Fruity

This week's abstract is in honor of the news of the closure of PEAR.

PEAR, or Princeton Engineering Anomalies Research operated for almost thirty years. PEAR's studies looked at the ability for human consciousness to interact with the physical world. In some cases they used machines that use various schemes to create random numbers. The researchers asked people to influence the outcome of binary events controlled by these random machines. Using statistics to analyze extremely large samples, they came up with some indications that the conscious intentions of their subjects could affect the physical world. There are a lot of objections to these experiments, both methodological and theoretical.
















The main objection to these experiments, beyond their methodology, is the idea that scientific research should build on what came before; new experiments and hypotheses should be formed in the context of current understandings. However, others argue that we don't have to accept the idea that these are paranormal phenomena, and the rejection of all evidence and study on these topics is based on certain beliefs that also cannot be proven.

An article in today's New York Times on Carl Sagan brings up some interesting points on the intersection of science and religion but somehow tows the line that investigation is more important than confirming our beliefs.

“It goes with a courageous intent to greet the universe as it really is, not to foist our emotional predispositions on it but to courageously accept what our explorations tell us.”

Oobleck

I thought I would join the YouTube bandwagon for this post. I used "science" as a search term and came up with one pretty cool example. (I do hope it's real, I found some fake science experiments in my search. The best by far is the Look Around You series.)

Here's a second video with a much bigger vat of cornstarch.

I looked around for some cornstarch articles on Google Scholar and PubMed but most of them had to do with eating cornstarch instead of walking on it.

Oobleck behaves as a non-newtonian fluid. Newtonian fluids react in a fixed proportion to pressure. If you push twice as hard, there's twice as much resistance. So when you try to step on water you push right through, there is nothing special about the molecules near your foot.

Non-newtonian fluids can have non-proportional reactions due to their sensitivity to gradients in flow speeds.

Oobleck gets incredibly viscous over small areas when strong pressure is applied. Oobleck molecules do care about their neighbors, a lot. If your foot is creating a change in the flow gradient, pushing one area of the liquid around a lot faster than the neighbors are being pushed, they stiffen up and push back. The reaction of the liquid isn't proportional to the pressure applied, it's complicated by the locals.

Okay, that hurt my brain so I'm not even going to attempt to explain what's happening in the video up top.

More fun with cornstarch (or sand or sugar). Sorry about the noise.

Now, let's combine crazy liquids with art (video). These artist/scientists used magnetic liquid in their sculpture. The magnetic fields are controlled by a computer that detects sound in the room. As a result, you get crazy movement when there's lots of noise. One of the artists, Sachiko Kodama, has a new solo project using magnetic liquids.

Magnetic liquids can be used in inkjet printers so that text or patterns can be read by machines.

Dampening is more common use for these liquids. Magnetic liquids can be manipulated by applying magnetic fields. When the field is off, the substance behaves as a liquid. With the application of the field the substance becomes thicker and resists motion. Some car shocks use this property to adjust stiffness depending on road conditions.