Legends change the world they don’t need prizes…
Legends change the world they don’t need prizes…
In bobsleigh, two- and four-person teams compete across four runs down an ice track. The shortest cumulative time wins, and since typical runs are separated by hundredths of a second, teams look for any advantage that helps them shave time. The size, weight, and components of a sled are restricted by federation rules; for example, teams cannot use vortex generators to improve their aerodynamics. Instead bobsledders work with companies like BMW, McLaren, and Ferrari to engineer their sleds. Both computational fluid dynamics and wind tunnel tests with the actual team in the sled are used to make each sled as aerodynamic as possible. (Image credit: IOC, Gillette World Sports, source)
Four years ago in Sochi, Under Armour’s suits for the U.S. speedskating team took a lot of flak after the team failed to medal. The company defended the physics and engineering of their suits, and an internal audit of the speedskating program ultimately placed blame on flaws in their training regimen, unfamiliarity with the new suits, and overconfidence.
This time around Under Armour has taken a more hands-on approach with the team, helping with training regimens in addition to providing suits. Under Armour spent hundreds of hours testing the suits in Specialized’s wind tunnel, including testing many fabrics before settling on the slightly rough H1 fabric used in patches on the skater’s arms and legs. Like the previous suit’s dimpled design, the roughness of the fabric promotes turbulent flow near it. Because turbulent flow follows curved contours better than laminar flow does, air stays attached to the athlete for longer, thereby reducing their drag. The suit is also designed with asymmetric seams that help the athlete stay low and comfortable in the sport’s frequent left turns.
U.S. speedskaters have been competing in a version of the suits since last winter, ensuring that athletes are familiar with the equipment this time around. Whether the new suits and training program will pay off remains to be seen. After their disastrous experience in Sochi, both the team and the company are shy about setting expectations. (Image credits: D. Maloney/Wired; US Speedskating)
Technology is impressive
At first glance, the drinking bird is a simple desk toy, but the physics and engineering behind the device is clever enough to have challenged many great minds. In this video, Bill Hammack dissects the drinking bird, revealing the heat engine beneath the felt and feathers. The bird’s drinking is driven by thermodynamics and the relative pressures of fluids in its head and body. When the beak is wetted, fluid wicks up the felted head and slowly evaporates, thereby cooling the vapor inside the head. Some of that vapor condenses, lowering the vapor pressure in the head and allowing liquid to rise from the body. When enough fluid reaches the head, the bird tips forward. This allows vapor to rise up the liquid column into the head, equalizing the pressure between the two ends. The bird sits up with a freshly wetted head and starts the cycle over. Check out the full video for more detail, including a look at what other methods can drive the bird, including bourbon and light bulbs. (Video and image credit: B. Hammack; via J. Ouellette)
Microfluidic devices are valuable tools in a lab, but they are difficult and time-consuming to manufacture. Researchers looking to simplify the building of such fluidic circuits have turned to toys. The uniformity and modularity of LEGO bricks makes them a promising platform for modifiable microfluidics. Using a micromilling machine, researchers cut narrow channels into bricks, then sealed the channel with clear adhesive and a set of tiny O-rings. Their results allow them to build and rebuild simple microfluidic devices in moments. There are limitations, though. Micromills cannot cut the smallest size channels used in today’s microfluidic devices, and the plastic of the LEGO bricks restricts the chemicals and temperatures scientists can use. Nevertheless, this could be a useful teaching tool and a new method for testing and prototyping microfluidic devices. (Image credit: MIT, source; research credit: C. Owens and A. Hart)
The smog pattern from the rocket launch
The Greatest Scientific Experiments In History
If you search the web for the greatest, or most famous experiments in history, no site will mention any of the many experiments conducted by Nikola Tesla. What you will find are wonderful, and very important experiments–like those of Isaac Newton, Galileo Galilee, William Harvey, Michael Faraday and Luigi Galvani, but nothing about Tesla, whose investigations into electricity make history’s more recognized experiments look like high school science. Many people today do not know that Nikola Tesla was one of the greatest experimental scientists of all-time.
Throughout the scientist’s investigations into high frequency phenomena, Tesla satisfied himself with a conclusion that an electrostatic field of sufficient intensity could fill a room and light wireless lamps. In 1891, he demonstrated this fact in a lecture given before the American Institute of Electrical Engineers, and left an audience of America’s greatest engineers spell-bound as he demonstrated by experiments a new theory of light. He showed that by connecting two large sheets of zinc to the terminals of a circuit with the sheets being spread apart about fifteen feet away from each other, he could create an electrostatic field between the two. The sheets served as condensers, and both received the charge of electricity from the wires connecting the sheets to the transformer. Tesla would then introduce vacuum tubes and place them between the zinc sheets, illuminating the tubes and lighting the room. He waved the vacuum tubes around like a Jedi showcasing the first light sabers, and the tubes continued to glow as long as they remained in the electric field. With these results, Tesla theorized that it was possible to use the earth as a conductor of energy, create an electrostatic field in it, and send power to distant parts of the globe.
To further develop and prove his wireless theory, Tesla spent time in Colorado Springs, from June 1, 1899 to January 7, 1900, to research and experiment with high voltage and high frequency electricity. He chose Colorado Springs because of the high elevation and low air pressure suitable for experimenting with electricity. Also, because he was in such as open area compared to his lab in New York that he was free to experiment with any such desire of voltage and frequency. With his new and improved disruptive coils (Tesla Coils), which could produce electrical vibrations into the millions of horsepower, Tesla was set test the limits of electricity.
It’s clear from his notes that his principal aim was to find ways to manipulate the forces of nature and to utilize them for the advancement of mankind. He expressed that he had three main goals:
- To develop a transmitter of great power.
- To perfect means for individualizing and isolating the energy transmitted.
- To ascertain the laws of propagation of currents through the earth and the atmosphere.
In his 7 months of work, Tesla obtained voltage and frequencies in the hundreds of millions of horse power, producing sparks over 100 feet in length. He sent energy through the earth to light multiple lamps which were placed dozens of miles away from his transmitter, and discovered stationary waves deriving from lightning discharges which his receiver could detect hundreds of miles away from his station–a discovery proving that power could indeed be transmitted through the earth. He also discovered that the earth, as a whole, had certain natural periods of vibrations, and by using his inventions he could impress electrical vibrations at the same periods upon it, and the globe would be thrown into oscillations of such nature that massive amounts of energy could be created, collected, and transmitted to any distance. This process is called constructive interference (the interference of two or more waves of equal frequencies resulting in mutual reinforcement and producing double the amplitude). By doing this repeatedly, and by using the massive amounts of energy unheard of before, Tesla was able to transmit energy from his transmitter all the way around earth and back to his receiver traveling at a mean velocity of 292,815 miles per second. Witnessing these experiments and measurements, space, according to Tesla, was completely annihilated.
Fully confident that he accomplished what he set out for, Tesla journeyed back to New York to patent improved apparatuses, and to build a new system on a much larger scale. This would lead to his World Wireless System, known as his Wardenclyffe Tower. Unfortunately, Tesla would not complete his dream of providing mankind with cheap, unlimited energy… But his legacy and his dream should live on through these experiments in Colorado Springs.
“My project was retarded by the laws of nature. The world was not prepared for it. It was too far ahead of time. But the same laws will prevail in the end and make it a triumphal success.”
(“My Inventions – V. The Magnifying Transmitter.” Electrical Experimenter. February, 1919.)
[Fig. 1.] — Nikola Tesla’s building in Colorado Springs which he called his “Experimental Station.”
[Fig. 2.] — Experiment to Illustrate the Capacity of the Oscillator For Producing Electrical Explosions of Great Power: The coil, partly shown in the photograph, creates an alternative movement of electricity from the earth into a large reservoir and back at a rate of one hundred thousand alternations per second. The adjustments are such that the reservoir is fulled full and bursts at each alternation just at the moment when the electrical pressure reaches the maximum. The discharge escapes with a deafening noise, striking an unconnected coil twenty-two feet away, and creating such a commotion of electricity in the earth that sparks an inch long can be drawn from a water main at a distance of three hundred feet from the laboratory.
[Fig. 3.] — Coils Responding to Electrical Oscillations: The picture shows a number of coils , differently attuned and responding to the vibrations transmitted to them through the earth from an electrical oscillator. The large coil on the right, discharging strongly, is tuned to the fundamental vibration, which is fifty thousand per second; the two larger vertical coils to twice that number; the smaller white wire coil to four times that number, and the remaining small coils to higher tones. The vibrations produced by the oscillator were so intense that they affected perceptibly a small coil tuned to the twenty-sixth higher tone.
[Fig. 4.] — Burning the Nitrogen of the Atmosphere: This result is produced by the discharge of an electrical oscillator giving twelve million volts. The electrical pressure, alternating one hundred thousand times per second, excites the normally inert nitrogen, causing it to combine with the oxygen. The flame-like discharge shown in the photograph measures sixty-five feet across.
[Fig. 5.] — Illustrating An Effect of An Electrical Oscillator Delivering Energy at a Rate of Seventy-Five Thousand Horse-Power: The discharge, creating a strong draft owing to the heating of the air, is carried upward through the open roof of the building. The greatest width across is nearly seventy feet. The pressure is over twelve million volts, and the current alternates one hundred and thirty thousand times per second.
[Fig. 6.] — Experiment Illustrating the Capacity on the Oscillator for Creating a Great Electrical Movement: The ball shown in the photograph, covered with a polished metallic coating of twenty square feet of surface, represents a large reservoir of electricity, and the inverted tin pan underneath, with a sharp rim, a big opening through which the electricity can escape before filling the reservoir. The quantity of electricity set in movement is so great that, although most of it escapes through the rim of the pan or opening provided, the ball or reservoir is nevertheless alternately emptied and filled to over-flowing (as is evident from the discharge escaping on the top of the ball) one hundred and fifty thousand times per second.
[Fig. 7.] — A double-exposure photograph of Tesla sitting in front of his electrical oscillator. Of course he’s not really sitting there with the machine on. He would die.
[Fig. 8.] — Experiment Illustrating an Inductive Effect of an Electrical Oscillator of Great Power: The photograph shows three ordinary incandescent lamps lighted to full candle-power by currents induced in a local loop consisting of a single wire forming a square of fifty feet each side, which includes the lamps, and which is at a distance of one hundred feet from the primary circuit energized by the oscillator. The loop likewise includes an electrical condenser, and is exactly attuned to the vibrations of the oscillator, which is worked at less than five percent of its total capacity.
[Fig. 9.] — Experiment Illustrating the Transmission of Electrical Energy Through the Earth Without Wire: The coil shown in the photograph has its lower end or terminal connected to the ground, and is exactly attuned to the vibrations of a distant electrical oscillator. The lamp lighted is in an independent wire loop, energized by induction from the coil excited by the electrical vibrations transmitted to it through the ground from the oscillator, which is worked only to five per cent. of its full capacity.
Photos and captions courtesy of Tesla Collection –