My crazy idea for an interstellar probe with near-present technology

Basically, the idea is to launch the probe at nearly the speed of light
from a particle accelerator. That gets us to Alpha Centauri in less
than 5 years, and the data back in less than 10.

I see big engineering challenges, but no theoretical obstacles.

1. The probe must be small enough and the accelerator big enough that
they're compatible.
2. The probe must be launched in a vacuum, meaning the accelerator must
be built in space.
3. The small probe must be able to transmit to earth from trillions of
miles away.
4. The probe must be able to resist the magnetic & electrical fields in
the accelerator.

One thing that helps is that 90% of the speed of light would suffice.
Thus, no Tevatron required.

Comments? Am I crazy?

Greg

wrote:
Basically, the idea is to launch the probe at nearly the speed of light
from a particle accelerator. That gets us to Alpha Centauri in less
than 5 years, and the data back in less than 10.

I see big engineering challenges, but no theoretical obstacles.

1. The probe must be small enough and the accelerator big enough that
they're compatible.
2. The probe must be launched in a vacuum, meaning the accelerator must
be built in space.
3. The small probe must be able to transmit to earth from trillions of
miles away.
4. The probe must be able to resist the magnetic & electrical fields in
the accelerator.

One thing that helps is that 90% of the speed of light would suffice.
Thus, no Tevatron required.

Comments? Am I crazy?

Greg

I think the idea is workable with a slight modification. The problem
is there would be limited science you could do with such small
particles. So instead fire the small particles with the inbuilt ability
to assemble themselves into a larger device. I'm thinking of particles
the size of a virus or perhaps a bacterium. There have already been
cases where a synthetic virus has been created from scratch. I believe
there is ongoing research to create synthetic bacteria.
Probably a synthetic life form with the complexity of a virus would be
sufficient to be able to assemble itself and its fellow particles into
their correct positions for a workable scientific instrument. You could
probably fire the paricles from the ground if you had sufficient
redundancy so that if some are lost on contacting the air, they could
still assemble themselves into a workable device at their destination.
The nice thing about this approach is that the virii wouldn't have to
all have the insructions for creating the large instrument or
spacecraft themselves. The complexity and size of the instrument could
be built up step by step. The initial virii would only have simple
instructions for coming together in interlocking pieces to form larger
components. Then when these larger components are formed they would
automatically have the more complex intructions and propulsion means
formed to construct the full spacecraft.
I think this is doable with current technology. A question though is
how high is the mass that particle accelerators can accelerate
particles to near light speed? I know they can accelerate helium nuclei
for example. Can they accelerate uranium nuclei? How many uranium
nuclei would a virus weigh?



- Bob

Robert Clark wrote:
wrote:
Basically, the idea is to launch the probe at nearly the speed of light
from a particle accelerator. That gets us to Alpha Centauri in less
than 5 years, and the data back in less than 10.

I see big engineering challenges, but no theoretical obstacles.

1. The probe must be small enough and the accelerator big enough that
they're compatible.
2. The probe must be launched in a vacuum, meaning the accelerator must
be built in space.
3. The small probe must be able to transmit to earth from trillions of
miles away.
4. The probe must be able to resist the magnetic & electrical fields in
the accelerator.

One thing that helps is that 90% of the speed of light would suffice.
Thus, no Tevatron required.

Comments? Am I crazy?

Greg

I think the idea is workable with a slight modification. The problem
is there would be limited science you could do with such small
particles. So instead fire the small particles with the inbuilt ability
to assemble themselves into a larger device. I'm thinking of particles
the size of a virus or perhaps a bacterium. There have already been
cases where a synthetic virus has been created from scratch. I believe
there is ongoing research to create synthetic bacteria.
Probably a synthetic life form with the complexity of a virus would be
sufficient to be able to assemble itself and its fellow particles into
their correct positions for a workable scientific instrument. You could
probably fire the paricles from the ground if you had sufficient
redundancy so that if some are lost on contacting the air, they could
still assemble themselves into a workable device at their destination.
The nice thing about this approach is that the virii wouldn't have to
all have the insructions for creating the large instrument or
spacecraft themselves. The complexity and size of the instrument could
be built up step by step. The initial virii would only have simple
instructions for coming together in interlocking pieces to form larger
components. Then when these larger components are formed they would
automatically have the more complex intructions and propulsion means
formed to construct the full spacecraft.
I think this is doable with current technology. A question though is
how high is the mass that particle accelerators can accelerate
particles to near light speed? I know they can accelerate helium nuclei
for example. Can they accelerate uranium nuclei? How many uranium
nuclei would a virus weigh?



- Bob

Bob, I think you need to check some of your
numbers and assumptions.

Your fundamental misconception is that you seem to believe there's
some advantage to launching a bunch of very small things as opposed
to one large thing. Yes, particle accelerators can accelerate things
up to heavy neuclei to very close to the speed of light, BUT the
numbers they
accelerate are orders of magnitude smaller than Avagadro's Number,
which is the scale you would need to assemble something macroscopic,
even if you could figure out a way to do such a thing.

If you could figure out a way to accelerate that many particles, then
it would take just as much energy as assembling it beforehand and
launching it whole.


-jc

wrote:
Basically, the idea is to launch the probe at nearly the speed of light
from a particle accelerator. That gets us to Alpha Centauri in less
than 5 years, and the data back in less than 10.

I see big engineering challenges, but no theoretical obstacles.

1. The probe must be small enough and the accelerator big enough that
they're compatible.
2. The probe must be launched in a vacuum, meaning the accelerator must
be built in space.
3. The small probe must be able to transmit to earth from trillions of
miles away.
4. The probe must be able to resist the magnetic & electrical fields in
the accelerator.

One thing that helps is that 90% of the speed of light would suffice.
Thus, no Tevatron required.

Comments? Am I crazy?

Hmmm. I wouldn't say that this can be done with "near"-present
technology.

The Fermilab Tevatron pumps protons up to just barely c. At the very
front end of the acceleration process there's one of those metal
cylinders, like the ones you can see at a carnival full of helium for
childrens' balloons. At the lab that bottle is full of hydrogen, which
gets pumped into the accelerator. How long does it take for the lab to
use up that one bottle of hydrogen for the expriments? It takes on the
order of a year or so to use up just that small mass of hydrogen. The
Tevatron, currently the world's highest energy collider, takes all year
to accelerate a very, very small amount of mass up close to c. A probe
would be very much more massive than the gas in that bottle, and so
would require an incredible quantity of work to accelerate it up to
near c.

And protons aren't easily broken. The Tevatron gets them up nearly
to c in just a matter of seconds. Protons can withstand such a high
acceleration. A probe laden with instruments would be rather delicate,
and there's just no way it could withstand such acceleration. It'd be
smashed. It would need to be accelerated much more gently, for its own
sake, and would take quite a long time to get close to c.

-Mark Martin

jcon wrote:
Robert Clark wrote:
I think the idea is workable with a slight modification. The problem
is there would be limited science you could do with such small
particles. So instead fire the small particles with the inbuilt ability
to assemble themselves into a larger device. I'm thinking of particles
the size of a virus or perhaps a bacterium. There have already been
cases where a synthetic virus has been created from scratch. I believe
there is ongoing research to create synthetic bacteria.
Probably a synthetic life form with the complexity of a virus would be
sufficient to be able to assemble itself and its fellow particles into
their correct positions for a workable scientific instrument. You could
probably fire the paricles from the ground if you had sufficient
redundancy so that if some are lost on contacting the air, they could
still assemble themselves into a workable device at their destination.
The nice thing about this approach is that the virii wouldn't have to
all have the insructions for creating the large instrument or
spacecraft themselves. The complexity and size of the instrument could
be built up step by step. The initial virii would only have simple
instructions for coming together in interlocking pieces to form larger
components. Then when these larger components are formed they would
automatically have the more complex intructions and propulsion means
formed to construct the full spacecraft.
I think this is doable with current technology. A question though is
how high is the mass that particle accelerators can accelerate
particles to near light speed? I know they can accelerate helium nuclei
for example. Can they accelerate uranium nuclei? How many uranium
nuclei would a virus weigh?



- Bob

Bob, I think you need to check some of your
numbers and assumptions.

Your fundamental misconception is that you seem to believe there's
some advantage to launching a bunch of very small things as opposed
to one large thing. Yes, particle accelerators can accelerate things
up to heavy neuclei to very close to the speed of light, BUT the
numbers they
accelerate are orders of magnitude smaller than Avagadro's Number,
which is the scale you would need to assemble something macroscopic,
even if you could figure out a way to do such a thing.

If you could figure out a way to accelerate that many particles, then
it would take just as much energy as assembling it beforehand and
launching it whole.


-jc

Check on how accelerators work. My understanding is that they will
accelerate any charged body in the device because they work by magnetic
fields; large particles though will be accelerated to lower speeds.
Some ref's put the number of particles accelerated in modern
accelerators at the tens of trillions. So put large numbers of the
synth-virii in the device and run it continuously.


Bob Clark

Robert Clark wrote:
jcon wrote:
Robert Clark wrote:
I think the idea is workable with a slight modification. The problem
is there would be limited science you could do with such small
particles. So instead fire the small particles with the inbuilt ability
to assemble themselves into a larger device. I'm thinking of particles
the size of a virus or perhaps a bacterium. There have already been
cases where a synthetic virus has been created from scratch. I believe
there is ongoing research to create synthetic bacteria.
Probably a synthetic life form with the complexity of a virus would be
sufficient to be able to assemble itself and its fellow particles into
their correct positions for a workable scientific instrument. You could
probably fire the paricles from the ground if you had sufficient
redundancy so that if some are lost on contacting the air, they could
still assemble themselves into a workable device at their destination.
The nice thing about this approach is that the virii wouldn't have to
all have the insructions for creating the large instrument or
spacecraft themselves. The complexity and size of the instrument could
be built up step by step. The initial virii would only have simple
instructions for coming together in interlocking pieces to form larger
components. Then when these larger components are formed they would
automatically have the more complex intructions and propulsion means
formed to construct the full spacecraft.
I think this is doable with current technology. A question though is
how high is the mass that particle accelerators can accelerate
particles to near light speed? I know they can accelerate helium nuclei
for example. Can they accelerate uranium nuclei? How many uranium
nuclei would a virus weigh?



- Bob

Bob, I think you need to check some of your
numbers and assumptions.

Your fundamental misconception is that you seem to believe there's
some advantage to launching a bunch of very small things as opposed
to one large thing. Yes, particle accelerators can accelerate things
up to heavy neuclei to very close to the speed of light, BUT the
numbers they
accelerate are orders of magnitude smaller than Avagadro's Number,
which is the scale you would need to assemble something macroscopic,
even if you could figure out a way to do such a thing.

If you could figure out a way to accelerate that many particles, then
it would take just as much energy as assembling it beforehand and
launching it whole.


-jc

Check on how accelerators work. My understanding is that they will
accelerate any charged body in the device because they work by magnetic
fields; large particles though will be accelerated to lower speeds.
Some ref's put the number of particles accelerated in modern
accelerators at the tens of trillions. So put large numbers of the
synth-virii in the device and run it continuously.


Several comments:
1. Accelerators accelerate with electric fields. The magnetic fields
are there only to steer the particles back around to the electric field
again.
2. The rate of acceleration is roughly proportional to q/m where q is
the charge of the particle and m is the rest mass. This also constrains
how big the steering magnet field has to be. Thus, if you want to get
the same acceleration for a particle of A nucleons as you do for a
proton, then you have to give it a charge of Ae. Not doing so lowers
the energy obtained AND forces the ring to be larger.
3. Giving a particle of mass A daltons a charge of Ae is conceivable
for single nuclei, but would immediately disrupt the bonds of any
molecule, let alone one the size of a virus.
4. A free beam of charged particles diverges naturally because of,
well, their charge. This is corrected for in a storage ring with
focusing magnets, but those would not be available in the long run
between here and Alpha Centauri. A free beam of particles would diffuse
hopelessly well before leaving the solar system.
5. Alignment in accelerator rings is done to the tens of microns and
relies on firm anchoring in bedrock. (LEP saw the effect of the tides
on its measurements of the Z mass.) Accomplishing this in a ring of
this size in orbit would be a, let's say, costly exercise.
6. The number of particles stored in a beam is indeed (on a good day)
tens of trillions of particles. That's 1E13. A store usually takes an
hour to fill and ramp up. It's been pointed out to you that what would
be required would be a collection of particles (all within close
proximity) of order a mole. A mole is of order 1E23. That is ten
billion stores, or ten billion hours, or a bit over a million years.

This might work for a cute science fiction story, but not as a
technical proposal. Not even on the back of an envelope.

PD

Robert Clark wrote:
jcon wrote:
Robert Clark wrote:
I think the idea is workable with a slight modification. The problem
is there would be limited science you could do with such small
particles. So instead fire the small particles with the inbuilt ability
to assemble themselves into a larger device. I'm thinking of particles
the size of a virus or perhaps a bacterium. There have already been
cases where a synthetic virus has been created from scratch. I believe
there is ongoing research to create synthetic bacteria.
Probably a synthetic life form with the complexity of a virus would be
sufficient to be able to assemble itself and its fellow particles into
their correct positions for a workable scientific instrument. You could
probably fire the paricles from the ground if you had sufficient
redundancy so that if some are lost on contacting the air, they could
still assemble themselves into a workable device at their destination.
The nice thing about this approach is that the virii wouldn't have to
all have the insructions for creating the large instrument or
spacecraft themselves. The complexity and size of the instrument could
be built up step by step. The initial virii would only have simple
instructions for coming together in interlocking pieces to form larger
components. Then when these larger components are formed they would
automatically have the more complex intructions and propulsion means
formed to construct the full spacecraft.
I think this is doable with current technology. A question though is
how high is the mass that particle accelerators can accelerate
particles to near light speed? I know they can accelerate helium nuclei
for example. Can they accelerate uranium nuclei? How many uranium
nuclei would a virus weigh?



- Bob

Bob, I think you need to check some of your
numbers and assumptions.

Your fundamental misconception is that you seem to believe there's
some advantage to launching a bunch of very small things as opposed
to one large thing. Yes, particle accelerators can accelerate things
up to heavy neuclei to very close to the speed of light, BUT the
numbers they
accelerate are orders of magnitude smaller than Avagadro's Number,
which is the scale you would need to assemble something macroscopic,
even if you could figure out a way to do such a thing.

If you could figure out a way to accelerate that many particles, then
it would take just as much energy as assembling it beforehand and
launching it whole.


-jc

Check on how accelerators work. My understanding is that they will
accelerate any charged body in the device because they work by magnetic
fields; large particles though will be accelerated to lower speeds.
Some ref's put the number of particles accelerated in modern
accelerators at the tens of trillions. So put large numbers of the
synth-virii in the device and run it continuously.


Several comments:
1. Accelerators accelerate with electric fields. The magnetic fields
are there only to steer the particles back around to the electric field
again.
2. The rate of acceleration is roughly proportional to q/m where q is
the charge of the particle and m is the rest mass. This also constrains
how big the steering magnet field has to be. Thus, if you want to get
the same acceleration for a particle of A nucleons as you do for a
proton, then you have to give it a charge of Ae. Not doing so lowers
the energy obtained AND forces the ring to be larger.
3. Giving a particle of mass A daltons a charge of Ae is conceivable
for single nuclei, but would immediately disrupt the bonds of any
molecule, let alone one the size of a virus.
4. A free beam of charged particles diverges naturally because of,
well, their charge. This is corrected for in a storage ring with
focusing magnets, but those would not be available in the long run
between here and Alpha Centauri. A free beam of particles would diffuse
hopelessly well before leaving the solar system.
5. Alignment in accelerator rings is done to the tens of microns and
relies on firm anchoring in bedrock. (LEP saw the effect of the tides
on its measurements of the Z mass.) Accomplishing this in a ring of
this size in orbit would be a, let's say, costly exercise.
6. The number of particles stored in a beam is indeed (on a good day)
tens of trillions of particles. That's 1E13. A store usually takes an
hour to fill and ramp up. It's been pointed out to you that what would
be required would be a collection of particles (all within close
proximity) of order a mole. A mole is of order 1E23. That is ten
billion stores, or ten billion hours, or a bit over a million years.

This might work for a cute science fiction story, but not as a
technical proposal. Not even on the back of an envelope.

PD

My idea was to launch fully assembled, yet very small probes, so beam
divergence would not be an issue. Point 5 is a very good one. Maybe
build it on the moon?

It also seems that at the very least, the probe could not have any
moving parts, thus limiting its design.

I'm not about to suggest this is a technical proposal, just an envelope
back. Or better, a bar napkin. Most proposals for interstellar travel
require Star Trek technology. My idea may be theoretically possible,
even if it is an engineering impossibility.

Thanks,
Greg

Dear PD:

"PD" wrote in message
oups.com...
....
4. A free beam of charged particles diverges
naturally because of, well, their charge. This
is corrected for in a storage ring with focusing
magnets, but those would not be available in
the long run between here and Alpha
Centauri. A free beam of particles would
diffuse hopelessly well before leaving the
solar system.

If we are improving the science fiction story, the self-assembly
could begin immediately after acceleration ceased. No need to
wait for diffusion to occur. In fact you could direct another
beam, one of electrons to neutralize the repulsive charge pf the
outgoing "charged bodies"...

The idea is still very broken, but this part I can "fix"... ;)

David A. Smith

Apparently there is research on table-top accelerators to accelerate
molecules up to 10,000 atomic mass units:

Tabletop linear accelerator for massive molecules
Creator/Author Hendell, E. ; Even, U. [Raymond and Beverly Sackler
Faculty of Exact Sciences, School of Chemistry, Tel Aviv University
(Israel)]
Review of Scientific Instruments ; VOL. 66 ; ISSUE: 7 ; PBD: Jul 1995
"A simple, tabletop, linear accelerator based on low duty factor square
wave pulses has been developed to accelerate very heavy molecular ions
(100--10 000 a.m.u.) to energies of tens of keV. The accelerator can be
added to existing mass spectrometers to improve the detection
efficiency (secondary electron yield) of both positive and negatively
charged clusters.{copyright}{ital 1995}{ital American}{ital
Institute}{ital of}{ital Physics}."
http://www.osti.gov/energycitations/...osti_id=165353

Though I don't know what speeds can be achieved with these heavy
molecules. These are table-top intruments. So could be ramped up to
accelerate very many of these molecules.

Bob Clark


PD wrote:
Several comments:
1. Accelerators accelerate with electric fields. The magnetic fields
are there only to steer the particles back around to the electric field
again.
2. The rate of acceleration is roughly proportional to q/m where q is
the charge of the particle and m is the rest mass. This also constrains
how big the steering magnet field has to be. Thus, if you want to get
the same acceleration for a particle of A nucleons as you do for a
proton, then you have to give it a charge of Ae. Not doing so lowers
the energy obtained AND forces the ring to be larger.
3. Giving a particle of mass A daltons a charge of Ae is conceivable
for single nuclei, but would immediately disrupt the bonds of any
molecule, let alone one the size of a virus.
4. A free beam of charged particles diverges naturally because of,
well, their charge. This is corrected for in a storage ring with
focusing magnets, but those would not be available in the long run
between here and Alpha Centauri. A free beam of particles would diffuse
hopelessly well before leaving the solar system.
5. Alignment in accelerator rings is done to the tens of microns and
relies on firm anchoring in bedrock. (LEP saw the effect of the tides
on its measurements of the Z mass.) Accomplishing this in a ring of
this size in orbit would be a, let's say, costly exercise.
6. The number of particles stored in a beam is indeed (on a good day)
tens of trillions of particles. That's 1E13. A store usually takes an
hour to fill and ramp up. It's been pointed out to you that what would
be required would be a collection of particles (all within close
proximity) of order a mole. A mole is of order 1E23. That is ten
billion stores, or ten billion hours, or a bit over a million years.

This might work for a cute science fiction story, but not as a
technical proposal. Not even on the back of an envelope.

PD