14 Amazing Spiders

FASCINATING AND WEIRD SPIDERS

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   Smiling spider

This is an amazing creation of nature-a spider taking the shape of a happy face. It is harmless as it seems. This interesting spider is found in the forests of Hawaii. It has eight legs like many other spiders but its smile makes it special. 

Smiling spider

2. DADDY LONG-LEGS

This species of spider has only two eyes, unlike the other species having six or eight eyes. The spider has very long legs, eight in number, giving it the name, Daddy Long Legs. It is also known as harvestman. It uses it’s fangs to inject venom into its prey to kill it. But they are not harmful to humans.

Daddy long-legs

3. PURSE WEB

They are shiny black spiders, medium in size with an over-sized chelicerae (mouth parts). They have eight sprawling legs and two body parts. They are hatched from eggs and travel long distances in search of females once grown. Instead of weaving a web, they knit a tight and upright silken tube. They feed on insects and small spiders. They bite and are dangerous to those sensitive to spider bites. But for the rest, they cause no harm.

Purse web

4. CRAB SPIDER

This eye catching spider, blending beautifully in its surroundings, among colourful flowers is known as Thomisidae and belongs to the family, Philodromidae. The spider doesn’t build web, but waits for its prey among the flowers. Some species can change colour to match the flower or leaf they sit on. Their 2nd pair of legs is longer than the 1st, 3rd and 4th pair. They are mostly yellow, green, orange, white or grey. They get their name due to their resemblance with crabs.

Crab spider

5. GREEN JUMPING SPIDER

This is an Australian spider from the family Salticidae. The females are 12mm in length. The spider is found in New Guinea, New South Wales and Western Australia. The male spiders have bright and sharp colours. They have long and attractive white “side whiskers” and a topknot of black hairs. Females lack the whiskers and topknot, but have a red and white elegant mask.

Green jumping spider

6. GOLIATH BIRD EATING SPIDER

This weird spider belongs to the Tarantula family. It is found in South American forests. It has a leg span of up to 12 inches. They usually don’t eat birds. But they are seldom found eating a baby bird. Usually they eat mice, mealworms and crickets. They build no web. Their legs make hissing sounds. They are very harmful. On contact, they cause severe irritation to human skin.

Goliath bird eating spider

7. Wasp Spider

Wasp spiders are usually found in Europe. This spider lives in rough grassy lands and makes its web on grass. It makes a beautiful zig-zag web and has a poisonous venom. It captures its prey in its silken web and injects the insect with a paralyzing venom and protein dissolving enzyme. It has a unique black and yellow pattern on its abdomen.

Wasp spider

8. Writing Spider

Spiders no doubt are amazing artists. They build their home skilfully and artistically and have striking coloured abdomen. They get their name as they build their web in a pattern of Zs and Xs down the centre. They bite but are not dangerous. The male spider is much smaller than the female spider in size. He spins a companion web alongside the female spider and then the female lays eggs. The female spider then places her egg sac containing 400-1400 eggs into the web.

Writing spider

9. Fishing Spider

These spiders belong to the family of Pisauridae. It is found near puddles and lakes. It sits quietly waiting for its prey. Once it finds it target, it darts out onto the insect in the water and grabs the prey. They can swim and walk on water.

Fishing spider

10. Huntsman Spider

It belongs to the family of Sparassidae and measures around 4 inches. Different species of the Huntsman Spider are found around the globe. It lives in plants like ivy which offer the spider shelter. They are mostly grey and brown in colour.

Huntsman spider

11. Arrowhead spider

The Arrowhead Spider belongs to the Verrucosa genus. It lives mostly in the forests of America. It’s colourful and beautiful. It has a red head and yellow abdomen which is arrow-shaped, narrow in the front and ending behind two large spread spines. The abdomen has a very attractive and beautiful pattern. It has defensive horns and can be found during spring, summer and fall. It is absolutely harmless to humans but its flower-like appearance often befools insects.

Arrowhead spider

12. Bridge spider

This spider is typically found near bridges and water and hence got its name. It is also known as Gray Cross Spider. It’s a large orb-weaver and loves to live on steel objects. The male spider is smaller than the female. They hide themselves during daytime and catch their prey at night.

Bridge spider

13. Camel spider

This bright and colourful spider is also known as Sun Spider or Wind Scorpion. It belongs to Arachinda order and has around 1000 species in 150 genera. A camel spider can run at 30mph and has a very high pitched scream. They are 7cm in length. Their venom can cause paralysis in 7 out of 10 lizards. They live in deserts and got their name.

Camel spider

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14. Assassin spider

It occurs in Madagascar, Australia and Africa. It eats other spiders and has evolved elongated jaws and necks for catching them. But it is harmless to humans. 

The spider assassin

Problem with Organic Chemistry? Check this out!

sp HYBRIDIZATION OF CARBON

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The electronic configuration of carbon in its ground state is:

Ground state

The promotion of one of the two 2s electrons to the empty pz orbital gives the excited state.

Excited state

This time we follow a different course than that used for sp2 hybridization, in which case one 2s and two 2p orbitals were mixed. Instead, the 2s electron and just one of the three 2p orbitals are mixed or hybridized to form two new equivalent orbitals. These two new orbitals are known as sp orbital because they are formed by interaction of one s and one p orbital. The other two 2p orbitals (py and pz) are left unhybridized. The electronic configuration of carbon in its sp hybridized state is:

Hybridized state

Each sp orbital contains an unpaired electron. The shape of an sp orbital is similar to that of an sp2 orbital.

Formation of equivalent sp orbitals

They sp orbitals obtained are identical, that is, they have same the same energy and shape. They differ only in their orientation in space with respect to each other. They lie in a straight line, that is, the angle between the two sp orbitals is 180°. 

Orientation of two sp orbitals

The linear arrangement is favoured because it allows the sp orbitals to stay as far apart from each other as possible and thereby reducing the electron-electron repulsions. The unhybridized py and pz orbitals are at right angles to the line of the sp orbitals. 

Orientation of the unhybridized orbitals

Whenever carbon is bonded to two other atoms or groups it always uses sp hybrid orbitals and two 2p (py and pz) orbitals to form its bonds. For example, acetylene.

Bonding in acetylene

BONDING IN ACETYLENE

In acetylene (H-C≡C-H) each carbon atom is attached to one hydrogen atom by a single covalent bond and to another carbon atom by a triple bond. Since each carbon is attached to two other atoms it uses sp hybrid orbitals and two unhybridized 2p orbitals (py and pz) to form its bonds.

In acetylene there are two C-H single covalent bonds and one C-C triple bond. Each C-H bond is a sigma bond and results from the overlap of an sp orbital from carbon and 1s orbital from hydrogen.

One of the three bonds in C-C triple bond is also a sigma bond and results from the linear overlap of the two sp orbitals, one from each carbon.

The other two bonds in the triple bond are pi bonds and results from the lateral overlap of the unhybridized p orbitals on each carbon.

Formation of the two pi bonds in acetylene

Although the C-C triple bond is represented by three equivalent lines, remember that one line represents a sigma bond and the other two the pi bonds. 

Triple bond in acetylene

Problem with Organic Chemistry? Check this out!

sp2 HYBRIDIZATION OF CARBON

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The electronic configuration of carbon in its ground state is:

Ground state

The promotion of one of the two 2s electrons to the empty pz orbital give the excited state.

Excited state

At this point we follow a different course than that used for sp3 hybridization, in which case one 2s and three 2p orbitals were mixed. Instead, the 2s electron and just two of three 2p orbitals are mixed or hybridized to give three new equivalent orbitals. These new orbitals are referred to as sp2 orbitals, because they are formed by interaction of one s and two p orbitals. Third 2pz orbital is left unhybridized. The electronic configuration of the carbon atom in its sp2 hybridized state is:

Hybridized state

Each sp2 orbital has an unpaired electron. The shape of sp2 orbital is similar to that of an sp3 orbital.

Formation of three equivalent sp2 orbitals

The sp2 orbitals obtained are identical, that is, they have the same energy and shape. They differ only in their orientation in space with respect to each other. The three sp2 orbitals lie in the same plane with their axes directed towards the corners of an equilateral triangle. The angle between any pair of orbitals is 120°.

Orientation of three sp2 orbitals

The smaller lobes are not indicated because they do not extend sufficiently far from nucleus to participate in bond formation. The trigonal arrangement is favoured because it allows the sp2 orbitals to stay as far apart from each other as possible and thereby reducing the electron-electron repulsion.

The unhybridized pz orbital is oriented along an axis perpendicular to the plane of sp2 orbitals, with each lobe above and below the plane of the sp2 orbitals. 

Orientation of the pz orbital

Whenever carbon is bonded to three other atoms or groups it always uses sp2 orbitals and a pz orbital to form its bonds. For example, ethylene. 

BONDING IN ETHYLENE

Each carbon atom in ethylene (H2C=CH2), is attached to two hydrogen atoms by single covalent bonds and to another carbon atom by a double bond. Since each carbon is attached to three other atoms, it uses sp2 hybrid orbitals and an unhybridized pz orbital to form its bonds. 

Bonding in ethylene

In ethylene there are four C-H single covalent bonds and one C-C double bond. Each C-H bond is a sigma bond and results from the overlap of one sp2 orbital from carbon and 1s orbital from hydrogen.

One of the two bonds in the double bond is also a sigma bond and results from end-to-end overlap of the sp2 orbitals, one from each carbon atom.

The second bond in the double bond is a pi bond results from the lateral overlap of two unhybridized pz orbitals, one from each carbon atom. pz orbitals can overlap only when all the six atoms lie in the same plane, that is, the plane of sigma bonds. Like the p orbitals from which it is formed, a pi bond consists of two equal parts. One part lies above the plane of the carbons and hydrogens and the other part lies below this plane. These two parts together make up one pi bond. 

Formation of the p bond in ethylene

 Although the C-C double bond is represented by two equivalent lines, remember that one line represents a sigma bond and the other the pi bond.

Double bond in ethylene

The Power of Power Naps

POWER NAPS CAN CHANGE YOUR LIFE

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Feeling groggy, tired or unmotivated in the afternoon? Using coffee, soda and energy drinks we often try to push through the dreaded long day yawning through the hours and fighting the fatigue. But just so happens that the solution is the very thing we’ve been trying to avoid all day long, sleep. The truth is, the power nap is perhaps the most effective way to rejuvenate our brain.

Lack of sleep

There are four main stages of our sleep cycle. The first two are relatively light sleep, while the third brings us into a deep slumber. The final stage known as rapid eye movement or REM for short, is where most of our dreams begin. The benefits of napping are tied to length of time in which we are asleep. Naps thirty minutes in length generally only allow time to enter the first stages. In stage one, slow eye movement begins and if woken we often feel as though we didn’t even sleep. But as we continue into stage two, our brain begins to inhibit processing and ignores external stimuli that it deems non-dangerous in order to relax us and give us a tranquil sleep. It also begins memory consolidation, in which information we learn is processed. Waking at the end of these stages has shown benefits including increased productivity, increased cognitive function, enhanced memory, boosted creativity and most importantly, feeling less tired. Beyond thirty minutes we enter stage three and experience something known as sleep inertia when awakened. This is because our body is coming out of a deep sleep, motor dexterity is decreased while grogginess and the longing to go back to sleep increases.

Dreaming- Final Stage

Many people falsely deem naps non-beneficial for themselves. But the truth is, they have simply napped too long. As the benefits of napping became clearer, many nap salons were opened throughout Japan where workers can pay to have a brief lunch time nap on a daybed to increase alertness at work. So maybe it’s about time we all start sleeping on the job a little more. Just tell your boss, “Science said so.” 

Power nap

Misconceptions

SOME MISCONCEPTIONS IN PHYSICS

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Imagine learning for the first eighteen years of your life that the earth is flat. All through elementary school and high school you grow up hearing about the flat earth we live on and doing boring flat earth physics homework, and then if you’re lucky enough you get to college and psych! For the first time they show you a globe and say, “Sorry for lying. The earth is actually round”. Well, this is unfortunately exactly what we do with gravity. You probably learned that objects attract each other based on their mass, so you probably grew up thinking that light can’t possibly be affected by gravity because it is massless. I know I did. Well guess what? The source of gravity is not mass, it’s energy and momentum, which light certainly has. Of course, regular matter does too. So, not only does light get bent passing by a star or a planet or a black hole, but light attracts the planet or the star or the black hole in return. To be sure, it’s a very very small amount. But, that small amount is not zero. Anyway, the point is that Newton’s law of gravitation is just an approximation, good enough to get us to the moon. But it’s not perfect. General relativity is better.

Next comes special relativity. You probably have also learned that if a sheep is moving 2mph relative to a train and that train is moving 2mph at the same direction relative to the ground, then the sheep is moving 4mph relative to the ground. 

Special relativity

2mph + 2mph = 4mph   

Right?

Wrong!

Experiments in special relativity have confirmed that velocities don’t simply add together.  So the sheep will in fact be moving very very ever so slightly slower than 4 mph relative to the ground. The formula that correctly predicts this deviation from just adding velocities is:

The formula

 It’s not a very big effect, but then again, the earth looks pretty flat doesn’t it?

But it isn’t flat. If I walk 10,000km away from my cat, and you continue on walking  10,000km more, you’re not 20,000Km away from my cat. You’re just 12,750km away. In fact, the farthest on earth you can get from anything on earth is 12,750km. It’s the earthly distance limit, though we normally call it the diameter of the earth. Similarly, when you try to add two velocities together, there’s a cosmic speed limit of 300,000,000m/s, that is, the speed of light.

Earthly distance limit

 So, just because to our eyes the earth looks flat, velocities look like they simply add together, and light looks like it doesn’t attract gravitationally, is that an excuse to mislead ourselves about the true nature of things?