Tag Archives: fun

Friday Fun: Dolphins Play with Air Bubble Rings

Bubbles in water

The bubble is the most stable situation for an amount of gas phase in water (liquid phase). A surface tension is associated with the surface between the gas phase and the liquid phase, the surface tension tends to minimize the surface area. This is also described in the section on bubbles in bubble models. Given a volume of gas, the sphere (bubble) shape is the shape that has the smallest surface area with respect to the containing volume.

The situation of a bubble in water is comparable to a balloon. The balloon surface is elastic. The tension of it tries to minimize the surface: if you don’t tie a knot in the balloon after blowing it up, air escapes and the surface of the balloon is minimized to the initial unstretched situation.

Bubbles do not turn into rings naturally. Something has to be done for that. However, they have long lives and often make it up to the surface. Hence they are stable structures.

Dolphins create bubble rings by blowing air in a water vortex ring: by flipping a fin they create a vortex ring of water. The then blow air in the ring, which goes to the center of the vortex ring. In the water vortex ring the natural location of the air is in the center of the vortex. When air and water move in a circular path like they do in the vortex ring, air and water are separated due to the centripetal force. Since density of water is larger than air, water moves at the outside, while the air ends up in the middle.

Follow the link for much more on the physics of bubble rings.

Related: Colored BubblesDolphins Using Tools to HuntDo Dolphins Sleep?posts on animals

Buy Your Own Electron Microscope

Buy your own electron microscope from the state of South Carolina, USA.

You will be bidding on a Hitachi Electron Microscope and Accessories Lot (detailed info below). The agency is reporting the basic scope worked when last operated about two years ago. The x-ray detector computer is broken but that is an add-on accessory feature that does not affect operation as an electron microscope. Also, the forepumps and air compressor are missing. These two items will need to be replaced before someone attempts to use it. This is an old electron microscope but is good for basic microscopy. The electron microscope has been disassembled and palletized by the Medical University of South Carolina. This equipment was used by the Medical University of South Carolina and is located in North Charleston, South Carolina. The overall condition of this property is unknown to the Surplus Property Office.

Detailed Lot Info:

  1. Hitachi H7000 Electron Microscope
  2. Kevex Computer (model Delta)
  3. Kevex Monitor
  4. Okidata Printer (model 320)
  5. Hitachi KS55 Camera

Current bid: $460. Auction expires 5 June 2009 at 3 PM USA Eastern Time. Getting the equipment to your location will likely cost much more than that.

This item is for pickup only at the Medical University of South Carolina in North Charleston, South Carolina. The winning bidder is responsible for the loading and removal of this property. MUSC will try to assist if employees are available during the loading.

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Automatic Dog Washing Machine

I think this is pretty cool; I’m sure some will object though. It was “designed by a team of veterinarians and engineers to clean the dog very very well. Its very very safe.” You probably can’t afford one for your house though: it cost $30,000. The
The Dog-Washing Machine is available in France and elsewhere, too (the video above is from Vancouver, Canada).

The brainchild of French entrepreneur Romain Jerry, the Dog’O’Matic takes about 30 minutes: 5 minutes for the actual washing with soft jets of water and a mild shampoo and an additional 25 minutes for drying with warm air.

A French reporter tried the invention with her own dog, and though the pooch initially tried to jump out of the machine, the dog quickly calmed down once the process started and completed the wash.

I imagine some will react emotionally that it must be mean because a machine sounds mean. I don’t really see why it must be mean. Plenty of people pay others to wash their dogs and the dogs jump around and bark and shake when they are getting lathered up. That isn’t cruel, I don’t see why this would be.

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Friday Fun: Bird Using Bait to Fish

In the webcast an Aukuu bird (Black-crowned Night Heron) fishes using bread as bait. They normally hunt by waiting at the side of a lake and fishing. This individual learned how to bait the fish with bread and improve the fishing results. It also passed on that method to other birds that learned how to use the bait method themselves.

Another bird using bait (with turtles trying to get the bait) and another bird using bait (with a stork trying to steal the fish). And another one. The videos seem to be different species of birds to me.

Related: Orangutan Attempts to Hunt Fish with SpearDolphins Using Tools to HuntBird Brain experimentposts on animals

New Yorkers Help Robot Find Its Way in the Big City

Tweenbots by Kacie Kinzer

I wondered: could a human-like object traverse sidewalks and streets along with us, and in so doing, create a narrative about our relationship to space and our willingness to interact with what we find in it? More importantly, how could our actions be seen within a larger context of human connection that emerges from the complexity of the city itself? To answer these questions, I built robots.

Tweenbots are human-dependent robots that navigate the city with the help of pedestrians they encounter. Rolling at a constant speed, in a straight line, Tweenbots have a destination displayed on a flag, and rely on people they meet to read this flag and to aim them in the right direction to reach their goal.

The results were unexpected. Over the course of the following months, throughout numerous missions, the Tweenbots were successful in rolling from their start point to their far-away destination assisted only by strangers. Every time the robot got caught under a park bench, ground futilely against a curb, or became trapped in a pothole, some passerby would always rescue it and send it toward its goal. Never once was a Tweenbot lost or damaged. Often, people would ignore the instructions to aim the Tweenbot in the “right” direction, if that direction meant sending the robot into a perilous situation. One man turned the robot back in the direction from which it had just come, saying out loud to the Tweenbot, “You can’t go that way, it’s toward the road.”

Very cool, fun and interesting. Cute integration of technology, psychology and an inquisitive scientific mind.

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What is on the Other Side of Earth?

Do you ever wonder what is on the exact opposite side of Earth? This website uses Google Maps to let you see: Antipodes Map. It also makes clear how much of the earth is covered in oceans. The entire continental USA is opposite ocean. Hawaii is opposite Botswana and Namibia. Hong Kong is opposite Argentina. Singapore opposite Ecuador. India, Ireland, Turkey, France and Egypt are among the many countries that opposite oceans. Madrid is opposite New Zealand.

Related: science factsMicrobes Beneath the Sea FloorCool Mechanical Simulation System

Pi Ice Cube Trays

Pi ice cubes

Liven up a drink with Pi shaped Ice “cubes” from Think Geek:

But how about ice? You were planning to use that standard vaguely cubical stuff?… or worse the boring half-moon shape your fridge churns out? Well fear not intrepid nerdy party planner! ThinkGeek is here with the geekiest ice you’ll ever find… Pi ice! Yep these stylish silicone ice trays cast frozen H2O into the symbol for your favorite irrational number.

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Home Engineering: Gaping Hole Costume

photo of gaping hole Halloween costume by Evan Booth, 2006

This great Halloween costume by Evan Booth shows what a bit of imagination and engineering can do. A projection screen over his stomach displays a live video image of a camera on his back giving the illusion of a gaping hole. Photos via flickr. Very cool.

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