6 Scientific American, December 2019
LETTERS
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CANCER CONTROL
As a community oncologist, I enjoyed
James DeGregori and Robert Gatenby’s
article “Darwin’s Cancer Fix.” Their ap
proach to treating metastatic prostate can
cer by managing its growth, rather than
trying to kill all cancer cells, to avoid drug
resistant tumors is intriguing and de
serves a large randomized phase III trial.
But it is very important to remember that,
biologically, cancers are extremely hetero
geneous, and there are caveats to the prin
ciples the authors outline.
First, certain advanced cancers (espe
cially testicular cancer, Hodgkin’s disease
and largecell lymphoma) are curable with
vigorous, optimum therapy. Substantial
evidence demonstrates failure to maintain
dose intensity and interruptions in the
treatment schedule compromise chances
for a cure. Second, longterm, typically un
interrupted hormonally based treatment
for local breast cancer is crucial to prevent
ing metastases. Studies show that for
many, 10 years of treatment is superior to
five. Third, one of medicine’s greatest suc
cesses—pediatric acute lymphoblastic leu
kemia, which now has a cure rate of 80
to 90 percent—requires both optimum ini
tial intensity and longterm, uninterrupted
treatment, often for three years.
For the majority of advanced, meta
static cancers not known to be curable,
optimum scheduling of therapy certainly
deserves careful study. When it comes to
human cancers, however, many theories
about how treatment should work have
not panned out.
Cary Peterson Lincoln, Neb.
AD ASTRA
“The Good Kind of Crazy,” by Sarah Scoles,
describes research on exotic propulsion
technologies for spacecraft being con
ducted by Heidi Fearn and James F. Wood
ward, both at California State University,
Fullerton. I was a coorganizer of the 2016
conference in Estes Park, Colo., that is fea
tured in the article, and I am a technical
witness to much of what Scoles sets out.
I have worked on exotic propulsion—in
the area of gravitational physics—for more
than 20 years and know this field is diffi
cult to effectively report on as a journal
ist—or to collaborate on as a researcher.
Many press reports are fawning and un
critical. Scoles does a very good job of pre
senting and balancing the differing per
spectives in this field.
Woodward has been a great inspira
tion in the field, and Scoles is right to rec
ognize him. But she distinguishes herself
by also taking care to note results that
contradict his claims. Such criticism is im
portant, even necessary, to push the enve
lope. What Scoles may not have realized,
however, is that such work in exotic pro
pulsion is a search for one of the greatest
discoveries in gravitational physics. A pro
pulsion application is the goal, but its
glamour makes us overlook the larger im
plications such a mechanism might por
tend for gravitational theory. And it makes
us complacent.
Some of the results Scoles describes
would constitute important discoveries in
gravitational physics if they are confirmed.
Yet it is rare for an exotic propulsion re
searcher to present such results to gravita
tional scientists at their meetings or in
their journals. Integration with textbook
gravitational physics is missing from some
prominent areas of exotic propulsion re
search. There is, however, a new genera
tion of exotic propulsion researchers who
are committed to integrating these excit
ing propulsion possibilities within the
framework of known gravitational physics,
where they belong.
Lance Williams Konfluence Research
Institute, Manitou Springs, Colo.
POCKET TECHNOLOGY
In “The Big Slowdown” [Ventures], Wade
Roush claims we live in a time when tech
nological shifts are increasingly rare in
comparison with the century prior to
- But as I see it, we are living in a time
when technology has brought on remark
able, worldshifting change.
I am referring, of course, to the new era
of electronic communication. Roush nods
toward this “outlier” when he mentions
the rise of smartphones, but he pauses
only long enough to mention the dangers
they bring, not their revolutionary impact.
When worlds change, change changes
as well. We miss this process if we look for
shifts in the wrong places. Roush men
tions consumer robotics and space explo
ration as areas that have not seen dramat
ic successes recently. Yet that is because
moving mass from one place to another is
no longer the arena where the real shifts
are happening. Instead it’s all about our
ability to communicate and gain access
to information. Because we are walking
around with computers in our pocket that
make all this possible, we are living in a
different world than three decades back.
Jack Petranker Center for Creative
Inquiry, Berkeley, Calif.
STOPPING GUN VIOLENCE
In “Gun Research Needs More Firepower”
[Science Agenda], the editors urge scien
tists to utilize funding for gun violence
prevention research if an appropriations
bill passes the Senate.
Some steps can be taken immediately
that would have a significant impact on
gun use: First, enact a very large excise tax
on the manufacture and sale of all ammu
nition and on materials and equipment to
make D.I.Y. ammunition. Second, prohibit
the import of those objects. Third, elimi
August 2019
“ When it comes to
human cancers,
many theories about
treatment have
not panned out.”
cary peterson lincoln, neb.
© 2019 Scientific American