Large Decorative House

Why does distant light flickers?

When looking at light from a large distance it looks flickering like a gemstone. This is the case when you are in a place and looking towards a faraway community or town, the light from the houses and the streets flickers like decorative light. Any explanation?

There are at least three contributors to the phenomenon (4, if you count the “speckle” of laser light — http://en.wikipedia.org/wiki/Speckle ):

(1) how pointlike the light source is. Distributed light sources (like the sun, or a close car headlight) don’t suffer from the flickering as much. This is mainly a signal-to-noise ratio issue;
(2) The angular sensitivity of the human eye, and saccades. Human eyes naturally undergo small lateral movements, both to keep the more movement-sensitive cones able to detect things like stalking predators, and to “refresh” the brain so that patterns don’t get “tired” and overlooked. With point sources (and especially at night, when saccade amplitudes tend to get larger with no constant reference points), these saccades can more easily result in flicker of the point sources;
(3) The presence of refracting material (e.g. the atmosphere) between the light source and our eyes. This is by far the main contributor to the phenomenon. Light always travels so that the path it takes is an extremum (usually that means that the path it takes is a minimum in time). Small changes in the index of refraction of the air mean that light can suddenly switch the path by which it gets to our eyes, and therefore come from slightly different angles. It can appear that the light source is jumping around, whereas it’s actually the path the light is taking which is jumping. Sometimes, the path means that pointlike sources miss our eyes altogether, which leads to flickering.

Sal Grosso Brazilian Steak House

Wilton 2104-7778 Master Tip Set $28.95 With more than 50 tips included in this professional-quality cake decorating set, your imagination is the limit. Garlands, rosettes, stars, flower petals–if you can dream it up there’s a tip designed for the job. The angled coupler assists in certain decorating operations, and a standard coupler plus two flower nails for creating roses are included. The set comes packaged in a white plastic stora…

Wine Bottle Cork Cage | 91-035 $19.00 Keeping the corks from a special bottle of wine, party or event adds up quicker that you’d think. But what to do with those special occasion corks? If you’re like most of us, you tuck them in a drawer or box until you can create a special cork craft. But why keep them out of sight? Why not store them in something unique and fun?Our answer to cork storage is the wine bottle Cork Cage. This singular…

Wilton Gum Paste Flowers Set $19.00 With this set, you’ll open a new world of decorating possibilities for your cakes. Cut petals and leaves used to make exquisite gum paste flowers with the great variety of cutters and ejectors included. Cutters are comfortable to hold, with a contoured top and precise cutting edges. Ejectors cut blossom and hydrangea shapes, then imprint beautiful texture on both sides using the custom impression …

Dalen OW6 Gardeneer 16-Inch Molded Owl $11.25 DALEN GREAT HORNED OWL *18″ high *Hand painted *Plastic *Natural predator of small animals and birds *Effective scarecrow…

RoomMates RMK1439SLM Scroll Tree Peel & Stick Wall Decal MegaPack $24.49 …

Honeywell Econoswitch RPLS740B 7-Day Solar Time Table Programmable Switch for Lights and Motors $36.00 The Honeywell RPLS740B 7-Day Solar Time Table Programmable Switch for Lights and Motors helps you save money by ensuring that your lights come on only when you need them. This unit works with incandescent, halogen, and fluorescent lighting, making it ideal for indoor or outdoor use. It also works with ceiling fans, bathroom fans, pond pumps, and pool pumps. Featuring three operating modes and sev…

Flag Tropical Flamingos $11.99 Handcrafted flag made from soft, high-quality special treated fabric. Flag features hand-painted artwork reproduced on both sides of the flag. Flag is water repellent & UV resistant to extend life and vibrancy. Spot clean only & line dry….

Halloween decoration – GIANT Creepy Cloth SPIDER – extends 4 feet! $22.95 Giant Creepy cloth spider This foam spider is shrouded in creepy cloth! Hang this decoration outdoors to scare trick-or-treaters or indoors to creep out haunted house guests! This eight-legged creature is sure to add fright to your Halloween night! Includes hanger. 4 ft….

Feit Electric BP60ST19 60-Watt 120-Volt Vintage Style Clear Bulb, Medium Base $10.81 Unit Sold: 1 CardPart Number: BP60ST19Manufacturer Name: FEIT ELECTRIC COUPC: 17801178418Weight (lbs): 0.17 Length (in): 2.5 Width (in): 5.88 Height (in): 8.5…

Music Skins MS-T10023 Netbook Large- 9.8 x 6.7- Tupac- House Of Blues Skin $20.50 MusicSkins LLC is the industry leader in music, fashion, art, television, and pop culture premium quality, vinyl skins. We envision all iPods, mobile phones, PDAs, gaming devices, laptops, iPads, cameras, hard drives, e-readers and other personal electronics as portable canvases for style and individuality. Our focus on pop culture and personalization has created a stylish way for bands, brands, a…