[et_pb_section fb_built=”1″ fullwidth=”on” _builder_version=”4.14.8″ _module_preset=”default” background_image=”\/wp-content\/uploads\/2022\/04\/slider-corpo2.jpg” height=”114px” global_colors_info=”{}”][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.14.8″ _module_preset=”default” custom_margin=”||0px||false|false” custom_padding=”||0px||false|false” global_colors_info=”{}”][et_pb_row _builder_version=”4.14.8″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.14.8″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.14.8″ _dynamic_attributes=”content” _module_preset=”default” custom_margin=”0px||0px||false|false” custom_padding=”0px||0px||false|false” global_colors_info=”{}”]@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoicG9zdF90aXRsZSIsInNldHRpbmdzIjp7ImJlZm9yZSI6IjxoMSBjbGFzcz1cImVudHJ5X3RpdGxlXCI+IiwiYWZ0ZXIiOiI8L2gxPiJ9fQ==@[\/et_pb_text][et_pb_text _builder_version=”4.14.8″ _dynamic_attributes=”content” _module_preset=”default” custom_margin=”0px|5px|0px||false|false” custom_padding=”0px||0px||false|false” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″ custom_css_main_element=”display: inline-block;”]@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoiY3VzdG9tX21ldGFfZmVjaGFfZXZlbnRvIiwic2V0dGluZ3MiOnsiYmVmb3JlIjoiIiwiYWZ0ZXIiOiIiLCJlbmFibGVfaHRtbCI6Im9mZiJ9fQ==@[\/et_pb_text][et_pb_text _builder_version=”4.14.8″ _dynamic_attributes=”content” _module_preset=”default” custom_margin=”0px|5px|0px||false|false” custom_padding=”0px||0px||false|false” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″ custom_css_main_element=”display: inline-block;”]@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoiY3VzdG9tX21ldGFfaG9yYV9ldmVudG8iLCJzZXR0aW5ncyI6eyJiZWZvcmUiOiIiLCJhZnRlciI6IiIsImVuYWJsZV9odG1sIjoib2ZmIn19@[\/et_pb_text][et_pb_text _builder_version=”4.14.8″ _dynamic_attributes=”content” _module_preset=”default” custom_margin=”0px||0px||false|false” custom_padding=”0px||0px||false|false” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″ module_class=”event-organizations”]@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoiY3VzdG9tX21ldGFfb3JnYW5pemFjaW9uZXMiLCJzZXR0aW5ncyI6eyJiZWZvcmUiOiIiLCJhZnRlciI6IiIsImVuYWJsZV9odG1sIjoib2ZmIn19@[\/et_pb_text][et_pb_text _builder_version=”4.14.8″ _dynamic_attributes=”content” _module_preset=”default” custom_margin=”0px||0px||false|false” custom_padding=”0px||0px||false|false” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″]@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoiY3VzdG9tX21ldGFfbHVnYXJfZXZlbnRvIiwic2V0dGluZ3MiOnsiYmVmb3JlIjoiIiwiYWZ0ZXIiOiIiLCJlbmFibGVfaHRtbCI6Im9mZiJ9fQ==@[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.14.8″ _module_preset=”default” custom_margin=”0px||||false|false” custom_padding=”0px||||false|false” top_divider_color=”RGBA(255,255,255,0)” top_divider_height=”0px” global_colors_info=”{}”][et_pb_row _builder_version=”4.14.8″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.14.8″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/www.ieec.cat\/wp-content\/uploads\/2022\/12\/1607601693_2b467c5b46df2bfc1813b7c381f9a2a9_2020_12_enrique_gaztanaga.jpg” alt=”Euclid inside a Black Hole” title_text=”Euclid inside a Black Hole” _builder_version=”4.14.8″ _module_preset=”default” width=”600px” module_alignment=”center” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.14.8″ _module_preset=”default” global_colors_info=”{}”]The researcher Enrique Gaztañaga, from Institute of Space Sciences (ICE,CSIC\/IEEC), will talk about Euclid inside a Black Hole.<\/p>\n
I will present a brief introduction (for non experts) to the metric of space-time and what role the metric plays in our understanding of Gravity (General Relativity). Euclid of Alexandria (300 BC), the Greek mathematician, was the founder of geometry. In the early 20th century, his only surviving book, the Elements, was the second best selling book of all times. In the Elements, Euclid lay down the properties of the simplest possible metric, corresponding to that of flat space. This was generalised by Einstein's Special Relativity and Minkowski to that of flat space-time. Minkowski flat metric corresponds to empty space. The second simplest metric is the Schwarzschild metric, which represents empty space outside a static star or a Black Hole of mass M. I will then show how the metric of our expanding Universe can be interpreted as the inside of a Black Hole. For an external observer our Universe will look like a static Black Hole of mass M=5.8E22 solar masses. The accelerated expansion of the Universe today is then caused by the Black Hole event Horizon.<\/p>\n