Tag Archives: scientific inquiry

More Mysterious Space Phenomenon

One of the things I really hope this blog helps accomplish is to show how science progresses (which explains why I use that tag so often, 3rd most, other popular tags: animals (most used), engineers 2nd, fun and webcasts tied for 4th).

Science is a process of continual learning as curiosity leads us to seek better understanding. On a small scale this can mean a person learning more about knowledge already understood by others. But it also means the scientific community facing new questions and coming up with new explanations for the new questions raised by observations (and testing those new explanations…). Mysterious New ‘Dark Flow’ Discovered in Space

Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can’t be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon “dark flow.” The stuff that’s pulling this matter must be outside the observable universe, researchers conclude.
…
They discovered that the clusters were moving nearly 2 million mph (3.2 million kph) toward a region in the sky between the constellations of Centaurus and Vela. This motion is different from the outward expansion of the universe (which is accelerated by the force called dark energy).

“We found a very significant velocity, and furthermore, this velocity does not decrease with distance, as far as we can measure,” Kashlinsky told SPACE.com. “The matter in the observable universe just cannot produce the flow we measure.”

10 Most Beautiful Physics Experiments

Science’s 10 Most Beautiful Experiments by George Johnson

Galileo’s experiment on falling objects

In the late 1500’s, everyone knew that heavy objects fall faster than lighter ones. After all, Aristotle had said so. That an ancient Greek scholar still held such sway was a sign of how far science had declined during the dark ages.

Galileo Galilei, who held a chair in mathematics at the University of Pisa, was impudent enough to question the common knowledge. The story has become part of the folklore of science: he is reputed to have dropped two different weights from the town’s Leaning Tower showing that they landed at the same time. His challenges to Aristotle may have cost Galileo his job, but he had demonstrated the importance of taking nature, not human authority, as the final arbiter in matters of science.
…
Young’s double-slit experiment applied to the interference of single electrons

Though it is not simply made of particles, neither can it be described purely as a wave. In the first five years of the 20th century, Max Planck and then Albert Einstein showed, respectively, that light is emitted and absorbed in packets — called photons. But other experiments continued to verify that light is also wavelike.

It took quantum theory, developed over the next few decades, to reconcile how both ideas could be true: photons and other subatomic particles — electrons, protons, and so forth — exhibit two complementary qualities; they are, as one physicist put it, ”wavicles.”

Eratosthenes’ measurement of the Earth’s circumference -the librarian at Alexandria in the third century B.C. estimated the circumference of the planet

Assuming the earth is spherical, its circumference spans 360 degrees. So if the two cities are seven degrees apart, that would constitute seven-360ths of the full circle — about one-fiftieth. Estimating from travel time that the towns were 5,000 ”stadia” apart, Eratosthenes concluded that the earth must be 50 times that size — 250,000 stadia in girth.

Related: Book, The Ten Most Beautiful Experiments by George Johnson (not the same experiments) – Home Experiments: Quantum Erasing – Particles and Waves – theory of knowledge – scientific experiments

8 Percent of the Human Genome is Old Virus Genes

In Our Genes, Old Fossils Take On New Roles

It turns out that about 8 percent of the human genome is made up of viruses that once attacked our ancestors. The viruses lost. What remains are the molecular equivalents of mounted trophies, insects preserved in genomic amber, DNA fossils.

The thousands of human endogenous retroviruses, or HERVs, sketch a history of rough times during the 550 million years of vertebrate evolution. The best-preserved one, HERV-K113, probably arrived less than 200,000 years ago, long after human beings and chimpanzees diverged from a common ancestor.

But these retroviruses are more than just curiosities. They are some of the most important enemies we ever had. They helped mold the immune system that is one of the evolutionary marvels of life on Earth.

I must say there is tons of amazing stuff I learn about but I still find retroviruses amazing.

Dolphin Kick Gives Swimmers Edge

photo of Michael Phelps diving

Dolphin Kick Gives Swimmers Edge

Rajat Mittal, a professor of mechanical and aerospace engineering at the George Washington University, was studying dolphins for the U.S. Navy five years ago. “We were asked to understand how fish swim so efficiently,” Mittal says, “and it seemed like a natural extension to apply this to human swimming.”
…
They decided to “essentially compare these swimmers to the dolphin, assuming that the dolphin is the ultimate swimmer,” Mittal says. “And the thing that we found is that Michael [Phelps] is able to use his body in a way that is very, very different from the other athletes, and also seems to be much closer to dolphins than we have seen for any other swimmer.”

The dolphin kick first hit Olympic swimming big-time 20 years ago, after Harvard backstroker David Berkoff figured out something fundamental. “It seemed pretty obvious to me that kicking underwater seemed to be a lot faster than swimming on the surface,” Berkoff says.

That’s because there’s turbulence and air on the surface of the water, and they create resistance. The “Berkoff Blastoff,” as it was called, was used at the start and after turns, with long stretches of that underwater undulating kick.

Follow the link for a video of Michael Phelps demonstrating the technique and more interesting details. Photo by A. Dawson shows Michael Phelps diving into the water at the 2008 U.S. Olympic Swimming Trials.

How Humans Got So Smart

Cooking and Cognition: How Humans Got So Smart

For a long time, we were pretty dumb. Humans did little but make “the same very boring stone tools for almost 2 million years,” he said. Then, only about 150,000 years ago, a different type of spurt happened — our big brains suddenly got smart. We started innovating. We tried different materials, such as bone, and invented many new tools, including needles for beadwork. Responding to, presumably, our first abstract thoughts, we started creating art and maybe even religion.

To understand what caused the cognitive spurt, Khaitovich and colleagues examined chemical brain processes known to have changed in the past 200,000 years. Comparing apes and humans, they found the most robust differences were for processes involved in energy metabolism.

The finding suggests that increased access to calories spurred our cognitive advances, said Khaitovich, carefully adding that definitive claims of causation are premature.

Nice example of scientific discovery in action. The direct link from cooking to brain development is far from proven but it is interesting. I also like “the same very boring stone tools for almost 2 million years” – maybe that is because I am too cynical (but while evolution is amazing – sometimes it is amazing how slow progress is).

Viruses and What is Life

Viruses are generally considered not to be alive (they must use a host cell of something else to reproduce). However, defining exactly what life is, is not as easy as you might think.

The debate about what counts as a living thing is fuelled today by the discovery of the first virus that is able to fall “ill” by being infected with another virus.
…
the discovery of a giant virus that itself falls ill through infection by another virus seems to suggest they too are alive, highlighting how there is no watertight definition of what exactly scientists mean when they refer to something as “living”.

“There’s no doubt, this is a living organism,” the journal Nature is told by Prof Jean-Michel Claverie, director of the Mediterranean Institute of Microbiology in Marseilles, part of France’s basic-research agency CNRS. “The fact that it can get sick makes it more alive.”

Werner Heisenberg

photo of Werner Heisenberg

Read a very nice biography from Center for History of Physics of the American Institute of Physics for Werner Heisenberg, the founder of quantum mechanics, and the Heisenberg uncertainty principle:

Heisenberg set himself the task of finding the new quantum mechanics upon returning to GÃ¶ttingen from Copenhagen in April 1925. Inspired by Bohr and his assistant, H.A. Kramers, in Copenhagen, Pauli in Hamburg, and Born in GÃ¶ttingen, Heisenberg’s intensive struggle over the following months to achieve his goal has been well documented by historians. Since the electron orbits in atoms could not be observed, Heisenberg tried to develop a quantum mechanics without them.

He relied instead on what can be observed, namely the light emitted and absorbed by the atoms. By July 1925 Heisenberg had an answer, but the mathematics was so unfamiliar that he was not sure if it made any sense. Heisenberg handed a paper on the derivation to his mentor, Max Born, before leaving on a month-long lecture trip to Holland and England and a camping trip to Scandinavia with his youth-movement group. After puzzling over the derivation, Born finally recognized that the unfamiliar mathematics was related to the mathematics of arrays of numbers known as “matrices.” Born sent Heisenberg’s paper off for publication. It was the breakthrough to quantum mechanics.

Learning How Viruses Evade the Immune System

photo of Naama Elefant

MicroRNA genes are a class of very tiny genes found in a variety of organisms. First discovered in 1993 and at the time considered relatively unimportant, they are now recognized as major players in diverse biological processes.

MicroRNAs are important regulators of protein production. Proteins, the building blocks of the cell, must be produced precisely at the right time and place. MicroRNAs specifically latch on to other genes (their targets) and inhibit the production of the protein products of these genes. Hundreds of microRNAs have already been discovered, but the identity of their target genes remains mostly unknown and presents a great challenge in the field.

Elefant developed a computer algorithm that predicts the targets of microRNAs. Her algorithm, named RepTar, searches the thousands of genes in the human genome and through sequence, structural and physical considerations detects matches to hundreds of microRNAs.

For her work in this field, Naama Elefant, a student of Prof. Hanah Margalit of the Faculty of Medicine at the Hebrew University and an Azrieli fellow, was named one of this year’s winners of the Barenholz Prizes for Creativity and Originality in Applied Computer Science and Computational Biology. This discovery also was declared by the magazine Nature Medicine as ”one of the ten notable advances of the year 2007.”
Continue reading →

Science Based Triathlete

The Making of a Olympian by Arianne Cohen

In a break with training orthodoxy, Potts and his coach have created a regimen called feedback training in which the training plan is reassessed every 24 hours based on the constant monitoring of three variables: wattage (the power Potts’s body produces), cadence (the tempo of his arm and leg movements) and heart rate. No lap times. No mileage. No grand training schedules planned months in advance. Only raw biological data. “My coach and I talk a lot about engines,” Potts says. “In auto racing, you want to put out the highest amount of power with the least amount of fuel. We do the same thing. My heart and lungs are my engine. The goal is to always increase the efficiency of the engine.”

Every night, Doane analyzes his athlete’s response to the day’s training. He’s looking for the best way to expand Potts’s aerobic capacity, power output and lactate threshold, without overtraining. If Doane sees that Potts’s heartbeat has been sluggish—say, beating 140 times per minute while Potts is trying to produce 410 watts—that means his body is struggling to recover from earlier training, so he’ll dial back the intensity of his workouts. If, on the other hand, his heart rate stays in the sweet spot around 165 while he churns through a series of 360- to 400-watt intervals, that means he’s fully recovered and ready to be pushed again. “We’ve created a feedback loop,” Doane says. In other words, Doane subjects Potts to a careful dose of punishment, and Potts’s body tells Doane, through empirical data, what he needs to do next.

Nice article. As it mentions really almost all Olympic athletes today use a great deal of science in their training.

Science and the Excitement, the Mystery and the Awe of a Flower

Pleasure of Finding Things Out by Richard P. Feynman is a great explanation of how scientists think: “The science knowledge only adds to the excitement, the mystery and the awe of a flower”

I did post on this before. Related book: Classic Feynman: All the Adventures of a Curious Character.