Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; plgContentJComments has a deprecated constructor in /var/www/astarmathsandphysics/plugins/content/jcomments/jcomments.php on line 25 Call Stack: 0.0001 360784 1. {main}() /var/www/astarmathsandphysics/index.php:0 0.0478 1209528 2. Joomla\CMS\Application\SiteApplication->execute() /var/www/astarmathsandphysics/index.php:49 0.0478 1209528 3. Joomla\CMS\Application\SiteApplication->doExecute() /var/www/astarmathsandphysics/libraries/src/Application/CMSApplication.php:267 0.1131 4107336 4. Joomla\CMS\Application\SiteApplication->dispatch() /var/www/astarmathsandphysics/libraries/src/Application/SiteApplication.php:233 0.1144 4134808 5. Joomla\CMS\Component\ComponentHelper::renderComponent() /var/www/astarmathsandphysics/libraries/src/Application/SiteApplication.php:194 0.1151 4152520 6. Joomla\CMS\Component\ComponentHelper::executeComponent() /var/www/astarmathsandphysics/libraries/src/Component/ComponentHelper.php:356 0.1152 4183552 7. require_once('/var/www/astarmathsandphysics/components/com_content/content.php') /var/www/astarmathsandphysics/libraries/src/Component/ComponentHelper.php:381 0.1162 4206272 8. ContentController->execute() /var/www/astarmathsandphysics/components/com_content/content.php:42 0.1162 4206272 9. ContentController->display() /var/www/astarmathsandphysics/libraries/src/MVC/Controller/BaseController.php:710 0.1645 4895160 10. ContentController->display() /var/www/astarmathsandphysics/components/com_content/controller.php:113 0.1679 5087312 11. Joomla\CMS\Cache\Controller\ViewController->get() /var/www/astarmathsandphysics/libraries/src/MVC/Controller/BaseController.php:663 0.1684 5108240 12. ContentViewArticle->display() /var/www/astarmathsandphysics/libraries/src/Cache/Controller/ViewController.php:102 0.1799 5365632 13. Joomla\CMS\Plugin\PluginHelper::importPlugin() /var/www/astarmathsandphysics/components/com_content/views/article/view.html.php:189 0.1800 5365888 14. Joomla\CMS\Plugin\PluginHelper::import() /var/www/astarmathsandphysics/libraries/src/Plugin/PluginHelper.php:182

Gravitational Lensing

Gravitational lensing is one of the predictions of General Relativity. It predicts that massive objects can act as lenses to shift the position of distant objects or produce multiple images.

In Einstein's General Theory of Relativity the path taken by light from a source to an observer is along a geodesic in a four dimensional spacetime. In this theory, gravitational forces act as distortions to the surface. The theory predicts that the path of light is bent by gravitational forces – confirmed in 1919 by Eddington's measurements of the positions of stars during a solar eclipse.

The departure from a straight line depends on the mass of the body between source and observer. If the mass is big enough then multiple images of the source may be seen.

The lensing object can be any massive object eg a black hole or galaxy. The images of the source are usually distorted by the lensing object, and is confirmed by other means – such as spectrographic analysis - to be images of the same object.

Add comment

Security code
Refresh