{"id":60415,"date":"2024-06-13T10:38:30","date_gmt":"2024-06-13T10:38:30","guid":{"rendered":"http:\/\/a054170e-1181-43f7-b3f9-ddbcff03bdfb"},"modified":"2024-06-13T11:39:42","modified_gmt":"2024-06-13T11:39:42","slug":"understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe\/","title":{"rendered":"Understanding the Big G. What the gravitational constant is and why it’s fundamental to our study of the Universe"},"content":{"rendered":"

<\/p>

By <\/p>

Published: Thursday, 13 June 2024 at 10:38 AM<\/p>

\n\n

The gravitational constant, or G, is a way of representing, mathematically, the force that any two objects in the Universe exert on each other due to gravity<\/a>.<\/p>

Isaac Newton\u2019s universal law of gravitation<\/a>, for instance, says that this force can be calculated by the equation:<\/p>

F_{g<\/sub>\u00a0=\u00a0G (m_{1 <\/sub>m_{2<\/sub>) \/ R^{2<\/sup><\/strong><\/em><\/p>}}}}

F_{g<\/sub><\/strong> is the total gravitational force between the two objects (measured in Newtons), m_{1<\/sub><\/strong> and m_{2<\/sub><\/strong> are the masses of the two objects (measured in kilograms) and r<\/strong> is the distance between the two objects (measured in metres).<\/p>}}}

G is usually expressed as 6.674\u00d710^{\u221211<\/sup>\u00a0N m^{2<\/sup>\u00a0kg^{\u22122<\/sup>, and is sometimes referred to as the universal gravitational constant, or Newton\u2019s constant.<\/p>}}}

It\u2019s also often known colloquially as \u2018Big G\u2019, which is a handy way of differentiating the gravitational constant G from g, which describes the local gravitational field of Earth.<\/p>

The gravitational constant was calculated using a torsion balance, an instrument for measuring weak forces of attraction between masses, from the amount by which they twist a fine wire. Photo by SSPL\/Getty Images<\/figcaption><\/figure>**The value of G and why the gravitational constant is important<\/strong><\/h2>**Originally defined by Isaac Newton<\/a> in 1680, the gravitational constant was first calculated accurately by English physicist Henry Cavendish in the late 18^{th<\/sup> century.<\/p>}
He used a device called a torsion balance<\/a> to determine the near-infinitesimal gravitational attraction between two small lead balls, then fed that measurement into the equation above as F_{g<\/sub> and worked backwards from there.<\/p>}
Understanding the gravitational constant enables astronomers and astrophysicists to work out all kinds of information, such as calculating the mass of a star based on the mass and orbital speed of the planets around it.<\/p>
As such, G can be said to underpin much of our modern understanding of how the Universe works.<\/p>
$\"The$
The gravitational constant enables astronomers to calculate the mass of a star based on the mass and orbital speed of the planets orbiting it. Credit: Thibaut Roger\/NCCR PlanetS, CC BY-NC-SA 4.0<\/figcaption><\/figure>
So it\u2019s a little odd that even our current definition of G is fairly vague, extending only to five decimal places.<\/p>
That\u2019s partly because any experimental attempts to measure G will themselves be subject to the gravitational pull of nearby objects.<\/p>
It\u2019s also partly because gravity, though an omnipresent force, is also a very weak one.<\/p>
Try dropping a box of paperclips on the floor, for instance.<\/p>
It\u2019s gravity that makes them fall to the floor, sure, but once they have, you\u2019ll find you can easily overcome the entire gravitational pull of planet Earth using nothing more than a tiny fridge magnet!<\/p> <\/body><\/html>\n
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By Published: Thursday, 13 June 2024 at 10:38 AM The gravitational constant, or G, is a way of representing, mathematically, the force that any two objects in the Universe exert on each other due to gravity. Isaac Newton\u2019s universal law of gravitation, for instance, says that this force can be calculated by the equation: Fg\u00a0=\u00a0G […]<\/p>\n","protected":false},"author":24,"featured_media":60416,"template":"","categories":[1],"acf":{"readingTimeMinutes":"2"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/06\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe.jpg",1200,1200,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/06\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/06\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe-300x300.jpg",300,300,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/06\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe-768x768.jpg",768,768,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/06\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe-1024x1024.jpg",800,800,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/06\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe.jpg",1200,1200,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/06\/understanding-the-big-g-what-the-gravitational-constant-is-and-why-its-fundamental-to-our-study-of-the-universe.jpg",1200,1200,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Published: Thursday, 13 June 2024 at 10:38 AM The gravitational constant, or G, is a way of representing, mathematically, the force that any two objects in the Universe exert on each other due to gravity. Isaac Newton\u2019s universal law of gravitation, for instance, says that this force can be calculated by the equation: Fg\u00a0=\u00a0G…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/60415"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/60416"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=60415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=60415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}