h a l f b a k e r yNaturally, seismology provides the answer.
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I imagine pairs of flashes could be very insightful, too, particularly if the
time between them was known very accurately - something which I
believe is quite possible with thermonuclear weapons. |
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hmmmm... - <handwaving> the atom bomb dropped on
Hiroshima
released about 60 x 10^12 Joules of energy. The
surface of a sphere 1,000,000 km in radius (i.e.
really, really tiny in astronomical terms) is about
12
x
10^12 km^2, so the energy per square km is about 5
Joules. Sunlight at the earth's surface is 1.3 x
10^9
W/km^2, so you're about 9 orders of magnitude away
from sunlight with this illumination (and of
course,
sunlight is continuous, not a brief flash).
</handwaving>
This kind of calculation makes
you appreciate how much energy the sun must be
putting out to be able to deliver 1.3kW/m^2 to the
Earth's surface, 150m km away... |
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"These are very small ... the ones out there are far away ..." |
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Of course it's nowhere near the same illumination as your planet gets, but it will be more than the ambient illumination. And it's controllable; an instant yes/no result, little flashes of reflected light with a precisely known spectrum and intensity curve. |
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Jupiter is about 5 times as far away from the sun as
the Earth, so asteroids at that distance should
receive 1/25th of the energy per unit of surface area
as we do on the Earth. So these objects you're hoping
to detect will still be receiving 7 or 8 orders of
magnitude more light from the sun than from your
bomb. |
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Yes ... that's not the point. It's not the absolute magnitude, it's the controlled change in magnitude at a known time that's useful. |
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//asteroids at that distance should receive 1/25th of the
energy// |
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This is a problem. Especially as the flash lasts, as far as I can
tell <1ms, although it doesn't matter if that's wrong by 100
fold. To solve the problem of a small amount of light coming
back, normally you'd just increase the light duration and
keep the shutter open longer. That's not going to work here.
It would work for closer, tricky to observe moon surfaces
and such. |
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//it's the controlled change in magnitude at a known time
that's useful// - controlled change, for 1ms, 7 or 8 orders
of magnitude dimmer than the ambient light
There's a very small chance this approach might work if
you
first go out there and coat all these undetected objects
with mirrors. |
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Or fluorophores carefully lined up with the notches in the
sun spectrum. |
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Thing is, what would be the point? CGI can give you really super pictures of asteroids, comets and even giant spiders. |
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//[T]he flash occurs when the device is transiting behind one of the
planets.// |
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So, presumably there won't be any sunlight hitting the target objects
at the same time as the flash? |
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//CGI can give you really super pictures of asteroids, comets and
even giant spiders.// |
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But CGI explosions aren't real. |
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They must be - I've seen them in the movies. |
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You mean Tom Cruise is real too? <shudders> |
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Yrs, but fortunately he's only about 7 inches tall. |
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... and what's more, if you look really closely, you can see the strings ... |
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Why do I have the uncomfortable feeling that this is just all
leading up to some gag about flashing Uranus, 8th? 'Gag'
being the operative word here. |
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From A. C. Clarke's SETI League guest editorial, "Where is
everybody?": |
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"In my 1993 novel, The Hammer of God, I described the possibility
of a gigaton bomb being exploded in Earth orbit, but on the other
side of the Sun, so that microwaves from that explosion will sweep
right across the solar system, in all directions. Thus Project
EXCALIBUR helped detect not only all the known satellites, comets
and asteroids, but every object more than a metre in diameter." |
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So, at least previously half-baked. |
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To be developed by a nuclear fusion flashmob. |
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/microwaves from that explosion/ |
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Does a fusion bomb radiate across the spectrum? |
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We might as well use the biggest bomb we can - so 100 Megatons which is something like 5000 times more than Hiroshima. And maybe it's possible to shape the blast so it forms a cone rather than a sphere - let's assume we can and we can focus all the energy into 1/10 of the surface of a sphere. Hopefully, this will make things a bit brighter. |
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Obviously, we would need lots pointing is all different directions, but that's OK. |
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Shirley you don't want to mess around with a piddly H-bomb; what you want is a supernova. I read somewhere that, if the sun went nova and you were standing on Earth looking at it, the energy that would hit your retina would be approximately the same as if you had your eye pressed up against the casing of an H-bomb when it went off. That is going to be some serious dazzle. |
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That was on XKCD (link) - a supernova seen from the Earth
at the
distance the sun is from the Earth would be brighter than
an atom bomb exploding in your face - about a billion times
brighter |
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I think it's one of those questions that can only be settled by experimentation. |
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Actually those two things work synergetically. |
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You're right, of course. Come on, [bungston], you're up next. Just stand there, on those chalk marks, and look towards the big cylindrical thing on the cradle ... |
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Stand down, [bung]. I've just found a ShitZu. |
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"Put the Ewok down, and step away from the thermonuclear weapon" |
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