Originally Posted by pichlo

I don't think we need to concern ourselves with aliens from other galaxies. Even within our own, the interstellar distances are prohibitively large. Mutiply that by several orders of magnitude and add the fact that galaxies speed away from each other and you quickly arrive at a conclusion that an intergalactic invasion is not something you need to lose sleep over.

Dark matter? It may be a convenient shortcut to explain certain aspects of the universe expansion but to me, it reeks too much of "horror vaccui", the medieval idea that nature abhors empty space and wants to fill it. That's why when you suck on a tube whose other end is immersed in water, the water fills the tube, right? Wrong, as it turned out. It is the weight of the surrounding air that pushes the water into the tube. I suspect that dark matter and dark energy will find a similar, more natural explanation one day. I wish science were more humble and honestly admitted, "I don't know yet, but I may one day", rather that coming up with esoteric conceps like dark matter. Though I admit that "dark matter" sounds catchier.

Originally Posted by pichlo

I don't think we need to concern ourselves with aliens from other galaxies. Even within our own, the interstellar distances are prohibitively large. Mutiply that by several orders of magnitude and add the fact that galaxies speed away from each other and you quickly arrive at a conclusion that an intergalactic invasion is not something you need to lose sleep over.

Dark matter? It may be a convenient shortcut to explain certain aspects of the universe expansion but to me, it reeks too much of "horror vaccui", the medieval idea that nature abhors empty space and wants to fill it. That's why when you suck on a tube whose other end is immersed in water, the water fills the tube, right? Wrong, as it turned out. It is the weight of the surrounding air that pushes the water into the tube. I suspect that dark matter and dark energy will find a similar, more natural explanation one day. I wish science were more humble and honestly admitted, "I don't know yet, but I may one day", rather that coming up with esoteric conceps like dark matter. Though I admit that "dark matter" sounds catchier.

Originally Posted by mscion

When you suck on a straw that has one end in water, you are causing a decrease in pressure in the straw. As a result the pressure in the straw is less than that in the surrounding air. The difference in air pressure is what drives the fluid into the straw.

In regards to it being impossible for aliens to come here due to prohibitive distances, it may be that they know something more than us mere human know about physics, that can be utilized by them to get here or to influence us...

Originally Posted by Dave999

When did Noah build the ark?

Originally Posted by pichlo

Indeed. And what is causing the pressure? The weight of the column of air above.
Whatever you call it, it is definitely not the nature's fear of the vacuum.



True. All the more reason to be cautious.

Originally Posted by mscion

Which color do you like?
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