Something that causes doubt

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Polak said:
Just recently, I had another ‘attack of doubt’ and this one related to the universe.
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Attacks of “Doubt” are as temptations given into …

Which in this case looks like a What If? totally speculative - Fool’s Errand - bound to infuse Doubt

Why not of course focus upon what we know ? rather than (think now) what we do not know

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Freddy said:
It is physically impossible. Parts of the distant observable universe expand at such a rate that they eventually exceed the speed of light in relation to us (they are not moving at the speed of light - space is expanding so they don’t break any physical laws). So they will literally dissapear. The light that they emit is moving away from us faster than it is moving towards us.
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Who knows? Wormholes? Use of black holes for travel? The point is we don’t know how we might find a way to overcome the limitation.

And besides which, the observation that “it doesn’t make any sense” could hold for any earthly species that goes extinct, couldn’t it? And that’s not being argued here…
 
Gorgias said:
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Freddy:
It is physically impossible. Parts of the distant observable universe expand at such a rate that they eventually exceed the speed of light in relation to us (they are not moving at the speed of light - space is expanding so they don’t break any physical laws). So they will literally dissapear. The light that they emit is moving away from us faster than it is moving towards us.
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Who knows?
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Exactly the point. It all made sense with one planet. It makes no sense now.
 
Freddy said:
It does. It is physically impossible. Parts of the distant observable universe expand at such a rate that they eventually exceed the speed of light in relation to us (they are not moving at the speed of light - space is expanding so they don’t break any physical laws). So they will literally dissapear. The light that they emit is moving away from us faster than it is moving towards us.

So ever since the dawn of creation, the universe has been dissapearing from us. There will be literally less to see when you get to the end of this sentence then when you started it.
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That’s not how it works. The speed of light doesn’t change based on the velocity of the object that emits it. A planet moving 1,000,000 m/s away from us does not send light at us at c-1,000,000 m/s. It sends light at us at c. Instead the planet’s velocity changes the frequency of the light, shifting it towards lower and lower frequencies the faster the object moves away from us.

If stars are disappearing it is not that they are getting so fast we cannot catch up, it is that they are getting so fast that the light from them is shifting into frequencies we can no longer detect (or more likely, that do not stand out from background noise).
 
Inquiry said:
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Freddy:
It does. It is physically impossible. Parts of the distant observable universe expand at such a rate that they eventually exceed the speed of light in relation to us (they are not moving at the speed of light - space is expanding so they don’t break any physical laws). So they will literally dissapear. The light that they emit is moving away from us faster than it is moving towards us.

So ever since the dawn of creation, the universe has been dissapearing from us. There will be literally less to see when you get to the end of this sentence then when you started it.
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That’s not how it works.
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…the universe does expand faster than the speed of light, and, perhaps more surprisingly, some of the galaxies we can see right now are currently moving away from us faster than the speed of light! As a consequence of their great speeds, these galaxies will likely not be visible to us forever; some of them are right now emitting their last bit of light that will ever be able to make it all the way across space and reach us (billions of years from now). After that, we will observe them to freeze and fade, never to be seen again.’ Is the universe expanding faster than the speed of light? (Intermediate) - Curious About Astronomy? Ask an Astronomer

If the universe was not expanding and the stars were moving away from us then the light would always reach us. But if the space between us and the star expands at a rate over that of the speed of light then we will receive no further information about it.
 
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Freddy said:
But if the space between us and the star expands at a rate over that of the speed of light then we will receive no further information about it.
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Just a curious thought. Doesn’t that make the observable universe sort of like a reverse black hole? In that, instead of light not being able to get out…it can’t get in.

Hmmm, I never thought about that before. Strange how some things just never occur to me.
 
Polak said:
… the way that Bible is written, while it might not strictly say it, makes it seems like we have the world where we are, down here, and God, up there. It doesn’t make it sound like there is much else outside that, and yet we know that are many other planets orbiting around a sun in our solar system and even other suns and planets orbiting around them in the universe in general. It really does seem like the earth is a [tiny speck] of what exists, and yet this is the focal point God focuses on?
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The Bible is not a science book. The Bible is all about God’s love for us and his plan for our salvation. That’s why it says so much about us and our tiny little planet.
 
I mean you misunderstand. The light they emit is not moving away from us faster than it is moving towards us. It is moving towards us at c. No change. Instead, the space between us and the light emitted by the galaxy is increasing at a faster rate than the speed of light. That’s a very important distinction, because it means that the author you cited potentially missed something.

There’s actually a classic paradox that goes something like this: An immortal ant is at one end of an infinitely stretchy rubber rope. It starts to cross to the other side at 1 cm/s. At the very moment it does, the two ends of the rope start stretching away from each other at 1 km/s. Will the ant ever reach the other side?

And surprisingly the answer is yes.

It actually doesn’t matter that the rope is increasing in length faster than the ant can move. Every step the ant takes decreases the percentage of the rope it has left to travel. It doesn’t matter that the rope is increasing in length faster than the ant can move, because each second more of the rope is behind the ant. Each second, less of the expansion matters. It still ends up taking the ant an absurdly long time (somewhere on the order of 1x10^43,500 years, give or take a few hundred orders of magnitude), but it does reach the other end.

The same principle would apply here, except that the ‘rope’ isn’t increasing nearly as fast compared to the ‘ant.’

Now it is a little more complicated than that since the universe may be increasing its rate of expansion, but until we know the reason for the acceleration we can’t assume that it is a constant. Indeed there are quite a few out there who think that it is not constant, and others who think it is not accelerating at all.
 
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Inquiry said:
I mean you misunderstand. The light they emit is not moving away from us faster than it is moving towards us.
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The light is travelling at a constant speed. And it would be a constant speed relative to us and the star that produced it if it were just the star moving away from us. But the star star isn’t moving. The space between us is increasing.

If the rate of expansion of space is greater than the speed of light then light emitted from one source CANNOT reach the other. It will be forever lost to us. And the amount of the universe that is already lost is debatable. But could be infinite.

Again, who is it there for if not us.
 
Gorgias said:
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Freddy:
Exactly the point. It all made sense with one planet. It makes no sense now.
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Not seeing how you’re reaching that assertion…
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I have something here. You don’t know what it is. You will never know what it is. You cannot access it. It will be forever unobtainable to you.

Did I make it for you? Obviously not. It would be nonsensical to suggest that.

So that about which we will never have any information, that which we cannot ever access, that which will be forever unobtainable…was it made for us? Obviously not. It would be nonsensical to suggest that.

So who is it for?
 
thistle said:
Does not seem much conversion there!
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I was thinking of the cases I knew about.
Three women who had married three Jews and converted. Two of the women were Catholic, but I am not sure about the third although I know she was Christian and had to convert as per her future husband’s requirement. I attended the wedding at the invitation of a friend and I heard the bride declare her loyalty to Israel and the Jewish people as part of the wedding ceremony.
A Catholic student at a local Catholic college who became a rabbi.
You are right, it is only those four cases that I am personally familiar with and it doesn’t sound like a whole lot of people.
 
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That’s not true, though. As I said, the ant can reach the end of the rope even though it is expanding faster.
 
Inquiry said:
That’s not true, though. As I said, the ant can reach the end of the rope even though it is expanding faster.
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You really need to do some checking on this matter. Let me know when you have something based on cosmology rather than entomology.
 
Gorgias said:
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Freddy:
I have something here. You don’t know what it is. You will never know what it is. You cannot access it. It will be forever unobtainable to you.
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Ahh… but, although I may not know what it is, I know that it is!
Freddy said:
So who is it for?
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Still could be for my edification, even if not for my enjoyment / use… 😉
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I guess that’s the best you could come up with. Although I think that ‘I dunno’ would have served you better.
 
Math actually, not entomology. The ant thing was an example of a principle, not a property exclusive to bugs.
 
Inquiry said:
It doesn’t matter that the rope is increasing in length faster than the ant can move, because each second more of the rope is behind the ant.
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That seems irrelevant because each second the opposite end moves a net distance away from ant (500m - 1cm) and every second forever that is true so I don’t see how ant ever reaches other side. I must be missing something?
 
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Think of it this way: if the ant was sitting in the center it would be 50% of the way to the end. If it waited a minute it would still be 50% there. The rope stretching doesn’t change its %. When it takes a step though, it gets slightly closer percentage wise. That means more of the stretching is behind it than before. Every step is progress percentage-wise and therefore it will eventually reach its destination. Even if that takes 10,000 times as long as the current age of the universe.
 
I agree stepping will go from 50% to less 50% but can’t see how ever reaches since every second forever the end moves 495.9 m away from the ant. So conceptually seems impossible to ever reach
 
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