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The universe is expanding faster than expected

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Re: The universe is expanding faster than expected

#191

Post by insulanus »

Razengan wrote: post #188
vecter wrote: post #176

Earlier quoted context omitted.

Your balloon analogy is almost correct but it's missing one important piece. In that analogy, the surface of the balloon itself is the entire universe. It is a two-dimensional universe. Imagine that there is no other space except for that surface of the balloon. No emptiness inside and no space outside that it's "expanding into". The entire space is the infinitesimally thin surface which is the balloon surface, yet i…

But what's filling the space between the dots? Is it new space? If I have a long ass string, is the string gradually getting longer, or will it break apart?

The string won't break apart, because the forces that are holding it together are so much stronger than the "force" that is pulling our universe apart.

Unfortunately, it doesn't answer your more fundamental question of "if I make 2 marks in space, and then those expand apart, what is in the new space, and how do I know they really are farther apart?"

I have never heard a good description of this on human scales, only at stellar and galactic scales.

Re: The universe is expanding faster than expected

#193

Post by Razengan »

vecter wrote: post #190
Razengan wrote: post #188

Earlier quoted context omitted.

But what's filling the space between the dots? Is it new space? If I have a long ass string, is the string gradually getting longer, or will it break apart?

More space. It's pretty nuts. Imagine you were stretching a rubber band. What's in-between two points on that rubber that was stretched? Just rubber, albeit thinner and less dense. In our universe, however, the space that's created is the same as the space that was just there. It'd be like if the rubber band stretched, but didn't lose any density while it did so. Insane, I know.

So, is it like, the number of pixels on the screen stay the same, but it takes more “ticks” for a variable representing coordinates to go from 1 to 2: x += 0.09 instead of x += 0.1

Re: The universe is expanding faster than expected

#194

Post by drukenemo »

ta8645 wrote: post #149
drukenemo wrote: post #143

Earlier quoted context omitted.

I’m amazed how the God hypothesis seems to not exist amongst the modern, smart tech world. Everything is science, science one day will know...

You're right. I'm also amazed how the Magic Unicorn hypothesis seems to not exist amongst the modern, smart tech world. It's hard to imagine why they ignore us.

The magic unicorn bear no weight in tradition , people’s experiences and written records. You are being purely cynical.

Re: The universe is expanding faster than expected

#195

Post by codeflo »

eurasiantiger wrote: post #186
est31 wrote: post #154

Earlier quoted context omitted.

I can imagine scientists in a couple billion years debating whether the historic records of other galaxies existing should be believed or whether one should dismiss them as crazy religious texts someone faked a couple million years ago... (obviously by then we'll probably uploaded ourselves to computers and turned into totally different beings from what we are now, but the problem of trusting historic data still exis…

Finally, an actual use case for a blockchain!

I know you’re joking, but I’m genuinely wondering, would that actually resolve the problem of (then) ancient forgery?

Our proof-of-work difficulty is trivial compared to what’s possible a few thousand years from now. So for people a million years from now to trust our records, they’d also have to trust people a thousand years from now not to simply have forged our part of the blockchain, which might be trivial for them given their hash power.

Re: The universe is expanding faster than expected

#197

Post by jl6 »

codeflo wrote: post #195
eurasiantiger wrote: post #186

Earlier quoted context omitted.

Finally, an actual use case for a blockchain!

I know you’re joking, but I’m genuinely wondering, would that actually resolve the problem of (then) ancient forgery? Our proof-of-work difficulty is trivial compared to what’s possible a few thousand years from now. So for people a million years from now to trust our records, they’d also have to trust people a thousand years from now not to simply have forged our part of the blockchain, which might be trivial for th…

Spoiler: the energy to power all that hashing is where the other galaxies went.

Re: The universe is expanding faster than expected

#198

Post by pratyushc »

azernik wrote: post #130
pratyushc wrote: post #120

Earlier quoted context omitted.

> Could the great filter be something like developing language? Perhaps it's a combination of factors? Dolphins are social animals that appear to be capable of complex communications among themselves, but don't have hands to manipulate their environment the way we can. Apes have hands, but don't have complex language.

Another interesting one I've heard is getting into space, period. It's possible that there are other technological civilizations out there, but all stuck under a few hundred km of ice or on a 2-earth-mass monster where it's impractical to reach orbit. Earth may only be special in being in a sweet spot between Mars (too small to hold an atmosphere or protect from cosmic radiation, hence no life) and Gliese 832c (with…

> protect from cosmic radiation

That raises another issue of the planet having a magnetic core...

Re: The universe is expanding faster than expected

#199

Post by cygx »

pdonis wrote: post #129
cygx wrote: post #62

Earlier quoted context omitted.

Note that the most distant astronomical object we've observed has a redshift of 11, corresponding to a light travel distance of 13.4Gly. This means that if our models are correct and the universe is indeed about 13.8 billion years old, then we've seen 97% of the universe's history. Including the microwave background in that pushes the number to 99.997%.

> the most distant astronomical object we've observed has a redshift of 11 And even though that seems like a large distance , it is a very small redshift compared to the total time the universe has existed. The cosmic microwave radiation background, for comparison, was emitted at a redshift of about 1100. So a redshift of 11 only covers 1 percent of the expansion of the universe since the CMBR was emitted. > we've se…

No, we haven't. See above.

No we have. See above: While redshift goes all the way up to infinity, in terms of cosmological time, there's still only 0.4 billion years between z=11 and z=∞, or about 3% of the age of the universe.

Re: The universe is expanding faster than expected

#200

Post by bencollier49 »

vecter wrote: post #190
Razengan wrote: post #188

Earlier quoted context omitted.

But what's filling the space between the dots? Is it new space? If I have a long ass string, is the string gradually getting longer, or will it break apart?

More space. It's pretty nuts. Imagine you were stretching a rubber band. What's in-between two points on that rubber that was stretched? Just rubber, albeit thinner and less dense. In our universe, however, the space that's created is the same as the space that was just there. It'd be like if the rubber band stretched, but didn't lose any density while it did so. Insane, I know.

So as the universe grows, am I growing as well?

How much is the space inside me growing on a daily basis?

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