Sky Definition and 257 Threads

I think it's the first 1000 digits. wish I could have been there https://www.youtube.com/watch?v=4iALEU1dD1A

Homework Statement An arrow is fired upward with an initial speed of 38 m/s. What is it's maximum height? How long does it take to return to the ground? How high is it at 1.3 seconds? How high at 3.8 seconds? Homework Equations x = Vo*t + .5*a*t^2 y = .5gt^2 etc. The Attempt at a...

http://s579.photobucket.com/albums/ss234/theranker24/Night%20Sky/ can someone look at them two photos i have linked on photobucket and tell me what it is that I am seeing. and

Hi friends, I am confuse in Rayleigh scattering formula. It says that the intensity of the light corresponding to a wavelength in the scatterd light varies inversely as the fourth power of the wavelength. Hence the blue light scatters more then red light. Hence the sky seems blue. But the...

Here are my two questions: 1) When i look up to a night sky, do i see mostly stars and galaxy's rather then planets? Here is my logic: Since star is many many times more brighter then reflected light of planets i see brightest object and since we are looking form Earth planets and stars...

Hello Forum, I understand how the primary rainbow is formed: dispersion by water droplets suspended in the air. A single internal reflection takes place. Red color (wavelength) emerges at about 42 degrees with respect to the observer... but why is the sky below the primary rainbow not...

When we look up into the cosmos wt we see at the end is a definite boundary or are we just gazing at empty space?

Wouldn't do me any good. I live in the middle of a major city, and, the last time I looked at the night sky at my true local astronomical midnight, it looked like God had turned out the lights.

Mysterious Night Sky Object - Help!? Well, I've commented on others' questions on a number of occasions, but something just occurred which has thrown me for a loop, and I could really use an opinion or two. I've been into amateur astronomy for 43 years, and have seen any number of very...

Sky waves transmission is done using the total internal reflection phenomena. The waves reflect as we go to a rarer medium from a denser medium. My book states that high frequency waves cannot be used for sky waves. IT says it will penetrate the atmosphere. I don't get it refractive index...

Hello. Last night i was stargazing with my skymaster 15x70 binoculars. everything went as usual - i observed star clusters, airplanes and sattelites passing by, etc. while watching a little group of stars almost right above my head (85-90 degrees declination) a little "star" suddenly...

As the title. How many precent of the entire sky is investigated by the kepler telescope? I'm aware of that it's very little, but does anyone find a good page of this? I've looked, without results. I'm very thankful for help! :biggrin:

Venus' synodic period is 583.92 days. Does that mean that Venus is 583.92/2 days the evening star and 583.92/2 days the morning star (with some period in between when it's probably to close to the sun to be visible)? What I want to know is some kind of formula so that I know where and when to...

hi , please tell me why sky is blue?

This is even weirder than mammatus clouds. http://news.yahoo.com/giant-tsunami-shape-clouds-roll-across-alabama-sky-192102289.html http://news.yahoo.com/photos/giant-tsunami-shaped-clouds-1324327483-slideshow/

Homework Statement Augustine continues to run around. He gets to the park and has the overwhelming urge to jump off a cliff and try to fly. He does so at an angle of 50 degrees to the horizontal while running at 14.5m/s. With his arms flapping, he rises in the air. a) what is the highest...

Have you ever experienced the wonder of the night sky? If yes, then you know that the universe has so much to offer us. However, within the next decade or so, the beauty of the night sky will fade away with time itself. Why? Light Pollution is taking control of our night skies. What is this...

Sunlight takes eight minutes to reach Earth. Meanwhile the sun and Earth have moved/rotated. Suppose that the sun emitted two types of light, the 8-minute light and a spooky “zero-time light”. Where in the sky would we see/measure the second spooky sun - the real position of the sun? The...

Color of Sky Without Atmosphere or 50 Times Denser What would be the color of the sky if the Earth had no atmosphere? Since the scattering of light is due to the fact that the wavelengths of blue are small enough to be obstructed by the particles in the atmosphere, whereas longer wavelengths...

Assuming, of course, that we simply rescaled our color perspectives so that longest wavelengths = red, shortest wavelengths = violet. Are there any such pictures?

why sky is blue in colour?? why sky is blue in colour??

is that true that the colour of sky is blue or is it just the reflection of sea water

My curiosity has been aroused by climate change debates, but my physics is inadequate. Perhaps I can get some help. My question is simply: As viewed from the Earth surface, what percentage of the area of the visible sky is occupied by CO2 molecules? This could be expressed in simple terms...

Hey guys. I want to get started in looking at the night sky from my roof etc etc. I was thinking of getting Celestron SkyMaster Giant 15x70 Binoculars with a tripod as a starting tool which is only about $70-80. I don't want to buy a $4,000 telescope without knowing what I'm looking for lol...

Anyone know if Firefly is going to have a second season? I'm hoping so since it's being shown on the Science Channel now.

When I look into space, I can't make it out, but I am looking at so much. It depresses me to that I may never know what's out there, that all of the questions I have may never be answered. Does anyone else feel this way?

Homework Statement I need to find how long it will take a supernova explosion to be a size of one arc sec here on earth, the distance to this explosion is 50 kilparsec Homework Equations The Attempt at a Solution Any clue on what the formula is? thanks

Hi, for all of you we´ve made new user-friendly interactive 3D model of solar system and night sky with real-time planet´s positions. http://www.solarsystemscope.com/ (requires flash) Application in a simple way helps students and laymen to understand the movements of the planets and...

I know the direction to the center of the galaxy is near Sagittarius. Therefore is it safe to conclude that the direction of our solar system's travel through the galaxy is 90 degrees from that point, along the strip of the Milky Way in the sky? As we are in the Orion arm, is the Orion...

How can one determine the color of another planet's sky from its atmosphere composition and parent star color? Earth's atmosphere is blue for most of the day, then turns red at sunset. Mars is sort of the opposite: it has a red sky which turns to a bluish hue at sunset. Until someone tells me...

A star that has been ejected from a galaxy probably wouldn't be any different from stars within galaxies. It could be possible for a planet to orbit this star. What would the night sky appear like? Would the galaxies be too dim to see, and the night sky fully black? Lets say that the star is...

When I point a camera at the sky and use the flash, it brightens up all the stars I'm looking at (not just the ones on the screen). Does anybody know why this is?

Dont ignore this as a hypothetical one, but really I have some doubt... suppose we made a very bright torch light and took it to Mars. Now assuming that the light is bright enough for me to observe it from Earth with the naked eye, would we see the light twinkling? Is the twinkling only...

hi all im studying polarization, and i want to check if i have the right idea about sky polarization. basically i want to find the position of the sun when i know the angle theta (refer to the attachment) of the sun but doesn't know the exact position. so i look at the portion of the sky...

Hi, I was just wondering if some astronomers here could help me indentify 2 bright things in the sky. I'm not an astronomer, but I'm quite interested in the subject. One of these things can be seen at about 6.00 P.M. to about 10.30 P.M. where I'm from (Southern Europe). It shows up in the...

I was wondering how someone would go about charting stars on their own, pencil and paper style. Particularly, I was curious how astronomers charted the positions of stars and paths of planets hundreds of years ago, and was hoping to replicate this. I understand it's probably very involved, but...

Why is the sky polarized?

Why does smoke from a campfire look blue against trees near the ground but yellow against the sky?

Sky is supposed to blue during the day because of maximum scattering of violet and blue light. But if they get scattered in the sky, how do they reach our eyes? With this logic i think the sky should be yellowish red during the day (which it surely isn't!) With this notion i can understand why...

Given the following: Its a polar graph. I am trying to figure out when is VENUS visable in the sky during this period (dawn, dusk, noon, midnight) ? How do you figure that out? Also, Venus is red, Earth is green on the chart. Thanks!

I was wondering if anyone here had experience using the image dataset of the Sloan Digital Sky Survey. Specifically, I want to find images of Mars from within their data. However, because they take one picture of the sky a night, and at a very small section of the sky, it's hard to predict...

Hello, PF community. Past wednesday I was visiting the National Astronomical Observatory, which is located pretty close to my home, in Chile. It was about 10 pm, and I was waiting for my turn to see through the main telescope, while some astronomers were teaching us about the common stars in...

I guess I don't have much to say about this other than it's pretty amazing if it's true and I wanted to bring it to everyone's attention here. http://www.sciencedaily.com/releases/2010/09/100909004112.htm http://arxiv.org/abs/1008.3907

[SIZE="3"][FONT="Arial"]I just watched this http://www.youtube.com/watch?v=TFwtJC9_dXs" that said it's because the universe has a finite existence and the light from most of the stars hasn't reached us yet and this would be an argument against an infinitely old universe. Is this correct?

I understand that there are different meteor showers at different times of year, and that they are named for the constellation from which the meteors seems to come from (to an Earth-based observer). Does the point of "exit" for arbitrary meteors all year follow a pattern or a great circle on the...

So basically I want to write some code in Python to project the movement of the moon and sun across the night sky. Basically, I need a projection such that the shape of the moon won't change as it moves in the sky (especially when it's near the horizon) - the objects have to look fairly good...

Hi I want to know how astronomers count the number of stars (or any other celestial object for that matter) in the sky. Will they take a photograph and do some signal processing like counting the number of brightest spots? Is it possible to count accurately since there are billions and...

1. What are two examples of physics found in Apollo 13 or October Sky Physics 3. When they slingshot around the moon and in October Sky when they do the projectile and when the mine caves in. I need one more for Apollo 13..with explanation please

Ok, my brother & I were trying to work this out. Without directly knowing the angles is it possible to work out how far away a plane is in the sky? For example, a boeing 747 is about 70m long. It appeared to be about 0.001m holding out a ruler about 80cm from my eye. I look forward to...

Is there a 2010 sky almanac on line? Hello. Is there any on-line resource that I can obtain a nice star almanac like the one in the January issue of Sky and Telescope? I realize I can buy it for $6.00 through Sky and Telescope but does anyone know if I find a similar one on the web that I can...