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First images from Euclid are in

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Re: First images from Euclid are in

#131

Post by mlyle »

cvoss wrote: post #107
mlyle wrote: post #99

Earlier quoted context omitted.

Possibly, but the challenges to do so are immense. Using the sun as a giant gravitational lens seems much more tractable.

Really? I wouldn't think the sun is nearly massive enough to do what would be required here. Stars visible near the edge of the Sun appear in slightly different spots from their actual locations. If there was a distant planet directly behind the Sun whose light were focused back to an image on our side of the Sun, you'd have to get really far back from the Sun to resolve the image, no? And furthermore, it's exceeding…

https://en.wikipedia.org/wiki/Solar_gravitational_lens

> you'd have to get really far back from the Sun to resolve the image, no?

Yah, a few hundred AU.

> you are beholden to the orbital mechanics of your viewing satellite as it plods along.

Yah, any mission like this -- interferometry or gravitational lensing -- is going to be super long and hit very few targets.

> Whereas, multi-site telescopes spread across the Earth have already been demonstrated as a feasible technology

Yah, at radio frequency while pinned to a common rock. The wavelength of visible light is hundreds of nanometers and we're talking across massive distances and significant gravity gradients and even relativistic corrections. The "big" space interferometers currently being considered are in the mid-infrared (e.g. longer wavelengths) across baselines of hundreds of meters.

All of these ideas are really hard.

Re: First images from Euclid are in

#132

Post by feoren »

wayoverthecloud wrote: post #55
neom wrote: post #10

Some of that zooming in made me feel pretty damn uncomfortable. It really is f'ing massive out there huh. Makes me wonder what this is all about, I'm sure it's something, I wonder what. :)

I think that too. That it's surely meant to be something. But sometimes I think what does "meaning" even mean? Does universe really have any "meaning", the term that humans invented and that even they are unsure of? Then, I think it's a big randomness, a random accident, a big joke, just happening with nothing to make sense of.

It's not a joke, because jokes have underlying meaning. It is somewhere between a "random accident" and the only way it could have possibly been given the constraints of fundamental physics. I suspect that everything that could possibly be, is, but it's random that you are you and I am me and we find ourselves here in this corner of this galaxy in this part of the universe which might itself be the inside of a giant black hole. But even if our universe is random, that doesn't mean there's nothing to make sense of. There's lots to make sense of.

Re: First images from Euclid are in

#134

Post by thenobsta »

renegade-otter wrote: post #56
neom wrote: post #10

Some of that zooming in made me feel pretty damn uncomfortable. It really is f'ing massive out there huh. Makes me wonder what this is all about, I'm sure it's something, I wonder what. :)

The Cosmic Deep State went to great lengths to make all of this very.... big.

Big Universe has it out for the little guy. It's trying to make it very hard to make sense of its master plan.

Re: First images from Euclid are in

#135

Post by skykooler »

cvoss wrote: post #107
mlyle wrote: post #99

Earlier quoted context omitted.

Possibly, but the challenges to do so are immense. Using the sun as a giant gravitational lens seems much more tractable.

Really? I wouldn't think the sun is nearly massive enough to do what would be required here. Stars visible near the edge of the Sun appear in slightly different spots from their actual locations. If there was a distant planet directly behind the Sun whose light were focused back to an image on our side of the Sun, you'd have to get really far back from the Sun to resolve the image, no? And furthermore, it's exceeding…

Yes, you'd need to get quite far from the Sun to use it as a lens - about 650 AU is where it starts becoming practical. It would also not be re-orientable, so any "telescope" launched to that location would only be able to observe a single target. (But, notably, it is far easier to send a probe to a far point in our own solar system than it is to send it to another star entirely.) There's a paper that goes into much more detail at https://arxiv.org/pdf/1604.06351

So why not use interferometry instead? Well, it has some significant drawbacks. For example: the Event Horizon Telescope used radio telescopes - and pretty much had to, due to how interferometry works: you need to be able to compare the phase shifts between the multiple telescopes, which means you need to be able to sample the signal faster than the radio frequency you're using and record it. The EHT records 64 gigabits per second for each telescope, and then all this data needs to be combined to compute the resolved image. This amount of data would be problematic for space-based telescopes - even on Earth, it was not practical to send multiple petabytes over the internet, so it was saved to hard drives which were shipped by truck instead. This isn't practical in space, so you would need to transmit the data by radio, which means you'd end up with some crazy ratio of thousands of hours of transmitting for every one hour you spend recording.

Re: First images from Euclid are in

#136

Post by caf »

phito wrote: post #125
imchillyb wrote: post #66

Earlier quoted context omitted.

So many rules, laws, and systems for all of this to be random. Seems a waste of good code if everything is random. Is an ecosystem random? What happens when one outside force is added to an ecosystem? There's plenty of examples around the globe of this. Life doesn't 'find a way' and balance. The ecosystem is damaged, and often times destroyed by adding a single non-native species. That doesn't seem random does it? Ra…

Ecosystems do adapt. They look broken to us because of our ridiculously small life span. That's why I dislike framing climate change actions as "saving the planet". The planet will be just fine. We won't.

You could think of it in the sense of "saving money" - if you're a notorious spendthrift, the money hasn't actually disappeared, but it's of no use to you anymore.

Re: First images from Euclid are in

#137

Post by ChocolateGod »

rvnx wrote: post #39
ekianjo wrote: post #14

Earlier quoted context omitted.

Life? Probably. Something that has thinking capabilities? Much more doubtful.

It depends what you call Life. If it is a machine that can reproduce itself, growth, collect energy, use energy, do actions based on events, etc, then animals match this profile (perhaps even plants), and also, at some point computer will probably reach that goal. Despite that, computers won't have a "soul", so where this soul comes from is a big mystery. I'm not even sure that two humans can prove with certainty tha…

Unless the "soul" or the feeling of self is a property of the universe itself and could apply to computers given enough computer power and "free will".

Re: First images from Euclid are in

#138

Post by TeMPOraL »

imchillyb wrote: post #66
wayoverthecloud wrote: post #55

Earlier quoted context omitted.

I think that too. That it's surely meant to be something. But sometimes I think what does "meaning" even mean? Does universe really have any "meaning", the term that humans invented and that even they are unsure of? Then, I think it's a big randomness, a random accident, a big joke, just happening with nothing to make sense of.

So many rules, laws, and systems for all of this to be random. Seems a waste of good code if everything is random. Is an ecosystem random? What happens when one outside force is added to an ecosystem? There's plenty of examples around the globe of this. Life doesn't 'find a way' and balance. The ecosystem is damaged, and often times destroyed by adding a single non-native species. That doesn't seem random does it? Ra…

> Life doesn't 'find a way' and balance. The ecosystem is damaged, and often times destroyed by adding a single non-native species.

Of course it does. "Ecosystem" and "species" and "native" are human terms referring to categories we invented to make sense of things. Life itself is one ongoing, unbroken, slow-burn chemical reaction at planetary scale. It's always in flux, it's always balanced in myriad ways on some timescales, unbalanced in others.

Even without getting reductive to this degree, there's hardly a case an ecosystem was destroyed. Adding non-native species ends up rebalancing things, sometimes transforming them into something dissimilar to what came before - but it's not like life disappears. The ecosystem is there, just different. Though it sure sucks to be one of the life forms depending on the "status quo".

> That doesn't seem random does it?

Yes, it very much is random. If thermodynamics teaches us anything, it's that random looks quite organized if you zoom out enough and smooth over details.

Re: First images from Euclid are in

#139

Post by gary_0 »

lefrenchy wrote: post #63

It's just so crazy to me to see a galaxy 420 million light years away. That is so much time for what we're seeing to have changed. I presume life can form within that window given the right conditions, so to some degree it just feels a bit sad that the distance is so great that we can't actually see what may exist in this moment that far away

Given that the speed of light is the speed of causality, technically it's not really 420 million years in the "past" in any meaningful sense. The present is relative, not universal. The collected light we see in our telescopes is a lie about a particular universe that will never be, at least in any tangible way. On a cosmic scale, every spot in the universe sees its own unique sequence of events going on around it, all of it rendered virtually immutable by the relative slowness of c.

It's a beautiful nightmare, isn't it?

https://en.wikipedia.org/wiki/Relativity_of_simultaneity

Re: First images from Euclid are in

#140

Post by lnenad »

mcmoor wrote: post #87
6stringronin wrote: post #62

Earlier quoted context omitted.

So you're saying out of the trillions upon trillions of stars that the chances are no life can think but us? I think the odds are that at least one of them does.

We're multiplying a very large number (number of planets) with a very small number (chance of intelligent life). The margin can make the answer go either way.

You are basing the chance of intelligent life number on what? Reality is we have no clue what this number is.
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