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?

@RenegadeMrs

The fact that boggles my mind is that some infinities are bigger than others!

I get it now, but it blew my mind when I first learnt about it.

What

The universe is not infinite. But there are infinite universes.

You can theoretically travel faster than the speed of light because the speed of light is not a constant (Einstein was wrong). The speed of light changes depending on gravitational fields. They discovered this by watching black holes.

Time is also not a constant. It flows at different speeds depending on how fast you travel AND the gravitational fields you generate and travel through.

NASA is doing warp bubble experiments using magnetic fields to compress space time in front of a laser, and then expand space time behind it. The lasers light particles are just proxies for future starships. Anyway, they can get lasers to go faster than light. All we need is a huge energy source that can move a whole starship that fast AND keep carbon lifeforms alive otherwise it will be robot drones we’ll be sending out to explore the galaxy.

In addition, wormholes do exist, these are rifts in time and space and can transport particles from one part of universe to another part of the universe faster than light either by slowing down time or making it go backwards. Or even hop to another universe. We even know how to make one by putting magnetic arrays in orbit of a black hole. No one has gone through one yet, so no one knows where they go. We don’t even know if we have the right spaceship materials and internal life support technology to survive such a trip.

Number is stars to grains of sand. Who knows. Probably more grains of sand because a lot of stars have sandy planets around them. Too, if you count cosmic dust....that’s outer space sand and is everywhere.

But our descendents will hopefully get there one day.

@Tryingtryingandtrying

There are actually believed to be more stars in the sky than grains of sands on ALL OF THE BEACHES IN THE WORLD. Not just your local beach.

wonders how many grains of sand there are in the world............

Thanks @PlanDeRaccordement I enjoyed reading that.

I love stuff like this.

Fascinating. I really admire people who can wrap their brains around this.

It makes me anxious thinking about grains of sand/stars. I have no clue why.

Meanwhile here's me on the sofa avoiding sleep avoiding thinking about tomorrow!!

I miss having these topics of conversation, feels like a proper conversation to me.

@00100001

If it's expanding.... What's it expanding in to??

A way I part talk about this is to imagine we are attached to the surface of a balloon with with lots of other objects (stars/planets).

We blow the balloon up and all the rubber in between all the things will expand at once. in this analogy, the balloon is the whole universe. The third dimension (the air around the balloon) is not part of the analogy - it doesn't come into it. If all the dimensions there are on the surface of the balloon, can you see how for the surface of the balloon to stretch, it doesn't need anything to stretch into?

The term Big Bang was used by Descartes as a joke as he opposed the theory. It just kind of stuck and is an unfortunate fact of history - it's more aptly described as the Big Expansion of Everything at Once.

I love listening to people talking about space, it’s one of those subjects where a good speaker can persuade you, for a while, that you understand a bit about it. Sadly I find that five minutes afterwards my ignorance is overwhelmed by the numbers, which I simply can’t visualise. The furthest ever space thing we have observed is GNz11 , spotted by Hubble, it is about 13 billion light years away. I can’t even start to think how far that is.

I can’t get my head around Hubble either, or Voyager. The thought that space exploration has evolved so quickly in my lifetime is something that leaves me breathless, how can mankind be so daring, determined and inventive in one sphere of endeavour, yet so blindly slow ignorant and obstructive in others.

(I spent a happy evening at the Kielder observatory a few years ago, amazing place, run by knowledgeable and kind people who try their best to explain stuff to ignorant people! Great for a visit if you are ever in the area.)

Well, if you go by the multiverse theory that shroedinger pioneered and Stephen Hawking espoused, our universe is expanding into other expanding universes so there is outside pressure as well when we bump up against other universes...which explains why our universes expansion has not been constant. It was fast, then slowed down, and then 5bn yrs ago started to speed up again. Although some scientists are arguing that the universe hasn’t been changing expansion speed at all, but rather time has been changing its speed which makes it look like objects are changing speed. Hmmm

@littlepattilou
Thank you. I really enjoy it too.

You can theoretically travel faster than the speed of light because the speed of light is not a constant (Einstein was wrong). The speed of light changes depending on gravitational fields. They discovered this by watching black holes.

Time is also not a constant. It flows at different speeds depending on how fast you travel AND the gravitational fields you generate and travel through.

You are trying to shoe horn 'special relativity' and quote partial Maxwell's theory's and say that Einstein is wrong despite getting it wrong in your head.

Einstein wasn't wrong, you are trying to quote a theory of relatvitiy (special relativity), you in a ship observing another ship going in the opposite direction. Both are correct but no we cannot move faster than light, and Nasa are pumping thier money into just trying to work on succesful ramjets that would not even get us close tolightspeed.

I remember someone telling me that if someone on a planet 10 light years away looked through a telescope and could see earth, they would see us all as we were 10 years ago. I know that is super basic compared to some of the terrifying intelligence in this thread but that messed with my head!

@TinySongstress

Oh I'm absolutely obsessed with quantum theory. Have you looked into the Double Slit Experiment and the ramifications thereof? 🤯

Essentially, nothing-and all possible manifestations of everything exist until observed, when the electron wave function collapses and determines reality. Therefore, nothing actually exists until observed. 😳

I have to google this now

@Tryingtryingandtrying

Is it infinite though? Is that proven?

If it's not infinite is there an edge to the universe where it ends? What's on the other side of that? What surrounds the universe?

The dc and i we're discussing these topics earlier tonight. It hurt all our heads.

@Justanotherlurker

You can theoretically travel faster than the speed of light because the speed of light is not a constant (Einstein was wrong). The speed of light changes depending on gravitational fields. They discovered this by watching black holes.

Time is also not a constant. It flows at different speeds depending on how fast you travel AND the gravitational fields you generate and travel through.

You are trying to shoe horn 'special relativity' and quote partial Maxwell's theory's and say that Einstein is wrong despite getting it wrong in your head.

Einstein wasn't wrong, you are trying to quote a theory of relatvitiy (special relativity), you in a ship observing another ship going in the opposite direction. Both are correct but no we cannot move faster than light, and Nasa are pumping thier money into just trying to work on succesful ramjets that would not even get us close tolightspeed.

Er, no I’m not. Look up VSL and FTL theories. Since light speed is variable, then theoretically, objects can travel faster than light. I never said we currently have the ability to travel faster than light. Only that it is theoretically possible. We do have ability to communicate FTL via quantum teleportation.

They went through the numbers of this very question on BBC More or Less.

I can't remember the answer. I think it was yes, or definitely in the same ballpark, depending on the assumptions you make.

@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?

A lit of what you're looking at and counting as a star, is actually a galaxy

I honestly think we don’t know how many stars there are, whether the universe is infinite etc.

What does a finite universe expand into exactly?

This has fucked my mind for decades

This is a good summary of the sand vs stars question: www.npr.org/sections/krulwich/2012/09/17/161096233/which-is-greater-the-number-of-sand-grains-on-earth-or-stars-in-the-sky?t=1611555783383

The stars vs grains of sand on the earth is actually within estimation error-we don’t know. They are both of the order of 1022 to 1028. Both are hard to estimate exactly as there is a lot of sand on the sea bed.

Re Young’s slits (and Schrödinger’s cat), a collapsing wave function was (and, is still, to me) the most accepted explanation. People now prefer the multiverse with interference between photons in a parallel universe being the explanation as to why a single photon forms an interference pattern.

As to faster-than-light travel, I am still with Einstein. Quantum entanglement is beyond my level of expertise but, having done a quick Google (having been shocked that someone suggested FTL speed was now possible) the suggestion is that the entangled particles communicate at FTL speed but it is meaningless as, for a variety of reasons, you cannot send a message FTL. An interesting article is below:

quantumxc.com/is-quantum-communication-faster-than-the-speed-of-light/

The whole explanation of Einstein’s 4 dimensional space time cone is to do with sending information (which equates to travel), and this has not been violated.

Great thread, nothing massively important I can add but I my ds9 loves watching universe size comparison vids on YouTube, you get a good idea just how sodding massive the universe is.

This has fucked my mind for decades

What I can’t get my head around is the size we think the universe is, 50 odd billion light years, versus the age of the universe which is only 14 billion years. Makes my brain hurt that one

Sorry to be a nerd, but our solar system is roughly estimated to contain at least 70 septillion stars

Our solar system contains 1 star, known as the sun.

As to the speed of light being a limit, during the Inflationary epoch we are told that it was far exceeded when the metric changed. I think the truth is we don't fully understand this, hence the need for awkward things like the gravitational constant.

It's impossible to comprehend because the universe is fucking massive.

Look at one of the hubble deep field images of different galaxies. Even those pictures are a tiny speck pointing in one direction.
Mind blowing.