5 ms·

(ignore what I said here)

by afreak 10y ago

zeven7 10y ago
The laser is only on each device for 10 minutes. And there are 1,000 of them. So the hope is that at laest 1 in 1,000 will make it.
- dingbat 10y ago
  if even a tiny fraction of those 1000 tiny probes hit that planet at 20% of speed of light, could that pose a problem? it sounds like a shotgun approach, not so figuratively, using pellets loaded with plutonium.
  - jessriedel 10y ago
    The probes would each be only a few grams, so they'd have about 10^13 J of relativistic kinetic energy, or a half kilotons of TNT equivalent. This can be compared with the 15 kilotons for the (small, by modern standard) Little Boy atomic bomb. So it's probably noticeable for any inhabitants in the area, depending on how the energy is dissipated in the atmosphere, but still quite small on the scale of a planet.
    - mikeash 10y ago
      It should be noted that meteors explode with Hiroshima-like force fairly regularly within Earth's atmosphere, on the order of once a decade or so. It happens high up enough that nobody notices beyond an occasional light show. The meteor explosion which hurt a bunch of people in Chelyabinsk a few years back was about 500 kilotons.
      - dingbat 10y ago
        cool, good to know that raining down a bunch of probes in this manner would most likely be a pretty light show. still i wonder about the plutonium aspect of this? it might be prudent to first consult with the legal experts and diplomats of the Galactic Council, to clear this type of activity with them first, minimize interpretation of this probing as a hostile interstellar act.
        mikeash 10y ago
        I don't think the plutonium would be enough to have any real effect, although it might irritate the inhabitants if there are any. Certainly, we've put far more plutonium into Earth's atmosphere by blowing up thousands of nuclear bombs in it, and we survived. Clearing it with the Galactic Council definitely sounds like a good idea. Do you have their phone number handy? I seem to have deleted their contact info by accident.
      - Stratoscope 10y ago
        And so many of those people were injured because they went to a window to see the spectacle, not knowing about the shock wave that was coming. It made me realize that the civil defense films we watched in the '50s weren't so misguided after all: https://www.google.com/#q=when+you+see+the+white+flash+duck+and+cover https://www.google.com/#q=when+you+see+the+white+flash+duck+...
        mikeash 10y ago
        Indeed, that's pretty much what "duck and cover" was all about. There was even a school teacher in Chelyabinsk who apparently remembered her Cold War drills and had her students take cover, saving them from injury.
    - kamaal 10y ago
      >>So it's probably noticeable for any inhabitants in the area An intelligent civilization with a 1000 year head start whose presence was just proven by device that arrived at 10% the speed of light would pretty much scare any government on earth. I would assume it would scare the aliens there too.
malz 10y ago
Also at 10% the speed of light the probe zips by the planet in a fraction of a second. There's no slowing down in this scenario.
- mrfusion 10y ago
  Could they carry mini solar sails to slow down? Solar parachutes if you will. Or if we sent them in single file several seconds apart they could each relay what they see to the ones behind them and then back to us. Effective oh giving us a long exposure.
- elektropionir 10y ago
  There are ideas for slowing them down and even returning them back to Earth, at least in principle: http://www.centauri-dreams.org/?p=31913 http://www.centauri-dreams.org/?p=31913 Nothing that could be implemented in any foreseeable future though.
- sevenless 10y ago
  You can slow down - just that the probe won't remain intact. But perhaps that isn't necessary for the probe to be useful. We can also use these space probes to do geological and atmospheric surveys of the planet when they arrive. Simply: we slam the probe into the planet, a few milliseconds after it transmits the final images. One gram going at 20% of the speed of light has kinetic energy that bears comparison to the Hiroshima bomb. At a steep angle of entry, the huge entry glow will give a reading of the atmospheric molecular makeup. And if we can ionize some of the crust, massive space telescopes can get a spectroscopic measurement of the composition, four light years away.
  - onion2k 10y ago
    Let's hope any alien race living there doesn't have the same idea and send a few probes to smash in to Earth.
    - sevenless 10y ago
      That would be like Christopher Columbus, mid-Atlantic crossing, encountering a gunpowder-equipped Mayan navy going off to conquer Europe. Not likely.

(ignore what I said here)

by afreak 10y ago

(ignore what I said here)

The laser is only on each device for 10 minutes. And there are 1,000 of them. So the hope is that at laest 1 in 1,000 will make it.

dingbat 10y ago
if even a tiny fraction of those 1000 tiny probes hit that planet at 20% of speed of light, could that pose a problem? it sounds like a shotgun approach, not so figuratively, using pellets loaded with plutonium.
- jessriedel 10y ago
  The probes would each be only a few grams, so they'd have about 10^13 J of relativistic kinetic energy, or a half kilotons of TNT equivalent. This can be compared with the 15 kilotons for the (small, by modern standard) Little Boy atomic bomb. So it's probably noticeable for any inhabitants in the area, depending on how the energy is dissipated in the atmosphere, but still quite small on the scale of a planet.
  - mikeash 10y ago
    It should be noted that meteors explode with Hiroshima-like force fairly regularly within Earth's atmosphere, on the order of once a decade or so. It happens high up enough that nobody notices beyond an occasional light show. The meteor explosion which hurt a bunch of people in Chelyabinsk a few years back was about 500 kilotons.
    - dingbat 10y ago
      cool, good to know that raining down a bunch of probes in this manner would most likely be a pretty light show. still i wonder about the plutonium aspect of this? it might be prudent to first consult with the legal experts and diplomats of the Galactic Council, to clear this type of activity with them first, minimize interpretation of this probing as a hostile interstellar act.
      - mikeash 10y ago
        I don't think the plutonium would be enough to have any real effect, although it might irritate the inhabitants if there are any. Certainly, we've put far more plutonium into Earth's atmosphere by blowing up thousands of nuclear bombs in it, and we survived. Clearing it with the Galactic Council definitely sounds like a good idea. Do you have their phone number handy? I seem to have deleted their contact info by accident.
    - Stratoscope 10y ago
      And so many of those people were injured because they went to a window to see the spectacle, not knowing about the shock wave that was coming. It made me realize that the civil defense films we watched in the '50s weren't so misguided after all: https://www.google.com/#q=when+you+see+the+white+flash+duck+and+cover https://www.google.com/#q=when+you+see+the+white+flash+duck+...
      - mikeash 10y ago
        Indeed, that's pretty much what "duck and cover" was all about. There was even a school teacher in Chelyabinsk who apparently remembered her Cold War drills and had her students take cover, saving them from injury.
  - kamaal 10y ago
    >>So it's probably noticeable for any inhabitants in the area An intelligent civilization with a 1000 year head start whose presence was just proven by device that arrived at 10% the speed of light would pretty much scare any government on earth. I would assume it would scare the aliens there too.

malz 10y ago

Also at 10% the speed of light the probe zips by the planet in a fraction of a second. There's no slowing down in this scenario.

mrfusion 10y ago
Could they carry mini solar sails to slow down? Solar parachutes if you will. Or if we sent them in single file several seconds apart they could each relay what they see to the ones behind them and then back to us. Effective oh giving us a long exposure.
elektropionir 10y ago
There are ideas for slowing them down and even returning them back to Earth, at least in principle: http://www.centauri-dreams.org/?p=31913 http://www.centauri-dreams.org/?p=31913 Nothing that could be implemented in any foreseeable future though.
sevenless 10y ago
You can slow down - just that the probe won't remain intact. But perhaps that isn't necessary for the probe to be useful. We can also use these space probes to do geological and atmospheric surveys of the planet when they arrive. Simply: we slam the probe into the planet, a few milliseconds after it transmits the final images. One gram going at 20% of the speed of light has kinetic energy that bears comparison to the Hiroshima bomb. At a steep angle of entry, the huge entry glow will give a reading of the atmospheric molecular makeup. And if we can ionize some of the crust, massive space telescopes can get a spectroscopic measurement of the composition, four light years away.
- onion2k 10y ago
  Let's hope any alien race living there doesn't have the same idea and send a few probes to smash in to Earth.
  - sevenless 10y ago
    That would be like Christopher Columbus, mid-Atlantic crossing, encountering a gunpowder-equipped Mayan navy going off to conquer Europe. Not likely.