Let say if one is travelling in a desert or sailing in a boat or ship in pitched dark night and has got no means of navigation or finding his way.How he can use his knowledge of Astronomy to locate himself and find his way through stars? How can one gain and use practical knowledge of Astronomy.Can someone refer me good books,websites and other sources?
200611
Use the North Star like you would a compass.\n\nThe North Star is a title of the star best suited for navigation northwards. A candidate must be visible from Earth and circumpolar to the north celestial pole. The current one is Polaris. It is the star at the end of the "handle" of the Little Dipper asterism in the constellation Ursa Minor.\n\nThe North Star has been historically used by explorers to determine their latitude. At any point north of the equator the angle from the horizon to the North Star (its altitude) is the same as the latitude from which that angle was taken. For example, the angle to the North Star for a person at 30° latitude will be about 30°.\n\nPolaris has a visual magnitude of 1.97 (second magnitude). In 3000 BC the faint star Thuban in the constellation Draco was the North Star. At magnitude 3.67 (fourth magnitude) it is only one-fifth as bright as Polaris. The first magnitude star Vega will be the North Star by AD 14,000.\n\nCurrently, there is no South Star as useful as Polaris; the faint star σ Octantis is closest to the south celestial pole. However, the constellation Crux, the Southern Cross, points towards the south pole.
510917
The way to measure it is to measure the redshift of galaxies at different distances. Are they starting to slow down, or not? But like was said above, I'm not going to worry about it. Not that cosmology isn't a fun thing to study, but as far as applications it's just about there with Abstract Art. I would say let's concentrate on applied physics, earth and solar science first, develop some new technologies, maybe colonize Mars, some other solar systems, or a good fraction of the galaxy and then we can worry about the fate of the universe when we have more tools, power and understanding to explore or do something about it. It's noble and admirable, but might be like a caveman pondering the lifespan of the sun - that large bright circle that goes around the flat earth. Occasionally skipping ahead is rewarded - most times it's a shot in the dark.
669055
why space\n\nbecause we seriously know nothing about whats around us\n\nwe don't' know anything about other galaxies slash never even been to another plant.  Why not space...\n\nthere is so much more to learn and know... don't u ever want to get out of are solar system and meet another species
373454
The Geminids ramp up over a few days, and should be visible most of the night, from around 10PM to dawn. Basically you need a location where you can see as many stars as possible.
29682
There is a surprisingly simple answer to your great question: Each month we see different stars, so to answer for a specific night of the year at your specific location on Earth depending on your eyesight and how bright the city lights around you are might be hard to pin down. \n However there is a magnitude scale that astronomers use to describe how bright objects in the sky are. Without getting into details on how that works, the average human being can see down to about magnitude 6 ( brighter objects have lower magnitude until you reach zero. Then even brighter objects use negative numbers for their magnitudes which is a bit weird, isn't it?) Therefore, all you have to do is get a map of the whole sky showing anything brighter than magnitude 6 and count the stars. If you are fortunate to be away from bright city lights and you can see the Milky Way, you would be really surprised to know that you can only see about 6,000 stars. That's the number of stars above magnitude 6 in the entire sky.
85752
1) At what latitude do you live?\n2) What time of night is it?\n3) What direction are you looking in the sky?\n4) How strong are background/city lights where you are?\n\nWhat you are experiencing is called "averted vision".  The portion of our retina most sensitive to faint light is not directly behind the pupil, but off to the side a bit.  You are looking at a deep sky object (star cluster, nebula or galaxy), but to know which one for certain, I need the answers to the above questions.  At this time of year, it is most likely the Pleiades or the Orion Nebula.
153875
There are various things that you might want to read about, horizon theory & donut theory might be a good place to start. Much as we once thought the world was flat and we'd fall off the edge, but then discovered that is was round when we sailed from one side of the world to the other the same is thought (by some) to also be true about the universe, you travel in a line for long enough, you start off where you left off!
407542
Almost none. The Andromeda spiral is visible without a telescope or binoculars and the Magellanic clouds are also. There are the only galaxies visible without some optical aid. The previous poster forgot the Magellanic clouds, which are visible from the southern hemisphere.
166208
Ah a question right up my alley...Moon - no you cant see the mirror, it would take 6 seconds for a light beam to get from here to there and back. Look for the crater Tycho (most notible because of the "ray" pattern) it is in the NE corner of the moon (you will see it in the SW corner because telescopes invert the image. Several other craters and mountains, make note of shadow positions. Using a lunar chart, find the Sea of Tranquility (Mare Tranquillium) where we first set down in 1969.\n\nSun - Using a white card held up to the eyepiece (some scopes have a bracket that can do this) Line the scope up so that it points to the sun DO NOT LOOK THRU THE SCOPE USE THE SHADOW ON THE GROUND. Focus the suns image on the white card and follow sunspots.\n\nOther planets Mars - track mars throughout the year and note the stars behind it.  As you see in just a few months mars will appear to go backwards in the sky then go forward again,  This is called retrograde.\n\nYou know of jupiter and saturn ring tilt, great spot moons etc.\n\nStar clouds and star clusters - you will need a star chart and not all are visable at the same time - M42 Orion Nebulae in his belt, M31 Andromada galaxy, the only object outside our galaxy visable to the naked eye located just above the second of third pair of stars coming off the great square pegasus - in the big dipper, second star in the handle should see a double star, this was used to test ship navigators in olden times, they had to be able to see the two stars with the naked eye.\n\nThat should keep you busy for one night LOL just kidding...email me anytime you need help
13605
hi louise try this http://www-istp.gsfc.nasa.gov/stargaze/Strig3.htm, if not just use a search engine such as google or yahoo. hope this helps
461333
No,\nI wouldn't say that's entirely impossible but it'd be a small technical challange.\n\nIf you can't afford a telescope you should contact your local astronomical society. Many will let members borrow telescopes for free or they may be able to tell you of a star party where you can go and others will let you look through their telescopes.
155992
Just singular? Sceintist or professor? Maybe you meant scientists or professors. Not that the professors are the leading authority on celestial discoveries. They more of just train others to go outside and look straight up in the air. Usually they use a telescope. In some cases, they consult the spheres. In your case, I'm surprised you even know what the word discover means.
325524
no, i haven't been to space or around the world. then again, not many people have.\n\nit would be ok and all but just thinking about being out there not knowing "exactly" where you're headed. i'll pass. what if you run out of gas and your ship is stuck out there? what if you lose contact with humans on earth, how will you let them know that you need help??? but then again on the other hand, you are in space seeing everything with your own eyes. nah, i'll stick to seeing space through internet and through my dreams..i'm a lot safer in my bed dreaming...
532342
There is an awful lot of info. You are talking about a field to which tens of thousands of people have each dedicated a lifetime of study!  If you are studying for a test, you need to focus on the contents of that particular test.  \n\nA nice site I like that has cursory information on many thing astronomical and space related written for the lay person is the Astronomy Picture of the Day.\n\nhttp://apod.gsfc.nasa.gov\n\nThe archives go back to 1994, with few repeats.
304657
what do we do at night..?? what can we do at night..??\n\n\n\n\n\nSleeeeeeeeeeep..!
260245
Travel close to the speed of light or get really close to the event horizon of a black hole.\n(Well, you DID ask it in the physics forum!)\n\nIf you just want to relax, why not spend some time on Yahoo! Answers!!!!! It's fun.\n\n\n:)
412355
Wow! Thanks for the "heads up".  I wasn't aware of that.  I'm in Florida, so around 2pm here I should be able to set up some equipment so that the whole office can see it.  We have a lot of optical equipment here so it'll be a great opportunity.\n\nFor Jessi:\nYou can take a telescope and point it towards the sun. (Don't look through the telescope)  Then project the sun's image onto a blank sheet of paper and focus until you see the sun's image.  You'll be able to see sunspots and Mercury passing from right to left along the bottom side of the image.  It should last from about 2pm edt until sunset.