Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

 2 Removed my obnoxious formatting. edited Nov 7 '15 at 22:28 HDE 226868♦ 80k1818 gold badges249249 silver badges452452 bronze badges TL,DR: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? My TL;DR: Yes. Could such a scenario (referring to the planet being within the habitable zones of all three stars) exist? I'd think not. This arrangement would not be stable. Sure, multiple-star systemsmultiple-star systems exist - and there have been systems discovered with up to 7 stars - but there's almost no way the planet could continue to be in the habitable zone of all three for more than a very short amount of time. In fact, I think it's likely that the system would consist of one star orbiting the other two, as is the case in Alpha Centauri. But I guess I'll disregard that, although I think this is a valid point for the reality-check tag. I can elaborate on this if you want me to, but I can avoid it for now. Back to the question: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? I'll go with a sad yes here. It does depend on how far away from each of the stars the planet is, but I think that, given how large the stars are, that the output of radiation will be pretty huge. The SunSun has a luminosity of 3.826 $$3.826 \times 10^{24} \text { Watts}$$$$\times$$ 1024 Watts. Adding together the probable luminosities of these three stars, we get $$518 \text { solar luminosities}$$518 solar luminosities (a red giantred giant, e.g. AldebaranAldebaran) $$+ 1 \text { solar luminosity}$$+ 1 solar luminosity (a Sun-like star) $$+ 91,000 \text { solar luminosities}$$+ 91,000 solar luminosities (a blue star, e.g. Zeta OphiuchiZeta Ophiuchi) $$=91,519 \text { solar luminosities}$$$$=$$ 91,519 solar luminosities. That's pretty bright. It also means a lot of UV radiation, meaning that unless there's a thick ozone layer on the planet, these people are going to be pretty unhappy. TL,DR: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? My TL;DR: Yes. Could such a scenario (referring to the planet being within the habitable zones of all three stars) exist? I'd think not. This arrangement would not be stable. Sure, multiple-star systems exist - and there have been systems discovered with up to 7 stars - but there's almost no way the planet could continue to be in the habitable zone of all three for more than a very short amount of time. In fact, I think it's likely that the system would consist of one star orbiting the other two, as is the case in Alpha Centauri. But I guess I'll disregard that, although I think this is a valid point for the reality-check tag. I can elaborate on this if you want me to, but I can avoid it for now. Back to the question: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? I'll go with a sad yes here. It does depend on how far away from each of the stars the planet is, but I think that, given how large the stars are, that the output of radiation will be pretty huge. The Sun has a luminosity of $$3.826 \times 10^{24} \text { Watts}$$. Adding together the probable luminosities of these three stars, we get $$518 \text { solar luminosities}$$ (a red giant, e.g. Aldebaran) $$+ 1 \text { solar luminosity}$$ (a Sun-like star) $$+ 91,000 \text { solar luminosities}$$ (a blue star, e.g. Zeta Ophiuchi) $$=91,519 \text { solar luminosities}$$. That's pretty bright. It also means a lot of UV radiation, meaning that unless there's a thick ozone layer on the planet, these people are going to be pretty unhappy. TL,DR: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? My TL;DR: Yes. Could such a scenario (referring to the planet being within the habitable zones of all three stars) exist? I'd think not. This arrangement would not be stable. Sure, multiple-star systems exist - and there have been systems discovered with up to 7 stars - but there's almost no way the planet could continue to be in the habitable zone of all three for more than a very short amount of time. In fact, I think it's likely that the system would consist of one star orbiting the other two, as is the case in Alpha Centauri. But I guess I'll disregard that, although I think this is a valid point for the reality-check tag. I can elaborate on this if you want me to, but I can avoid it for now. Back to the question: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? I'll go with a sad yes here. It does depend on how far away from each of the stars the planet is, but I think that, given how large the stars are, that the output of radiation will be pretty huge. The Sun has a luminosity of 3.826 $$\times$$ 1024 Watts. Adding together the probable luminosities of these three stars, we get 518 solar luminosities (a red giant, e.g. Aldebaran) + 1 solar luminosity (a Sun-like star) + 91,000 solar luminosities (a blue star, e.g. Zeta Ophiuchi) $$=$$ 91,519 solar luminosities. That's pretty bright. It also means a lot of UV radiation, meaning that unless there's a thick ozone layer on the planet, these people are going to be pretty unhappy. 1 answered Nov 11 '14 at 0:11 HDE 226868♦ 80k1818 gold badges249249 silver badges452452 bronze badges TL,DR: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? My TL;DR: Yes. Could such a scenario (referring to the planet being within the habitable zones of all three stars) exist? I'd think not. This arrangement would not be stable. Sure, multiple-star systems exist - and there have been systems discovered with up to 7 stars - but there's almost no way the planet could continue to be in the habitable zone of all three for more than a very short amount of time. In fact, I think it's likely that the system would consist of one star orbiting the other two, as is the case in Alpha Centauri. But I guess I'll disregard that, although I think this is a valid point for the reality-check tag. I can elaborate on this if you want me to, but I can avoid it for now. Back to the question: TL,DR: Would humans beings from Earth be seriously injured or killed from the long period variation of the main color a bunch of stars projects on a planet? I'll go with a sad yes here. It does depend on how far away from each of the stars the planet is, but I think that, given how large the stars are, that the output of radiation will be pretty huge. The Sun has a luminosity of $$3.826 \times 10^{24} \text { Watts}$$. Adding together the probable luminosities of these three stars, we get $$518 \text { solar luminosities}$$ (a red giant, e.g. Aldebaran) $$+ 1 \text { solar luminosity}$$ (a Sun-like star) $$+ 91,000 \text { solar luminosities}$$ (a blue star, e.g. Zeta Ophiuchi) $$=91,519 \text { solar luminosities}$$. That's pretty bright. It also means a lot of UV radiation, meaning that unless there's a thick ozone layer on the planet, these people are going to be pretty unhappy.