When sunlight passes through the window of your house, the dust particles scatter the light making the path of the light visible.

When sunlight passes through window of classroom its path is visible. This is due to scattering of light. Light scattering can be thought of as the deflection of a ray from a straight path, for example by irregularities in the propagation medium, particles, or in the interface between two media.

Tyndall Effect When a beam of sunlight enters a dusty room through window, then its path becomes visible to us. This is because the tiny dust particles present in the air of room scatter the beam of light all around the room. And when this scattered light enters our eyes, we can see the beam of light.

Sunlight is “a continuous stream and a deluge of particle-like photons, both at the same time,” said Dana Longcope, a professor of physics at Montana State University. “Due to the weirdness of quantum mechanics, things are neither always particles or always waves. They can be either.”

The higher the frequency of the incident light, smaller the particles one can see. This is similar to why we need particle accelerators to see the fundamental particles of the universe. Since sunlight sunlight comprises of high frequency /high energy light,it can reflect off of fine dust particles in the air.

But you can see air – when you look up at the sky! That’s the nitrogen particles scattering blue light. In liquids, where molecules are closer together, you can more easily see the scattering, even if you have a small quantity – but with gasses, you need huge volumes to see the effect.

Air looks invisible because it sends very little color to our eyes. Air is a mixture of gases, mainly nitrogen and oxygen, with small molecules that are far apart. Wavelengths of light may pass by these molecules without hitting them.

While you can’t see or taste the air, that is because as a gas, its particles are very far apart. When air is condensed into its liquid form, it becomes visible. It still doesn’t have a flavor (not that you could taste liquid air without getting frostbite).

There is more than just air in the sky. There are also billions of tiny floating particles called aerosols or particulates. In each cubic centimeter of air, there can be hundreds or thousands of aerosols!

Human vision can detect single photons or single particles of light, according to a new study showing it is possible for the naked eye to see a particle that is smaller than an atom.

Our eyes can detect a single speck — what scientists call a photon or light particle, a new study suggests. The new study also showed that the human eye detects single photons better when it has just seen another photon.

To give you a better idea of just how small a micron is, consider this: the diameter of a human hair is 80 to 100 microns in size. If (A) is the diameter of a human hair (100 microns), then (B) is the size of the smallest particle visible to the human eye (50 microns), and (C) is the size of a 0.5 micron particle.

hyoid bone

Skin is the human body’s largest organ. Body organs aren’t all internal like the brain or the heart. There’s one we wear on the outside. Skin is our largest organ—adults carry some 8 pounds (3.6 kilograms) and 22 square feet (2 square meters) of it.

The largest solid internal organ is your liver. It weighs approximately 3–3.5 pounds or 1.36–1.59 kilograms and is about the size of a football. Your liver is located beneath your rib cage and lungs, in the upper right area of your abdomen.

Stretched out a little to the right side under your rib cage, the liver’s main responsibility is to filter the blood coming from your digestive tract, before it returns to the rest of your body. In fact, it is the bloodiest of all organs and can hold as much as 10 percent of all your blood at any instance.

lung

Some of the easily recognisable internal organs and their associated functions are:

• The brain. The brain is the control centre of the nervous system and is located within the skull.
• The lungs.
• The liver.
• The bladder.
• The kidneys.
• The heart.
• The stomach.
• The intestines.

stapes

Top 10: What are the heaviest organs in the human body?

• Liver. Liver © iStock.
• Brain. Brain © iStock.
• Lungs. Lung © iStock.
• Heart. Heart © iStock. Average weight: 300g.
• Kidneys. Kidneys © iStock. Average weight: 260g (pair)
• Spleen. Spleen © iStock. Average weight: 175g.
• Pancreas. Pancreas © iStock. Average weight: 70g.
• Thyroid.

Vital organs These are the brain, heart, kidneys, liver and lungs. The human brain is the body’s control center, receiving and sending signals to other organs through the nervous system and through secreted hormones.

Heart. Every cell in the body depends on this muscle, the body’s hardest-working organ.

Tooth enamel is the hardest substance in the body. The shiny, white enamel that covers your teeth is even stronger than bone. This resilient surface is 96 percent mineral, the highest percentage of any tissue in your body – making it durable and damage-resistant.

Diamond

8 Hardest Languages to Learn In The World For English Speakers

1. Mandarin. Number of native speakers: 1.2 billion.
2. Icelandic. Number of native speakers: 330,000.
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5. Korean.
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