Perpetual Motion Squad ! [Can we travel faster than light ? ]

[GeneralTheoryOfBadassery]

This is a Thread for Physics lovers like me !!

You can post recent discoveries , some problems which don't require complex math to solve , your personal theories , your views on various theories and pretty much anything related with physics !!

Have fun !!

Edited February 21, 2015 by GeneralTheoryOfBadassery

[Pyromaniac225]

I just finished my Physics 20 final

 

I'm in.

[Virgule]

For those interested in free basic physics lessons, this youtube channel is amazing : https://www.youtube.com/user/viascience

[Real_PhillBert]

OP, how tall are you and where in India are you located?

 

@GeneralTheoryOfBadassery

[GeneralTheoryOfBadassery]

OP, how tall are you and where in India are you located?

 

@GeneralTheoryOfBadassery

How does it matter ?

[AlwaysFSX]

I sketched a thing together of an orb spinning by magnets to generate electricity but I don't know where that picture went.. Might do it in paint if you fancy a look.

[Real_PhillBert]

How does it matter ?

For the sake of physics, yes.

 

Humor me.

[Art Vandelay]

some problems which don't require complex math to solve 

You mean problems which don't require difficult math to solve or problems that don't use complex numbers?

 

The former basically makes content beyond a highschool level impossible.

[GeneralTheoryOfBadassery]

You mean problems which don't require difficult math to solve or problems that don't use complex numbers?

 

The former basically makes content beyond a highschool level impossible.

Problems that don't very difficult maths that some people may not understand ..

Problems that require basic knowledge of logarithms , calculus should be fine ..

Any high school student should be able to understand it

[GeneralTheoryOfBadassery]

For the sake of physics, yes.

 

Humor me.

5'10 , Pune-Maharashtra

[GeneralTheoryOfBadassery]

I sketched a thing together of an orb spinning by magnets to generate electricity but I don't know where that picture went.. Might do it in paint if you fancy a look.

Cool !!

I would love to see it

[GeneralTheoryOfBadassery]

Here is a problem .. !!

Two astronauts whose masses are 80 kg , are travelling in outer space on a space craft of mass 100,000 kg .

The astronauts decide to workout and decrease their mass to 70 kg .

Initially they were moving at a velocity of 10,000 m/s

Find the velocity of the spacecraft after both of them reduce their mass to 70kg.

[Art Vandelay]

Here is a problem .. !!

Two astronauts whose masses are 80 kg , are travelling in outer space on a space craft of mass 100,000 kg .

The astronauts decide to workout and decrease their mass to 70 kg .

Initially they were moving at a velocity of 10,000 m/s

Find the velocity of the spacecraft after both of them reduce their mass to 70kg.

That completely depends on what happened to their mass. If it left the ship at the same speed as the ship, then velocity is the same; if it left the ship at v=0, then it's a simple momentum problem and their velocity would increase by 2m/s; if the mass just disappeared magically, the laws of physics don't apply anymore.

[GeneralTheoryOfBadassery]

That completely depends on what happened to their mass. If it left the ship at the same speed as the ship, then velocity is the same; if it left the ship at v=0, then it's a simple momentum problem and their velocity would increase by 2m/s; if the mass just disappeared magically, the laws of physics don't apply anymore.

Good !! But I think it should remain constant , cause .. There is just no way mass can escape at v=0 with out any external force .. And that's just against the laws of physics !

Stopping 20 kg of mass in outer space which is moving at the velocity of 10,000 m/s without any external force is just impossible

[GeneralTheoryOfBadassery]

Hydroplaning !!

Today we are going to learn how to drive your bike on water !!

Most of you may have seen various videos on YouTube about people driving their bikes and snowmobiles on water .

Today I will try to explain how the hell that works in simple laymen terms

And , as a bonus , I will teach you how to do it too !

So , what is hydroplaning ?

Many of you won't be interested in knowing , but now that I've told you that its related with driving vehicles on water which are not ment to be driven on water , I think you would be interested .

Hydroplaning is a phenomenon in which a liquid like water, acts as a solid !

Now , we are not talking about freezing water and turning it into ice so that we can drive on it . we are talking about stuff which is way cooler than that .

When as object is thrown inside a puddle , it sort of , makes the water go around it before actually going inside it.

If you throw the stone at a particular range of angles , with a velocity greater than certain threshold, the stone will bounce from the water .

The reason behind this , is that the stone has two velocities. One in vertical direction and other in horizontal Direction.

When the stone , hits the surface , as I said before, water tries to go around the stone , for that it require some time .

If the horizontal velocity of the stone is large, the stone moves ahead before the water gets the time it requires, to move and go around it. That is how the stone bounces .

If you've been to a swimming pool , I guarantee you that you have tried skimming your palm over the surface of the water.

Did you notice that the water feels harder ?

Another example is when you bellyflop in a pool.. When you hit the water surface, the greater surface area demands the water to cover more distance in order to enclose you. So naturally, it requires more amount of time to envelop you.

Hence you remain in contact with the surface for a longer period of time and so the red spot on your belly.

Now , to the main point of the post. How do you drive your bike or a snowmobile on water?

Is quite simple actually ( atleast theoretically ) .

It's just like skipping stones.

Drive very fast, and make sure that the surface arts in contract with water is very large and the angle is minimum.

There you have it ! That how you drive your bike on water !

http://m.youtube.com/watch?v=aGW7zbe6jiM

[Art Vandelay]

Good !! But I think it should remain constant , cause .. There is just no way mass can escape at v=0 with out any external force .. And that's just against the laws of physics !

Stopping 20 kg of mass in outer space which is moving at the velocity of 10,000 m/s without any external force is just impossible

It can escape with V=0 from an internal force, if the ship fires it backward at 10,000 m/s.

 

It's equivalent to throwing a ball backward while standing on a skateboard, which is a common basic momentum example.

[GeneralTheoryOfBadassery]

But the only way that something will go behind at 10,000 m/s so that its velocity becomes zero , for the engine to throw it back ! And if the engine is running , the spaceship has to accelerate ! But its moving at constant velocity, so can safely assume that the engines aren't running .

So the mass has to escape at the velocity of 10,000 m/s :sick:

[GeneralTheoryOfBadassery]

5 theories that will completely blow your mind !! [ and will probably f**k your mind ]

Warning !! Before reading this , you should know that I just copy pasted this article that I saw online . !!

It contains significant amount of profanity too !

You've been warned !

There are generally two types of science: first, there's the type that makes computers work, allows us to ride around in metal boxes propelled by continuous explosion, and makes it so that milk doesn't taste all gross. Then there's the fringe science, the stuff that shoots up your nose like mathematical horseradish and dances a jig on your brain...or brane, as it were (that's the nerdiest joke in the article, we promise). So kick off your work boots, put on your thought slippers, and prepare for a science course so mind-blowing, it's written almost entirely in italics.

So.. Here are the five theories that will completely blow your mind !!

#5. The Theory: Quantum Entanglement

The Crazy Part:The part where you jiggle an electron on one side of the universe and an invisible force traverses millions of light years and smacks another electron into wiggling instantaneously, which is about a million years faster than is technically possible without time travel.

What It Says: That if two electrons are created together, they are forever entangled, much like you and your high school sweetheart according to some shitty poems you wrote in tenth grade. And, also like you and your ex-love, regardless of the distance between the two electrons, a change in quantum spin in one electron will immediately cause the other electron to change spin as well. So like, when she has sex with Bob Feeney, the teams QB after the first date, even though youre home alone playing Tetris, your heart will ache with a sudden and unmistakable pain. Thats the pain of entanglement, my friend.

So What Does This Do For Me? Teleportation, holmes. Only really tiny. In theory, you could separate two electrons by as much space as you wanted (say, the breadth of the universe), and theyd still be linked in such a way that actions taken on one would affect the other instantaneously. Meaning information is being transmitted at speeds faster than light. Meaning, if you want to really go nuts, time travel. And though the party pooping scientists have been busy coming up with limitations on the kind of information that could be transmitted (it seems super-fast computers that allow you to play Gears of War against people in parallel dimensions may be a ways off), no one has yet been able to disprove the theory that there is an invisible force in the universe capable of affecting matter millions of light-years awayinstantly.

Wait, It Gets Worse: If you subscribe to the whole Big Bang thing, then there was a point in the past in which every atom in the universe was condensed into a singularity. Which means everything, even you and that bastard Bob Feeney, are quantumly entangled. Some scientists have even gone so far as to claim that quantum entanglement shows that there is no such thing as space, and that everything in the universe is still touching. Space is just an illusion created by our flawed perceptions, and were all one. The hippies were right after all.

Level Of Mind Blowing-ness: A fistful of acid tabs followed by the flume ride at Disneyworld.

#4. The Theory:Evolution

The Crazy Part: The part where the family tree of every living creature on Earth collides at a single point on a single day in the past, making you related to Hitler as well as every insect you've ever killed..

What It Says:Were all familiar with the basics of evolution: that a munificent monkey-goddess birthed us all from Her banana-scented womb. But there are some lesser-discussed implications of natural selection that are just plain weird. For one, scientists have concluded that around 140,000 years ago in Kenya, there lived a woman called Mitochondrial Eve (cavemen had weird names), so named because today, every living human on Earth has her mitochondrial DNA in their body (cavemen were also prescient). And only 3,000 years ago lived a person known as the Most Recent Common Ancestor, who, through exponential growth of the family tree, is the ancestor of every single person on Earth. And did you know that, based on the same principles (and a lot of rape), Genghis Kahn has over 16 million descendants? Whos your Daddy now?!So What Does This Do For Me? Well, for one, you can rest assured than anyone you ever have sex with in your entire life is at least your distant, distant cousin. So thats nice. And if youre really a nut for genealogy, why not trace your heritage back to the Last Universal Ancestor, the single-celled organism who, about 4 billion years ago, decided to go ahead and give rise to every living creature that will ever exist on the face of the Earth? Talk about a pimp. In essence, the whole of life on the planet can be considered one long, unbroken chemical reaction that is still resolving itself, like the foam flowing out of a science fair volcano.

Wait, It Gets Worse: The genetic chaos continues. The Endosymbiotic Theory says that the mitochondria in our bodies, without which we couldnt live, let alone write snide humor articles, was at one point a separate organism that invaded our cells and set up camp. They formed a symbiotic relationship so beneficial that weve never booted them out. Furthermore, large chunks of the human genome are thought to be ancient retroviruses that managed to transcribe themselves into our DNA and have spent the remainder of their days happily clambering up and down our nucleotides like the McDuck children on a mansion banister. Basically your cells are millions of individual organisms, all huddled together in a you-shaped beehive. Now see how long you can go before wanting to shower.

And lastly, a thought for the right-wingers out there: At some point half of you was an egg in your Mothers womb. That egg existed in her body from the day she was born. And a long, long time ago, she too was an egg in her Mothers womb, who had that egg ready for use from the moment she squirmed out of your Great Grandmas nethers. The point being, technically speaking, theres no break in the chain of existence, no time when you are not a life form of at least the most rudimentary sort. Your family, at least on your Mothers side, could theoretically be considered an immortal, constantly-regenerating organism. Of course that would make men, whose sperm has to be created years after the moment of birth, just disposable donors here to fuel the everlasting fire of womanhood. You go girls!

Level Of Mind Blowing-ness: Four Hemmingway suicides.

#3. The Theory: The Copenhagen Interpretation

The Crazy Part: The part where the furniture in your house behaves differently when you're not around.

What It Says: Besides sounding like the subtitle of The Da Vinci Code II, The Copenhagen Interpretation is probably the most widely accepted explanation for the observations made through quantum mechanics. It came about in part to explain the infamous Double Slit Experiment, which is the one your physics professor probably made you do. The Double Slit Experiment shows that an electron, fired at a wall with two slits in it, will sometimes go through sometimes go through one, sometimes through the other, and sometimes it will go through both slits simultaneously (meaning, a single thing will be in two places at once). In short, it goes batshit fucking insane. The twist is, if you try and observe the electron at the moment it passes through the slitsyou know, to figure out what the hell is wrong with itthe electron goes back to behaving like a normal electron, and innocently shoots through one of the slits while giving you, and reality, the finger. The details of why this happens are sort of technical.

So What Does This Do For Me? The Copenhagen Interpretation is the result of a lot of smart people trying to figure out what the fuck was going on with these damn electrons. What they came up with is that all particles exist as waves of probability. From the observers perspective, theres only a certain chance that a given electron will go through the left slit or right slit. When you dont watch, it remains a cloud of probability and sort of does a little of everything. When you watch, the act of observing it somehow causes the cloud to pick a side. So the next time you observe a particle, be warned: they know youre watching, and as soon as you stop, theyre going to start a party.

Wait, It Gets Worse: If you apply the Copenhagen Interpretation to bigger objects, it gets even weirder. The infamous Schrodingers Cat thought experiment, the one your physics professor probably got fired for doing, said that if you put a cat in a box and press a button that has a fifty percent chance of filling the box with poison gas, then until you go and look in the box, the cat exists as a cat-cloud which is simultaneously both alive and dead. And theres more: if everything exists as a probability wave, then that means that technically, anything possible could happen at any time. Theres nothing stopping a big floppy dick from sprouting out of your forehead right now; its just highly unlikely. You feel lucky, punk?

Level Of Mind-Blowig-ness: Lets just say it might be time to invest in a tarp.

#2. The Theory: The Many Worlds Theory

The Crazy Part: The part where you realize that somewhere in some parallel universe you just died while reading this sentence.

What It Says: The Many Worlds Theory rejects The Copenhagen Interpretations crazy idea that particles can change their behavior seemingly at will, and replaces it with the much crazier idea that the only reason we think particles are changing their behavior is that were only seeing that particles action in one universe, rather than the infinite number of universes that actually exist. So an observed particle with two optionssay, to pound beers at a Van Halen tribute show or drop E and storm a techno clubactually does both, even though we may only observe the techno club, in some other universe, parallel to our own, that particle is rocking out to Eruption instead of rubbing itself ferociously on anything with a body temperature.

So What Does This Do For Me? If you buy into the Many Worlds Theory, the implications are infinite. And lets be clear about what infinite means here. For every action youve ever taken, every movement youve ever made, even down to the atomic level, theres a parallel universe out there where you did something else instead. Anything else. Instead of learning guitar, you burst into flames. Instead of opening the fridge, you freebased black tar heroin. Instead of nude rock climbing, you went nude bungee jumping. Instead of reading this article, you worked productively and got a handsome raise. Think about it: in some parallel universe out there, you and your high school sweetheart are making hot, reconciliatory love atop Bob Feeneys smoldering corpse after you killed a laser-breathing velociraptor with your bare hands. If that thought doesnt make you feel better about how mundane your actual life is, we dont know what will.

Wait, It Gets Worse: If you think The Many Worlds Theory is a tad too far fetched an explanation for some electrons behaving weirdly, youre not alone. In an effort to simplify things, scientists have come up with The Many Minds Theory, which says your brain splits up at the instant you make an observation, and then your many brains observe every possible outcome. Yes, thats right, an infinite number of parallel brains, existing without universes (let alone skulls) to house them in. Awesome. Much simpler.

Level Of Mind Blowing-ness: A TNT-tipped jackhammer to the eye socket.

#1. The Theory: The Universe Is Big

The Crazy Part: The part where the Universe isn't just bigger than you can possibly comprehend, but according to recent evidence, billions of times larger than that.What It Says: That the universe is big. So big, that just that fact, just its mere bigness, is enough to blow your tiny ant mind. And it just keeps getting bigger. Lets examine the famous Hubble Ultra Deep Field image, the most massive photo ever taken

There are approximately 10,000 galaxies in that photo

Each of those galaxies contains anywhere from ten million to one trillion stars.

The average star is roughly a million times the size of Earth.

And yet, with all that junk, the Universe is more than 90 percent empty space.

All of that, in this tiny photo. A photo that took 400 orbits and 800 exposures to take.

And the kicker? The photo covers one thirteen-millionth of the entire night sky.

So What Does This Do For Me? If youre like us, it leaves you alternately awash with spiritual wonder and horrified feelings of utter insignificance. Actually imagining just how infinitesimal you are in the scope of the universe is like autoerotic asphyxiation: its not as pleasant as youd think, and if you do it wrong you can end up a vegetable. And without getting too Douglas Adams on you, can you possibly imagine that much space and that many planets and stars and atoms smashing together without intelligent life forming? Now its just a matter of getting around that pesky general relativity and well be chilling with aliens in no time. Or, like, a million years.

Wait, It Gets Worse: So all that shit we just said about how big the universe is (at least 90 billion light years)? Forget it. Thats small beans. The Cosmological Horizon is here to make your day a whole lot more complicated. Since we can only observe stellar bodies that have had some effect on us (usually bombarding us with light), there is an outer limit to what we can see of the universe. Hence, the observable universe. What about the rest? The parts of the universe beyond our Starcraft-style fog of war? Well, according to some math we have no interest in going into, the size of the actual universe is so large that if the universe we just described (the impossibly, mind-bogglingly large one) were the size of a quarter, the actual universe would be the size of the Earth. Daaaaaaaamn.

Level Of Mind Blowing-ness: The sound of one hand clapping for a tree falling in the woods while no ones around except a guy whose skull is wired with C4.

[Hatsune Miku 「 」]

Physics ftw and already read all those theories

[GeneralTheoryOfBadassery]

Physics ftw and already read all those theories

Physics Ftw !!!

And I knew all these theories before actually reading them too ! But the way these are presented for physics noobs is kinda fun to read !

[Toddwjp]

The quantum entanglement theory is wrong, that's not how quantum entanglement works, if you want I could give an explanation here,

[GeneralTheoryOfBadassery]

Yes please !

The quantum entanglement theory is wrong, that's not how quantum entanglement works, if you want I could give an explanation here,

[Art Vandelay]

The Crazy Part:The part where you jiggle an electron on one side of the universe and an invisible force traverses millions of light years and smacks another electron into wiggling instantaneously, which is about a million years faster than is technically possible without time travel.

 

Entanglement is based on the spin of two particles, not wiggling or whatever you called it.

 

Also, from my understanding (I only have a basic mathematical knowledge of quantum physics), entanglement is not the product of any force, but the breakdown of a quantum wave-function.

 

 

The Double Slit Experiment shows that an electron, fired at a wall with two slits in it, will sometimes go through sometimes go through one, sometimes through the other, and sometimes it will go through both slits simultaneously (meaning, a single thing will be in two places at once). In short, it goes batshit fucking insane. The twist is, if you try and observe the electron at the moment it passes through the slitsyou know, to figure out what the hell is wrong with itthe electron goes back to behaving like a normal electron, and innocently shoots through one of the slits while giving you, and reality, the finger. The details of why this happens are sort of technical.

 

So What Does This Do For Me? The Copenhagen Interpretation is the result of a lot of smart people trying to figure out what the fuck was going on with these damn electrons. What they came up with is that all particles exist as waves of probability. From the observers perspective, theres only a certain chance that a given electron will go through the left slit or right slit. When you dont watch, it remains a cloud of probability and sort of does a little of everything. When you watch, the act of observing it somehow causes the cloud to pick a side. So the next time you observe a particle, be warned: they know youre watching, and as soon as you stop, theyre going to start a party.

Wait, It Gets Worse: If you apply the Copenhagen Interpretation to bigger objects, it gets even weirder. The infamous Schrodingers Cat thought experiment, the one your physics professor probably got fired for doing, said that if you put a cat in a box and press a button that has a fifty percent chance of filling the box with poison gas, then until you go and look in the box, the cat exists as a cat-cloud which is simultaneously both alive and dead. And theres more: if everything exists as a probability wave, then that means that technically, anything possible could happen at any time. Theres nothing stopping a big floppy dick from sprouting out of your forehead right now; its just highly unlikely. You feel lucky, punk?

 

The double slit experiment was basically just a demonstration that a stream of particles fired through the slit diffract, regardless of the intensity of the stream. Thus, if you fire one particle, it will still somehow interact with itself and diffract.

 

If you observe the particle as it's going through the slit, it will no longer diffract because you've interrupted the quantum wave, but it will still be a wave beyond that point.

 

Also, the Schrodinger's cat thought experiment was just a joke.

 

The Crazy Part: The part where you realize that somewhere in some parallel universe you just died while reading this sentence.

What It Says: The Many Worlds Theory rejects The Copenhagen Interpretations crazy idea that particles can change their behavior seemingly at will, and replaces it with the much crazier idea that the only reason we think particles are changing their behavior is that were only seeing that particles action in one universe, rather than the infinite number of universes that actually exist. So an observed particle with two optionssay, to pound beers at a Van Halen tribute show or drop E and storm a techno clubactually does both, even though we may only observe the techno club, in some other universe, parallel to our own, that particle is rocking out to Eruption instead of rubbing itself ferociously on anything with a body temperature.

So What Does This Do For Me? If you buy into the Many Worlds Theory, the implications are infinite. And lets be clear about what infinite means here. For every action youve ever taken, every movement youve ever made, even down to the atomic level, theres a parallel universe out there where you did something else instead. Anything else. Instead of learning guitar, you burst into flames. Instead of opening the fridge, you freebased black tar heroin. Instead of nude rock climbing, you went nude bungee jumping. Instead of reading this article, you worked productively and got a handsome raise. Think about it: in some parallel universe out there, you and your high school sweetheart are making hot, reconciliatory love atop Bob Feeneys smoldering corpse after you killed a laser-breathing velociraptor with your bare hands. If that thought doesnt make you feel better about how mundane your actual life is, we dont know what will.

Wait, It Gets Worse: If you think The Many Worlds Theory is a tad too far fetched an explanation for some electrons behaving weirdly, youre not alone. In an effort to simplify things, scientists have come up with The Many Minds Theory, which says your brain splits up at the instant you make an observation, and then your many brains observe every possible outcome. Yes, thats right, an infinite number of parallel brains, existing without universes (let alone skulls) to house them in. Awesome. Much simpler.

 

The many worlds theory doesn't really apply to macroscopic events like that...

 

 

 

The quantum entanglement theory is wrong, that's not how quantum entanglement works, if you want I could give an explanation here,

Can you give an actual mathematical explanation of it in something as short as a forum post?

[Toddwjp]

Yes please !

 

Entanglemen

 

 

the basics of quantum entanglement. and why it wont be useful for sending traditional information.

 

lets start with an analogy.

 

okay we have a quantum entanglement machine that produce 2 balls (these are our entangled particles) one is black and one is white. now without looking at the balls i give one to each of you and close your hand around it so that you cannot see it.  now i tell one of you to go into another room. I tell the person with me to open there hand and observe the colour of the ball. there's is black. we now know that the ball belonging to the person in the other room is white. however they do not know this and so they have to receive a message from us telling them what colour it is.

 

essentially we have the uncertainty principle, the effect of observation and the transfer of information. the uncertainty come from no one observing the balls. therefore due to the way quantum mechanics work both balls are both black and white at the same time. After one of them is observed the other ones colour is 100% known, this represents the information being transferred. called a qubit. this information can travel faster then the speed of light because time does not apply to it. however the person with the other ball does not know this information even though it has been transmitted to the other ball. and for them to be informed of this they need a normal message to reach them. and so entanglement cannot be used for communication of standard information at faster then light speeds.

[Art Vandelay]

the basics of quantum entanglement. and why it wont be useful for sending traditional information.

 

lets start with an analogy.

 

okay we have a quantum entanglement machine that produce 2 balls (these are our entangled particles) one is black and one is white. now without looking at the balls i give one to each of you and close your hand around it so that you cannot see it.  now i tell one of you to go into another room. I tell the person with me to open there hand and observe the colour of the ball. there's is black. we now know that the ball belonging to the person in the other room is white. however they do not know this and so they have to receive a message from us telling them what colour it is.

 

essentially we have the uncertainty principle, the effect of observation and the transfer of information. the uncertainty come from no one observing the balls. therefore due to the way quantum mechanics work both balls are both black and white at the same time. After one of them is observed the other ones colour is 100% known, this represents the information being transferred. called a qubit. this information can travel faster then the speed of light because time does not apply to it. however the person with the other ball does not know this information even though it has been transmitted to the other ball. and for them to be informed of this they need a normal message to reach them. and so entanglement cannot be used for communication of standard information at faster then light speeds.

Isn't the uncertainty principle a minimum precision of basic properties of matter and unrelated to waveform decay?