It is not only that nothing does go faster than light: is is impossible for anything to go faster than light, for if it did, relativity would be false.

Not at all. I think that those two things are consistent. The DN model explicates that is means for an event to be consistent with the laws of nature. It must be deducible from them together with initial conditions.

You're correct that I'll never be certain that "nothing accelerates faster than the speed of light" because I won't be around forever. However, I'm already agreeing for the sake of argument that the statement "nothing ever has or ever will accelerate faster than the speed of light" is true. Taking that truth into account, it's still not true that "nothing can accelerate faster than the speed of light". It can but it won't. There's a difference.

Can we ever be positively (not absolutely) certain that any particular thing doesn't exist?

No, not really. The human senses are just that - human senses. I've often wondered if there are tons of animals running around that can't be seen, heard, smelled, tasted, or felt, but are still there. Interesting thought.

What about Wittgenstein's Tractatus...

6.37 There is no compulsion making one thing happen because another has happened. The only necessity that exists is logical necessity.

6.375 Just as the only necessity that exists is logical necessity, so too the only impossibility that exists is logical impossibility.

we know that in the Universe absolute nothing does not exist

You mean that something does exist, namely, the universe.

I could however do the phenomenology of a unicorn but its existence is unknown to me (and I most certainly dont care about its existence). Just a thought. :-o

Phenomenologically, that unicorn you speak of exists as an object of your conscious thought and known to you. It's known and exists in a different way than, say, this book next to me, but it does exists.

If all conscious thought is composed of an Act, a Content, and an Identical Object in a relationship, then the conscious relationship You have with said unicorn is also composed of an Act, Content, and Identical Object. It seems to me that the content is known to you, an thus the unicorn's existence is known to you.

Phenomenologically, that unicorn you speak of exists as an object of your conscious thought and known to you. It's known and exists in a different way than, say, this book next to me, but it does exists.

No it doesn't. The concept of a unicorn exists. A unicorn does not exist.

Concepts, objects, words, things

I love this game. Which one doesn't belong, right? Oh, I've got it. "Words" doesn't belong because "concepts", "objects" and "things" are similar but many different words can relate to similar or identical concepts.

I did not quite have that in mind. What I had in mind is that just as there is a big difference between concepts and objects, so there is a big difference between words and things. And that it makes a big difference whether a concept of object exists, and it makes as big a difference whether a word or thing exists.

And, if unicorns don't exist in one way, well, they exist in another way. What's the difference?

That's nice and all but how does it directly relate to what I said? Are you saying that concepts don't exist? Are you saying that the concept of a unicorn doesn't exist? What exactly is it that you are trying to prove by calling something navel-gazing?



There is a big difference and it seems you are getting annoyed and being abrasive because you think I meant to imply the difference was trivial. Well, that's your mistake. I never implied that.

The difference between the existence of a concept and the instantiation of a concept is very important and very practical. The concept of a sandwich cannot fill your belly. An instantiation of the concept of a sandwich can.

I'm sure you'll find some way to miss the point as usual but let's stop acting like I'm saying something outrageous.

So, if I think of the Spaghetti Monster, it thereby exists? What a wonderful way to create anything you like! I am going to try to work it with a billion dollars, and take it to the bank. Want to come along. Should I deposit it by the ATM do you think? I don't care if it "exists in a different way" just as long as I can spend it. And if I cannot spend it, then why should I care about it existing in a different way? I think by "exists in a different way", all you mean is that it does not exist, but that you are thinking about it. Right?