AIBU to question the popular belief that there are more stars in the sky than grains of sand on earth?

[Tryingtryingandtrying]

How can this possibly be true? Tbh I'd question if there were more stars than grains of sand on my local beach? I've read a bit around it and still is impossible for me to comprehend. Any other facts or theories that just don't make sense to you?

It seems incredible, but there are billions of galaxies, and each galaxy contains billions, sometimes trillions of stars. The Milky Way is part of a supercluster of 100,000 galaxies, called Laniakea - the sheer size of it just makes you boggle. So I think the stars have it.

Technically there aren't any stars "in the sky." The sky is within our atmosphere. Stars are in space. Far far away from Earth.

The more you know

Astudy keeps flouncing but is the back again. Hilarious stuff.

burfordbrown

I didn’t flounce at all. Why do you think that?

One of the largest stars we’ve discovered is UY Scuti. It’s the same size as Jupiter’s orbit around the sun ()and you can fit 4 quadrillion earths inside it apparently.

Woah

@AStudyinPink

burfordbrown

I didn’t flounce at all. Why do you think that?

You kept saying 'anyway I'll leave it there' but you never actually left it anywhere

That’s not a flounce, is it? I just decided to stop and then changed my mind. Flouncing is when you’re mad. I’m not mad.

@AStudyinPink - the best I can do is this. How could you tell if something was expanding? From a distance, where you can see the edges, you could take a sequence of photos and compare the sizes over time. But what if you can't see the edges? Like if something really big like the Earth were expanding (and we had no satellites or distant vantage points). Well, we could stick two stakes in the ground and measure the distance between them with a ruler and see if they were moving apart. We'd need a lot more than two stakes, because we'd want to see that it was a global things, not just something like a landslip dragging one of the stakes somewhere. That method would work whether there were an edge and we couldn't see it, or there were no edge.

The galaxies we see out there are what we use instead of stakes in the ground. And everywhere we look they are moving away from us, the further away the faster. Furthermore, if you look at the pattern of movement in detail, it turns out that it wouldn't matter where you stood - you would always see the same thing, everything far from you moving away, the further the faster. That means that there's no center that everything is moving away from, but rather everything is moving away from everything else. What better word for that than expansion?

So "space is expanding".

I explained the reason for "infinite" earlier. The laws of physics look the same everywhere we can see and the universe looks the same everywhere we can see. So you have to assume that the laws change somewhere in order to get an edge. It's a bit like (before the 1960s) it was only an assumption that the moon had an other side. We'd never seen it until the Apollo missions, so a strict positivist would have regarded the hypothesis that it has an other side as unproven. But every other thing we've ever seen has a reverse side if it has a front side, and a thing that had only one side and just wasn't there from the other side is so alien to everything that we know that it's implausible. So it is with the universe. Everywhere we can see, you would see the same thing, everything travelling away from you. Why would that change somewhere we can't see? "Because you find the conclusion unintuitive" is not such a reason.

So space is expanding and it's infinite.

There are an enormous number of holes in that explanation. If you want a robust model, you need the maths.

What is being said here, on a basic level, makes no sense (and that has been admitted above)

Assuming you're referring to me with "admitted above", that's not quite what I said. I said the "space expanding" explanation was "unsatisfying" and that it might in some senses be better to say other things (but all those other things have problems too), and that a rigorous model is mathematical. I never said "space expanding" makes no sense.

I’ll have a look at that tomorrow, Spev. Tired now.

I have some sympathy with those who feel that everything should be explainable in terms they understand. I've long accepted that it isn't, but it still bothers me a little. Part of me wishes (like hoping to win the lottery) that we'll find some key fact that will make everything else fall into place and make sense. Ordinary everyday sense so we can understand the universe like we understand chairs.

It's probably worth remembering that the brains we are trying to use to understand the universe evolved to help us pick the best berries and hide from predators. It's amazing that we can understand as much as we do.

We may never understand it all, but we sure left those left those Lions, Tigers and Bears in the dust didn't we. Oh my.

All I can say is there are some very clever people on this thread! It’s fascinating.

I actually can’t even conceive of how you could discuss if the universe is expanding using maths, it blows my tiny mind that you can communicate the kind of concepts discussed here using only numbers. I’m not doubting it at all, I’m just saying it is waaay beyond me!

@SpeverendRooner it’s interesting what you say about models being proven right usually. I watched a documentary on them taking the picture of the black hole and I was fascinated to see it looked exactly like they thought it would!

A very simple concept which I find interesting is that there might be a hidden 9th planet in our solar system way way out, which explains some or the behaviour of objects in our solar system.

I love shit like this, it blows my tiny mind

@AStudyinPink

unmarkedbythat

Well, sure, but when a reality is shared across languages, it should be translatable. And that is the case here, since these are concepts that exist in English: space, matter, infinity, expanding etc.

It doesn’t make sense to say, “Space (which means the same as nothing) is both infinite and expanding into more nothing”. If the words aren’t adequate to the descriptive task, make new ones; don’t just make a word salad and then suggest the problem is with everyone else!

The thing is people who do understand it don't share this sense of wtaf bafflement most of us do when trying to get our heads round the concept of actual nothing. The words do make sense to them. The concepts are real and the applications make sense. Just because I don't get it doesn't mean they don't get it and aren't engaging in perfect description. I can't understand what DH says if he speaks Russian, but all the words have meaning. I just don't know it. To people who know about this shit, the words make sense.

No offence op but your post reads a bit like a letter to Viz. 'it's one rule for stars in the sky and another for the rest of us'.

Disclaimer: I haven't read the whole thread.

The universe is infinite, and is only a part of a multiverse of stellar gloom that no one mind can claim to comprehend.
Sand like life, is finite. Space is big.

Haven't RTFT so someone may have mentioned it already, but there are more trees on Earth than there are stars in the Milky Way.

Trying to understand some if this is literally making my brain hurt! Agree with PP that there are some very clever people on this thread, and also about what our brains were evolved to do.
And the Double Slit experiment is mind blowing too. Never actually heard of that one before. I used to be able to think better, think I need to retrain my brain, in particular around the use of maths to understand concepts and quantity/size

YANBU to question it.

The observable universe is finite whether or not the whole Universe. It appears that stars in the observable universe outnumber sand grains on Earth, but it's not a sure thing.

There are also about as many atoms in a spoon of water as there are stars in the sky. And about as many spoons of water in the oceans as there are atoms in each spoon.

Not in the angry sense.

What do you mean?

The thing is people who do understand it don't share this sense of wtaf bafflement most of us do when trying to get our heads round the concept of actual nothing. The words do make sense to them.

So they say. That’s nothing to do with me. When the words don’t make sense in English but there is some hidden esoteric meaning that I will understand when I access their higher plane of thought (where ‘space’ doesn’t mean ‘nothing’ - but does - and ‘expands’ means something other than ‘gets bigger’) I maintain my simple stance that I have my doubts and will believe it when it is properly explained in clear factual language.