The Algebraist by Iain Banks

[nquixote]

Originally Posted by psikeyhackr

There are a lot of people that try to make science seem more difficult than it really is. And also try to use psychological debating bullshit to win simple disagreements about physics.

Telling kids about entertaining sci-fi stories with ACCURATE SCIENCE would help them integrate real science into their thinking while their mental sponges are still working well.

Agreed...it would be nice if kids grew up knowing that light has momentum...

[psikeyhackr]

Originally Posted by nquixote

Agreed...it would be nice if kids grew up knowing that light has momentum...

Never said it didn't. There have been sci-fi stories about light sail ships for decades. But how much momentum? The numbers must be CORRECT for the understanding of physics to be correct. The laws of physics don't give a damn if we get it wrong even if it kills us.

http://en.wikipedia.org/wiki/The_Cold_Equations

psik

[Ropie]

Originally Posted by psikeyhackr

Telling kids about entertaining sci-fi stories with ACCURATE SCIENCE would help them integrate real science into their thinking while their mental sponges are still working well.

Yeah, and having all the protagonists be nice to one another and demonstrating peaceful, environmentally friendly attitudes in which no one is at war with anyone else would help instil a sense of world peace in the impressionable. Authors are under no obligation to educate or, for the most part, be blamed when people take them too literally. Equally, story writers can not be expected to be experts in every field in which they write.

[nquixote]

Originally Posted by Ropie

Yeah, and having all the protagonists be nice to one another and demonstrating peaceful, environmentally friendly attitudes in which no one is at war with anyone else would help instil a sense of world peace in the impressionable. Authors are under no obligation to educate or, for the most part, be blamed when people take them too literally. Equally, story writers can not be expected to be experts in every field in which they write.

Not saying they should, just that a bunch of the errors in Consider Phlebas annoyed me.

I often enjoy sci-fi with bad physics, like the movie Independence Day.

[Fung Koo]

Originally Posted by nquixote

You don't need mass-energy equivalence to find the momentum of light.

The full version of E = mc^2 is E^2 = p^2*c^2 + m^2*c^4. Light has no mass, so m=0, therefore m^2*c^4 = 0, so for light, E=pc.

Flip that to p=E/c, and that is required to figure out the momentum of a photon. Sure, that's not technically mass-energy equivalence, but I hope you can see where this can become confusing.

That's not the issue. The issue is how much momentum the light that actually leaves the laser has.

For the basic physics of it, yes -- you got me there.

But firing a laser isn't precisely identical to firing a gun. I was trying to work out how it would be different, and what aspects of the total system determines the net recoil effect. That may not be the immediate issue, but it's at least related.

I don't have the text in front of me, so I'm not sure how explicit Banks is about the lack of recoil or the nature of the laser. If he says that lasers just plain do not have recoil, period, then he made a mistake (as I did) -- you win. But, if he just says anything to the effect that the shooter simply didn't experience the recoil, there's a variety of explanations for how that could be. So what are we talking about? Perception or Reality?

But yes -- the momentum of the light that leaves the laser, and its intensity, will determine the recoil. On that, I doff my hat.

The momentum of the light leaving the barrel of the laser cannon, in this case, can be found from the energy needed to vaporize a quantity of steel. That's a very easy calculation and has nothing to do with the inner workings of the laser.

But how is the energy being delivered to the block of steel?

The amount of energy required can be delivered in a variety of ways. And different methods of delivery will make more sense some scenarios than others.

You could use a lower-power beam, but fire it longer. Or you could use a higher-power beam and fire it for a shorter length of time. Or you could divide the total energy required into any number of pulses over a given amount of time (so long as it is above the minimum to keep the steel from getting rid of the energy as heat faster than it accumulates energy from the laser).

The recoil then changes in effect, though not in amount overall.

In practical terms, that goes a long way to determining the actual kick experienced by the shooter/gun mount. Sure, the recoil is the same regardless, but would you rather get one large recoil from a single, short, high powered blast, or a gentler, vibrating recoil from 1000 pulses?

Science Fiction lasers being what they are (*cough*fictional*cough*), if the author hasn't told us why, then it may not be accurate to say that the author is saying that there's no recoil -- it might just be that there's no sensation of the recoil, or maybe neither. If the text isn't explicit, then...

Well, sorry for being rude, but I get tired of people who don't what they're talking about telling me I don't know what I'm talking about...

OK, so what are your qualifications? I haven't seen anywhere that you've indicated that you're anything other than a layman. What assurances do I have that your understanding is any better than mine?

...especially when your posted "proof" of laser gun recoil comes from a science fiction roleplaying game. Surely you can see how that might lead others to believe you're also a mere layman, and equally as likely to be wrong.

[psikeyhackr]

Originally Posted by Ropie

Authors are under no obligation to educate or, for the most part, be blamed when people take them too literally. Equally, story writers can not be expected to be experts in every field in which they write.

And I never said any of those things. But adults that give a damn can steer kids toward or away from certain authors.

Of course I did notice that some adults got pissed off when a kid knew more than they did. But they also tended to assume it came from school. My grade school teachers didn't teach science AT ALL. The sci-fi led me to the material.

psik

[deez sniderz]

I loved The Algebraist, personally.

Now, Consider Phlebas I got about 1/2-way through and hated it, but after seeing some of the above posts maybe I should try to get on with the Culture series...hmmm.

[Chuffalump]

Originally Posted by deez sniderz

I loved The Algebraist, personally.

Now, Consider Phlebas I got about 1/2-way through and hated it, but after seeing some of the above posts maybe I should try to get on with the Culture series...hmmm.

I think CP is the Banks book that would best translate into a Hollywood movie, due to the reasons that started this discussion in the first place.

However, give the rest of his SF work a try. It's worth it.

[Ropie]

Originally Posted by psikeyhackr

But adults that give a damn can steer kids toward or away from certain authors.

I wouldn't steer anyone away from Banks as he is actually a fine writer with good technical skills and enjoyable prose. If his science is not accurate I would consider that less important. It's not what he says but how he says it that makes him an author worth reading, IMO.

[Fung Koo]

I'll echo the above statement. Consider Phlebas would make a decent movie, but is probably his worst book IMO (which is excusable as it's his first published SF work). Banks' writing is really very good and engaging and clearly expressive.

It should be pointed out, too, that the Culture novels are full of non-real science. Don't go into them expecting exact science. A gigawatt laser in reality has recoil of about the same magnitude as holding a large cantaloupe against the pull of gravity, but to Banks this equals "no recoil."

Consider yourself warned!

[psikeyhackr]

I'm trying to figure out which equation is correct:

SF - S = F or SF/S = F

Science Fiction minus Science or divided by Science equals Fantasy.

psik

[Hitmouse]

Well I liked the Algebraist. Consider Phlebas is not the greatest but is not bad. His best SF IMHO is the magnificent Feersum Endjinn which is really worth a go. Banks' most interesting and likeable personalities are the minds. The Culture is also one of the most interesting and appealing societies in SF.

To trash a book because of some perceived sleight about recoil of a laser cannon is sort of missing the point. If one is going to get that picky then one might as well dismiss any SF novel requiring FTL travel etc etc.

[mylinar]

Originally Posted by psikeyhackr

I'm trying to figure out which equation is correct:

SF - S = F or SF/S = F

Science Fiction minus Science or divided by Science equals Fantasy.

psik

Ummm..... doesn't the F in the above equation equal 'Fiction'? Just saying

[psikeyhackr]

Originally Posted by mylinar

Ummm..... doesn't the F in the above equation equal 'Fiction'? Just saying

Of course. The equation is allegorical.

psik

[pontmercy]

I liked CP.
I also think that the pointlessness of the protagonist's actions was saying something quite profound (though cliched now) about the essiential nature of war. The whole issue of capturing the mind only really accounted for a few months increase or decrease in the length of the war; but how many people died in ww1 over a few yards of muddy turf?
In a way you could say that CP is quite a deep book hiding behind a hollywoodesque facade - the action at the light temple is a microcosm of the idiran/culture war. The scene with fwi-song is quite an interesting statement on the culture and the idirans - he is like an amalgam of the two: he has the religious fanaticism (his followers and and rituals) combined with the cultures decadence (his size and cannabilism).
This use of analogy within the book world to make comments on the main groups in the book world which in turn are analogies for societies and indivual stereotypes within our (seemingly) real world is one of the many reasons why writers like tolstoy are considered great.
So though the action seems to make it a "hollywood" book to those that can't really make abstract connections between events in a plot it may seem shallow - - - but it isn't. it's message is cliched though.