4 ms·

You have to assume they already know we are, at best, inherently dangerous, and at worst, a threat. Anyone observing has detected the nearly 2,000 nuclear weap

You have to assume they already know we are, at best, inherently dangerous, and at worst, a threat. Anyone observing has detected the nearly 2,000 nuclear weapons tests we've conducted in the past. Those tests produce gamma rays that can be detected at cosmic distances, and the frequency of events would have been a curiosity. So imagine yourself an alien observer. Over the course of decades, you watch flashes of gamma rays originate from one location in the galaxy. Naturally curious, you send a probe or scout to get a closer look. From observable techno-signatures, you deduce there is an advanced civilization in a great war or a species crazy enough to explode powerful weapons on their home-world for shits & giggles. Would you want to visit?

LinuxBender 4y ago
If I am an advanced civilization I might not see nukes as a threat to my own people. I might see it as a strange behavior, that a planet would destroy itself in attempt to harm me. In such a case I might just stealth visit the planet and nobody would be any wiser.
delecti 4y ago
Given cosmic distances (and assuming FTL travel isn't in the equation), it seems more likely that any aliens arriving are coming because they detected molecular oxygen in the atmosphere and it took them a while to arrive. They detected a planet that probably had life, and sent out an exploratory mission many millions of years ago. I can only imagine the disappointment of waking up from cryo-sleep or whatever and finding a planet whose occupants are seemingly deliberately reverting the atmospheric composition back to CO2.
- zabzonk 4y ago
  > millions of years ago much longer than that, if you are using balloons
- PM_me_your_math 4y ago
  I don't know. Oxygen isn't exactly rare. It is the third most common element. A CO2 level of 0.04% is hardly reverting the atmosphere to the Ordovician, which of course, will never occur, and we'd need to reach levels of 3000 to 9000 ppm to do so. Even if we burn every drop of oil and every lump of coal we could find, reverting the atmosphere is impossible. The earth sequesters CO2 and plants consume it via photosynthesis, and produces the oxygen we rely on. Any life is likely to be significantly different from us, so they might just want to take some CO2 home with them.
  - zabzonk 4y ago
    it's not rare in combination with other elements. it is rare on its own, as it is so reactive. there would be very little free molecular oxygen in earth's atmosphere if it was not being actively produced via photosynthesis and any life we encounter is unlikely to be based on anything but carbon, because it is the only element capable of forming likely complex structures because of thermodynamics, among other things
  - delecti 4y ago
    Yes bound oxygen isn't rare, which is why I specified molecular oxygen. An alien race that could detect our atmosphere's composition (not outlandish, we've detected exoplanet atmospheres) would see the molecular oxygen and find it very intriguing (assuming they were susceptible to intrigue). If we detected an exoplanet with a 20% molecular oxygen atmosphere, it would be revolutionary. The bit about us reverting the atmosphere to the CO2 composition a couple billion years ago was a bit tongue in cheek, but not a very good job at humor on my part.

LinuxBender 4y ago

If I am an advanced civilization I might not see nukes as a threat to my own people. I might see it as a strange behavior, that a planet would destroy itself in attempt to harm me. In such a case I might just stealth visit the planet and nobody would be any wiser.

delecti 4y ago

Given cosmic distances (and assuming FTL travel isn't in the equation), it seems more likely that any aliens arriving are coming because they detected molecular oxygen in the atmosphere and it took them a while to arrive. They detected a planet that probably had life, and sent out an exploratory mission many millions of years ago. I can only imagine the disappointment of waking up from cryo-sleep or whatever and finding a planet whose occupants are seemingly deliberately reverting the atmospheric composition back to CO2.

zabzonk 4y ago
> millions of years ago much longer than that, if you are using balloons
PM_me_your_math 4y ago
I don't know. Oxygen isn't exactly rare. It is the third most common element. A CO2 level of 0.04% is hardly reverting the atmosphere to the Ordovician, which of course, will never occur, and we'd need to reach levels of 3000 to 9000 ppm to do so. Even if we burn every drop of oil and every lump of coal we could find, reverting the atmosphere is impossible. The earth sequesters CO2 and plants consume it via photosynthesis, and produces the oxygen we rely on. Any life is likely to be significantly different from us, so they might just want to take some CO2 home with them.
- zabzonk 4y ago
  it's not rare in combination with other elements. it is rare on its own, as it is so reactive. there would be very little free molecular oxygen in earth's atmosphere if it was not being actively produced via photosynthesis and any life we encounter is unlikely to be based on anything but carbon, because it is the only element capable of forming likely complex structures because of thermodynamics, among other things
- delecti 4y ago
  Yes bound oxygen isn't rare, which is why I specified molecular oxygen. An alien race that could detect our atmosphere's composition (not outlandish, we've detected exoplanet atmospheres) would see the molecular oxygen and find it very intriguing (assuming they were susceptible to intrigue). If we detected an exoplanet with a 20% molecular oxygen atmosphere, it would be revolutionary. The bit about us reverting the atmosphere to the CO2 composition a couple billion years ago was a bit tongue in cheek, but not a very good job at humor on my part.