Where would modern astronomy be without scientists like Galileo Galilei, Nicolaus Copernicus or Johannes Kepler? We probably would not be scanning the stars of the Milky Way Galaxy for exoplanets only 450 years later. We owe a lot to these scientists for their ingenuity.
NASA Exoplanet Exploration
We have moved on from handheld telescopes in the 1600’s to ones that now orbit the Earth and our Sun. More specifically, I am referring to the Kepler Space Telescope which has been operated by the National Aeronautical & Space Administration since its launch in March 2009. In the earliest days of astronomy, scientists exploration of the cosmos was limited by the technology at the time. The first handheld telescope was created by Hans Lippershey in 1608, and it wasn’t until 1990 when the Hubble Space Telescope was launched that we could begin to learn more about our past. Kepler took to the skies 19 years later for a precise mission to understand more about our Milky Way Galaxy.
NASA Jet Propulsion Laboratory
Kepler’s job is simple. Launch up from Earth and orbit around the Sun where it will scan the same 150,000 stars in the Cygnus constellations. In doing so, NASA is hoping to confirm the existence of exoplanets orbiting stars outside of our solar system. It is remarkable, to think that in just over 400 years we have progressed from an Earth-centric model of our solar system; to understanding and accepting that we revolve around the Sun and finally to confirm the existence of thousands of planets orbiting hundreds of thousands of stars. This is just the tip of the iceberg to discovering life on other planets.
Kepler uses what is known as the transit photometry method to discover exoplanets. This means that Kepler stares at the same 150,000 stars looking for a decrease in the amount of light produced by any star in its field of view. When these dips in light have been recorded various times astronomers can confirm the existence of an exoplanet using data analysis. The following video demonstrates the transit photometry method at an accelerated rate.
Youtube NASA Video Channel
The transit photometry method is currently our best opportunity for discovering more exoplanets. We have seen a tremendous increase in confirmed discoveries since its launch, and Kepler is consistently delivering more confirmed exoplanets every day. Unfortunately, Kepler encountered technical difficulties in 2014 and its mission was restructured and released as K2. Its mission has been altered but currently remains in service.
The scientific advancements made by the Kepler team at NASA are on the cutting edge of astronomical discovery. Due to low federal funding in space exploration, I believe this is a subject that deserves more of the public’s attention. There was a time when we thought we were alone in the universe, it is becoming abundantly clear we may have had neighbours the entire time.
“Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.” – Arthur C. Clarke
Have you ever gotten splashed by a car while walking on the streets? Have you ever been driving on a rainy day and were unable to see properly through the windscreen? In fact both of the situations are related to the water spray of car wheels.
The video above is about people splashed by cars which is quite common during a rainy day.
The spray and splash of wheels can cause serious consequences such as car accidents. As there will be a myriad of puddles during a rainy day, it reduces the visibility of road users every time when a wheel hits a puddle and causes the splash and spray. Therefore drivers average a longer reaction time to avoid any potential collisions with other cars. According to previous studies, car accidents are 70% more likely to happen on rainy days than during dry conditions. In addition, rainfall and wet pavement can cause approximately 12,000,000 accidents per year. The following picture is an example of a reduced visibility during a rainy day.
Title: Scene of a rainy day by a driver’s perspective Source: https://www.shutterstock.com/video/clip-20356243-stock-footage-pov-close-up-cars-speeding-on-dangerous-multilane-highway-with-poor-visibility-on-dark-foggy-and.html
Researchers from the University of Southern California explored the mechanisms behind water spray using fluid mechanics (the response of fluids to the forces exerted on them); however, the basic mechanism behind this can be explained by the contact between the puddle and the car wheel. When a car is driven pass a puddle in a high speed, a huge amount of water drops attaches to the wheel and have the same angular acceleration (the acceleration of an object moving in circular motion) as the wheel. As the car continues to travel in a high speed, the water drops will gain enough inertia and leave the tire.
Sketch of water leaving a rolling car wheel Source: http://www.wp-industrial.co.uk/Elastohydrodynamic_Lubrication.html
Above is a sketch of water leaving a rolling wheel. Since the water is travelling with an angular acceleration, it will leave the wheel with a velocity and continue on the path represented by the big red arrow.
In order to increase driver’s visibility on rainy days, researchers have come up with the idea of Curtair to reduce the volume of water sprays. Curtair is an air curtain that surrounds a car wheel with air nozzles and a moisture sensor. When the car is driven under wet conditions, the sensor will be able to detect water and make the air nozzles release air. Thus, a smaller volume of water spray will be produced.
Photo of a new technology (Curtair) Source: https://projects.ncsu.edu/project/nsaudiovideo/pdf/curtair-poster.pdf
There are no further discussions regarding the results of Curtair, but we can reasonably predict that the invention may positively impact the visibility of drivers.