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 Περίεργα δωράκια για ...επιστήμονες : Gifts to impress science geeks

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Αριθμός μηνυμάτων : 8056
Registration date : 10/07/2008

ΔημοσίευσηΘέμα: Περίεργα δωράκια για ...επιστήμονες : Gifts to impress science geeks   20.03.12 9:35


The EcoSphere is sealed blown-glass miniature aquarium produced by Ecosphere Associates, Inc., of Tucson, Arizona, United States. Spherical or ovoid, the aquaria range from roughly baseball-size to soccer-ball-size. They are sold worldwide as scientific novelties and decorative objects. The spheres are populated by tiny red-pink shrimp, which swim energetically around the aquarium, eat the brown bacterial and algal scum on the glass, consume the filamentous green algae which sometimes forms a globular pillow in the water, and perch on a fragment of coral.

Each EcoSphere is a materially closed ecological systems which is self-sustaining over a period of years. At room temperature, and with only low inputs of light, the algae produce oxygen which supports the shrimp and bacteria. Bacteria break down the shrimps’ wastes. The breakdown products provide nutrients to the algae and bacteria upon which the shrimp feed. The manufacturer states that shrimp live in the EcoSphere for an average of 2 to 3 years, and are known to live over 10 years.

The coral is dead and plays no active biological role in the system, however it does increase the surface area for beneficial bacteria and algae, and the calcium carbonate in the coral acts as a pH buffering agent.

A magnetic scrubber is enclosed in each EcoSphere. By passing another magnet over the outside of the glass, the owner can manipulate the scrubber to clean the inside of the EcoSphere. Prior to 1997, the EcoSpheres contained at least one snail at the time of purchase, which would clean the glass (but they were removed to make the sphere self-sustaining).

It is possible to purchase Halocaridina shrimp from Hawaiian aquarium dealers and create home-made sealed aquaria with no other special supplies. Sand, gravel, crushed shell, and very well cycled filtered water from a successful saltwater aquarium, with the lowest attainable ammonia content, should be used. A small inoculation of live Spirulina algae may be introduced. Certain ubiquitous algae and bacteria are likely to be carried by the shrimp themselves and will soon colonize the walls of the container. There is a risk that pathogens also may be introduced.

Every manmade closed system inevitably degrades. The EcoSphere and comparable closed systems are actually ‘self-sustaining’ only in comparison to systems which degrade much more quickly. In any closed, unfiltered, unaereated aquarium, it must be expected that the larger organisms will reach the end of their lifespans, die, and pollute the water with a sharp influx of decay products; or the nutrients in the food cycle will gradually get ‘locked up’ in unusable forms; or the pH of the water will fall outside the survival range of the organisms. The EcoSphere is remarkable in that its degradation is so slow, supporting relatively large, complex organisms (the shrimp) for years, cycling nutrients many times.

The advantage of an aquarium closed with a lid (rather than a permanently sealed plug, which is found in the base of an EcoSphere) is that if the system goes out of equilibrium, the owner can remedy conditions and prevent a complete die-off. Intervention to maintain good water quality allows a larger number of shrimp to live in the open system than can survive in the relatively poor quality closed environment.


Έχει επεξεργασθεί από τον/την Admin στις 20.03.12 9:39, 2 φορές συνολικά
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ΔημοσίευσηΘέμα: Απ: Περίεργα δωράκια για ...επιστήμονες : Gifts to impress science geeks   20.03.12 9:37

11 cheap gifts guaranteed to impress science geeks

1. Aerogel

Science comes up with a lot of awesome stuff, and you don’t need a Ph.D, a secret lab, or government funding to get your hands on some of the coolest discoveries. We’ve got a list of 11 mostly affordable gifts that are guaranteed to blow your mind, whether or not you’re a science geek.

Also known as frozen smoke, Aerogel is the world’s lowest density solid, clocking in at 96% air. It’s basically just a gel made from silicon, except all the liquid has been taken out and replaced with gas instead. If you hold a small piece in your hand, it’s practically impossible to either see or feel, but if you poke it, it’s like styrofoam.

Aerogel isn’t just neat, it’s useful. It supports up to 4,000 times its own weight and can apparently withstand a direct blast from two pounds of dynamite. It’s also the best insulator in existence, which is why we don’t have Aerogel jackets: it works so well that people were complaining about overheating on Mt. Everest.

Price: $35

2. EcoSphere

Inside these sealed glass balls live shrimp, algae, and bacteria, all swimming around in filtered seawater. Put it somewhere with some light, and this little ecosystem will chug along happily for years, no feeding or cleaning necessary, totally oblivious to the fact that the rest of the world exists outside.

EcoSpheres came out of research looking at ways to develop self-contained ecosystems for long duration space travel. They’re like little microcosms for the entire world, man. But ask yourself: are we the shrimp, or the algae?

Price: $80

3. Mars Rock

NASA has been trying to figure out how to get a sample of rock back from Mars for a while now. You can beat them to the punch and pick up a little piece of the red planet without having to travel a hundred million miles, by just taking advantage of all the rocks Mars sends our way.

Every once in a while, a meteorite smashes into Mars hard enough to eject some rocks out into orbit around the sun. And every once in a while, one of these rocks lands on Earth. It doesn’t happen often, but it does happen, and whoever finds the meteorite is allowed to cut it up into bits and sell it to people who want to have their very own piece of another planet.

Price: $70+

4. Gömböc

The Gömböc is a self-righting object, which means that no matter which way you put it down, it stands itself back up. It’s like a Weeble, except it doesn’t cheat by having a weight at the bottom, and it’s the only shape that can do this.

The existence of a shape with these properties was conjectured in 1995, but it took ten years for someone to figure out how to actually make one that worked. And then everyone was embarrassed when it turned out that turtles had evolved this same basic shape in their shells a long time ago, to make it easier for them to roll themselves back over if they get flipped.

Price: $150

5. Violet Laser Pointer

It’s no longer geeky enough to have a red laser pointer, or a green laser pointer, or even a blue laser pointer. Keep moving up the spectrum until you get to violet, and you’ll find the new hotness at 405 nanometers.

So what’s next year’s new color going to be? It’s looking like orange, but they’re not quite what I’d call affordable yet. Something to look forward to for next year, especially if you’re going for your own personal laser rainbow.

Price: $110

6. Gallium

Gallium is a silvery metal with atomic number 31. It’s used in semiconductors and LEDs, but the cool thing about it is its melting point, which is only about 85 degrees Fahrenheit. If you hold a solid gallium crystal in your hand, your body heat will cause it to slowly melt into a silvery metallic puddle. Pour it into a dish, and it freezes back into a solid.

While you probably shouldn’t lick your fingers after playing with it, gallium isn’t toxic and won’t make you crazy like mercury does. And if you get tired of it, you can melt it onto glass and make yourself a mirror.

Price: $80

7. Miracle Berries

By themselves, Miracle berries don’t taste like much. The reason to eat them is that they contain a chemical called miraculin that binds to the sweet taste receptors on your tongue, changing their shape and making them respond to sour and acidic foods.

The upshot of this effect is that some things you eat taste spectacularly different. Straight Tabasco sauce tastes like donut glaze. Guinness tastes like a chocolate malt. Goat cheese tastes like cheesecake. After about an hour of craziness, your taste buds go back to normal, no harm done.

Price: $15

8. DNA Genotyping

There’s nothing more personal than someone’s own DNA. And there are ways to give the gift DNA that won’t get you children or arrested. With just a little bit of spit, you can get an genotype analysis that will reveal fun insights about longevity, intelligence, susceptibility to diseases, and even food preferences.

While the technology hasn’t reached the point where you can affordably get a complete sequence of an entire genome, looking at specific markers is still good enough to suggest some things worth looking out for while spurring a lively nature versus nurture debate.

Price: $100

9. Klein Bottle

If you want to give a mathematician something to try to wrap their head around, a Klein bottle is a good place to start. A real Klein bottle is an object with no inside and no outside that can only exist in four dimensions. These glass models exist in three, which means that unlike the real thing, they can actually hold liquid.

The difference between the models and the real thing is that by adding an extra dimension, you can make it so that the neck of the bottle doesn’t actually intersect the side of the bottle. Take a couple aspirin and try to picture that in your head.

Price: $35

10. Giant Plush Microbes

They’re cute! They’re fuzzy! They’re potentially deadly! All of the microbes, bacteria, and viruses that you know and love (or maybe not) are available in huggable forms about a million times larger than real life. In the picture are gonorrhea, syphilis, mono, and herpes.

These giant plushes are the perfect way to make the holidays even more awkward, when you present your friends with a variety of adorable STDs. Microbiologists, at least, will appreciate that they’re more or less anatomically correct, too.

Price: $9

11. Ferrofluid

Magnetic particles suspended in oil never looked so sexy. That’s all a ferrofluid is, and it looks pretty gross until you put it in close proximity to a magnet, at which point it grows spikes all over the place as the fluid flows out along magnetic force lines.

Ferrofluids are found in everything from speakers to hard drives, but it’s much more fun to play with when when you’ve got a puddle of it naked and out in the open.

Price: $40

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ΔημοσίευσηΘέμα: Απ: Περίεργα δωράκια για ...επιστήμονες : Gifts to impress science geeks   20.03.12 9:37

Star Theater

Learn about the wonders of our galaxy as you explore the night sky with this planetarium!

The Star Theater projects major constellations (including stars, connecting lines, and names) on the walls and ceiling of any darkened room, with accurate star positions for any given season, date and time.

It’s an easy way to learn the position of stars and constellations before going outside to find them in the night sky. An access code is included to download an audio tour about the sun, stars, constellations and more.

Plus you'll get a "meteor maker" flashlight! Requires 3 AAA batteries, not included. Ages 8 & up.

Star sphere with positions of major stars and constellations marked

Halogen bulb for clear projection of constellations

Access code to download an audio tour of the night sky

6-page instruction book


Stellarscope 2 Star Locator

Quickly locate and identify stars visible to the naked eye with this unique device.

The Stellarscope® 2 star maps are accurate every night of the year. Just attach the adapter for your latitude, rotate the time/date selector for the current day and time, and look through the Stellarscope® 2 with proper east-west orientation and you have a star map aligned with the actual night sky.

Includes star maps for both the Northern and Southern hemispheres with over 1500 stars identified and the brightest stars identified by name.

The star maps are accurate between 20° and 60° North or South latitude.

Includes a night-viewing light. The Stellarscope® doesn't track the planets, since their position changes constantly.

Ages 9 & up.

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