Tuesday, 30 July 2013
आपली आकाशगंगा |
आपली पृथ्वी ज्या सूर्यमालेमध्ये आहे ती 'मंदाकिनी' नावाच्या आकाशगंगेमध्ये आहे. अवकाशातील सर्वच गोष्टीचे एकमेकांपासून अंतरच फार असल्याने दोन अवकाशीय गोष्टींमधील अंतर प्रकाशाच्या वेगाने मोजले जातात. आपल्या पृथ्वीवरून दिसणार्या जवळपास सर्वच गोष्टी आपल्या आकाशगंगेमधील आहेत याचाच अर्थ आपल्या आकाशगंगेचा आकार प्रचंड मोठा आहे.
थोडक्यात प्रकाशाच्या वेगाची आपणास कल्पना द्यायची झाल्यास सूर्यापासून निघालेल्या प्रकाशाला पृथ्वी पर्यंत पोहोचायला ८ मिनिटे लागतात व प्लुटो पर्यंत पोहोचायला ५ तास लागतात. त्यानंतरच्या सर्वात जवळच्या तार्याजवळ प्रकाशाला पोहोचायला ४ वर्ष लागतात. तर या सर्वांना सामावून घेणार्या आकाशगंगेच्या एका टोकापासून दुसर्या टोकापर्यंत प्रकाशाला पोहोचायला जवळजवळ १ लाख वर्षे लागतात.
आपल्या आकाशगंगेमध्ये साधारण २०० अब्ज तारे आहेत. आपल्या आकाशगंगेमध्ये आपल्या सूर्यापेक्षा लहान तसेच आपल्या सूर्यापेक्षाही हजारो पट आकाराने मोठे तारे, तारकागुच्छ, तेजोमेघ, वायूचे ढग, धुळीचे ढग, मृत तारे, नवीन जन्माला आलेले तारे अशा अनेक गोष्टी आहेत.
आपल्या आकाशगंगेच्याच जवळ एक लहान व एक मोठा असे विस्कटलेले असे दोन ढग आहेत. मॅगेलीन या खलाशाने ते सर्वप्रथम पाहिल्याने त्यांना मॅगेलीनचे ढग असे नाव देण्यात आले आहेत. त्यानंतर आपल्या आकाशगंगेच्या जवळ असलेली आकाशगंगा 'देवयानी' या नावाने ओळखली जाते. पृथ्वीवरून पाहताना ती देवयानी तारकासमुहामध्ये दिसत असल्याने 'देवयानी' हे नाव देण्यात आले. आपल्या आकाशगंगेपासून जवळपास २२ लाख प्रकाशवर्षे अंतरावर ही 'देवयानी' आकाशगंगा आहे.
आपली आकाशगंगा ज्या इतर आकाशगंगांच्या समूहामध्ये आहे त्या समूहाला स्थानिक दिर्घिका समूह ( Local Group of Cluster) असे म्हटले जाते या स्थानिक दिर्घिका समूहामध्ये आपली आकाशगंगा मिळून इतर ३० दिर्घिका आहेत. आकाराने लहान मोठ्या असलेल्या ह्या आकाशगंगा जवळपास १ कोटी प्रकाशवर्षे एवढ्या अंतरामध्ये पसरलेल्या आहेत.
अनेक आकाशगंगा तसेच त्यांचे स्थानिक समूह मिळून त्यांचा महासमुह ( Super Cluster) तयार होतो. अशा महासमुहाचा व्यास जवळपास १०*८ प्रकाशवर्षे एवढा मोठा असतो. आपली आकाशगंगा असलेला स्थानिक समूह कन्या दिर्घिका समूहाचा भाग आहे. शास्त्रज्ञांच्या अंदाजाप्रमाणे विश्वामध्ये अशाप्रकारचे कोट्यवधी महासमुह आहेत.
आकाशगंगेचे प्रामुख्याने तीन भाग पडतात.
१) सर्पिलाकार -
ह्या प्रकारामध्ये गोल सर्पाप्रमाणे पसरलेल्या भुजा असलेल्या आकाशगंगा आढळतात.
२) लंबवर्तुळाकृती -
ह्या प्रकारामध्ये लंबवर्तुळाकृती आकार असलेल्या आकाशगंगा आढळतात.
३) अनियमित -
ह्या प्रकारामध्ये आकाशगंगेला ठराविक आकार नसतो, त्या कोणत्याही वेड्यावाकड्या आकारामध्ये आढळतात.
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Save Environment
Saving the Environment – Every little steps count
"Why hasn't anyone done careful environmental measurement before? Businessmen always say, ‘what matters gets measured'. Social scientists started quantitative measurement 30 years ago, and even political science turned to hard numbers 15 years ago. Yet look at environmental policy, and the data are lousy."
Nor is this dearth of reliable and unequivocal information likely to end soon. Even the Millennium Ecosystem Assessment, supported by numerous development agencies and environmental groups, is seriously under-financed. The conspiracy-minded attribute this curious void to the self-serving designs of the apocalyptic school of environmentalism. Ignorance and fear, they point out, are among the fanatic's most useful allies. They also make for good copy.
Saving energy and the overall environment is a topic that has gained public attention more recently. People are realizing that at the rate we are using earth's valuable resources, we will face serious shortage in a near future.
Water is the first resource we have been wasting in the past. We have to be aware that everyday, people worldwide are dying from lack of drinkable water. Yet, in our "civilized" countries, we let purified water go to waste in many ways daily.
Small steps a person can take to limit her consumption of water is: only wash the dishes or do the laundry when there is a full load to be done, do not let tap water run for long periods while brushing one's teeth. Other obvious drinkable water savings would be not to use sprinklers on rainy days or using a broom to sweep one's carport instead of the garden hose.
"Why hasn't anyone done careful environmental measurement before? Businessmen always say, ‘what matters gets measured'. Social scientists started quantitative measurement 30 years ago, and even political science turned to hard numbers 15 years ago. Yet look at environmental policy, and the data are lousy."
Nor is this dearth of reliable and unequivocal information likely to end soon. Even the Millennium Ecosystem Assessment, supported by numerous development agencies and environmental groups, is seriously under-financed. The conspiracy-minded attribute this curious void to the self-serving designs of the apocalyptic school of environmentalism. Ignorance and fear, they point out, are among the fanatic's most useful allies. They also make for good copy.
Saving energy and the overall environment is a topic that has gained public attention more recently. People are realizing that at the rate we are using earth's valuable resources, we will face serious shortage in a near future.
Water is the first resource we have been wasting in the past. We have to be aware that everyday, people worldwide are dying from lack of drinkable water. Yet, in our "civilized" countries, we let purified water go to waste in many ways daily.
Small steps a person can take to limit her consumption of water is: only wash the dishes or do the laundry when there is a full load to be done, do not let tap water run for long periods while brushing one's teeth. Other obvious drinkable water savings would be not to use sprinklers on rainy days or using a broom to sweep one's carport instead of the garden hose.
My mother essay
My mother is my first teacher. She taught me first of all how to read and write both Hindi and English. She still helps me in my home task. She taught me good manners.
My mother has very fair complexion. She is tall. She worked as a teacher in a school. She wanted to devote all her care and attention to her children.
At home my mother has to do a lot of work. She looks after our every comfort. I am really proud of my mother. She loves us all so much. We are really very fortunate to have her as our mother. My elder sister helps my mother in her work as best as she can. My mother is an excellent cook. She takes good care of me, my father, sister and all other guests who come to our house.
She is a religious lady. She starts her day early in the morning with a prayer. She ends her day late at night chanting her favourite Shloka as her prayer. She visits a nearby temple regularly. We love her a lot but have no less respect for her.
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