Discussion:
OT: Sci-fi fantasy - Torchships!
(too old to reply)
Rich Grise
2011-02-26 22:54:18 UTC
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I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.

This could be either:
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic

depending on the style of story you're writing. :-)

Anyhoo, I looked up some numbers, and Wiki sez:
http://en.wikipedia.org/wiki/Nuclear_fusion

The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"

So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?

Would it be like a particle beam weapon? =:-O

Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.

The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)

Thanks,
Rich
John - KD5YI
2011-02-26 23:23:05 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Thanks,
Rich
Well, starting from the surface of the earth, you have 1 G of
acceleration upward and 1 G of gravity pulling you back down, so you
won't go anywhere.

But, for the extremely simplistic exercise you're thinking of, your
answer is 18,166 seconds.

You're welcome,
John
Rich Grise
2011-02-28 06:23:05 UTC
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Post by John - KD5YI
Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They
say, "Fusion of deuterium with tritium creating helium-4, freeing a
neutron, and releasing 17.59 MeV of energy, as an appropriate amount of
mass converting to the kinetic energy of the products, in agreement with
E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Well, starting from the surface of the earth, you have 1 G of
acceleration upward and 1 G of gravity pulling you back down, so you
won't go anywhere.
But, for the extremely simplistic exercise you're thinking of, your
answer is 18,166 seconds.
So, with my fantasy torchship (assume I meant _net_ acceleration; we
can start in orbit) You could get to the moon in FIVE HOURS!!!

Now, there's a goal worth striving for. ;-)

Hey, John KD5YI, since you seem to know the numbers, do you feel like
working out the same ones for, say, the planets and stuff?

I also wonder how long it would take to get into time dilation
territory. ;-)

Thanks!
Rich
Bill Sloman
2011-02-26 23:36:47 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
Anyhoo, I looked up some numbers, and Wiki sez:http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Not really. The reaction you are interested in is what powers the
sun.

http://science.howstuffworks.com/sun2.htm

It is very slow, even at 15 million degrees Kelvin at the centre of
the sun - you have to get the protons travelling very fast in roughly
opposite directions if they are going to have any chance of fusing
when they collide.

Any technique that could get them to fuse in your black box would be a
sufficiently advanced technology to look very like magic to us.

If you want to speculate about some other kinds of black box, Robert
L. Forward thought of a few that might conceivably work, as did
Charles Sheffield

http://www.ansible.co.uk/writing/proteusu.html

The did rely on black holes, which - in principle - convert matter
entirely into energy, which would utilise your hydrogen atoms rather
more efficiently.

--
Bill Sloman,
Joseph Gwinn
2011-02-27 00:37:02 UTC
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The original ScFi torchships were spherical, and powered by total
conversion of mass into energy. I recall reading the Heinlein stories
in the 1960s or so. <http://www.worldlingo.com/ma/enwiki/en/Torchship>

Heinlein's torchships could lift off from the ocean, far from land. The
exhaust "rocket" beam was all photons, so think the mother of all
metal-cutting lasers. At distance, they were still intolerably bright.
Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
I'll make the calculation, but at say one megawatt, the dose at ten
meters from the reactor will be immense, being instantly lethal. My
initial calculation yields 500,000 REM per second per square meter. It
takes about 500 REM to kill half those exposed.

Do you recall the Cold Fusion episode? The biggest problem that the
Physics community had was that if the claimed power levels really came
from the D-T fusion reaction as claimed, the neutron flux should have
killed everyone in the lab. And this was at a trivial power level,
compared to what's needed for a starship.

By the way, of the total 17.6 Mev total, 14.1 Mev is carried by the
neutron, and 3.5 Mev by the Helium nucleus, so the neutron energy must
be captured for efficiency. Most likely, the neutrons would be captured
in a liquid lithium blanket, where the neutrons produce more tritium, as
planned for fusion power plants.
Post by Rich Grise
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
The problem will be the immense neutron flux, which will necessitate an
immense shield. This may require that the ship be built in orbit, so it
need not lift its own weight.
Post by Rich Grise
Would it be like a particle beam weapon? =:-O
Oh yes. Neutrons everywhere, plus the rocket exhaust, which will be
quite directional and will likely be quite capable of cutting stone and
steel.
Post by Rich Grise
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Look up Bussard Ramjet. <http://en.wikipedia.org/wiki/Bussard_ramjet>


Joe Gwinn
Rich Grise
2011-02-28 06:18:09 UTC
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Post by Joseph Gwinn
Post by Rich Grise
Would it be like a particle beam weapon? =:-O
Oh yes. Neutrons everywhere, plus the rocket exhaust, which will be
quite directional and will likely be quite capable of cutting stone and
steel.
No, no, you're missing the point here. I'm talking about a fantasy
black box, that doesn't have any of those real-world problems; that's
taken care of by either

a) technology that is yet to be developed
b) alien technology
c) fuckin' magic.

I was only interested in the numbers, like how many MeV in a joule,
and how fast that makes a helium atom go, and what the resulting thrust
would be.

But, I admit, that's rocket science, so I'm not ashamed to not know it.

Thanks,
Rich
Tim Wescott
2011-02-27 03:22:39 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
E = mc^2. Look up the atomic mass of H-2, and look up the atomic mass
of He-4. From that you can calculate the mass lost as a Kg of H-2
converts to slightly less than a Kg of He-4. That lost mass turns to
energy, so you can figure out how much energy _in Joules_ is in that Kg
of He-4. From that you can figure out velocity out the tail pipe, and
from that the momentum change. Then from that you can figure out thrust
/ mass flow rate.

Then look at this page: http://en.wikipedia.org/wiki/Ramship.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html
CaveLamb
2011-02-27 06:19:45 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
Larry Niven did it - quite ell in fact.
--
Richard Lamb
email me: ***@earthlink.net
web site: http://www.home.earthlink.net/~cavelamb
Bill Sloman
2011-02-27 10:36:26 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
Anyhoo, I looked up some numbers, and Wiki sez:http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Nobody in their right mind.

Robert L. Forward and Charles Sheffield have played with this kind of
idea, but they used minature black holes to convert the whole mass of
the hydrogen atom (or whatever) into energy, rather than than the
difference in mass defect between hydrgen and helium, which may be
good enough for main sequence stars, but won't do for a supernova, let
alone a galaxy.

--
Bill Sloman, Nijmegen
Dancing Fingers
2011-02-27 13:01:34 UTC
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Speaking of sci-fi and fusion I watched Watson on Jeopardy with
sadness, for us humans, and excitement. I would love to be a Fusion
researcher and have Watson as my partner. If we could plug all the
available fusion data into Watson and then ask him questions it would
be fascinating.

Chris
Bradley K. Sherman
2011-02-27 15:17:34 UTC
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Post by Dancing Fingers
Speaking of sci-fi and fusion I watched Watson on Jeopardy with
sadness, for us humans, and excitement. I would love to be a Fusion
researcher and have Watson as my partner. If we could plug all the
available fusion data into Watson and then ask him questions it would
be fascinating.
That reminds me of the story about the smart missile developed
by DARPA in the 1980's. Hundreds of NSA superprogrammers
instilled in it a fuzzy-logic brain that was capable of
anticipating threats and maneuvering on its own. They gave
it a Steven Hawking voice and natural language recognition.
Finally George H.W. Bush gave it the command to strike Iraq.
Nothing happened. Mission control queried the missile as
to what the problem was. "I'd rather take up gardening,"
replied the missile.

--bks
Charlie Gibbs
2011-02-28 01:43:59 UTC
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In article
Post by Dancing Fingers
Speaking of sci-fi and fusion I watched Watson on Jeopardy with
sadness, for us humans, and excitement. I would love to be a Fusion
researcher and have Watson as my partner. If we could plug all the
available fusion data into Watson and then ask him questions it would
be fascinating.
That reminds me of the story about the smart missile developed
by DARPA in the 1980's. Hundreds of NSA superprogrammers
instilled in it a fuzzy-logic brain that was capable of
anticipating threats and maneuvering on its own. They gave
it a Steven Hawking voice and natural language recognition.
Finally George H.W. Bush gave it the command to strike Iraq.
Nothing happened. Mission control queried the missile as
to what the problem was. "I'd rather take up gardening,"
replied the missile.
That sounds like the smart bomb in the movie "Dark Star".
--
/~\ ***@kltpzyxm.invalid (Charlie Gibbs)
\ / I'm really at ac.dekanfrus if you read it the right way.
X Top-posted messages will probably be ignored. See RFC1855.
/ \ HTML will DEFINITELY be ignored. Join the ASCII ribbon campaign!
Rich Grise
2011-03-01 11:26:08 UTC
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Post by Charlie Gibbs
Post by Bradley K. Sherman
Post by Dancing Fingers
Speaking of sci-fi and fusion I watched Watson on Jeopardy with
sadness, for us humans, and excitement. I would love to be a Fusion
researcher and have Watson as my partner. If we could plug all the
available fusion data into Watson and then ask him questions it would
be fascinating.
That reminds me of the story about the smart missile developed
by DARPA in the 1980's. Hundreds of NSA superprogrammers
instilled in it a fuzzy-logic brain that was capable of
anticipating threats and maneuvering on its own. They gave
it a Steven Hawking voice and natural language recognition.
Finally George H.W. Bush gave it the command to strike Iraq.
Nothing happened. Mission control queried the missile as
to what the problem was. "I'd rather take up gardening,"
replied the missile.
That sounds like the smart bomb in the movie "Dark Star".
Yeah! I remember seeing that one, and Bradley's story reminded me
of it too! ;-)

Cheers!
Rich
Bill Sloman
2011-02-27 16:10:53 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
Anyhoo, I looked up some numbers, and Wiki sez:http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Nobody in their right mind.

The idea that you have chanced on is old hat.

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

The more interesting fantasies - from Robert L. Forward and Charles
Sheffield, amongst other, used a small - portable - black hole to
convert the whole of the mass of an hydrogen atom (or whatever) into
energy, rather than the derisory porportion converted to energy by
fusion to helium. Supernovas do better - they fuse the nuclei down to
iron, which has the biggest mass defect - but it's still kid's stuff
when compared with a black hole.

Since your brain seems to have stopped working properly in the early
1950's, it isn't really surprising that you've missed the more recent
stuff.

--
Bill Sloman, Nijmegen
Dirk Bruere at NeoPax
2011-02-27 18:11:33 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Thanks,
Rich
Plasma Focus Fusion:
http://en.wikipedia.org/wiki/Dense_plasma_focus

http://focusfusion.org/index.php/site/category/C36/
--
Dirk

http://www.neopax.com/technomage/ - My new book - Magick and Technology
Bill Sloman
2011-02-28 11:34:45 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
Anyhoo, I looked up some numbers, and Wiki sez:http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
This is going to be third time I've tried to post a response to this
antiquated idiocy. The Bussard interstellar ram-jet or ram-scoop was
originally proposed in 1960

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

and has shown up in quite a few science-fiction novels since then.

Robert L. Forward and Charles Sheffield are more partial to the idea
of exploiting a small and portable black hole to convert all the
incoming hydrogen (or whatever) into energy, which - if it could be
made to work - would make maximum use of the mass-energy available.

I've long been of the opinion that Rich's brain stopped working
sometime in the 1950s and this does tend to reinforce that point of
view.

--
Bill Sloman, Nijmegen
Bill Sloman
2011-02-28 16:51:16 UTC
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Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
Anyhoo, I looked up some numbers, and Wiki sez:http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
This makes my forth attempt to post a comment on this thread.

If Rich had remembered anything that he'd read since the 1960's he
might have realised that he'd just re-invented the Bussard
interstellar ram-jet

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

Larry Niven quite liked it, and wrote it into a few of his stories.
Science fiction writers who knew more physics - like Robert L. Forward
and Charles Sheffield - seem to preferred to fantasise about small,
portable black holes. These do have the virtue that every last gram of
mass that vanishes into the black hole is converted into energy in the
process, though you may have some trouble extracting the last of the
energy from the immediate vicinity of the event horizon.

--
Bill Sloman, Nijmegen
Chris
2011-03-01 09:25:17 UTC
Permalink
Raw Message
Called an interstellar ramjet
Post by Rich Grise
I was just musing about making fusion practical, and I've come up with
a science-fictional fantastical black box that takes hydrogen in one
end, and puts helium and a whole shitpot load of energy out the other.
1. Technology we haven't invented yet
2. Alien technology
3. F''king magic
depending on the style of story you're writing. :-)
http://en.wikipedia.org/wiki/Nuclear_fusion
The numbers I'm interested in are in the inset under "Overview." They say,
"Fusion of deuterium with tritium creating helium-4, freeing a neutron, and
releasing 17.59 MeV of energy, as an appropriate amount of mass converting
to the kinetic energy of the products, in agreement with E = ?mc2.[1]"
So, what I'm wondering is, how to convert those 17.59 MeV per event to
stuff like "how much electricity per gram" and specifically, if you
magickally imparted that 17.59 MeV to the helium atom, how fast would
it be going out the exhaust, and how much thrust would it generate?
Would it be like a particle beam weapon? =:-O
Admittedly, my fantasy is about plain hydrogen, but using deuterium
will get me in the ballpark, and H+H would be more.
The idea being a rocket that takes hydrogen for fuel, and spits out
very hot, very fast helium, accelerating at 1G half way and decelerating
at 1G the rest of the way. If you could do that, you could get from the
Earth to the Moon in, lessee ... s = (1/2) at^2; in CGS, 125,000 miles
is oh crap. MONGO centimeters; anybody wanna do my homework for me? ;-)
Thanks,
Rich
Rich Grise
2011-03-01 11:19:32 UTC
Permalink
Raw Message
Post by Chris
Called an interstellar ramjet
No, not a ramjet - I'll be carrying my own hydrogen, so it'd be a rocket.

Thanks!
Rich
Chris
2011-03-01 17:21:16 UTC
Permalink
Raw Message
I think this type of rocket was discussed in the British interplanetary
jounal under "project deadelus" which is the British star ship project.

Here pellets of lithium hydryde (h bomb fuel) are injected into a parabolic
reaction zone and ignited by laser compression to create a nuclear fusion
explosion to privide the rocket exhaust.

Your design is much more sophisticated. It has been discussed and reported
to have been made in an american secret project where Dueterium is ionised
and injected into a reaction chamber made with a mafnetic bottle and the hot
helium gas that is made by fusion is the rocket exhastst controlled by a
magnetic jet pipe and nozzle.

The report said is was very good and fast but could not be controlled but it
is still under development.

Chris.
Post by Rich Grise
Post by Chris
Called an interstellar ramjet
No, not a ramjet - I'll be carrying my own hydrogen, so it'd be a rocket.
Thanks!
Rich
Rich Grise
2011-03-01 21:17:31 UTC
Permalink
Raw Message
Post by Chris
I think this type of rocket was discussed in the British interplanetary
jounal under "project deadelus" which is the British star ship project.
Here pellets of lithium hydryde (h bomb fuel) are injected into a
parabolic reaction zone and ignited by laser compression to create a
nuclear fusion explosion to privide the rocket exhaust.
Your design is much more sophisticated. It has been discussed and reported
to have been made in an american secret project where Dueterium is ionised
and injected into a reaction chamber made with a mafnetic bottle and the
hot helium gas that is made by fusion is the rocket exhastst controlled by
a magnetic jet pipe and nozzle.
The report said is was very good and fast but could not be controlled but
it is still under development.
Kewl!
(if it's true.)

And then, of course, if the helium is ionized, you could use MHD on a
ground-based one to generate a bunch of electricity!

Thanks!
Rich
Chris
2011-03-02 09:42:01 UTC
Permalink
Raw Message
I have succeeded in transmuting hydrogen to helium by proton fusion in a
tiny reactor I built at home. It probably generated one microwatt for 4
minutes but this took 500 watt exciter power.

see:

http://www.chrisspages.co.uk and look under "my fusion reactor" or words to
that effect.

Chris.
Post by Rich Grise
Post by Chris
I think this type of rocket was discussed in the British interplanetary
jounal under "project deadelus" which is the British star ship project.
Here pellets of lithium hydryde (h bomb fuel) are injected into a
parabolic reaction zone and ignited by laser compression to create a
nuclear fusion explosion to privide the rocket exhaust.
Your design is much more sophisticated. It has been discussed and reported
to have been made in an american secret project where Dueterium is ionised
and injected into a reaction chamber made with a mafnetic bottle and the
hot helium gas that is made by fusion is the rocket exhastst controlled by
a magnetic jet pipe and nozzle.
The report said is was very good and fast but could not be controlled but
it is still under development.
Kewl!
(if it's true.)
And then, of course, if the helium is ionized, you could use MHD on a
ground-based one to generate a bunch of electricity!
Thanks!
Rich
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