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Shamim Ansary:
What Is the Most Common Vegetable In the World?
The vegetables that are grown in the largest quantities around the world are the tomato and the potato. But the most widely used vegetable is the onion!
The onion appears in more dishes and in more countries than any other vegetable. In some places, the onion is used to flavor dishes, while in other countries it’s eaten by itself as a vegetable.
The ancient Egyptians ate onions both ways, for the onion was the most common vegetable in Egypt 5,000 years ago. During the Middle Ages, the onion and a relative of the onion, the leek, were the only common vegetables in Europe.
Today, more than 20 billion pounds of onions are produced around the world each year!
Emperor Nero of Rome ate leeks because he thought they would improve his singing voice!
Shamim Ansary:
What Is the Most Common Vegetable In the World?
The vegetables that are grown in the largest quantities around the world are the tomato and the potato. But the most widely used vegetable is the onion!
The onion appears in more dishes and in more countries than any other vegetable. In some places, the onion is used to flavor dishes, while in other countries it’s eaten by itself as a vegetable.
The ancient Egyptians ate onions both ways, for the onion was the most common vegetable in Egypt 5,000 years ago. During the Middle Ages, the onion and a relative of the onion, the leek, were the only common vegetables in Europe.
Today, more than 20 billion pounds of onions are produced around the world each year!
Emperor Nero of Rome ate leeks because he thought they would improve his singing voice!
Shamim Ansary:
Why Is the Sky Blue On a Clear Day and How Does Rayleigh Scattering Cause the Red Colors at Sunset?
The sky is blue on a clear day because of a process called Rayleigh scattering.
Light arriving from the sun hits the molecules in the air and is scattered in all directions. The amount of scattering depends dramatically on the frequency, that is, the color of the light.
Blue light, which has a high frequency, is scattered ten times more than red light, which has a lower frequency. So the background scattered light we see in the sky is blue.
This same process also explains the beautiful red colors at sunset.
When the sun is low on the horizon, its light has to pass through a large amount of atmosphere on its way to us. During the trip, blue light is scattered away, but red light, which is less susceptible to scattering, can continue on its direct path to our eyes.
According to classical physics, an accelerated charge emits electromagnetic radiation.
Conversely, electromagnetic radiation may interact with charged particles causing them to oscillate. An oscillating charge is continually being accelerated and hence will re-emit radiation. We say that it becomes a secondary source of radiation.
This effect is known as the scattering of the incident radiation.
The atmosphere is, of course, composed of various gases that together form air. We may treat each air molecule as an electron oscillator. The electron charge distribution of each molecule presents a scattering cross-section to the incident radiation.
This is essentially an area upon which the incident radiation must fall for scattering to occur. The amount of scattered radiation will depend upon the magnitude of this cross-section.
In Rayleigh scattering the cross-section is proportional to the fourth power of the frequency of the incident radiation. Sunlight is composed of various visible frequencies ranging from low frequency (red) to higher frequency (blue) light.
Because it is of a higher frequency than other visible components, the blue part of the sun’s spectrum will be scattered more strongly. It is this scattered light that we see and so the sky appears to be blue.
Incidentally we are also able to explain why sunsets are red. When the sun is close to the horizon its light must travel through more atmosphere.
The blue light will be scattered strongly whereas red light, because it is of lower frequency is less prone to scattering and so is able to travel straight to the observer.
Shamim Ansary:
How Did Copernicus Change the Ptolemaic System?
The system introduced by Nicolaus Copernicus (1473–1543) was that Earth and all of the planets revolved around the sun in concentric circles. Copernicus was further able to reduce the number of postulated epicycles to 34, still saving the appearances, or not contradicting what was observed. This shifted the fundamental frame of astronomical reference from Earth to the fixed stars. As he wrote:
First and above all lies the sphere of the fixed stars, containing itself and all things, for that reason immovable; in truth the frame of the Universe, to which the motion and position of all other stars are referred. Though some men think it to move in some way, we assign another reason why it appears to do so in our theory of the movement of the Earth.
Of the moving bodies first comes Saturn, who completes his circuit in xxx years. After him, Jupiter, moving in a twelve year revolution. Then Mars, who revolves biennially. Fourth in order an annual cycle takes place, in which we have said is continued the Earth, with the lunar orbit as an epicycle. In the fifth place Venus is carried round in nine months. Then Mercury holds the sixth place, circulating in the space of 80 days.
Copernicus’ conclusions were based mainly on mathematics, drawing on the perennial value of simplicity and the doctrine that nature always behaves in the most “commodious†(simple) way. To the objection that objects would fly off a moving earth, he responded that a moving sky, because it was larger, would move even faster and do more damage.
Shamim Ansary:
How Much Newspaper Must Be Recycled to Save One Tree?
One 35 to 40 ft (10.6 to 12 m) tree produces a stack of newspapers 4 ft (1.2 m) thick; this much newspaper must be recycled to save a tree.
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