haha.nu » Science

Animal Olympians: Gymnastics

hahanu — Wed, 23 May 2012 09:58:43 +0000

The desert sands of Namibia are home to a remarkable miniature acrobat. The Golden wheel spider turns on a performance that rivals the tumbling floor routine of any gymnast.

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The Golden ratio explained

hahanu — Fri, 04 May 2012 17:13:12 +0000

Math geeks will love this. @ haha.nu Related posts:Craig Damrauer – More new math What if we are math geeks? Why I Will Never Have a Girlfriend Carl Sagan – 4-th dimension explained Math Education: An Inconvenient Truth Related posts:

Arthur Benjamin – Lightning calculation and other “Mathemagic”

hahanu — Thu, 26 Apr 2012 16:33:20 +0000

Another cool TEDTalks’ session, this time by the mathemagician Arthur Benjamin. @ haha.nu Related posts:R.I.P, Arthur C. Clarke Arthur Mole – the pixel-art artist Martin Mißfeldt – Painting Einstein Ian Benjamin Kenny – Garda Prank 2.2 million volt lightning strike Related posts:

ASIMO 2011 – What can he do now?

hahanu — Tue, 17 Apr 2012 17:11:46 +0000

The all-new ASIMO is now advanced from an “automatic machine” to an “autonomous machine” with the decision-making capability to determine its behavior in concert with its surroundings such as movements of people.

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Static flow of water

hahanu — Wed, 11 Apr 2012 15:44:33 +0000

Creating the illusion of a static flow of water using sound. Of course this isn’t my idea and plenty more refined examples already exist.

I tried this same experiment years ago but using a strobe light, but it’s harsh on the eyes after a while and hard to video successfully. It only dawned on me shortly before making this that for video purposes, no strobe light is required. This is because the frame rate and shutter of the camera is doing a similar job to the strobe.

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TEDTalks – Questions no one knows the answers to

hahanu — Sat, 07 Apr 2012 15:33:49 +0000

In a new TED-Ed series designed to catalyze curiosity, TED Curator Chris Anderson shares his obsession with questions that no one (yet) knows the answers to.

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How to see around corners

hahanu — Sat, 07 Apr 2012 15:33:45 +0000

This video shows how scientists at the MIT Media Lab reconstruct a hidden object using scattered laser light. Future applications may include seeing in dangerous or inaccessible locations, such as inside machinery with moving parts, or in highly contaminated areas.

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Planet Earth: Just the Sex

hahanu — Wed, 04 Apr 2012 11:12:41 +0000

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Can you guess what is this?

hahanu — Fri, 23 Mar 2012 09:09:50 +0000

A microcrack in steel through an electron microscope. The colors are not natural, they are added later because all photos from electron microscopes are black&white. Click to see the larger version.

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Homemade stirling engine

hahanu — Sat, 10 Mar 2012 11:52:13 +0000

A Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work.

Like the steam engine, the Stirling engine is traditionally classified as an external combustion engine, as all heat transfers to and from the working fluid take place through the engine wall. This contrasts with an internal combustion engine where heat input is by combustion of a fuel within the body of the working fluid. Unlike a steam engine’s (or more generally a Rankine cycle engine’s) usage of a working fluid in both its liquid and gaseous phases, the Stirling engine encloses a fixed quantity of permanently gaseous fluid such as air.

Typical of heat engines, the general cycle consists of compressing cool gas, heating the gas, expanding the hot gas, and finally cooling the gas before repeating the cycle. The efficiency of the process is narrowly restricted by the efficiency of the Carnot cycle, which depends on the temperature difference between the hot and cold reservoir.

Originally conceived in 1816 as an industrial prime mover to rival the steam engine, its practical use was largely confined to low-power domestic applications for over a century.

The Stirling engine is noted for its high efficiency compared to steam engines, quiet operation, and the ease with which it can use almost any heat source. This compatibility with alternative and renewable energy sources has become increasingly significant as the price of conventional fuels rises, and also in light of concerns such as peak oil and climate change. This engine is currently exciting interest as the core component of micro combined heat and power (CHP) units, in which it is more efficient and safer than a comparable steam engine.

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