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Posted

This years Ig Nobel Awards :geek:

 

Not going to cut and paste all the paragraphs and entries, but there are some quite amusing ones amongst them.

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“He who joyfully marches to music in rank and file has already earned my contempt. He has been given a large brain by mistake, since for him the spinal cord would surely suffice.” - Albert Einstein
 

Posted

The amplituhedron is a geometric model that somehow greatly simplifies the computation of particle interactions. It's an intriguing find and a quite interesting read, if you enjoy fundamental physics.

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"It has just been discovered that research causes cancer in rats."

Posted

This years Ig Nobel Awards :geek:

 

Not going to cut and paste all the paragraphs and entries, but there are some quite amusing ones amongst them.

This one made me laugh:

"Peace Prize: Alexander Lukashenko, president of Belarus, for making it illegal to applaud in public, and to the Belarus State Police, for arresting a one-armed man for applauding."

  • Like 2
I'd say the answer to that question is kind of like the answer to "who's the sucker in this poker game?"*

 

*If you can't tell, it's you. ;)

village_idiot.gif

Posted

Nice! That is awesome! Now, just solve the powersupply issue that I'm fairly confident is there. Pita to read through texts on white backgrounds at the moment, but I did'nt see them mentioning that at all.

 

Oh, and please develop eyes! :D

 

If it ever became affordable I would probably have all my limbs amputated, soooo frickin' cool. *_*

Civilization, in fact, grows more and more maudlin and hysterical; especially under democracy it tends to degenerate into a mere combat of crazes; the whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, most of them imaginary. - H.L. Mencken

Posted (edited)

Would be kinda scary to see rich people removing parts of their limbs, so they can wear cool mechanical replacements. I am wondering if we could reach a Deus Ex: Human Revolution kind of (social) level with this stuff.

Edited by Lexx
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"only when you no-life you can exist forever, because what does not live cannot die."

Posted

Would be kinda scary to see rich people removing parts of their limbs, so they can wear cool mechanical replacements. I am wondering if we could reach a Deus Ex: Human Revolution kind of (social) level with this stuff.

 

You mean scary as in injecting, say, silicone and botulinum toxin into your body or reshaping bones, removing tissue and whatever else they

 

 

Whoa, that's ten different kinds of creepy, but also very cool.

already do?

Civilization, in fact, grows more and more maudlin and hysterical; especially under democracy it tends to degenerate into a mere combat of crazes; the whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, most of them imaginary. - H.L. Mencken

Posted

Can you outrun it?

 

I cant wait until we have a robotic armed forces.

 

Oh gods. I might feel morally obliged to reapply... :( FFS

"It wasn't lies. It was just... bull****"."

             -Elwood Blues

 

tarna's dead; processing... complete. Disappointed by Universe. RIP Hades/Sand/etc. Here's hoping your next alt has a harp.

Posted

'God particle' theorists receive Nobel Prize in physics

 

The Higgs boson, the "God particle," which was discovered last year, garnered two physicists the Nobel Prize in Physics on Tuesday, but it didn't go to the scientists who discovered it.

Nearly 50 years ago, Francois Englert of Belgium and Peter Higgs of the United Kingdom had the foresight to predict that the particle existed.

 

 

 

http://www.cnn.com/2013/10/08/world/europe/sweden-nobel-prize-physics/index.html?hpt=wo_c2

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Posted

Well it's not new, but it's still a nice article:

 



io9 - Cool Physics Demonstration
 

 


 

 

Your guide to one of the coolest physics demonstrations of all time



original.gif
 

In this simple demonstration, we see what seems like a special effect. But it's not. Here's how laminar flow makes reality look like an optical illusion.


Top animation adapted from a demonstration video by the UNM Physics Department

It looks totally fake. Corn syrup dyed yellow, blue and red is added to a container full of undyed syrup. The combination is stirred, smearing the colors into a muddled streak of brownish orange. But when the stirring is reversed, the colors we thought were irretrievable whirl into view: the drops of yellow, blue and red are restored! Magic? Fakery? Nope and nope. It's the result of a phenomenon known as laminar flow. But HOW DOES IT WORK?

 

We first introduced you to this experiment and the wonders of laminar flow a couple years ago, with this video by the University of New Mexico's Physics Department. Since then, we've received a pretty steady stream of requests from people asking us to explain the demonstration in greater detail. We have heard your cries. Let's get right to it, then, shall we?

original.gif

So waaaay back in 2011, we told you that the reversibility of the mixing demonstrated in the video was due to an extreme form of laminar flow called Stokes flow. Also known as "creeping flow," Stokes flow is what you get when a fluid is so viscous that it resists the sort of irreversible mixing that we're used to seeing when we introduce motion to a liquid mixture.

 

Ever stirred cream into coffee? Then you've witnessed this kind of disorder firsthand. The instant that cream hits coffee, it starts to diffuse. A couple swirls with a spoon and things really get out of hand; if anything, reversing the direction of your stirring only agitates things even more. In a few seconds, things are looking pretty uniformly mixed. The effects of inertia on the fluid have won out over viscosity, and there's no going back.

 

In fluid dynamics, this competition between inertia and viscosity is described by a quantity called the "Reynolds number." I'm summarizing here, but the Reynolds number, R, can be described in simplest terms as the ratio of the inertial effects* over viscous ones for a given fluid. More formally, it's described as R=ρνR/η, where ρ is density, ν is the speed of the fluid, R is the size of the flow, and η is viscosity. To understand this conceptually, think back to our previous example: Coffee, which is mostly water, is not very viscous. Corn syrup, on the other hand, has a viscosity thousands of times that of water. Because the Reynold's number is inversely related to viscosity, η, corn syrup stirred in the manner demonstrated here has a very small Reynolds number. When a Reynolds number is much, much smaller than 1, it allows for the extreme form of laminar flow – aka Stokes flow – that we discussed above, and mixing becomes reversible:

 

ku-xlarge.gif


Animation adapted from Low-Reynolds-Number Flows via The National Committee for Fluid Mechanics Films

A common analogy states that a fluid with a sufficiently low Reynolds number will flow along distinct paths in parallel layers (like fanning a deck of cards), which prevents disruption of the fluid. "Fan the cards" back and you wind up right back where you started. Another great way of understanding Stokes flow is to consider it in terms of diffusion. One of the best explanations I've seen comes via the always-awesome F*ck Yeah Fluid Dynamics tumblr, which states that in examples of extreme laminar flow like the ones seen here, the motion of the fluid is the result of two forms of diffusion. The first is molecular diffusion, which describes the tendency for the dye molecules to disperse spontaneously and evenly throughout the liquid. The second is what's known as momentum diffusion:

 

 

 

 

The former is random but slow, and the latter is exactly reversible. Reversing the rotation of the fluid undoes the momentum diffusion and any distortion remaining is due to molecular diffusion of the dye.

 

 

 

Granted, not all laminar flow is inherently reversible, but there's almost always something more orderly about it. Flow lines that are laminar are often described as "coherent." It's a word that conveys consistency, order and unification. It stands in stark contrast against the disorder observed in what are known as "turbulent" flows. Laminar flows over an airplane wing are a good thing. Turbulent flows, unsurprisingly, give rise to nasty turbulence aren't actually responsible for the turbulence you experience on an airplane, but rather what are called "turbulent boundary layers," which – as nsharp points out below – leads to an increase in both drag and fuel-usage.

 

One thing the Reynolds number does really well is collect the various conditions that affect the flow of a fluid, and combine them to determine whether they might give rise to laminar or turbulent flow, or how a flow can transition from one state to another. In the demonstration seen here, for example (borrowed from this study by J. P. Kubitschek and P. D. Weidman), increasing the velocity at which a viscous liquid jet is rotating causes its rotational Reynold's number to increase, in turn resulting in a transition from laminar flow:

ku-xlarge.gif

To turbulent flow:

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This effect is also how we get gorgeous images like these. (Fun fact: you may notice there's still some "order" to this high Reynolds number, turbulent-flow. That's because rotating jets of viscous liquid jets tend to demonstrate a preference for what are known as "helical instabilities." The more you know, right?)

 

Just to clarify, something that the previous demonstration illustrates is that Reynolds number is not constant for any particular fluid. Remember: "R" is a quantity that describes several different factors, all of which are subject to change in and of themselves. A fluid's density, for instance, changes with temperature, and a fluid's speed can change dramatically depending on the forces acting upon it. Scientists and engineers weigh these properties to determine Reynolds number for a variety of applications, whether it's designing a city's sewer infrastructure or – a personal favorite – describing the motion of self-propelled organisms in water:


ku-xlarge.png
Table of self-propelled organisms by Vogel via Hitech Projects

 

Note that the Reynolds number range from very large values to very small, across a variety of water-dwelling organisms. The numbers indicate that for more massive organisms, like a whale, the effects of inertia dominate those of viscosity. This allows whales to coast for long periods of time with every stroke of their fins. Conversely, bacteria must contend with a small Reynolds number, denoting the strong influence of viscosity. A whale in motion will tend to stay in motion. A bacterium? Not so much.

 

 

 

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"Cuius testiculos habeas, habeas cardia et cerebellum."

Posted

Well it might be a few months old, but I thought this might catch some folks fancy..

 

DNA Fog

 

 

 

Imagine prowlers broke into your company warehouse over the weekend. The alarm sounded, but the devious blaggards got away with the goods before the police arrived. Your security cameras caught only dim, shadowy images of the intruders, not clearly enough for positive identification. DNA tagging could change that.

Normally, tracking a criminal using DNA requires, at a minimum, that the perpetrator leaves behind a DNA sample in some form or other. As they are not often so accommodating, the role of DNA in crime busting, while significant, has its limits.

 

Applied DNA Sciences (ADNAS) has developed a new approach to solve crimes using DNA tagging. The difference is that instead of tagging the objects being stolen, they tag the pilferer with DNA. While this has been tried before by applying the DNA to a fleeing criminal with a gun, ADNAS has adopted a more subtle approach.

For years banks have rigged bags of money with exploding dye packs, which mark the outlaw and the stash. The ADNAS system takes advantage of that basic concept, but implements it differently, so that a thief can be tagged without having a clue that their career will be cut short.

 

DNA Fog is an airborne suspension of artificial DNA molecules with a known but biologically inert sequence. The DNA molecules (Applied DNA's SigNature DNA) are artificially constructed, so that a strand of DNA with 20 base pairs can have over a trillion unique combinations. A security system could use one sequence per location, one sequence for each area within the location, or even use RFID tags to instruct a sophisticated spraying device to spray a unique DNA signature for each item stolen. Once released, DNA molecules attach onto a malefactor's clothing, shoes, hair, and skin, as well as the objects stolen. This is rather like putting exploding dye packs in bags of money, save that the perpetrator has no idea that he has been marked.

 

It is surprisingly hard to scrub all the DNA off of one's body, clothing, shoes and tools. Regardless of what conventional cleaning methods a thief chooses, they will be easily detected to have been at the scene of the crime at the time it was committed for a period of at least two weeks, and potentially for years. Should a guilty suspect be arrested, police would swab them and their clothes (and probably their apartment and car), then read the DNA samples using the polymerase chain reaction, which amplifies the genetic material from the sample to the point that it can be identified. The video below illustrates this reaction.

 

Amplifying makes the DNA samples easier to detect and analyze, and the overall process is simple and cheap enough that it can be done by non-specialists.

Can DNA Fog be defeated? There are couple of possibilities here. The low-tech approach is to wear an overall Tyvek suit with a diving mask. A higher-tech method is to swamp the DNA Fog system, perhaps by bathing with a body shampoo that contains millions of false DNA fragments. This would make it difficult for investigators to find the right sequence. It becomes a needle in a haystack problem, except the needle is also made of hay.

 

Applied DNA Sciences has recently entered into a two-way exclusive arrangement with SmokeCloak, a Danish security firm that manufactures security fog generators that can fill a room or a warehouse at up to 1600 cubic meters per minute, which is a depth of 1.5 feet per acre each minute

 

 

"Cuius testiculos habeas, habeas cardia et cerebellum."

Posted

This thing looks... strange.

"only when you no-life you can exist forever, because what does not live cannot die."

Posted

That lamellar flow piece made me immediately think of supersoaker fights. Must be an optimal viscosity to deliver maximum effective range.

"It wasn't lies. It was just... bull****"."

             -Elwood Blues

 

tarna's dead; processing... complete. Disappointed by Universe. RIP Hades/Sand/etc. Here's hoping your next alt has a harp.

Posted

 

What I love is how modern destroyers are basically battleships, but no-one wants to admit they are, because I guess it sounds profligate at committee.

 

Aside: WTF is up with the new Marine Corps headgear? What subgenius thought they should switch to nurses' caps?

"It wasn't lies. It was just... bull****"."

             -Elwood Blues

 

tarna's dead; processing... complete. Disappointed by Universe. RIP Hades/Sand/etc. Here's hoping your next alt has a harp.

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