1. 23:43 24th Aug 2014

    Notes: 1102

    Reblogged from colliderblog

    fouriestseries:

Gabriel’s Horn and the Painter’s Paradox 
Gabriel’s Horn is a three-dimensional horn shape with the counterintuitive property of having a finite volume but an infinite surface area.
This fact results in the Painter’s Paradox — A painter could fill the horn with a finite quantity of paint, “and yet that paint would not be sufficient to coat [the horn’s] inner surface” [1].
If the horn’s bell had, for example, a 6-inch radius, we’d only need about a half gallon of paint to fill the horn all the way up. Even though this half gallon is enough to entirely fill the horn, it’s not enough to even coat a fraction of the inner wall!
The mathematical explanation is a bit confusing if you haven’t taken a first course in calculus, but if you’re interested, you can check it out here.
Mathematica code:
x[u_, v_] := u
y[u_, v_] := Cos[v]/u
z[u_, v_] := Sin[v]/u
Manipulate[ParametricPlot3D[{{x[u, v], y[u, v], z[u, v]}}, 
    {u, 1, umax}, {v, 0, 2*Pi}, 
    PlotRange -> {{0, 20}, {-1, 1}, {-1, 1}}, 
    Mesh -> {Floor[umax], 20}, Axes -> False, Boxed -> False], 
    {{umax, 20}, 1.1, 20}]
Additional source not linked above.

    fouriestseries:

    Gabriel’s Horn and the Painter’s Paradox 

    Gabriel’s Horn is a three-dimensional horn shape with the counterintuitive property of having a finite volume but an infinite surface area.

    This fact results in the Painter’s Paradox — A painter could fill the horn with a finite quantity of paint, “and yet that paint would not be sufficient to coat [the horn’s] inner surface” [1].

    If the horn’s bell had, for example, a 6-inch radius, we’d only need about a half gallon of paint to fill the horn all the way up. Even though this half gallon is enough to entirely fill the horn, it’s not enough to even coat a fraction of the inner wall!

    The mathematical explanation is a bit confusing if you haven’t taken a first course in calculus, but if you’re interested, you can check it out here.

    Mathematica code:

    x[u_, v_] := u
    y[u_, v_] := Cos[v]/u
    z[u_, v_] := Sin[v]/u
    Manipulate[ParametricPlot3D[{{x[u, v], y[u, v], z[u, v]}}, 
        {u, 1, umax}, {v, 0, 2*Pi}, 
        PlotRange -> {{0, 20}, {-1, 1}, {-1, 1}}, 
        Mesh -> {Floor[umax], 20}, Axes -> False, Boxed -> False], 
        {{umax, 20}, 1.1, 20}]

    Additional source not linked above.

     
  2. 15:23 23rd Aug 2014

    Notes: 23071

    Reblogged from meiilan

    Tags: Judoseoi nageseoi-nagefake

    questionidilingua:


4gifs:

Residents of Pisa are getting tired of the tourists. [video]

Turisti, beware.


The Seoi Nage is the sholder throw from Judo which can be seen here. However,  it is not well performed here, the thrower doesnt’t have any controll over his “victims” shoulder.  Furthermore, the way that guy falls looks as if he had learned how to fall and it doesn’t look as if he was surprised, otherwise it would have taken him longer to stand up again. Thus, I conclude that this is staged. Well, I wouldn’t care to see Judo on tumblr, even if it is staged, but it should be good Judo…

    questionidilingua:

    4gifs:

    Residents of Pisa are getting tired of the tourists. [video]

    Turisti, beware.

    The Seoi Nage is the sholder throw from Judo which can be seen here. However, it is not well performed here, the thrower doesnt’t have any controll over his “victims” shoulder. Furthermore, the way that guy falls looks as if he had learned how to fall and it doesn’t look as if he was surprised, otherwise it would have taken him longer to stand up again. Thus, I conclude that this is staged. Well, I wouldn’t care to see Judo on tumblr, even if it is staged, but it should be good Judo…

    (Source: ForGIFs.com)

     
  3. 12:17

    Notes: 616

    Reblogged from fuckyeahsolarsystem

    Our solar system is fantastically bizarre. There are worlds with features we never imagined. Storms larger than planets, moons with under-surface oceans, lakes of methane, worldlets that swap places…and that’s just at Saturn.
    — Phil Plait (via fuckyeahsolarsystem)
     
  4. 12:16

    Notes: 1069

    Reblogged from sci-universe

    Tags: yep I just discovered Phil Plait

    Not everything that’s cool is science, but everything in science is cool.
     
  5. Linus Torvalds: Linux soll den Desktop erobern

    travelinks:

    heise.de meldet:
    Linus Torvalds möchte mit Linux noch immer den Desktop erobern. Der Kernel sei aber nicht das Problem, erklärte der Vater des freien Betriebssystems auf der LinuxCon…
    Quelle: http://www.heise.de/newsticker/meldung/Linus-Torvalds-Linux-soll-den-Des…

    imagehttp://dlvr.it/6hTV2b traveLink, its all about travel & news…

     
  6.  
  7. 21:15

    Notes: 305

    Reblogged from sofapizza

    sofapizza:

you win this round

Never understood how people can be attracted to butts.

    sofapizza:

    you win this round

    Never understood how people can be attracted to butts.

     
  8. 21:14

    Notes: 90

    Reblogged from diamidinophenylindolee

    diamidinophenylindolee:

Wiser words have never been spoken.

Credit: SMBC Comics

    diamidinophenylindolee:

    Wiser words have never been spoken.

    Credit: SMBC Comics
     
  9. The Theory of Everything (2014)

    It’s worth keeping an eye of this. A really touching trailer, but don’t watch it if you don’t want to be given away spoilers about Stephen Hawking’s live.

     
  10. 17:51

    Notes: 21

    Reblogged from fromquarkstoquasars

    fromquarkstoquasars:

The heartbreaking story of the Russian cosmonaut Vladimir Komarov: http://bit.ly/1lYIJQT

    fromquarkstoquasars:

    The heartbreaking story of the Russian cosmonaut Vladimir Komarov: http://bit.ly/1lYIJQT

     
  11. 10:52 17th Aug 2014

    Notes: 39

    Reblogged from fromquarkstoquasars

    fromquarkstoquasars:

Introvert or Extrovert, Normal or Abnormal?: The Problem With Personality Types

Stop with the quizzes already. Learn about the problems with “personalities” at:http://bit.ly/1yLjXZZ

    fromquarkstoquasars:

    Introvert or Extrovert, Normal or Abnormal?: The Problem With Personality Types

    Stop with the quizzes already. Learn about the problems with “personalities” at:
    http://bit.ly/1yLjXZZ

     
  12. 12:22 16th Aug 2014

    Notes: 8

    Reblogged from phoxbox

    (Source: saul-white)

     
  13. johndoomedbutlovingitegbert:


pikanan:

florawrsaurus:

adamspong:

florawrsaurus:

science side of tumblr? explain?

levitate egg sackiatoo

yeah okay thanks hp fandom

the burning candle uses up all the oxygen in the bottle, which creates and a vacuum, and the resulting suction makes the egg go nyooom.

Thank you science side


The explanation for why the egg levitates is wrong. There is no vacuum, there is just a lowered pressure, and even if there was a vacuum, vacuum alone never sucks. It’s just that the air pushes. However, air usually pushes from all sides with equal force and thus there is no motion. Because of the candle, the air pushes on the top less than on the bottom and thus there is a net force and the egg levitates. It’s important how you think about it, if you really want to understand it. The difference between pushing and sucking is essential.

For example, if your body would be suddenly exposed to a vacuum, as in space, you wouldn’t explode, as it is shown in many movies. Vacuum doesn’t suck, it’s just an absence of pushing and your skin is able to keep your organs and liquids inside even without the 1 bar of the air helping out. Of course, with time you extremeties would expand a bit because of the inner pressure and you bodily liquids would start boiling, when exposed to the vacuum, so better keep your mouth closed ;).

    johndoomedbutlovingitegbert:

    pikanan:

    florawrsaurus:

    adamspong:

    florawrsaurus:

    science side of tumblr? explain?

    levitate egg sackiatoo

    yeah okay thanks hp fandom

    the burning candle uses up all the oxygen in the bottle, which creates and a vacuum, and the resulting suction makes the egg go nyooom.

    Thank you science side

    The explanation for why the egg levitates is wrong. There is no vacuum, there is just a lowered pressure, and even if there was a vacuum, vacuum alone never sucks. It’s just that the air pushes. However, air usually pushes from all sides with equal force and thus there is no motion. Because of the candle, the air pushes on the top less than on the bottom and thus there is a net force and the egg levitates. It’s important how you think about it, if you really want to understand it. The difference between pushing and sucking is essential.

    For example, if your body would be suddenly exposed to a vacuum, as in space, you wouldn’t explode, as it is shown in many movies. Vacuum doesn’t suck, it’s just an absence of pushing and your skin is able to keep your organs and liquids inside even without the 1 bar of the air helping out. Of course, with time you extremeties would expand a bit because of the inner pressure and you bodily liquids would start boiling, when exposed to the vacuum, so better keep your mouth closed ;).

     
  14. 22:33 14th Aug 2014

    Notes: 918

    Reblogged from imathematicus

    ryanandmath:

    Mathematician Maryam Mirzakhani is the first woman and first Iranian to be awarded the Fields Medal!

    The Fields Medal is one of the highest honors granted in math. Every four years the medal is awarded at the International Congress of the International Mathematical Union to two, three, or four mathematicians under the age of 40. Along with the Abel Prize, it is considered “the mathematician’s Nobel Prize.”

    Mirzakhani’s work focuses on Riemann surfaces and their moduli spaces and connecting aspects of differential geometry, complex analysis, and dynamical systems. Currently she is working on developing the understanding of billiards and translation surfaces with fellow mathematician Alex Wright. A fantastic overview of her life can be found in this article.

    The Fields Medal was also awarded to Artur Avila (dynamical systems), Manjul Bhargava (number theory), and Martin Hairer (stochastic differential equations).

    (1, 2, 3, 4, 5)

     
  15. So this week I’ll get access to the KA-Grid which is part of the LHC Computing Grid. For me this is really exciting.