/sci/ - Science & Math

look towards the creationist thread.

Anyone?

>>5375854
Hardly any torque to move the generator.
>>5375861
No faster than light travel
>>5375862
This actually works. Its called an ice tray.

>>5375861
Wouldn't this actually work?
hypothetically

>>5375883

>>5375854
This is a good one - I haven't seen it before.

I think the equilizer is the valve separating the water from the air - the water pressure on the valve (and thus the force required to open it) would scale with depth.

Perpetual motion machines are always a fun exercise, in terms of figuring out why they don't work.

>>5375896
This is the best one

This might work if it's intercity

>>5375911
yeah you would absorbe quite a large portion of the kinetic energy of the plane and die.

>>5375899
it turns out the compression of the object and the wave traveling through it goes at the speed of sound.

>>5375887
Yes, as long as the mirror was built 10 years prior to you looking in the telescope. The "hurr durr" of it is if it's the same person who was the baby deciding to go out and build a mirror and then come back, look in the telescope, and see themselves as a baby. That's not possible without travelling to build the mirror faster than light (ie you have to out-run the light emitted from when you were the infant).

I'm out, if anyone has more feel free to dump

>>5375905
Can we get more Meta?

>>5375925
I have one more meta

>>5375896
I don't remember the rigorous contradiction of this, but it's to do with the fact that the object that you approach as you take this to infinity is not actually equivalent to a circle

>>5375899
The nudge travels through the rod as a vibration, ie. a sound wave. So it actually travels much, much slower than the speed of light. In wood the speed of sound is about 4000m/s, compared to light which is 300,000,000 m/s

>>5375930
Does it have a name?

d = 0.9999.....

10d = 9.9999....

10d - d = 9

9d = 9

d = 1

therefore

1 = 0.9999..

>>5375883
>Hardly any torque to move the generator.

>>5375920

I like this one, if the magnetic forces were equal, the turbine wouldn't spin. If one magnetic force were bigger than the other, than one part would just stick to the other and again it wouldn't spin.

>>5375935
1/3=0.3333
2/3=0.6666

1/3+2/3=0.9999
3/3=1
1=0.9999

>>5375917
If the tube is initially empty, it fill with air every time it opens and once it is filled with equal pressure to the outside, it cease to suck out trash.

>>5375935
This is correct, and not a troll. In the system of real numbers 1 is definitely equivalent to 0.9 recurring, there are many proofs.

If we extend beyond the scope of the real number system, then we can use the surreal numbers, where the difference between 0.9999... and 1 is a finite surreal number. See wiki.

>>5375932
Turns out I was a little off the mark with this. See http://qntm.org/trollpi - as this website says, while the limit of series of curves is technically a circle, it is not mathematically necessary that the limit of a series shares properties with the rest of the members of the series. This means that it's not correct to assume that the perimeter of the limit curve is 4.

>>5375935
>>5375941
Not sure if these actually belong to a trollsciencethread

Most plausable

>>5375930
A circle has tangents on every point. those tangents are perpendicular to the radius. (not the case here)
>the fact that the object that you approach as you take this to infinity is not actually equivalent to a circle

>smart idea
>should be better worded

>>5375945

>1.The picture describes a series of curves. (Here, "curve" is a generic term referring to any continuous line, be it straight or crooked or curved.)
>2.This series of curves converges on a limit curve.
>3.The limit curve is a circle. It is not a sawtoothed curve. It is not an "infinitely jagged" sawtoothed curve. It is not a fractal. The limit curve is a perfectly smooth perfect circle.
>4.The length of the limit curve is exactly pi (3.1 or so). (Because it is a perfect circle with diameter 1.)

>These facts are also true:

>1.Each curve in the series has a well-defined length.
>2.Each curve in the series has a length of exactly 4.
>3.Thus, the lengths of the curves also form a series: 4, 4, 4, 4....
>4.This series also converges on a limit.
>5.The limit is 4, not pi.

>And so is this final fact:

>None of these facts contradict each other.

Now I feel trolled

>>5375957
This is a good way to look at it but I don't think any geometric explanation can adequately explain what happens. If the limit of the series has infinitely close 'zigzags' then what defines the point where instead of each zig-zag having mutually perpendicular tangents, the zig-zags are all infinitely close together and are therefore essentially points and therefore the curve has tangents like a circle?

The answer is that there is no way you could ever draw any of this on paper. You could keep on dividing up your shape forever and never reach the limit. That means really the only way to answer this problem is to have a good, rigorous knowledge of the theory of limits and series, which I do not.

I like this problem because it highlights the fact that advanced math is a lot less crazy and esoteric than people like to pretend. This is a fairly simple problem that overestimates pi by 25%, but needs some serious Maths to disprove!

>>5375945
>http://qntm.org/trollpi
All I am getting from this is "because I say so" with no explanation given whatsoever.

>>5375945
>>5375968
So basically the shape progression converge toward a circle, but the calculation of the perimeter converge toward a constant number that isn't of the length of a circle.

And there is no contradiction with that and the reason of this is "because".

>>5375896

the troll part of this is that the first step should not be 4, but should be the hypotenuses of the four triangles, which is 2,8 vs the correct answer of 3.14.

at the next subdivision, the hypotenuses yield 3.1, which is already extremely close to the correct answer.

troll guy needs to lrn2geometry.

>>5375861
I chuckled.

No matter how infinitesimally close you get to the circle you're approximating, every single jagged peak of the zig-zig is still sticking out from the circle a little bit. There will always be a tiny little extra perimeter around that little triangle that you can't get rid of no matter how small you make the edges.

All that image is doing is redistributing the length from four big peaks to many small ones.

>>5376006
>>5375968
>>5375980
>>5375990

guys... look at this post.

>>5375991

>>5375896
Oh the pain when trying to explain this one.

>>5375930
>I don't remember the rigorous contradiction of this, but it's to do with the fact that the object that you approach as you take this to infinity is not actually equivalent to a circle
No, it will actually be a circle with most usual norms.
The reason it's wrong is something more fundamental, a mistake A LOT of students make.

The circumference of the limit IS NOT the limit of the circumference.

The sentence above would be true if the function associating a shape with its circumference was continuous. It's not.

OP is back
>>5375991
This guy figured it out

>>5376012
The posts aren't in conflict. In >>5376006 I was trying to explain why, with the system the image chose, it's expected that you wouldn't reach pi. >>5375991 was explaining an alternate counting system to reach pi.

>>5376017

nope. no matter how small you subdivide it, troll guy's approach NEVER converges to anything except 4.00000000000.

the hypotenuses, on the other hand, rapidly converge to pi.

>>5375990
The reason is "the perimeter function isn't continuous".

>>5375980
>advanced math
>knowing that lim f(u(n)) != f(lim u(n))
It's something you're supposed to learn in first year.

>>5376026
>nope. no matter how small you subdivide it, troll guy's approach NEVER converges to anything except 4.00000000000.
Yes. That's exactly my point, and why I wrote
>All that image is doing is redistributing the length from four big peaks to many small ones.

>>5375941
Can you really add and subtract non terminating decimals?

>>5376035

if that's what you call "explaining it", i hope to god you never have a job teaching anything at any level, including kindergarten.

>>5376038
>if that's what you call "explaining it", i hope to god you never have a job teaching anything at any level, including kindergarten.
Yeah, because fucking around on an imageboard talking about troll science pictures is clearly the context for careful rigor.

>>5375883
kill yourself.

>>5376035
Not that guy, but I'll assume you're not trolling and restate:
The shape sequence DOES converge to a circle. A real circle, not a "fractal" or "jagged circle".
Its perimeter DOES NOT converge to Pi.

And the reason is >>537603

>>5376041
It's clearly mentioned /sci/ is not for trolling.
Someone asks an explanation, he gets a real one, not some half-baked answer.

I hope you get banned eventually for that attitude.

>>5376048
>It's clearly mentioned /sci/ is not for trolling.
And I wasn't. Trolling requires intent to incite, not merely being wrong.

>>5376053
Then what are you complaining about?
You are giving to the reader the notion that math is about intuitive reasoning, we correct that, isall.

>>5376056
What complaining? I was correcting a mischaracterization of my argument. The argument, I now see, was wrong, but I did not know that at the time, and I believe I was within my rights to correct the other poster.

>>5375896
I don't understand

As you approach the infinite of the square, it comes a circle, but the circle is exactly the same as the original circle so somehow pi =4.

What happened? All the corners smooth out eventually after applying them an infinite time.

>>5375991

>Hypotenuse
>Perimeter

What?

>>5375907
It's one of the most often posted troll physics images on the Internet.

>>5375887
lol no think distance/speed

Good luck trying to debunk this clear example of perpetual motion using magnets.

>>5376986
force going both ways = 0
:)))))))))

>>5375965
kT is already the average energy for a system of 2-degrees of freedom.
Not a smart idea at all.

>>5375861
You'd have to wait 10 lightyears in order to get a picture, but then you'd be seeing the earth from 20 light years ago (so 10 years prior to setting up the mirror) So yes, you'd be able to see ten years into the past, but not twenty.

Assuming there is nothing between you and the mirror to distort/obscure your view, and assuming you have perfect optical clarity and near-infinite zoom, you only have the earth's atmosphere to crap all over your image quality. Even satelites peering into our atmosphere get a fuzzy picture of the ground at best. So, there would have to be a satelite in space looking at the mirror, and even then, you'd only get to see half of the earth in the mirror...

Lots of limitations, but at least you'd be able to track people if you knew where to look. You'd be able to see what color shirt they were wearing that day 10 years ago.

>>5375895

The thing about this is that it's actually valid, sort of. It's just that the amount of energy generated would be ridiculously small, and wouldn't be 'infinite'.

>>5375904
Would this theoretically be possible if you had enough suction and some way to breathe inside the tube?

>>5377935
surface tension doesn't scale, unfortunately.

>>5375896

To everyone still talking about this, the reason why this is wrong is because of the difference between 'pointwise convergence' and 'uniform convergence' It's a bit of tricky concept to explain to someone without any knowledge of analysis, but I'll try my best.

What is happening here is that we are 'deforming' one curve into another. We are trying to move points away from one curve to another in infinitely many steps. The way it is shown in this image though, the points don't all 'move' at the same rate. If you look at any 'step' there will still be points that are on the original square. This is an example of pointwise convergence.

If on the other hand, we looked at regular polygons, with its points on the circle, and kept increasing the number of sides of the polygon (ie start with a triangle, then go to a square, then a pentagon, etc.) we would have a series of curves uniformly converging to the circle. If we measured the perimeters of these polygons and worked out their limit, we would get pi.

Basically, the argument in the image works for uniform convergence but not for pointwise convergence.

>>5375893
If you can catch the air you will be able to last longer because your lungs do not absorb all the oxygen capable of being absorbed in one breath, but you will eventually run out of oxygen.

>>5375895
The magnetic field of the earth would hardly generate any electricity. There's not enough torque.

>>5375896
lol, this is just bologna. You measure it from the inside of the circle not the outside. Still probably the best one though.

>>5375899
if you could make a stick that big you wouldn't be able to test if the stick poked the guy at the other end faster than light.

>>5375901
No known compound that has enough tensile strength.

>>5375904
This would work.

>>5375911
The entire plane is made of the same material. In fact they put these boxes at the back of the plane so that the whole plane can act as a 'crush zone.' These boxes don't always survive.

>>5375913
>This might work if it's intercity.
Maybe, it depends on if the mailman would even pick it up.

>>5375917
gravity

>>5375920
opposing forces equal out.

>>5375888
>>5375939
>>5376043
C'mon guys. Having a bad day?

Btw, merry christmas everybody.

>>5375907
All you have to do is add more balls.

>>5377944
>No known compound that has enough tensile strength.
harpoons mofo

>>5377944
>if you could make a stick that big you wouldn't be able to test if the stick poked the guy at the other end faster than light.
lrn2clocks nigga

>>5377944
>This would work.
flip a cup upside-down and tell me that sh*t works

>>5377975
bullets travel a lot faster than harpoons

>>5377981
How would you know your communication was realtime?

>>5377994
There's no suction on the bottom of the cup when I turn it over.

>>5377997
let's try that again in a way you can understand, flip a bottle over

>>5377995
>bullets
yeah, that's why you'd have to use a harpoon

>realtime
If you are 100 light years apart, as long as your clocks are in sync within 100 years of each other you can do this test. You don't have to be "realtime" you just have to be within 99.9 years of each other

>>5377944
>if you could make a stick that big etc
It's wrong because the whole stick wouldn't move all at once, the compression wave is limited by the speed of sound in that object.
Even if the stick were made of neutronium it still wouldn't be faster than light.

>>5378003
The air trapped inside the bottle needs to be of a lower pressure than the air outside the bottle. The water is then held in the bottom of the bottle due to the suction of the low air pressure inside the bottle

>>5378006
>If you are 100 light years apart, as long as your clocks are in sync within 100 years of each other you can do this test. You don't have to be "realtime" you just have to be within 99.9 years of each other

The travel distance would dilate my clock to go much slower than yours would on earth. How would I correct this time dilation?

>>5378026
my bad, the clocks part is wrong, you don't need clocks -
Simply send a radio transmission at the time you push the rod. If you get the radio transmission first, the rod compressed too slowly. If you get the radio transmission after the poke, the rod transmitted kinetic motion faster than light.

yeah, the clock thing was wrong - they do need to be in sync, but you can sync it by calculating your distance (lets say 100 light years exactly) and a radio transmission or a blinky light or a laser or something in morse code, that says something like "at the time of this transmission it is 0215 December 23rd 2012" and then 100 years later the other guys on planet Bob would receive it and say "okay, now Earth is sitting at 0215 December 23rd 2112"

>>5378026
make ur clock speed up

>>5378020
So you're saying the material would crimp and extend like a worm? And when I pull on the stick the bonded particles would extend to their length and continually pull on the ones next to it producing a wave?

But I thought that metals all shared electrons with each other?

http://www.youtube.com/watch?v=tlx2PgESXhs

Real life troll physics.

>>5375904
This wouldn't work as the increase in surface tension isn't proportional to increase in mass. That's why you don't see gallon sized water droplets.

>>5378035
>>5378037

>>5378034
Okay yes this makes more sense. If you move the rod and send an electrical signal at the same time then you could see which one got there first.

>>5375920
If you had the magnets alternate between on and off then perhaps.

>>5378040
This will never work. Once you get out of the atmosphere, there won't be anything for the rocket exhaust to push against, and it will stop accelerating. Besides, the radiation belts would kill any human who went up.

>>5378040

Violates conservation of energy - you'd need a rocket weighing at least a million tons.

>>5378056
Umm... Newton's 3rd law applies in a vacuum. Also this is how they got to the moon, except they were inside.

>>5378062
>Implying humans went to the moon
>Implying that wasn't a Cold War propaganda lie

>>5378035
Can anyone explain the fallacy in this one.

>>5378071
Have you ever used a hose?

>>5378075
No.

>>5378026
>air trapped inside the bottle needs to be of a lower pressure than the air outside the bottle
So squeeze the bottle a bit, cup the opening, stop squeezing so that the bottle will try to expand (but be limited due to the vacuum of the air) and flip the bottle over, remove your hand from the opening. You'll find no matter how much suction you have (you could hook up a vaccum hose to a cutout in the bottle if you wanted) water simply does not have the surface tension to prevent air from getting into the bottle.

Straws work because air doesn't have enough room to squeeze past, bottle openings have plenty of room.

>>5378071
the water acts like a solid snake (imagine for a minute there is no fluid movement, the stream is actually a real live snake that is curved over into the pool from the opening in the garden hose) So when you hold the snake up high and then quickly bring your hose down, you'll notice that the snake bends in sort of an 'S' shape, so that part of the snake is still higher than the hose, part of the snake is still sticking out of the hose.

well, apply that shape to the water, and you'll realize you still have the same amount of water in the air, you've just moved your hose

>>5378078
I think they are thinking of the trick where you put a piece of paperboard over the cap. Bill Nye does it with a bucket in one episode of his show.

There of course, you have something that doesn't have the problems with surface tension blocking air from coming in.

>>5378084
That's a great example! Some people believe that a card wouldn't be enough to stop it either - I've met a few - but clearly it is!

>>5378078
How much water are you imagining? If you had a little water and a large vaccum, the water wouldn't drain.

>>5375896
That doesn't work simply because the area you reducing by cutting corners is outside the circle so the limit you are approaching is going to be a constant 4 which is not the limit of the circle's circumference.

>>5377944
>No known compound that has enough tensile strength.
Carbon nano tubes nigga.

>>5378120
It's even hinted in the drawing that this does not approximate a circle.

What does work though is approximating the diagonal of the unit square by cutting edges and thus get sqrt(2) = 2.

>>5378071
lifting the hose up reduces the bucket fill rate briefly.
dropping the hose down increases the bucket fill rate briefly.

fill rate is still 1L/sec on average

if i were to move away from the earth at light speed and look behind myself, would i see a still image of earth as i left it or would i have to slow down just enough so that i observe each light wave at a rate that would have the earth's aging appear to happen more slowly?

one i made long time ago

>>5375883

you must be a great scientist

>>5377944
Dude, don't explain obvious trolllogic. And don't make such incredibly stupid mistakes while doing it.

>>5377954
lel

>ITT: people posting detailed rebuttals of troll physics

You fucking aspoids

>>5375896
This makes a diamond, not a circle.

>>5375944
just make it not fill it air
connect a bag with the trash and vacuum it before opening the tube

>>5378726

The real problem is that since the whole tube is a vacuum the trash won't get sucked into space but just into the tube. Then gravity will just pull it to the bottom of the tube.

>>5377944
>actually replied to the 'breathe your own air' pictures

dude, get a fucking life, its a joke, ok?

HARD MODE:

Debunk these without resorting to 'herp derp theres not enough torque'

>>5378410
electrons are a cloud though, not precisely rotating particles

>>5375883
Austist or the troll of a generation. We may never know.

>>5375854
>filled with air
buoyant force stops acting once it's floating on the surface, kiddo.

Every object with mass has a debroglie wavelength.
The larger an object is the smaller that wavelength is.
When two objects with the same wavelengths touch resonance occurs and the objects break apart.
Fortunately however the universe itself still doesn't have a wavelength small enough to resonate with your mumma.

>>5378055
That would just be an electric motor though.

>>5375899
How about this: try swinging the stick around. What happens at the other end of the stick?

>>5378401
You would see yourself looking back at you, and it would be creepy as fuck

>>5378756
>knows what electrons look like

have you seen them nigga?

>>5378798
It wouldn't spin, it would wiggle

>>5378844
the stick would break in half,
but supposing you had perfect rigidity, the stick would have an insane amount of mass making it near impossible to move, but supposing it had rocket thrusters all along the stick,
the stick would only move as fast as the rockets could propel it.

I suppose you are wondering though, what if the rockets were moved further down the stick, so that the end of the stick would swing faster than the rockets... well... That's where the "you gain mass as you move faster" arguement comes into play. I don't understand how it works or why it's there, I'm not sure if I even believe it, but that's the arguement that would stop you from moving faster than light. Supposdely you gain mass when you increase velocity

>>5378858
hehehehe, awesome.

>>5375941
>Rounding errors

>>5378026
>Suction

NO

>>5375965
Ultraviolet catastrophe
Proved wrong by Planck
Too bad.

>>5380030

Truly, you are a dizzying intellect.

>>5378035
When you raise it up you make the water stream narrower so the second panel is incorrect. It is no longer 1L/sec entering the bowl because more water is stuck in mid-air. This water enters the bowl later when you quickly aim down. The bucket fills twice as fast instantaneously but on average is it the same because it's just making up for lost flow when you raised it up.

>>5380032
thx bro