The sun's expansion will happen over millions of years, so if Mars were to become habitable, it would likely be long before the Earth was swallowed by the sun, probably even before it swallowed Venus.
I don't remember the last count, but people who search space for Earth-like planets have found several in our galaxy alone. The idea that earth is the only one is about as crazy an idea as it gets.
Quick google search on "habitable planets found":
In November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way, 11 billion of which may be orbiting Sun-like stars.
God belief is for people who don't want to live life on the universe's terms.
KevinSim wrote:. He says there are over a hundred variables that have to do with whether a planet is habitable or not, and apparently they have to be just right, and he says that there aren't enough planets in the universe with those hundred variables for it to be likely that another planet has all those variables with the right values.
There are at least 1,000,000,000,000,000,000,000 (that is 1 billion trillion) stars in the universe. If there is only a single planet per star, (it is probable that there are more than that) then needing only a hundred variables to be right from 1 billion trillion chances is nearly a certainty.
"Any over-ritualized religion since the dawn of time can make its priests say yes, we know, it is rotten, and hard luck, but just do as we say, keep at the ritual, stick it out, give us your money and you'll end up with the angels in heaven for evermore."
KevinSim wrote:Because I remember hearing that in five million years the Sun would expand to engulf Earth's orbit.
That would be five BILLION, not merely five million.
That reminded me of the old Joke about a guy who experienced a panic attack when told by an astronomer that the sun would die in about 5 billion years.
"How long did you say?", he asked alarmedly?
"5 billion years", answered the astronmer.
"Whew!", exclaimed the man relievedly; "I thought you said 5 million."
No precept or claim is more likely to be false than one that can only be supported by invoking the claim of Divine authority for it--no matter who or what claims such authority.
“If you make people think they're thinking, they'll love you; but if you really make them think, they'll hate you.”
― Harlan Ellison
KevinSim wrote:. He says there are over a hundred variables that have to do with whether a planet is habitable or not, and apparently they have to be just right, and he says that there aren't enough planets in the universe with those hundred variables for it to be likely that another planet has all those variables with the right values.
There are at least 1,000,000,000,000,000,000,000 (that is 1 billion trillion) stars in the universe. If there is only a single planet per star, (it is probable that there are more than that) then needing only a hundred variables to be right from 1 billion trillion chances is nearly a certainty.
It is remarkable how many fail to understand probability. Given a sufficiently large universe or an eternity of time, anything that is merely improbable, no matter how improbable, must inevitably occur somewhere sometime. Almost everything we see and experience is the end result of a very long and extremely improbable sequence of events that would be incredibly unlikely to reoccur again if it were possible to reset time to the very beginning and start everything all over again.
No precept or claim is more likely to be false than one that can only be supported by invoking the claim of Divine authority for it--no matter who or what claims such authority.
“If you make people think they're thinking, they'll love you; but if you really make them think, they'll hate you.”
― Harlan Ellison
KevinSim wrote:I'm talking with someone on a traditional Christian forum who is trying to tell me that a consensus of astronomers have concluded that there probably are no habitable planets in the universe except for planet Earth. He says there are over a hundred variables that have to do with whether a planet is habitable or not, and apparently they have to be just right, and he says that there aren't enough planets in the universe with those hundred variables for it to be likely that another planet has all those variables with the right values.
He doesn't know what the hell he is talking about. The universe we observe is about 90 billion light-years in diameter, and the entire universe could be much much bigger, perhaps infinite. As for "hundreds of variables" he is talking about conditions for life as we know it here on Earth.
Last edited by Guest on Fri Jun 22, 2018 4:11 am, edited 1 time in total.
Physics Guy wrote:Before reading this thread I had never heard anyone argue that Earth is likely to be the only habitable planet in the galaxy, let alone the universe. So this is definitely not a consensus view among astronomers.
No kidding. Heck, they’ve already found evidence of possible organic matter next door on Mars.
DoubtingThomas wrote:He doesn't know what the hell he is talking about. The universe we observe is about 90 billion light-years in diameter, and the entire universe could be much much bigger, perhaps infinite. As for "hundreds of variables" he is talking about conditions for life as we know it here on Earth.
I believe the radius of the observable universe is 13.6 billion light years, given that's the approximate age of the universe. Any light cast outside that radius hasn't had time to reach earth yet.
God belief is for people who don't want to live life on the universe's terms.
Some Schmo wrote:I believe the radius of the observable universe is 13.6 billion light years, given that's the approximate age of the universe. Any light cast outside that radius hasn't had time to reach earth yet.
Google the radius of the observable universe. As space.com explains " If inflation occurred at a constant rate through the life of the universe, that same spot is 46 billion light-years away today, making the diameter of the observable universe a sphere around 92 billion light-years" https://www.space.com/24073-how-big-is- ... verse.html
Doubting Thomas, Some Schmo said the "observable universe." There is no reasonable doubt that the universe has continued to expand since the light from the farthest reaches of the universe that we can see began its journey to us 13.72 billion years ago, but where it has expanded to during those intervening billions of years cannot be part of the "observable universe", because the light from there has not yet had sufficient time to reach us.
No precept or claim is more likely to be false than one that can only be supported by invoking the claim of Divine authority for it--no matter who or what claims such authority.
“If you make people think they're thinking, they'll love you; but if you really make them think, they'll hate you.”
― Harlan Ellison