How is that any different? Sounds like "dark matter was introduced because, previously, all other matter interaction was pulling on something". It walks invisib

How is that any different? Sounds like "dark matter was introduced because, previously, all other matter interaction was pulling on something". It walks invisibly but quacks like matter (lensing, galaxy geometry, etc) so we call it dark matter. It's all the ways in which it doesn't act like matter which make it interesting.