It is a Venus-ruled sign along with Libra. In Greek mythology, Taurus was identified with Zeus, who assumed the form of a magnificent white bull to abduct Europa, a legendary Phoenician princess.
Taurus is known for its bright stars Aldebaran, Elnath, and Alcyone, as well as for the variable star T Tauri. The constellation is also home to the Pleiades Messier 45 , also known as the Seven Sisters, and the Hyades, the two nearest open star clusters to Earth.
Both names can be understood as titles of Nergal, the major Babylonian god of plague and pestilence, who was king of the Underworld. In Greek mythology, Gemini was associated with the myth of Castor and Pollux, the children of Leda and Argonauts both.
The constellation of Gemini is made up of two twins: Castor and Pollux. When Castor was killed in battle, Pollux pleaded with Zeus to bring him back. Zeus agreed to immortalize both Castor and Pollux, if they spend half of their time on the Earth and the other half amongst the stars in the heavens. Most people see the constellation Gemini as just two bright stars — Castor and Pollux — sometimes called the Gemini twins. Pollux is brighter and more golden in color. Castor is slightly fainter and white.
Gemini is fairly easy to spot in the sky, even for amateur stargazers. It is located northeast of the constellation Orion and between the Taurus and Cancer constellations. Best viewing is during February. By April and May, the constellation can be seen soon after sunset in the west. Gemini contains 10 named stars. The Solar Impulse has about the same wingspan as a airplane, and its wings are covered in nearly 12, solar cells. That's about square meters of solar cells.
Now, the amount of power delivered by sunshine is a well known number. If you ignore clouds, and average over day and night, it comes to about Watts delivered to every square meter of land.
This is the maximum amount of power that this airplane can theoretically capture from the sun, given its wingspan. But we don't have the technology to tap into all of this power. Remember that number, we'll come back to it. So far so good. On average, we've got 6, Watts being pumped out to fly this plane.
But is that enough? To answer this, we need to figure out how much power it takes to fly a plane. There are really two components to answering this question. Heavier planes need more power to fly them. That's because planes fly by throwing air downwards. They need to throw enough air downwards to counteract their own weight, so heavier planes need to 'work harder' on throwing air down.
To stay afloat, a heavier plane needs to fly faster than a lighter plane, so it can ram into more air each second, and hurl the air downwards, counteracting its own tendency to drop out of the sky.
If you'd like to read more on how this works, see my post entitled Can we build a more efficient airplane? Not really, says physics. So it takes more power to fly a heavier plane. That's pretty intuitive. By the way, since we're on the subject, this is also why it's wrong to say something like "The plane was flying anyway, so my flying on it was carbon-neutral.
Not to mention that airlines would fly fewer planes if there were fewer people flying. Some planes are just better at staying up than others.
If I throw a paper airplane, it'll glide across the room. If I take that same piece of paper, crush it into a ball, and throw it with same force, it won't go nearly as far.
The difference is that the paper airplane is more aerodynamic - it's better able to throw air downwards and keep itself afloat. This is also why, if a were to run out of fuel, it wouldn't just fall out of the sky like a rock, but would glide about as effectively as a paraglider. This ability to glide is captured by a number called the glide ratio. Here's how it works. Imagine that you switch off the engines in a Boeing mid-flight don't try this at home.
It will end up falling 1 foot for every 12 feet that it moves forward. It means there are more chances for one of these aircraft to succeed. While the technological limitations facing larger aircraft are undoubtedly significant, he praises the recent eCaravan experiment.
For small planes that carry a handful of passengers or some cargo, there is a small market of about vehicles per year. But it might represent some crucial baby steps on the way to that point. In the meantime, two other technologies for lowering the emissions of aircraft being considered are biofuels and hydrogen propulsion systems.
Each has problems of its own. Biofuels made from organic matter could be used by existing planes and may be greener than kerosene, but as yet the market for it is small and many biofuels come with their own environmental drawbacks. And hydrogen, while potentially clean if obtained from a renewable source , suffers from some of the same problems as electric batteries.
In other words, all three of these hopeful technologies — batteries, biofuels and hydrogen — require some major breakthroughs before they can revolutionise aviation. And the Covid pandemic, which has hit the airline industry very hard, may hold developments back even further.
Interest in greener travel is building, however. The emissions from travel it took to report this story were 0kg CO2: the writer interviewed sources remotely. The digital emissions from this story are an estimated 1. Find out more about how we calculated this figure here. Join one million Future fans by liking us on Facebook , or follow us on Twitter or Instagram. If you liked this story, sign up for the weekly bbc. Future Planet. Will Amazon, Google and others become the new carmakers and put the drivers in the back seat?
Interesting question — although self-driving cars have recently been dealt a setback. Testing at US company Uber was suspended after a self-driving car ran over a woman by night. Today the streets are clogged, lights are red, you're stuck in a traffic jam, going to miss that appointment. Car horns, anger, insults: that's stressful. But rage and provocation could become things of the past if self-driving cars become the norm.
Then, passengers can sit back and laugh about the old days. Order your ride or taxi by app. Public and collective transport is increasingly being organized via the internet. You can even pay for the service through your smartphone. The car's future is electric, that seems to be the consensus; the only question is, when? Despite investing billions into e-cars, there's a lack of options and sites for charging electric vehicles. Together with high costs, consumers are concerned.
Alternatives to e-cars could fill the gap: fuel-electric hybrids, and other vehicles powered by hydrogen or synthetic fuels. Postal workers are climate-friendly when they deliver letters by foot or bike, but for parcels they need vehicles. One of the challenges of the future is to make sure the electricity used in electric vehicles is also climate-friendly.
It looks a little like a Smart car, but it's actually an e-bike on four wheels. The Podride is 1. It travels file on snow and ice, it's heated, it can manage steep and uneven slopes, and there is even storage space. The driver steers by way of two levers at the seat and pedals to power the rear wheels with help from the electric motor.
From many clever minds comes a clever idea. A dozen companies are developing personal aircraft. This rocket-like Vahana flying car prototype from Airbus is designed to beam a passenger along at 9, meters 30, feet altitude, reaching speeds of kilometers miles per hour. Battery swaps would be like Formula 1 pit stops: quick landings, and on you go. The Bauhaus Luftfahrt association is developing an airport and aircraft concept. The Ce liner would be power by two electric engines with aerodynamically efficient C-shape wings.
Inner-city airports of the future would be arranged over several levels to save on space, with lift-off from the top level and battery charging on lower floors. The Swiss mountain village of Stoos boasts the steepest cable railway in the world. It rises up meters in altitude as it travels 1. The village has permanent residents, but 2, hotel beds for visitors to come and enjoy the view in the car-free resort.
Maybe someday the Himalayas will have a similar system? Can you imagine the world without your own car?
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