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प्रकाश प्रदूषण के खतरे

बचपन में जब मैं गर्मी की छुट्टियों में नाना - नानी के पास गाँव जाता था तो वहाँ खुली छत में सोने का मौका मिलता । वह चाँद - तारों की कहानियाँ सुनाती , मैं देर तक सुनता । उस समय घोर कालिमा में भी आकाश में तारे स्पष्ट दिखाई देते । वहाँ मैंने तारा समूहों को पहचानना सीखा । ऐसा लगता गाँव की जमीन आसमान के ज्यादा समीप है जबकि शहर में ऐसा नहीं हैं । बहुत दिनों बाद पता चला कि शहर में अत्यधिक प्रकाश व प्रदूषण के कारण आकाश स्पष्ट नहीं दिखाई देता । रोशनी मनुष्य निर्मित ऐसी समस्या है जो वास्तव में सम्पूर्ण प्राणी जगत को धीरे - धीरे अँधेरे में ढकेल रही है । आज दिन ढलते ही हम सभी कृत्रिम रोशनी का उपयोग करते हैं । चारो ओर फैली यह चकाचौंध रोशनी हमारे वातावरण में प्रकाश प्रदूषण का एक बड़ा कारण बनता जा रहा है , जो वायु तथा जल प्रदूषण जितना ही खतरनाक है । आवश्यकता से अधिक फैलाए गए कृत्रिम प्रकाश के अन्तर्गत राष्ट्रीय तथा राजमार्गों की लाइटें , शहरों तथा गाँवों में लगी जरूरतों से ज्यादा स्ट्रीट लाइटें , जगमगाते बाजार , मॉल्स , विज्ञापन बोर्ड , वाहनों , घरों तथा दफ्तरों की लाइटें शामिल हैं । वर्ष 2016 में ...

Why is the Ethnic composition of Belgium complex?

Because in Belizium various communities live together, such as 59%lives in the Flemish region, 40% lives in the waklonia region and remaining 1% Beligians.

Difference between homogeneous and heterogeneous mixture

Homogeneous mixture = A mixture which has the same appearance and chemical composition throughout . Example = air; mixture of gases etc. Heterogeneous mixture = Heterogeneous mixture is a mixture with a non - uniform composition. When you mix two components that remain seperate from each other, that mixture is called a heterogeneous mixture. Example A mixture of cement, sugar and water. etc.

What is permanent tissue?

The tissues made after division of meristematic cells are called permanent tissue.

why is el dorado famous and where is located?

why is el dorado famous and where is located? Answer. El Dorado is a legendary lost gold city. It has been a beacon for explorers and gold seekers. It is situated in America.

Class 10 Networking Basics of Internet and Mobile Technologies

Chapter outlines ❖Webpage  ❖Website ❖Homepage ❖Web Portal ❖Web Address ❖Blog ❖Newsgroup ❖E-Mail ❖E-Mail Services ❖Downloading ❖Uploading ❖SMTP ❖POP ❖ESMTP ❖HTTP ❖HTTPS ❖Telnet ❖FTP ❖SSH ❖SFTP ❖SCP ❖Video conferencing ❖E-learning ❖E-Banking ❖Search engine ❖Browsing history ❖Finding people  on Net Chapter outlines ❖ E-shopping  ❖E-reservation  ❖E-governance  ❖E-groups  ❖Social networking  ❖SMS  ❖MMS  ❖Generations of Mobile Technology  Webpage : A document which can be displayed in a web browser on the world wide web is called a webpage. A webpage contains digital information in the form of text, graphics, animation, audio and video. Webpage is classified mainly into two types such as: Static webpage: Static webpage is one where information is not changed frequently. In other words, static webpage contains fixed information to visitors. ...

What is amalgam? Which amalgam is used in the filling of teeth?

The alloy in which first metal is mercury, that alloy is known as amalgam. Uses: Dental amalgam is a mixture of mercury and a silver-tin alloy and is used for fillings in teeth. Amalgam fillings are often known as "silver fillings." Dental amalgam is a mixture of mercury, silver, tin and copper. Mercury, which makes up about 50% of the compound, binds the metals together to provide a strong, durable filling.