wolfclan96
Your friend's quote itself contains an outright contradiction: first it is stated that "something ELSE other than gravity that is holding the universe together" then "The existence and properties of dark matter are inferred from its gravitational effects on visible matter". Of course it could be said that it is gravitational attraction of visible massive matter which is meant under the term "gravity" in the first phrase but even so it's a sign of poor expertise.
Your friend's quote itself contains an outright contradiction: first it is stated that "something ELSE other than gravity that is holding the universe together" then "The existence and properties of dark matter are inferred from its gravitational effects on visible matter". Of course it could be said that it is gravitational attraction of visible massive matter which is meant under the term "gravity" in the first phrase but even so it's a sign of poor expertise.
