Symbol R_N
is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Published equation contexts
Why this formula appears here
Start with the least controversial position anyone has ever assigned to an extended body: the Newtonian, mass-weighted centroid, = / , a sum over the body’s constituent mass elements at positions , evaluated at one common instant. That last clause is doing all the work relativity is about to object to. “One common instant” means one value of a time coordinate t shared by every term in the sum — the coordinate time of whichever inertial frame is doing the summing, not any single mass element’s own proper time along its own worldline — and which value of t counts as simultaneous with which is exactly the freedom special relativity…
Read the representative guide
Symbol a
a appears in the bound of this sum. The bound states where the repeated operation starts, ends, or which values it includes.
Read this term in its guide →Symbol m_a
is an input to the expression that computes the quantity on the left.
Read this term in its guide →Symbol r_a
is an input to the expression that computes the quantity on the left.
Read this term in its guide →Starting index or lower bound: a
This label says where the repeated addition, multiplication, or accumulation starts. Read its value or condition together with the article’s description of the index.
Read this term in its guide →Starting index or lower bound: a
This label says where the repeated addition, multiplication, or accumulation starts. Read its value or condition together with the article’s description of the index.
Read this term in its guide →How to interpret it
Read it with the definitions, units, and assumptions supplied by the article.
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Published contexts (1)
A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.
Equation 1 · Evolutionary Physics
The Atlas That Refuses to Close
This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.
Start with the least controversial position anyone has ever assigned to an extended body: the Newtonian, mass-weighted centroid, = / , a sum over the body’s constituent mass elements at positions , evaluated at one common instant. That last clause is doing all the work relativity is about to object to. “One common instant” means one value of a time coordinate t shared by every term in the sum — the coordinate time of whichever inertial frame is doing the summing, not any single mass element’s own proper time along its own worldline — and which value of t counts as simultaneous with which is exactly the freedom special relativity…
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