Re: topmind spreads his seed

On 2006-07-02, topmind <topmind@xxxxxxxxxxxxxxxx> wrote:

z wrote:
On 29 Jun 2006 21:00:17 -0700, "topmind" <topmind@xxxxxxxxxxxxxxxx>
wrote:


A simpler way to picture this is to take your spores and put them on the
lattices of a 10000 x 10000 x 10000 cube. If the cube has an edge of two
light-years, then that's a distance of a couple of billion km between
spores.

I am not sure what this is meant to imply. They don't travel in a
strait line, but rather will tend to be attracted to stars due to
gravity.

And would tend to end up impacting said stars due to gravity. Last
time I checked, the Sun was by far the biggest gravity well in our
solar system.

Yes, but unless something heads nearly strait at it, it will not pull
it directly into it.


Their motion will be perturbed by any star they encounter.

Agreed, but that is not the point. My point was that smashing directly
into a star is not that likely.

If it is unlikely to hit the star directly, then how likely is it to
hit a habitable planet?

If it is unlikely for a spore to orbit the star, how much less likely for
it to be captured by a planet and orbit it?

If they
pass close enough to a target star system that they pass whithin the
orbit of a hospitible planet, they are definately going to be strongly
influenced by the stars gravity. They will either be captured by it,
get pulled in after a few orbits, or slingshot out at an even greater
clip. The chances of them hitting the "right" planet in the system
are really really tiny. And if they do, the odds of anything
surviving re-entry are really, really low. Speed kills.

That is why one send thousand of pods, and even more if they have the
budget.

What number of pods will be necessary to deliver to the bounds of a
particular remote system to ensure a 1% chance of one of them actually
survive reentry into a planetary atmosphere?

Look at what the Egyptions spent to build pyrimids.

"Egyptians." "Pyramids."

If Osama took over
the world, sending Koronic scriptures into space (on US rockets) would
not be that unexpected.

"Koranic" presumably.

Why is it that when you are asked to be more precise and less vague, you
simply divert into irrelevancies, fantasies and other distractions?

It's a rhetorical question: the answer is simply that you can't do anything
else.

Another calculation. Let's assume a conventional explosive. The Pioneer 10
will reach the vicinity of Aldeberan in about two million years. A typical
explosive creates a velocity of a few thousand meters per second, let's be
conservative and say 1 km/s. Now there are about 6e13 seconds in a two
million year period, so the spores would be dispersed over a couple of
light-years or so, supporting the previous calculation.

But when they come near a star system, a couple of light years is
enough to disburse them further. Ones slightly closer to a passing star
will be flung to a far different path than neighbors. This makes a much
more effective scatterer than our small explosives.

F=g*M1*M2/r^2 If the spores start together, they will end up
together. The M2 and r^2 kills that argument.

I don't think this is the case when grazing heavy bodies. Slight
differences do get magnified. When craft use the gas giants to gain
speed, their position with regard to the planet is very critical
because the "curve" away from the planet is heavily leveraged. Run a
few simulations and you will see the leveraging.


Yep a cloud of capsule that manages to fall sling-shot around a mass
will get spread out. They still will all be travelling in the same
direction. Remember Shoemaker-Levy 9? It got broken up and dispersed
by Jupiter. The fragments all stayed in pretty much the same orbit.

But they were together when broken up. If they were *already* a bit
apart, then they would have been pushed even further apart by passing
close. The "line" was not perfectly strait.

"Straight." But all ended up mashing into Jupiter. None were flung out
of the solar system.

Untill they hit Jupiter, that is. The spread of the impacts was
mainly due to the rotation of the planet as the train went in.

I suppose you could have multiple sequential such sling shots, each
seperated by time and end up with a decent dispersal of the objects.
This would require a lot of luck so most of the objects launched
together would tend to hit or miss the same systems.

Like I said, the disbursement explosion could happen around Mars orbit.
The pods then get disbursed much more by passing Jupiter and at least
one other gas giant before leaving the solar system.

All you have to do is actually fill in all the numbers, and you might
actually have a proposal.

1. What is the total mass of the spores?
2. Divided into how many capsules?
3. What is their velocity at Mars?
4. What distribution of should the "explosion" be designed to produce?
5. What is the relative position of Jupiter at the time of the explosion?

It may have died over the last million years
for any of a variety of reasons, including cosmic rays.

I discussed this already. Most will indeed die. But, it takes only one
to trigger life. We are using spores from the toughest bacteria, not
average bacteria.

http://www.livescience.com/animalworld/050207_extremophiles.html

"One species of bacteria, Deinococcus radiodurans, can withstand a
15,000 gray dose of radiation - 10 grays would kill a human and it
takes over 1,000 grays to kill a cockroach. Extraterrestrial life forms
would most likely need to possess similar tolerances to radiation, as
the atmosphere on other planets, or lack thereof, filters out much less
radiation than Earth's."

This is interesting too, although speculative of course:


What you've failed to take into account is that D. radiodurans needs
to be metabolically active to recover from that sort of damage. You
can't just fry it and leave it alone for a few million years and
expect it to be alive. This is not some bacterial X-men mutant power,
it's part of the organism's biology.

You are perhaps correct that the toughest spores don't necessarily make
the toughest bacteria. I don't know what the toughest spores are.
However, I imagine D.rad is used to living in harsh environments, and
thus has fairly tough spores to match.

D. radiodurans does not form spores. As far as we can tell, it's
niche is ephemeral and arid ecosystems. Unlike other non-spore
forming bugs, D. radiodurans is extremely dessication resistant and so
as can can survive when the water dries up.

That is more or less the same thing as a "spore".

Not in the sense that any biologist would claim.

The radiation resistance
is actual a side effect of this dehydration resistance. Dehydration
causes DNA fragmentation, so this puppy is really good at DNA repair.

There is an easy way to make D. radiodurans die from radiation- place
it in nutrient poor conditions. Like an alien planet, perhaps? Just
as an aside, D. radiodurans will not grow in the absence of 16 amino
acids and nicotinic acid.

I don't know what the bacteria has the most radioresistant spores.
AFAIK, none come close to D. radiodurans.

I did not tie the idea to only D.rad. Obviously the candidates would go
thru a battery of tests first.

I'm sorry, but you have used up your quota of uses of the word "test".
We'll have to start charging you from now on.

Nothing really wrong with gas giants. Life may do well on/in gas
giants. And meteors grazing their atmospheres may carry life to the
inner rocky planets. True, this is highly speculative, but so is SETI.
It may be easier to spread microbes than find intelligent radio
builders. Microbes can be tenacious, intelligent life is fragile (so
far).

That includes some singularlly silly statements. It is far easier for
an intelligent life form to spread an EM signal than to spread spores.

Not necessarily. Our radio leakage is only listenable for roughly 50
light years using equiv of our equipment. Second, it is fleeting. Radio
signals may last only a few decades, but DNA messages may last
billions. Duration trumps spread in this case.

No, our radio leakage bubble is determined by how long we have been
leaking radio-waves. About 100 light years.

From what I've read, the distance that we could "hear" our own signals
using our existing equipment is something like 50 to 200 light years
out, depending on how hard one tries a specific spot.


DNA messages will not last billions of years floating in space. As
I've meantionaed above, you have a limited shelf-life due to chemical
instability and radiation damage.

I've read estimates of 10 million years in asteroid transfer studies.
If we use the "best of the best" spores and pack them in densly, I'm
assuming we can increase that to about 100 million. The density of
spores in normal rock is going to be sparse. We would jack the spores
way up to increase the chance of at least one surviving.


The amount of energy needed to create the astronomical number of
packages you need to send out to have even the slimmest chance of a
successful landing is going to be far greater than you need to send an
EM signal. Which goes orders of magnitudes faster.

But again, does not last as nearly as long. If you really want to get a
message out, you use different approaches.

Mmmm. Handwavy goodness.



or even a dead rock or
an icy body in the Oort Cloud. On entry and impact, it is likely to be
destroyed.

This is not necessarily the case. The pod casing would break up fairly
easily such that some peices have a gentle decelleration. Some are
protected in the eddies behind the main object. Remember, caculations
show that microbes may survive a rocky blast from the surface of Mars
and reentry to Earth.

In order to get things into another star system, you are gonna have to
get whatever object moving at real high speeds. Much higher than Mars
escape velocity. There would be no such thing as gentle deceleration-
they hit planetary body with an atmosphere and they will cook. What
you need for survival is mass.

Well, it is certainly something to consider. Note that some asteriods
and comets are pulled into a planetary orbit before any collision.

They were not travelling at Sol escape velocity or higher prior to
capture.

We don't know that.

Oh dear lord.

The comet may have formed in our solar system,

Oh dear lord.

or
captured from another one long ago.

Another "what" long ago?

Which is what your pods would be.


If by some odd chance it survives a fall on a climatologically
stable planet with liquid water, it will probably be overcome by the
indigenous life that is highly adapted to survival on the planet.

Earth experience shows that indigenous species are often not able to
compete with invaders because it takes a while for preditors to adapt
to the foreigner. By that time the invador gets a good foothold. It is
like an army with a new weapon: they kick your *** until you figure
out a counter offensive, which usually takes a while.

You are talking about landing on a planet with out life- WTF would you
even mention competition?

Somebody else brought up "indigenous life".




What your hypothesis requires is an intelligent delivery system- not
bricks of spores. You need something that can slow down when entering
a star system at the very least. You don't need full on UFO's piloted
by BEM, but you do need something. You are tossing a perishable
product out there.

Let's put a picture of the spores on milk cartons :-)

I don't know if we currently have the technology for such long-duration
controlled unmanned flights. It would need some kind of self-repair
capability.

However, we do have the technology for a human-crewed
multi-generational colony ship powered by "nukes" that could visit the
stars.

Given that the furthest away from earth we've been is only 250,000 or so
miles, that seems like a pretty bold assertion. The distance to alpha
centauri is about 101 million times greater. It's kind of like saying
that if you can run a mile, you can run to the sun.

It would cost more than the Iraq war and Apollo put together,
though. Maybe the Mormans will take up such a project. They have the
money, the history, and the nutballs :-)


B Miller

-T-


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