# magnetism

magnetism + mango smoothie + good music

## Can you crush a soda can with lightning ?

Here you can see the lightning striking the empire state building three times.

As you might know skyscrapers like these have a lightning rod that will carry the lightning bolt’s electrical charge through the path of least resistance along the cable into the ground, reducing the risk of fire or heat damage from the strike.

But you might know from high school or college physics that when you have two current carrying wires parallel to each other, then they experience an attractive force towards each other.

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## Lightning carries 30000 amps

An average bolt of negative lightning carries an electric current of 30,000 amperes (30 kA).

So if you were to pass such high currents through a rod, then surely they must experience a substantial magnetic force towards each other and get crushed right ?

Absolutely, Physics always works ! Have a look at this metal tube:

This is what would happen when electric lightning is passed through a metal tube. Using magnetic forces to compress electrical filaments is known as ‘Pinching’.

## Can Crusher

One cool application for this would be for forming metal cans into interesting shapes.

As soon as the spark gap fires the capacitor discharges an enormous amount of current through the coil (tens of thousands of amperes).  This discharge creates a magnetic field around the coil.

As the flux lines pass through the cross section of the can, current is induced and flows around the can.

This induced current creates its own magnetic field which opposes the magnetic field from the coil.  Between the two magnetic fields there is now a force pushing inward on the can and outward on the coil.  Once the force is strong enough the can is crushed.

And with large enough voltage, one can blow the can in opposite directions too!

From generating X-rays to forming of metal into shapes, Pinches have a lot of interesting applications. The references section of the wikipedia is surely a fun ride; check it out and have a good one!

[A white fortune cookie paper with red text on the front reading: You have an unusual magnetic personality]

## Faraday’s Law of Electromagnetic Induction

The ball (also a magnet) is falling quite a bit slower than expected (despite the slow motion). This can be attributed to Faraday’s Law:

When a conductor is exposed to a changing magnetic field there is a current created within the conductor. Or more technically a magnetic flux changing over time produces an electromotive force across a conductor.

That’s not the whole explanation though…

## Lenz’s Law

When the magnet is falling the current in the cylinder is producing a magnetic field as well. Lenz’s Law states:

The induced current will produce a new magnetic field that will oppose the change in magnetic flux.

The produced field applies a force to the magnet resisting its fall. If the tube is long enough the magnet will reach a constant velocity because the magnetic force and weight will cancel each other out (no net force).

This works like air resistance on a falling object. Eventually the resistance completely counters the gravitational acceleration of the object.

Faraday’s and Lenz’s Laws basically tell us that the faster the magnet moves the more the conductor (tube) will resist the magnet’s fall.

if you ever feel pathetic just remember that qualified ap exam writers at collegeboard had trouble drawing straight lines on the 2012 AP Physics E&M exam

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Magnetic Tower pt 2

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I'm learning combinatorics now. Do you know any cool places they are used ? Sorry for bad english

Combinatorics is quite frankly an ocean with a wide variety of applications. But since you ask, let’s take a look at the example of a ‘Two state Paramagnet’.

## What is a paramagnet?

A paramagnet is a material in which the particles like compass needles align parallel to any applied magnetic field. But it is a temporary effect and the magnetization is lost when the field is removed

## Paramagnetism in Liquid Oxygen

One of the popular examples of paramagnetism is liquid oxygen.

When oxygen is liquefied and poured over a magnet, the magnetic effect of the electrons become substantially noticeable.

Molecules will align to the magnetic from the magnet creating an induced magnetic field of its own.

As the liquid oxygen boils off you can you can see for a moment a ‘mist’ that it gives off that is still attracted to the magnets. - Paramagnetism

## So, what can you do with that ?

One can find the net magnetization produced by the material based on the total number of dipoles facing up or down.

And essentially the total energy of the system (neglecting any interactions between dipoles).

We have come a long way from a simple combinatorics formula, now haven’t we?

Great question! Thanks for asking :)

Magnetic angst in a flannel is my aesthetic

An Example of the Coordination of Magnetic Field Lines from a Bar Magnet.

## Happy Lapidot Week 2k17~!!!Day 1: Water and Magnetism

This sketch was a mess. I initially had alot of ideas for this and got rid of them as I continued. Look at these gays go!
A Note: The episode The New Crystal Gems gave the perfect example of their beautiful harmony. That episode was a dream come true~!

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Physics: Ferrofluid

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A note on levitating frogs and superconductivity

Last week we took a look at diamagnetic levitation and how you can use a powerful magnetic field to levitate frogs, tomatoes and theoretically humans.

Another cool demonstration of diamagnetic levitation. is with an array of magnets and electrolytic carbon.

PC: UCLA

Electrolytic carbon being diamagnetic ( Remember that a diamagnetic material is one which would rather ‘die’ than be attracted to a magnetic field ) opposes the magnetic field set up by the magnet array and levitates !

## Superconductivity

Superconductors when cooled below a critical temperature in principle are just ideal diamagnets in that they completely  expel the magnetic field due to the meissner effect.

However, always keep in mind  that the fundamental origins of diamagnetism in superconductors and normal materials are extremely different and must not be confused.

A2A (Anonymous): Are superconductors and diamagnets the same ?

magnetism

CEO!BAEKHYUN SCENARIO

a/n: y’all i’m shook - what did i do. ALSO i won’t be able to finish the whole request in one part so look out for part 2? (there might be a few typos…)

word count: 1k

part one: the interview / part two: coming soon

summary: he’s the CEO - you’re his assistant; you both knew each other before, but like magnets, you both attract

Baekhyun has all he could ever dream about: cars, women, cash and people who worshipped him. He owns the biggest technologically advanced company in South Korea, TIO. After his father passed away, and seeing that he was the only son, he was appointed the position.

Before this Baekhyun had been anything but professional. As a teenager he worked day and night delivering chicken to people across Seoul. Now he spent his days drowning in paperwork and running meetings. The transition was much more difficult than he’d expected.

He had little to no free time, he couldn’t even make time to call his mother to tell her happy birthday. Working without break was starting to take a toll on him. Sleeping only two hours every night was less than ideal. Eating once a day wasn’t close to healthy, especially when his ‘meal’ was an apple with some banana milk. He either said he was fine or nothing at all and both were lies.

He would never dare to tell a soul about how broken he was. He’d never tell anyone that the nights kept up in his office weren’t because of paperwork, but due to his uncontrollable sobbing.

Tonight was one of those dreaded nights.

He sat on his chair, his arms holding his legs as his head fell on his lap; tears soaking his work pants. He shakily grabbed his paperwork and tried to finish signing it, but his hands couldn’t bare to write anymore. Throwing it across the room, he screamed.

Employees ran over to peak through his window. They saw a part of Baekhyun they didn’t know existed, a broken one. His assistant, Riu, ran in to call him down.

“Mr. Byun, you have to calm down. You’re making a scene.” She grabbed his shoulders and pointed his head towards the crowded window. He was fuming now.

“What am I? A show dog? Is a man crying that much a spectacle? I should fire all of you!” He yelled, his neck veins showing and eyes dark.

“Calm down! You’re being ridiculous! Everyone gets this way…don’t make a big deal out of it.” Riu’s eyes were glaring up ar the man.

Baekhyun scoffed.

“You’re unbelievable….acting as if you don’t do the same thing? All you talk to me about is that guy you had sex with once at the bar, you don’t even do your job. You’re such a slut.” Baekhyun rolled his eyes, shaking off her hold.

Riu’s eyes teared up as she slapped him. “How dare you! Mr. Byun, you know first hand how hard of a worker I am! You’re such a child…”

“Ahhhh, slapping me now, I see, Riu. I thought I was the child?” Baekhyun hid his tears with a smirk.

“Go to hell, Byun Baekhyun.” Riu was sobbing now.

“Leave. If I see you again, I’ll get you arrested.” Baekhyun dismissed her as he sat back down at his desk.

Her heels clicked against the floor as she walked out and Baekhyun fixed his tie.

“Looks like I’ll need a new assistant…”

-

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Self-Propelled Magnetic Motor

Chop a magnet in two, and it becomes two smaller magnets. Slice again to make four. But the smaller magnets get, the more unstable they become; their magnetic fields tend to flip polarity from one moment to the next. Now, however, physicists have managed to create a stable magnet from a single atom.

The team, who published their work in Nature on 8 March1, used their single-atom magnets to make an atomic hard drive. The rewritable device, made from 2 such magnets, is able to store just 2 bits of data, but scaled-up systems could increase hard-drive storage density by 1,000 times, says Fabian Natterer, a physicist at the Swiss Federal Institute of Technology (EPFL) in Lausanne, and author of the paper.

“It’s a landmark achievement,” says Sander Otte, a physicist at Delft University of Technology in the Netherlands. “Finally, magnetic stability has been demonstrated undeniably in a single atom.”