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| picture by Kenneth C. Zirkel |

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| picture by Kenneth C. Zirkel |
I was sitting in a park nearby my house, bored, having listened to all the trending songs in one go, when I saw a couple of Squirrels jumping from tree to tree. They reminded me of Toby Maguire and Andrew Garfield as Spiderman. More importantly, I was astonished at how they were using the principles of physics to go about their daily lives...
Although squirrels or any other animal for that matter are not consciously aware of physics, they certainly interact with physical laws in fascinating ways. I am sure you, the reader, must have come across these 10 ways in which squirrels use physics in their everyday lives:
1. Parabolic Jumping: When squirrels jump from one branch to another, they follow a parabolic ttrajectory. Not only that, they spread their arms and legs as if they were birds to increase the surface area and lift force. I wonder if squirrels calculate the optimal angle and velocity needed to reach their destination.
2. Gravitational Potential Energy: When squirrels climb trees, they increase their potential energy. As they descend, they convert this energy into kinetic energy. I have seen them speed up and down the tree like it was nothing. Their bodies are also very elastic, which helps them in their daily chores. I wish I could climb a tree like that.
3. Friction for Grip: Have you noticed how Squirrels have sharp claws? Tiny but still firm. These claws allow them to grip surfaces with high friction. This friction is essential for climbing vertical tree trunks, allowing them to move quickly and stay stable while navigating tricky terrain. No wonder I can't climb with ease as my hands are always sweaty.
4. Elastic Potential Energy: Squirrels' tails act like a rudder and balance aid, but they also store and release elastic potential energy from their tail when the squirrel jumps or changes direction mid-air. This helps them land more precisely or correct their movement in mid-flight. The tail makes up and significant portion of their body weight and acts like a mechanism to (almost) fly.
5. Rotational Motion: When squirrels leap or fall, they can twist their bodies in mid-air, adjusting their orientation using their limbs and tail. This rotational motion allows them to land feet-first and avoid injury.
6. Energy Conservation: Squirrels run very fast, but for shorter periods of time. Like a Cheetah. This combination of high-speed running and short bursts of activity allows them to conserve energy while traveling long distances or evading predators.
7. Bouncing: When squirrels jump off hard surfaces or onto bouncy objects (such as a trampoline-like surface in a tree), their bodies absorb and release energy through elasticity, softening the landing and reducing the risk of injury.
8. Inertia and Momentum: When a squirrel is running at high speed and suddenly changes direction, its body mass and velocity create inertia, making it harder to stop. But with enough friction, it can quickly change direction without sliding, maintaining its momentum.
9. Gliding: There is a species of squirrels which flies, aptly called the flying squirrel. They have a fluffy membrane between their fore and hind legs, helping them to glide. The physics of air resistance helps them stay in the air longer and glide to distant points safely. Not all squirrels can glide long distances though, which is disappointing.
10. Balance and Center of Mass: Squirrels constantly adjust their center of mass as they move along narrow branches or leap across gaps. By shifting their body position and adjusting their posture, they maintain balance and stability to prevent falling. Have you noticed how they pose like Spiderman when they land? That's them adjusting their center of mass to make a safe fall.
In all these (and possibly more) ways, squirrels engage with the principles of physics in daily life, allowing them to thrive in their harsh environments.




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| src: Wikimedia commons |
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| src: Bibliothèque nationale de France |
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| src: Brandon dinunno, wikimedia commons |

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| Earth as a point of pale blue light, picture by NASA |






Dirac made a breakthrough, a new method of doing physics. He had the courage to simply guess at the form of an equation, and to try to interpret it afterwards.
No matter how beautiful an equation is, no matter who made the equation or how genius he was, if it disagrees with experiment, it is wrong!




October 17, 1946D’Arline,I adore you, sweetheart.I know how much you like to hear that — but I don’t only write it because you like it — I write it because it makes me warm all over inside to write it to you.It is such a terribly long time since I last wrote to you — almost two years but I know you’ll excuse me because you understand how I am, stubborn and realistic; and I thought there was no sense to writing.But now I know my darling wife that it is right to do what I have delayed in doing, and that I have done so much in the past. I want to tell you I love you. I want to love you. I always will love you.I find it hard to understand in my mind what it means to love you after you are dead — but I still want to comfort and take care of you — and I want you to love me and care for me. I want to have problems to discuss with you — I want to do little projects with you. I never thought until just now that we can do that. What should we do. We started to learn to make clothes together — or learn Chinese — or getting a movie projector. Can’t I do something now? No. I am alone without you and you were the “idea-woman” and general instigator of all our wild adventures.
When you were sick you worried because you could not give me something that you wanted to and thought I needed. You needn’t have worried. Just as I told you then there was no real need because I loved you in so many ways so much. And now it is clearly even more true — you can give me nothing now yet I love you so that you stand in my way of loving anyone else — but I want you to stand there. You, dead, are so much better than anyone else alive.I know you will assure me that I am foolish and that you want me to have full happiness and don’t want to be in my way. I’ll bet you are surprised that I don’t even have a girlfriend (except you, sweetheart) after two years. But you can’t help it, darling, nor can I — I don’t understand it, for I have met many girls and very nice ones and I don’t want to remain alone — but in two or three meetings they all seem ashes. You only are left to me. You are real.My darling wife, I do adore you.I love my wife. My wife is dead.Rich.PS Please excuse my not mailing this — but I don’t know your new address.
