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Solar Sail Will Work, says Planetary Society
degauss writes "In response to Cornell Physicist Thomas Gold's paper declaring the theroy behind solar sails flawed (previously mentioned in this Slashdot article), Louis Freedman, executive director of the Planetary Society (the organization behind the COSMOS project), has written a brief rebuttal to the claims in Dr. Gold's paper regarding the feasibility of solar sails for use as a method of transportation in space. He does not go in to detail with equations and such, but does give an overview of the reasons he believes Gold's hypothesis is incorrect."
I have learned to use the word 'impossible' with the greatest caution.
To make laws that man cannot, and will not obey, serves to bring all law into contempt.
--E.C. Stanton
this alone calls into question Dr. Gold's ability
Depends on when he did this "seminal work on the steady-state theory". I'm in my 40s, and I remember when it was still considered acceptable to have some reasonable doubt about the big bang. If he's in his 70s, and did this work, say, 50 years ago, it's possible that the work was considered completely solid at the time. And the word "seminal" does imply that it was a while back.
I'm reminded of Stephen J. Gould's defense of the Bishop of Usher (the one who determined that the universe was created in 4004BC). Looking at that date based on what we know now, it's easy to assume that he was a religious fanatic, but if you look at what was known at the time he did the work, it turns out that he actually did some pretty solid scientific research to come up with that date. The fact that he was working from a set of bad assumptions was not really his fault.
So, back to Gold, if he's still a proponent of the steady-state, then he can probably be dismissed as a quack, but the fact that he once worked on the theory doesn't really say anything one way or the other.
I'm sorry, but no. I've not read Gold's work or even heard of him, but I read a number of Hoyle's papers. In the early 1950s, steady state was a perfectly respectable theory with a few minor bumps from observations (such as the Hubble expansion). In the subsequent 50 years, the observations have gotten much more rigorous, much more extensive, and much more valid. They have also become much, much, much more difficult to explain via steady state. Fred Hoyle -- admittedly once a great astronomer -- has become increasingly shrill and outlandish in his theoretical constructs designed to explain the "illusion" of the cosmic background radiation.
You're entirely right that the merits of a scientific position ought not be dismissed due to the personalities of the people who hold it. But equally true is the statement that no scientific position ought to be elevated merely because some proponents once did good work, in a different subdiscipline.
The Mongrel Dogs Who Teach
The main practical difficulty I see is stopping. You can't slap propelled rockets on the ship to do the job; if you did, I would want to know you didn't propell you ship with that to begin with.
Presumably you'd want to travel to another solar system. In that you'd set the sail in the other direction as you get closer.
Moreover, we wouldn't get very far away, because the force provided by sunlight diminishes exponentially as you move further away.
Rubbish. You are accelerating the whole time it takes you to leave the solar system. Just because you stop accelerating after that doesn't mean you stop. And the force acting on the sail drops off as 1/d*d which is polynomial, not exponential.
And going towards another star wouldn't help, because you can't sail against the "wind" in this case
You could collapse the sail.
We're getting to the point where it will just take too long to go where we want to go, and eventually it's going to make us ask if we really can go there. I mean, hundreds of years later, who's going to care that a probe, unable to communicate with us, is careening somewhere past Neptune? As for people, don't hold your breath on this transporting us; it just takes too long. I don't know about you, but going to another planet wouldn't be worth most of my life, if not the whole thing and part of my children's.
Not everyone is like you. (the kind of person who would sit back and say "impossible, the earth is flat" as Columbus sets sail.) I am kind of proud to think that the two Voyagers (both of which are still sending data) are out past Neptune. And the physicists who study the heliopause and the inter-stellar medium still find their data useful.
:wq