[_justinfunk]

All motion in space is relative. Wouldn't it also be equally accurate to say this object is motionless and everything else is passing it by at 1M mph?

[Djdjur7373bb]

It would be as accurate and make as much sense as saying the 100m finish line traveled to Usian Bolt in 9.6 seconds.

[_justinfunk]

I'm not being snotty. What is the fixed point from which they are measuring the speed? Is the object moving 1M mph relative to earth? The black hole at the center of Milky Way?

[gambiting]

>> What is the fixed point from which they are measuring the speed?

Rest of the milky way galaxy, presumably, given that it talks about escape velocity from it.

[ianburrell]

The paper says the Galactic rest frame.