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U.S. Navy goes Electromagnetic with Railgun and Fighter Catapult

Andrew — Tue, 28 Dec 2010 01:00:31 +0000

The United States Navy has tested two new pieces of similar technology this month, ushering in a new era for naval warfare. Earlier this month, the U.S. Navy successfully tested it’s new hypersonic railgun, capable of firing a projectile using electromagnetic force rather than a chemical explosive. On December 10th, a 20-pound aluminum slug was flung some 5,500 feet at a speed of Mach 7, nearly 5,000MPH. On December 18th, the Navy tested a similar device, but this one designed to catapult jet fighters off of the deck of an aircraft carriers. Known as the EMALS, Electro-Magnetic Aircraft launch System, the device would replace steam-powered catapults that have been in use since the 1950s.

U.S. Navy railgun ready for testing. Image Souce: U.S. Navy

The U.S. Navy hopes that it’s new railgun will replace conventional cannon on ships soon. The unit tested this month is capable of firing a projectile some 100 miles with an average hypersonic speed of Mach 5+. This test consisted of two separate shots, about an hour apart. The first shot produced around 32 mega-joules of power, the second 33 mega-joules. A bigger, more powerful railgun is planned, capable of 60_ mega-joules, which could give that weapon a range of 200 miles.

A major advantage of the railgun is that since no chemical explosive is used for fire the shell, ships will be able to carry several times more ammunition. Also, the railgun will give warships a major leap in ranged weapon fire. Inexpensive rounds of ammo can be rapid fired against targets many times further than conventional guns. This would enable a warship to attack targets at such ranges cheaper than using expensive guided missiles.

Likewise, the Navy plans to begin using the EMALS to launch planes from the next generation of aircraft carriers. The test last week involved a shore-mounted system which catapulted an F/A-18E Super-Hornet into the air. Aircraft carriers need to use catapults to launch modern jets since they are far heavier than planes of the World War Two era and before. Back then, a carrier simply turned into the wind and went to full speed to give aircraft an extra 30-50MPH needed to launch. Steam catapults used currently will accelerate a jet fighter to 150 knots in about 2 seconds.

Both of the U.S. Navy’s applications for electromagnetic railgun technology will improve the capabilities of our naval forces. Larger, heavier aircraft and bomb loads will be easier to launch from aircraft carriers. The 64 mega-Joule railgun planned for deployment in the next generation of cruisers will enable them to attack targets within a 200-mile radius. With projectile speeds of Mach 7, there is little, if anything, a target can do to escape destruction, let alone retaliate.

Navy Uses Electromagnets to Launch Fighter Jet

Futuristic weapon undergoes Navy tests

navy’s sci-fi railgun breaks record for most powerful gun on the planet (VIDEO)

Barnes & Noble Nook Color Unveiled

Chris — Sun, 14 Nov 2010 09:00:36 +0000

At a company hosted event today, Barnes & Noble introduced the Nook Color with a full 7-inch color touch screen. This is a huge improvement over the original Nook which only features an e-ink display. The new device is powered by Android, so it is capable of more than just books, and the new Nook Developer program will extend it even further as well.

The biggest surprise is that the price stays at a low $249. Don’t expect it to be a full-featured Android tablet though, Barnes & Noble has stated that is more like an e-reader with some additional tablet functionality. However it does have Wi-Fi (802.11n) and 8GB of storage, plus built-in integration for Facebook and Twitter. So it is primarily an e-reader, with web browsing and video playback being secondary.

The Nook Color is slightly less than half an inch thick, weighs just 15.6 ounces, and has a 7-inch IPS-panel touch screen running at 1024×600. Not much room to fit a hefty battery, but according to Barnes & Noble, it will give you 8 hours reading time without running out of juice, provided that you turn Wi-Fi off. This could be a problem for app development, but they have announced that Pandora will be shipping with it so I guess streaming music over the internet is not much of a problem.

Because it has a color touch screen, Barnes & Noble demonstrated full-color magazines, newspapers, and a new collection of “Nook Kids” books for children. They are clearly setting up for an interesting position in the e-reader market. By avoiding a complete feature comparison to the iPad they can have a low price color tablet capable of doing much more than the older e-ink model. It might not impress people who want an iPad, but for the casual e-reader user it might raise a brow, and with the Nook Developer program it might grow to be much more.

Barnes & Noble will ship the Nook Color on November 19 and pre-orders are available starting today. The original Nook will continue to be sold for $149, if you are still looking for an e-ink based reader. Check out the hands-on pictures and video of the Nook Color over at Engadget and CrunchGear.

Apple’s New MacBook Air, FaceTime for Mac, OS X Lion, and iLife 11

Chris — Wed, 20 Oct 2010 22:37:15 +0000

Today Apple held a press event called “Back to the Mac” and during it they made several announcements and introduced a couple updated products, all related to the Mac. With iPhone, iPod, and iPad being such a big focus from Apple recently, the name of the event set the theme for what was to come.

Before the event there was rumblings of a new MacBook Air and iLife. The new operating system codenamed OS X Lion was also set to play a part of the event. When CEO Steve Jobs stepped on stage, all the rumors became true, and demos were held to show off what is new.

It is one thing to say the names of what is announced, but here is an overview of what was a fairly eventful day in Apple land. There is much to be detailed, so check out the scoop below.

New MacBook Air: The iPad meets the Mac, well sort of. Starting at $999 it is available in 13.3 inch and 11.6 inch flavors. Core 2 Duo Processor running 5 hours of battery on the smaller one and 7 hours on the bigger one. Only 0.68 inches at the thickest point, with a durable aluminum unibody chassis. No optical drive, uses SSD like iPad (64GB, 128GB, and 256GB options). Because there is no optical drive, Apple has decided to include a “MacBook Air Software Reinstall Drive” which is essentially a USB stick with the OS reinstall image on it. Very cool way to distribute that.

FaceTime for Mac: Launches as a beta today, it is available for download. It works very similar to the iOS version, you use your email address to let people call you and start a video conference. The window automatically rotates when the other person rotates their camera. Any direction works, so you can have Mac to Mac calls as well. With over 19 million FaceTime devices already sold, and every Mac being sold with a built in camera, this opens the gates even further with ease-of-use video calling between desktop and mobile.

iLife 11: The same applications everyone loves, but updated with some new features. iPhoto gains a new full screen mode where you can literally do everything without exiting full screen. It also gains new slideshows and much better Facebook and Flickr integration including viewing others comments without leaving iPhoto. iMovie now has better audio editing, and a slick new movie trailer template feature which lets you make your own movie trailers. Garageband now has Flex Time and Groove Matching to refine your tracks, and introduces new guitar and piano lessons. It is available for $49 starting today.

Mac OS X Lion: Known as the king of the jungle, but will it be the king of the desktop? Signs of improvements are all around. To start with, Steve Jobs talks about how much they learned from iOS. This translates over to what they are working on in OS X Lion. There is now a Mac App Store that you can launch and be able to instantly buy and download new apps. This includes all the features of the iTunes App Store like Top Charts, App Updates, and Ratings. Following the iOS theme, there is a new feature called Launch Pad which brings up a “home screen” of all your installed apps. It looks and functions identically to the one in iOS. Finally there is Mission Control, which lets you quickly show all your running apps as well as spaces and full screen applications. It is essentially replacing Expose, but with a lot more features. These new features are backed by multi-touch gestures supported by trackpads or the Magic Mouse. Apple hopes to launch Mac OS X Lion in the Summer of 2011.

There you have it, way too much to cover but you can also check out some hands on video of the new MacBook Air over at Engadget and some Mac App Store submission guidelines on TUAW. It seems apparent based on the announcements that Apple is headed in a new direction with the Mac. It is a direction influenced by iOS and it’s touchscreen driven UI. As opposed to making a touchscreen Mac (though not entirely out of the picture) they are keeping the two platforms separate. They still believe that a keyboard and mouse, with a cursor on your screen is the best way to do the Mac desktop. They are just taking good ideas from iOS and working them into OS X. Not a bad way to go if you ask me.

It’s a Bird! It’s a Manta Ray! It’s the NASA X-48B Blended Wing Body Skyray!

Andrew — Wed, 06 Oct 2010 12:07:09 +0000

For plane watchers, the skies above Edwards Air Force Base is always a great place to see the most advanced aircraft in the world. Locals may begin seeing an odd, manta ray shaped aircraft again. NASA has resumed test flights of the X48B blended wing body (BWB) test plane. For almost 3 years, the unmanned X-48B, nicknamed the Skyray, flew 80 flights testing it’s radical design. After a major overhaul and upgrade, the X-48B is back in the skies again!

NASA’s X-48B Skyray tests blended wing body flight over the California desert. Image Source – NASA.gov

As you can see in the picture above (and others below), the X-48B is unlike most aircraft. The X48B is part of NASA’s Environmentally Responsible Aviation program, also known as ERA. The goal is to design aircraft of the future which are quieter, more fuel efficient, and less polluting. After it’s last flight in March of this year, the X48B was stripped down, refurbished and upgraded with new computers, instruments, and flight control systems.

Flown out of NASA’s Dryden Flight Research Center at Edwards Air Force Base in California’s high desert, the plane enjoys plenty of obstruction-free room to test it’s capabilities. The blended wing body design offers many advantages to conventional aircraft. The X48B is built by the Boeing Phantom Works in association with NASA, the U.S. Air Force and the British firm, Cranfield Aerospace.

The X48B is a scale flying model, about 21 feet wide and weighing about 500 pounds. If the design proves valid, it could lead to a full-sized version 240 feet wide and weighing 500 tons. Unlike today’s airliners and general aviation planes, where passengers ride in narrow tubes attached to wings, an entire BWB aircraft is one big wing. The crew and passenger sections are several times wider and capable of carrying 800 passengers.

The idea of the blended wing body design has been around for a long time. The first aircraft to be built was the Stout Batwing, a glider conceived of by William Bushnell Stout in 1917. Test flown over the skies of Detroit, Michigan in 1926, the single engine plane flew well, but the test pilot complained about the poor visibility.

Across the Atlantic in Germany, other designers pursued the BWB concept. The Junkers G.38 could carry 30 passengers, 6 seated in each wing with the rest in the center body. Equipped with 4 engines, the G.38 was 144 feet wide and could cruise 2,150 miles at a speed of 175 MPH. In 1931, Lufthansa began regular flights between Berlin and London. Two planes were built and later upgraded in 1934 to carry 34 passengers and additional cargo, but one crashed during a test flight. The second G.38 flew regular passenger service until pressed into the role of a military transport until shot down by the RAF in 1941.

During World War Two, the Horten brothers, Walter and Reimar, became very dedicated to developing a flying wing. With little formal training, the Hortens flew their first glider in 1933. In 1937, they designed and built a twin-engine wing. In 1939, they and a third brother, Wolfram, joined the Luftwaffe. Wolfram was shot down and killed over Dunkirk in 1940. Walter proved the better pilot, shooting down seven RAF aircraft during the Battle of Britain.

In 1942, the Luftwaffe became interested in the Horten brothers’ flying wing concept. Work began on a prototype which used two of the early jet engines available. Their design, the Ho IX V2 became the Ho 229 jet fighter bomber. Two were built but too late to enter service and one crashed during test flights. The U.S. Army captured the remaining prototype. After the war, the Hortens moved to Argentina to continue their work. In the early days of the UFO flaps in the late 1940s, the U.S. Air Force considered the possibility that UFOs were actually aircraft designed by the Horten brothers. A recent recreation of a Ho 229 shows that the plane does indeed have considerable stealth capabilities.

Britain and Canada also developed BWB aircraft in the 1940s. The Canadian plane was the Brunelli CBY-3 which could carry 24 passengers plus cargo, and cruise about 1000 miles at a speed 170 MPH. Despite successful test flights, the CBY-3 never went into production. In England, the Miles M.30 X Minor flew for the first time in 1942. The small test plane flew well, but again, a larger passenger version was never built.

Fast forward to July 20, 2007 when the X-48B ‘Skyray’ made it’s first test flight. Ushering in a new era in potentially cleaner, quieter and more economical commercial aviation. Engineers from Boeing and NASA predict as much as a 20% savings in fuel consumption for the X48B while carrying double or more the passengers and cargo of today’s jetliners. One of the two biggest obstacles confronting engineers now appear to be developing a non-cylindrical cabin which can be safely pressurized. The other is a psychological perception by passengers. In ground-based mock-ups, people did not like the seating arrangements and such large crowds packed in a small area. Even if passenger service may be an issue, the blended wing body design of the X48B Skyray could lead to military transports and refueling aircraft.

Related Articles:

NASA – Skyray 48 Takes Flight

Back in the Air: X-48B Resumes Flight Tests at NASA Dryden

Next Generation of Dreamliner

BlackBerry PlayBook 7-inch Tablet Announced, Arrives in 2011

Chris — Mon, 27 Sep 2010 22:16:32 +0000

Research in Motion made a big announcement at the BlackBerry Developer Conference today by introducing a new 7-inch tablet called the BlackBerry PlayBook. The company plans to use a new tablet OS based on QNX to power the platform, unlike their other products which use BlackBerry OS. Not much details were talked about, but it does seem to be targeted at Business users, a market which RIM maintains a firm grasp of.

They did announce some specs and spoke of some of it’s abilities as a tablet device. The BlackBerry PlayBook is powered by a dual core Cortex A9, and features two cameras (one for each side). The rear camera is 5 megapixel, while the front is 3 megapixel, and both can be used for video conferencing. The screen size is 7 inches, with a capacitive multitouch screen at a resolution of 1024×600. There is no official specs on how much storage it will carry, but many suspect it will be offered in both 16GB and 32GB flavors. Only Wi-Fi models will be available at first, with plans to release 3G and 4G versions in the future. All of this in a 0.4 inch thin, 400 gram, 7 inch tablet.

So what can it do with all this power? They briefly mentioned it’s ability to play Adobe Flash content, and how it would be an incredibly powerful gaming platform for developers. It can also provide 1080p video output through HDMI, so it would work great hooked up to an HDTV. The OS seems to feature some form of multitasking not unlike the WebOS “card” system. Some of the obvious built in applications are BlackBerry Messenger, and an HTML5 based web browser. Of course the usual Music, Photos, and Videos players are also present. RIM apparently wants to focus on social networking and gaming as well on the PlayBook.

No pricing or firm release date has been mentioned, but the BlackBerry PlayBook should launch in early 2011 according to RIM. With no pricing announced and so little details, it is hard to tell how well it could do against other tablets. Over the past few months the battle of the tablet market has really heated up. Recently Samsung announced their tablet called the Galaxy Tab, which is based on Android OS. Details on pricing and a US release date (though expected by the end of the year) for that tablet are also mysteriously missing. With more tablets on the horizon, it’s hard to not think about what Apple has planned for the iPad next year. It is about to get very interesting for people who are looking for a new tablet device. The choices between the BlackBerry PlayBook, the Samsung Galaxy Tab, the Apple iPad, and many others, the competition is really going to get crazy soon here.

Amateur Astronomy 101: Buying Your 1st Telescope – Eyepieces

Andrew — Sun, 26 Sep 2010 20:19:52 +0000

So far in this series we have discussed types of telescopes and mounts. The next part of decisions to make when buying your first telescope is what sort of eyepieces to have? Most telescopes come with two eyepieces when you purchase them. There are many types to choose from, each with advantages and disadvantages, depending on the type of telescope you bought and how you intend to use it. So I will take some time and go through the details.

First, why do you need more than one, may be your initial question? As you may recall in Part 1 of this series, a key element in any type of telescope is it’s ‘focal length’. This is the actual distance between the primary optic, be it a lens or a mirror, and the eyepiece focuser, an adjustable mount where you insert your eyepiece. As discussed before, each and every time the light from the object you are observing passes through an optical piece of glass, you loose a little light. The more light from the object, the better the image.

Since we know what the focal length of the telescope is, we use this to determine the magnification of the object that we are observing. This is done by dividing the focal length by the focal length of the eyepiece. For example, if the focal length of the telescope is 1000 millimeters (mm), and the focal length of your eyepiece is 50mm, then the magnification would be 20 times, or 20x. Typically, telescopes will come with two eyepieces, allowing for magnifications of about 30x and 90x or so.

Most inexpensive telescopes sold at department and toy stores have very cheap optics and use eyepieces that have a focuser diameter of 0.965 inches. These should be avoided! Not only are the optics very cheap, or poor quality, but you are very limited in the variety of eyepieces you can acquire. While some companies do make an adapter which allows you to mount a standard 1.25″ eyepiece in such telescope focusers. Larger telescopes may be built to use even wider, 2″ eyepieces. However, just as with the cheap optics, the focusers for such inexpensive telescopes are also low-grade.

Just as you want to have a stable mount for your telescope to reduce unwanted movement, so too for the focuser. Plus, just as you want a mount that can be adjusted and moved smoothly and steadily to track an object, likewise for the focuser as well. The ‘action’ must be very good as you make slow, short turns of the adjustment knob to focus the object into the best possible view. Having an extra adapter could throw off the precision and the ‘action’.

Two other important factors to consider before we get into the specifics of the different types of eyepieces; field of view and eye relief. Field of view is essentially the angular amount of sky you will be able to see with your telescope. Eye relief is the distance between the eyepiece itself with your own eye. In both cases, more is usually better for observing.

The most common types of eyepieces for telescopes are the following: Orthoscopic, Huygens, Ramsden, Monocentric, Kellner, Plössl, Erfle, and Nagler. These vary in design, using different numbers and types of optical elements. The first four are most often used with refractor telescopes for planetary observations. They typically consist two to four optical elements, have narrower fields of view and longer focal lengths for higher magnifications.

The Huygens and Ramsden designs are very old and typically are non-achromatic, meaning that their glass elements are not treated with an optical coating to reduce distortions associated with magnification. However, they do come in handy in some applications, such as image projection, commonly used for solar observations. A blank ‘card’ is mounted away from the eyepiece such that the Sun’s image is cast upon it, necessary since direct viewing of the Sun is dangerous and could cause blindness.

The Orthoscopic and Monocentric designs are more modern types of eyepieces used for planetary and general astronomy. Both consist of four elements. The Orthoscopic uses two ’singlet’ and one ‘doublet’ set of lenses. The Monocentric has one singlet and one triplet set of lenses. The doublets and triplets are optical elements glued together, reducing any distortions caused by air gaps between lenses while providing the extra corrective qualities. The Monocentric is the favorite of planet watchers.

The other four types: Kellner, Plössl, Nagler and Erfle, are generally used for reflector and catadioptic, or compound, telescopes. They work best for both general astronomy and more specifically, deep sky observations. These will have four or more optical elements and are usually have an ‘achromatic’ coating to limit distortions. The most popular among these are the Plössl, Kellner and Erfle. They offer good, overall optic characteristics, including wide fields of views, needed for deep sky observing. Nagler is the best, but also the heaviest and most expensive of the group.

Before we wrap this up, I should also mention the Barlow lens. This is an optical device that increases the magnification. Most on the market double the magnification, though some companies do make 1.5x and 3x Barlow lenses. Again, this is an adapter that is attached to the focuser and then an eyepiece is inserted onto the Barlow lens. Most telescopes come with one.

This has been a brief review of telescope eyepieces. You can read whole books on just them. The key points I am attempting to provide you with are; 1) buy the best you can afford and 2) buy what you need for you purposes. If you goal is to check out planets or the craters of our Moon, then a refractor telescope with some of the first group of eyepieces is best. If you intend to observe deep sky objects, like galaxies, or faint ones like comets, then a reflector is the best type of telescope to buy and acquire a collection of the second group of eyepieces. Or, split the difference and purchase a catadioptic telescope, such as the popular Schmidt-Cassegrain design and again, go for Group #2, with maybe one or two from Group #1 for planetary work.

Related Articles:

Amateur Astronomy 101: Buying Your 1st Telescope

Amateur Astronomy 101: Buying Your 1st Telescope – Mounting Systems

Amateur Astronomy 101: Binoculars

Amateur Astronomy 101: Your First Telescope – Mount Systems

Andrew — Thu, 16 Sep 2010 11:50:31 +0000

As described in the previous article, telescopes comes in three flavors, refractors which are great for planetary observations, reflectors which are great for ‘deep sky’ observations, and the composite or catadioptric telescopes which are composites of refractors and reflectors, such as the popular Schmidt-Cassegrain type. Well, there is one more major consideration in choosing your first telescope, the type of mount. There are two basic types, altazimuth and equatorial.

The altazimuth type is the simplest as it involves only two axis, altitude and azimuth. Usually based on friction or some other adjustable means of keeping the telescope pointed in a certain direction. Perhaps the simplest variation of these is the infamous Dobsonian telescopes. These are usually home-built and use some pieces of Teflon to allow for smooth and stable positioning of the telescope. One set controls the direction vertically, along the altitude, the other set controls the horizontal movement or it‘s azimuth.

Other types of altazimuth mounts use turn-able knobs that can tighten a screw which causes the friction to secure, or to loosen the telescope. Some of the more sophisticated types also allow for ’slow-motion’ controls, which can be turned to permit minor adjustments in the telescopes alignment. All of this is important when you want to look at a particular object in the sky.

Why? Because the Earth rotates. Any object in the sky will move at least one degree of arc across the sky every four minutes. In the cases of satellites, or the International Space Station, they move at an even faster rate across the sky. Meteors move the fastest.

So if your object of study some evening is Mars or the Andromeda galaxy, you’ll need to keep adjusting the direction of your telescope as these objects move across the sky based on the Earth’s rotation. Or, if all this adjusting seems too much work, you invest in a telescope with an equatorial mount. A mechanical device using weights as a counter balance to allow for smooth and accurate positioning.

The key advantage to an equatorial mount is that it uses a three-axis system to position a telescope. Star’s are usually mapped in the sky based on their ‘Right Ascension’ , their position on a longitude line, and their ‘Right Declination’ along a latitude line. With the equatorial mount, we also get a ‘Polar axis’, which positions the telescope on the basis of the Earth’s rotation by aligning the telescope with Polaris.

If you wanted to watch one particular object for a length of time, say long enough to take a photograph of it, then you only need one electric motor attached to the Polar axis to track the object once you had the other two axis ‘dialed in’. In your fully automated, computer-controlled telescopes, all the axis would be motorized.

Now, there are variations of everything these days. Some of the popular types of catadioptric telescopes use a ‘fork mount’ which is fully automated with computer controlled motors that are based on both the altazimuth and equatorial mounts. Again, these types are very easy to use. They come with a control device and usually with additional software for your home computer. You can literally plan out an observation schedule and program your telescope to execute it. On the other side of the coin, the Dobsonian is probably the simplest type of mount, and the cheapest. So if your budget is small and you want to buy the most ‘optics’, then this type is the best way to go.

But there is much to be said for the quaintness of the doing things yourself. So, when selecting your first telescope, the key factors to consider, along with price, are #1) What is your main interest? What do you want to see with it? #2) Where am I going to use it? How easy can I transport and set it up? #3) How well will it track an object in the sky? Well enough for photography? Once you establish these criteria, you then narrow your selection down to price. Keep in mind, that as with any hobby, there are always accessories, and that is what I will discuss next time.

Related Articles:

Amateur Astronomy 101 – Buying Your 1st Telescope

Amateur Astronomy 101: Binoculars

“How Telescopes Work”

New Twitter Redesign Announced, Embedded Videos, Photos, and More

Chris — Tue, 14 Sep 2010 22:40:46 +0000

It is no secret that Twitter.com is a website that has been long overdue for a redesign. Not much has changed since the site launched, and meanwhile mobile apps have continued to provide much better interfaces and extra features. They are finally doing something to fix that and make the service much more powerful when viewed in a web browser.

Today they announced the launch of a completely new Twitter redesign with a new interface and many new features. The first change is a two-pane view which shows your timeline on one side and additional content on the other. This second pane can change based on what you are doing, for example it might show a “mini-profile” of the person who created the tweet you are reading. It might also show a map of the location associated with the particular tweet.

They have also announced Twitter embedding of photos and videos from sixteen different content providers. So when someone posts a link to YouTube or TwitPic it will show the associated video or photo on the same page as the tweet. This is a fantastic addition that many mobile Twitter clients have had for a very long time. This is a feature that is helped by the new Twitter redesign, by using the two pane experience to bring content right onto the page rather than separating from the site. Another great thing they got rid of is the “more” button to load more tweets, there is now an endless timeline so you can just keep scrolling to read more.

The new Twitter redesign is scheduled to rollout to select users right away. They have not announced a firm date on when everyone will get access to it. I suppose with all the new features they want to be sure everything goes smoothly while they transition to make sure everything is stable. We should hear a lot more about everything as time goes on and more people can access the new site. It is to be hoped that it won’t take long for everyone to start playing with it. Undoubtably there will be some people upset with the new changes. Anytime you change something there is people who will want the old site back. I think what they are doing sounds positive so far. The new Twitter redesign should breathe some life back into the site at least.

Greeks earliest sighting of Halley’s comet

Andrew — Mon, 13 Sep 2010 11:33:57 +0000

Greeks earliest sighting of Halley’s comet in history around 466 BC say scientists. The Journal of Cosmology says that the Greeks may have seen the comet during a period of 80 days in 466BC. The previous earliest reference to Halley’s comet was by the Chinese is 240 BC, according to New Scientist magazine. But writings by the ancient Greeks about a large meteorite falling between 466 – 467 BC may change who saw Halley’s comet first.

Halley’s Comet as seen in 1986 by ESA’s Giotto space probe.

According to researchers, the ancient Greeks wrote about a large meteorite falling during the day in northern Greece. The object was large, described as a “wagon load” and said to be of “burnt color”. Aristotle wrote about the event a century later in his work, Meteorology. Aristotle added that about the same time the meteorite fell, “a comet was visible in the west”.

Two professors from Brigham Young University in Provo, Utah calculated the path of Halley’s comet. They determined that it would have been visible from June through August in 466 BC. Astronomer Eric Hintz and philosopher Daniel Graham are confident that the Greeks would have had an opportunity to see Halley’s comet for about 75 to 80 days during the summer of 466 BC.

If the ancient Greeks earliest sighting of Halley’s comet is true, then this changes the historic honors of the Chinese being the first to spot and record it’s arrival in 240 BC. Both the Chinese and the Babylonians made very detailed records of their astronomical sightings. The ancient Greeks, however, did not. If we can believe Aristotle (and why shouldn’t we?) then this also opens the door to another question. Was the meteorite that fell in northern Greece that year a fragment of Halley’s comet? That would be truly remarkable, especially if it’s remnants could be tracked down.

Related Articles:

Halley’s comet ‘was spotted by the ancient Greeks’

Ancient Greeks ’spotted Halley’s comet’

Greeks First To Spot Halley’s Comet

Solar Impulse Plane to make more flights in Switzerland

Andrew — Fri, 10 Sep 2010 21:52:01 +0000

Solar Impulse Plane to make more flights in Switzerland

The Solar Impulse plane has already set a new record in beating a 24-hour solar-powered flight. This week, the team announced plans for three longer flights across Switzerland. The ultimate goal for the Solar Impulse HB-SIA is to fly around the world on only the power of sunlight. They expect to begin transoceanic flights by 2013 and the non-stop global flight by 2014.

But first, more test flights in Switzerland. The next three flights will take place in Switzerland beginning later this month. Teams will be trained for coordinating with air traffic controllers across the globe for future long distance flights. Pilot Andre Borschberg will fly from Payerne to Geneva, then on to Zurich, and then back to Payerne. In July, Borschberg set a record for a 26-hour non-stop powered flight.

The Solar Impulse may be a one-seat plane, but it is large. With a wingspan equal that of a Boeing 777 passenger jet, about 205 feet. The plane is about 70 feet long and weighs just about one and a half tons. Four 10 horse-power electric motors provides the thrust to achieve a speed of about 44 MPH. Not exactly break-neck, but twice that needed to get the aircraft off the ground.

The tops of the wings and the stabilizer are coated with over 11,000 solar cells. Four pods hold the electric motors and the composite lithium batteries. The batteries are, apart from the structure of the plane, the heaviest item and major restraint. They represent one-quarter of the overall weight of the plane, nearly 900 pounds.

As the Solar Impulse plane prepares for more test flights in Switzerland, crews ensure that it is ready to go. Capable of flying at an altitude of over 27,000 feet, the solar-powered aircraft has already set a new record for non-stop electric flight of 26 hours. The single-seat plane will most likely be flown by pilot Andre Borschberg, again, for the next series of long-distance test flights.

Related Articles:

Solar Impulse plane to make more flights

Solar Plane Team Plans Flight Across Switzerland

Solar Impulse – Around The World In A Solar Plane