our skin to cool. When the temperature gradient (or difference) between the body and the air is high, heat flows easily from us into the environment, and we cool down.
But when the weather hovers around our internal temperature, our inner swelter lingers, and we feel hot and uncomfortable. Humidity makes things worse by interfering with the vaporization of sweat, one of the human body’s main cooling mechanisms.

By the same token, frigid weather draws the heat from our bodies faster than we can produce it, and our core temperature falls. A person’s thermal comfort, or satisfaction with the temperature of the environment, depends on factors as varied as metabolic rate, body fat, and age.

For instance, those with heavier builds have a lower ratio of skin surface area to mass—they evaporate heat less efficiently than the small-framed. And fat absorbs warmth readily, making the obese more susceptible to heat stress. Other groups shown to be especially sensitive to hot weather include pregnant women, the disabled, and people younger than 14 or older than 60. (The body’s effectiveness at thermoregulation declines with age.)

Source:-

http://www.slate.com/articles/news_and_politics/explainer/2012/07/my_body_temperature_is_98_6_degrees_so_why_is_98_6_degree_air_unbearable.html

Humidity

What Is Humidity?

Ever heard the phrase 'It's not the heat, it's the humidity'? People say this because humidity, which is the amount of water vapor in the air, can make hot temperatures even more unbearable than they already are. Humidity is actually a broad term, and we can describe different types of humidity in different ways.

Humidity is an important thing to understand because it affects both weather and climate as well as global climate change. Humidity also affects indoor environments, so understanding it can help you determine the best place to store your books, clothing and other important items in your house.

Relative Humidity

You've probably heard about relative humidity in weather reports. This is the amount of water vapor in the air relative to what the air can hold. Think about it this way: if you have a cup that is half-full of water, the cup contains 50% of what it can hold. Air works the same way.

Let's say that a certain parcel of air can hold 30 grams of water vapor per cubic meter of air, but it only has 15 grams of water vapor per cubic meter of air. We simply divide the amount of water present by the amount of water possible, so 15 divided by 30, and then multiply it by 100 to get a percent. So in this case, 15 / 30 = 0.5, multiplied by 100 gives us 50%. So the relative humidity is 50%, which means the air contains about half of the total water vapor it could possibly hold.

It's important to know that warm air can hold more water than cold air. You can think of different temperature air like different size cups: smaller cups hold less water than larger cups, right? In this case, cold air is a smaller cup and warm air is a larger cup. So when the air is colder, the same amount of water vapor will produce a higher relative humidity than the same amount of water vapor in warmer air. This is because we have to consider the amount of water vapor relative to what the air can hold.

Let's look at an example. You have two cups, one that can hold a maximum of 12 ounces and one that can hold a maximum of 24 ounces. Now put six ounces of water in each cup, and you'll notice that the smaller cup is fuller than the larger cup, even though they have the same amount of water in them.

There are 6 ounces of fluid in the 12-ounce cup, so 6 / 12 * 100 = 50%. There are 6 ounces of water in the larger cup as well, but this cup can hold a total of 24 ounces. So, 6 / 24 * 100 = 25%. If the 12-ounce cup represents cold air and the 24-ounce cup represents warm air, the relative humidity for the cold air is 50%, but for the same amount of water in warm air, the relative humidity is only 25%.

How full the cup is relates to how much the cup can hold overall. When we apply this to air, we can see that for the same amount of water vapor, the relative humidity will be higher for cold air than for warm air because the cold air is 'fuller' from the same amount of water.

Dew Point

When air becomes saturated, this means that it contains the maximum amount of water vapor possible. Just like relative humidity differs with different air temperatures, saturation is also temperature-dependent.

Remember our cups from before? Saturation occurs when the cups are completely full of water. Just like the smaller cup needs less water to become full, cold air becomes saturated from less water than it takes to saturate warm air. And just like if you kept filling the cups even though they were already full, the water would have to go somewhere, so it would spill out over the cup and fill the surrounding area.

Dew is when water condenses at ground level because the air is saturated. Just like the water spills over the side of the full cup, when air is saturated, the excess water 'spills over' and builds up on leaves, cars, buildings or anything else that is surrounded by the saturated air.

Therefore, the temperature at which saturation occurs is called the dew point. You most commonly see dew in the morning because air temperature goes down ove

Source:-

http://study.com/academy/lesson/what-is-humidity-definition-measurements-effects.html

Why dead bodies float on the surface of water after some days?

Immediately after death, water enters the lumen in the body and the body becomes denser and sinks. Later after a few hours, the various protein and lipid matter in our body undergo oxidation/decay to release gases which accumulates thereby pushing out water due to which the dead bodies float.

HOW WE SEE THE THINGS OR PERSONS MOVING IN A MOVIE?

Persistance of vision is the property of vision due to which the sensation of image formed on retina of our eyes persists in our brain for 1/10 sec. If any other image is formed on retina before that then we are unable to differentiate between those images.
This property of vision is called persistance of vision.

Persistence of vision is the commonly used term to describe the optical illusion whereby multiple discrete images blend into a single image in the human mind and believed to be the explanation for motion perception in cinema and animated films.

Here are 9 still pictures of a man riding on the horse. When these pictures are run fast continuously with a speed greater than 16 frames/sec then the effect is as shown in gif image.

Amazing Facts of Physics

1). Diamonds can be made from graphite by applying a temperature of 3000 Celsius and pressure as high as 100,000 atm.

2). One of the most amazing & interesting fact about Physics on earth is “The Dead Sea”, which is known for its density due to the presence of salt, as a result of which you can easily float on it without drowning, so one can always claim to be a swimmer there.

3). The flashing lightning bolt is 3 times hotter compared to the sun, seems like the sun also has to face competition.

The faster you move, the heavier you get

The faster you move, the heavier you get

If you run really fast, you gain weight. Not permanently, or it would make a mockery of diet and exercise plans, but momentarily, and only a tiny amount.

Light speed is the speed limit of the universe. So if something is travelling close to the speed of light, and you give it a push, it can’t go very much faster. But you’ve given it extra energy, and that energy has to go somewhere.

Where it goes is mass. According to relativity, mass and energy are equivalent. So the more energy you put in, the greater the mass becomes. This is negligible at human speeds – Usain Bolt is not noticeably heavier when running than when still – but once you reach an appreciable fraction of the speed of light, your mass starts to increase rapidly.

Source:- http://www.telegraph.co.uk/news/science/6546462/The-10-weirdest-physics-facts-from-relativity-to-quantum-physics.html