ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Modern astronomers

Updated on June 18, 2012

RIDDLE OF THE APPLE

The story that the English astronomer Sir Isaac Newton (1642-1727) worked out his law of gravity after watching the fall of an apple is probably true. But nobody can ever know for sure. What makes some scholars doubt the story is that most of Newton's early biographers made no mention of it - an extraordinary omission considering the importance of the discovery the apple is said to have inspired.

There are only two sources for the tale and neither was an eyewitness. One is a clergyman, the Reverend William Stukely, who reported in his biography of Newton-written in the 18th century but not published until the 20th century that the scientist told him of the incident one afternoon when they were having tea together in the apple orchard at Newton's home.

The other is Newton's niece, Catherine Barton Conduitt, who looked after Newton during his latter years. Mrs Conduitt was the source of the first published account of the incident. Her report appeared in Elements of Newtonian Philosophy by the French author and philosopher Voltaire. The book was published in 1738, eleven years after Newton's death and more than 70 years after the apple was said to have fallen.

PIPPED AT THEPUBLISHER

The German astronomer Friedrich Bessel (1784- 1846) is officially credited with being the first person to measure the distance from Earth to a star. In fact, he was merely the first person to announce his results, An English astronomer, Thomas Henderson (1799 - 1844), had taken all the measurements necessary to work out a star distance about six years earlier-but had not got around to turning his obser- vations into a distance.

Both men made their calculations by trigonometry, taking two bearings on their chosen stars at intervals of six months. In this way, they got two angles - one from each side of the Earth's orbit - and since they knew the size of the orbit, they were able to work out the distance to the star. Bessel announced his findings in 1838.

He reported that the distance to a star called Cygni. In the Northern Hemisphere constellation Cygnus, was 10.3 light years (near to the presently accepted figure of 11.08 light years). The following year Henderson finally came up with his long-delayed figure of 3 light years for the distance to Alpha Centauri. in the Southern Hemisphere constellation Centaurus.

Henderson had made his observations in 1832 - 3. While he was director of the Cape Observatory in South Africa. Alpha Centauri, now known to be 4.35 light years from the Earth, is the closest star visible to the naked eye, apart from the Sun.

KARL'S SPARKS

Radio astronomy began in 1932 when the American engineer Karl Jansky (1905 - 50) intercepted radio waves from the Milky Way-by accident. Jansky was using an improvised aerial built partly from a dismantled Ford car. He made his discovery while investigating static on long-distance radio communications for the Bell Telephone Company.

Jansky never followed up his breakthrough, however, because when he published his findings they aroused little interest. After 1937, Jansky's discovery was investigated by the US radio amateur Grote Reber, whose work inspired the growth of radio astronomy after the Second World War.

TOMB WITH A VIEW

The telescope at California's Lick Observatory also serves as a tomb. The 900mm (36in) refracting telescope is mounted on a pillar that contains the remains of James Lick (1796-1876), a wealthy philanthropist and landowner who financed the observatory's construction and after whom it is named.

ACCIDENTAL OVERLOAD

The Van Allen belts (radiation-charged zones that girdle the Earth) were discovered by accident. In 1958, the USA launched its first satellite, Explorer 1. It was designed to measure the intensity of cosmic radiation from space. But as the satellite soared out beyond the atmosphere, the radiation count suddenly dropped to zero. Or seemed to. Scientists on the ground were baffled until the US astrophysicist James Van Allen (1914- ) realised that the satellite's meters had simply been overloaded, and so had broken down. The radiation belts now named after him lie between 650 and 65,000km (400-40,000 miles) above the Earth.

Comments

    0 of 8192 characters used
    Post Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)