I will call this out as another example of "Fake News". Here, the report on the UPI website went further than what the press release stated, and in the process, made a critical error.
This
news article is reporting an interesting experimental result that created objects with "negative effective mass" in a superfluid. From what I can tell, the writer is basing the report not on the original paper, but rather from the
press release out of Washington State University.
The error comes in at the very beginning of the news article:
I took a look at the WSU press release and in the paper itself. Nowhere in there was any claim made that this phenomenon "...
ignores Isaac Newton's Second Law of Motion..." In fact, it HAS to obey the second law for it to have such a direction of acceleration.
The 2nd Law is basically
F =
ma.
1. For a positive mass, it means that
F and
a are in the same direction.
2. For a negative mass, then the 2nd law is
F = -|
m|
a. It means that
F and
a are colinear, but in the opposite direction. In other words, it is the 2nd law that actually tells you that for a negative mass, if you push on it away from you, it will accelerates towards you. This is exactly OBEYING the 2nd law, not ignoring it! In fact, if the negative mass actually moves away from you the way we normally think ordinary mass should, it is only then that this mass is ignoring the 2nd Law!
The claim that this experiment "ignores the 2nd Law" is Fake Science Reporting. It is introduced to possibly make the story sexier and in the process, made a very amateurish mistake.
BTW, negative effective mass isn't new. This is common in condensed matter/solid state physics, because we have positive holes in solids, and on how we define effective mass (the curvature of the dispersion).
Zz.