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.
> 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.
Yes, it is. It is 420 million years in the past in our frame of reference. The link you posted is about how frames of reference of other observers might differ from ours. However, doesn't make the notion "420 million years in the past [in our frame of reference]" any less well-defined.
I’ll admit I’m severely undereducated in this stuff, probably less than an average high schooler these day but nevertheless I feel like I’ve considered this before and never knew it had a name. Which makes me feel not completely stupid.
> whether two spatially separated events occur at the same time – is not absolute, but depends on the observer's reference frame.
But What I don’t understand about this is why is “time” framed as observer based? In my mind, the events do happen at the same time and just are unable to be observed as such. I feel like time is a figment of our imagination, it’s just a measurement. In my pea brain time makes sense more as a constant and the other things are something else that impacts the latency of observance
> But What I don’t understand about this is why is “time” framed as observer based? In my mind, the events do happen at the same time and just are unable to be observed as such. I feel like time is a figment of our imagination, it’s just a measurement. In my pea brain time makes sense more as a constant and the other things are something else that impacts the latency of observance
Its a logical consequence of the speed of light being constant in all inertial reference frames, regardless of the velocity.
This is an axiom of special relativity, but it has also been verified at (admittedly low) relative velocities.
That in itself is somewhat absurd, but it leads to further absurdities when you do the math. In order for the speed of light to remain invariant, you can no longer speak of an absolute (preferred) frame of reference.
You can of course, privilege certain reference frames e.g. Earth, but its rather arbitrary.
>> In my mind, the events do happen at the same time and just are unable to be observed as such.
Not so, I would say.
Space and time are inherently linked under special (and General) relativity. For two observers who have relative motion between them, the space (distance between two 'events') and time (between the said events) are both different.
When some poem or a song talks about the universe being frozen at a given instant of time, that can be only in a given reference frame. There's no absolute time for the universe.
If not for observation, what does "happen" mean? Keep in mind observation in the physics sense doesn't mean conscious observation but rather that anything experiences something at all.
Don't think about it too much. It's wrong. Relativity of simultaneity only kicks in when you have reference frames moving at noticeably different velocities. Which is... not entirely wrong in this case due to the expansion of the universe, but would be equally true of a nearby reference frame moving away equally fast. It's nothing to do with light travel time.
Ed: I've slipped into the fallacy a bit. Reference frames don't have locations, so they can't be "nearby". Just pretend I said "reference frame of a nearby object".
In another way it's really cool to be able to "see the past" even if all we see is always the past. At this level it is like a super power. If only some aliens had put a mirror somewhere far so we could see ourselves too. Or multiple mirrors at different distances.
With enough mirrors and light bouncing around the size of the universe itself can be a "storage media" of the past with different photons all around carrying "how this location looked X years ago". "All" you have to do to know what happened is find the right photon to see whatever it is you want to see.
"pingfs is a filesystem where the data is stored only in the Internet itself,
as ICMP Echo packets (pings) travelling from you to remote servers and
back again."
In theory, couldn't we focus on a perfect spot near a black hole where the light has been warped 180 degrees around it... i.e. if the black hole is 100 light years away, you'd see ( with perfect zoom, of course ) a picture of the earth 200 years ago...?
I understand that we'd have to account for the movement of objects, of course, but with computers, seems like a small hurdle...
Is there a science fiction universe that explores a hypothetical warp drive that lets you travel very far relatively quickly, but the travel is only possible with simultaneous backwards time travel that's proportionate to the distance traversed? So you can hop across star systems but can't do a roundtrip A -> B -> A without significantly shifting time from the point of view of A backwards (irreversibly from the point of view of the traveler).
- An Earth telescope will see the destination as it was when I left
- It will take another year to see me arrive
So in a way that's already happening because I'm traveling quite quickly - twice as fast as it seems from Earth's perspective - and I arrive in what appears from Earth to be the past.
It's perplexing because Elon is effective at fundraising and pursuing challenging and ambitious goals.
However now Tesla cars are protected by a 100% tariff on competitors, and Elon is campaigning for Trump who is now promising 200% tariffs on imported goods.
The gigapress sounded like a good idea when I first heard about it bc it could reduce manufacturing costs, yet Tesla does not seem to have realized any significant improvements in 2024 from it, and needs massive protectionist policies to compete.
It's interesting to imagine the price and performance we'd be seeing (and all the new dealerships and service centers popping up) of Chinese engineered and manufactured EVs if it weren't for the tariffs. Surely there would be some very capable options in the $20K range that would eat the Model 3's lunch. But Elon has government protection to the rescue and so he doesn't have to actually win at engineering or manufacturing, only lobbying.
You’re simplifying things a bit here. The tariffs are to protect all US car manufacturers (who all have EV directives) from BYD, who was strategically subsidized by the government to crush EV companies, including Tesla [1]. Tesla would be able to compete much easier if we were to throw out the environmental regulations and better utilize slave labor [2].
> The tariffs are to protect all US car manufacturers
Most of the US car manufacturers would have gone out of business in 2008 if the US government had not bailed them out. How can anything China is doing to help BYD compare with that? Yet Tesla still needs 100% tariffs on BYD vehicles to compete?!
Environmental regulations and alleged "slave labor" in China hasn't bothered the US government or US consumers for decades (most consumer goods are manufactured in China) yet somehow it matters tremendously in 2024 and necessitates 100% tariffs to protect US firms from competition?
Most of us lived through the era when the price per performance of computer hardware decreased rapidly and there was rapid price deflation on hardware that was only a few years old.
Right now, in 2024, American consumers should be benefitting from the far simpler design of EVs and car prices should be dramatically lower due to the benefits of EV tech. Car prices should have deflated but thanks to US policies entry level cars cost close to $30K now. The average price of a new car is $47,000
No, EVs do not need to be fancy, aluminum, giga-pressed luxury items! It's a battery and an electric motor and it should cost a LOT less than an internal combustion vehicle that has hundreds of precision moving parts.
We've seen the high quality engineering and low cost manufacturing China is capable of with scooters, hoverboards, etc. The essence of China's industrial policy is that in a few years some of those engineers start being able to design EVs that outcompete Tesla. Meanwhile in the US we are bringing back steel mills and coal fire power plants!
> Yet Tesla still needs 100% tariffs on BYD vehicles to compete?!
Why does Canada also have 100% tariff? Why do you think the tariffs are only for Tesla? Again, all US car companies have a fairly ludicrous government mandate [1] for EV production:
> In April, the EPA finalized its “Multi-Pollutant Emissions Standards for Light-Duty and Medium-Duty Vehicles for MY 2027 and Later” rule that could effectively call for 44% of new vehicles in 2030 and 56% of new vehicles sold in 2032 to be EVs. This rule greatly exceeds the current real-world consumer demand for EVs. Also, the rule projects that gas-powered vehicles (including hybrids and plug-in hybrids), now currently 92.9% of the market, could be reduced to 29% by 2032.
Chevy, Ford, and Toyota lose billions [2][3][4] per year making EV. They need this too. Tesla is the only US car company that profits from EV sales. Tesla, by every metric, needs it the least.
> necessitates 100% tariffs to protect US firms from competition
ICE cars are made of metal and plastic. There's a nice local and global market for these. BEV need lithium and cobalt. The US makes 2% of the lithium worldwide, with its single mine in a single location [5]. Lithium is 30-50% the final cost of a BEV. China makes 7%, but the Chinese companies have helped secure 80% of worldwide production [6]. Chinese companies owns 15 of 17 cobalt mines in DRC, where 80% of cobalt comes from [7]. The line between where a Chinese company ends and the CCP begins can be very very blurry. This is the result of very smart investment in China, and a big fuck-you to the environment and labor (making imports illegal [8]), like the good old days of the US.
> Meanwhile in the US we are bringing back steel mills and coal fire power plants!
China is responsible for 95% of new coal plant construction [9].
> giga-pressed luxury items
The giga pressing is to make them cheaper. Many car companies are looking at this for cost saving, including Toyota [10].
I agree with cars being too expensive. I've never looked into the breakdown for why. But, for the realm I work in, China is no longer much cheaper for labor. I suspect that's related.
So China is both using slave labor and also paying close to wage parity with the US? How can both of those assertions be true?
I think the lithium/cobalt argument is a bit of a straw man, since the generally accepted view is that the US likely has an abundance of such deposits but simply has not opted to do significant extraction.
Also, from the standpoint of the security risk associated with China controlling the supply, the US coudl also opt for strategic reserves of key items at a much lower cost than the cost of tariffs on the economy.
An easy way to help EV companies would be to stop spending trillions of dollars on petrolium-related wars. If you do the math, gas should cost at least double at the pump what it typically costs. The rest of the cost is the massive military operations needed to keep prices what they are. Those operations are not free by any means and are certainly not budgeted (so they are still yet to be paid for).
So in the supposedly capitalist US we have thousands in subsidy for EVs and Trillions in subsidies for petrolium related military operations, and now 100% tariffs on competitive EVs, etc. Why? Because China is evil? Because Saddam is evil?
> So China is both using slave labor and also paying close to wage parity with the US? How can both of those assertions be true?
Very trivial actually. The ones approaching wage parity are tech workers in big cities (what I deal with). The ones working as slaves are literally digging holes, sometimes in other countries. The battery supply chain contains both. The part that makes it easy for China to make cheaper batteries is the digging holes and fucking the environment part of it.
> the US coudl also opt for strategic reserves of key items at a much lower cost than the cost of tariffs on the economy.
They could, but they would, again, have to ignore environmental and labor concerns, which would require first changing federal laws that ban imported goods that used forced labor (see previous links).
> An easy way to help EV companies would be to stop spending trillions of dollars on petrolium-related wars.
Unfortunately, 93.2% of the 283 million cars on the road are ICE. This "easy" way involves a short term severe disruption, especially of the lower levels of the economy. But, I agree completely that subsidizing EV companies (including Tesla) and strategic foreign investments in REE is probably a better long term bet than building nice bombs.
I think the realistic result of all of this is that the economic pressures force the next gen of batteries to not use lithium or cobalt, or anything that China has 80% control of.
Interesting points. I appreciate the discussion a great deal.
I really want to believe that the US is doing state of the art engineering and manufacturing in the EV space. You've given me some good things to think about.
I disagree that it's the low risk, low reward path. The risk and reward isn't in the type of work but in the companies you choose. You can do boring low risk backend work, but at a startup with the opportunity to 100x your RSU's or lose your job.
So, the ending of twitter is to switch to Threads with FB's content moderation guidelines? I don't think so. We have social media fatigue rn. Twitter is is ok to get info really fast, rarely goes down, you have access to all kind of views (from extreme left to extreme right). This is the main reason gab, truth social, etc... won't be mainstream.
Fb hasn't been original from a long time. From trying to launch a substack competitor, stealing snapchat features, creating reels, etc. Now, developer wise, is a different game. React, Pytorch, Prophet, etc... hit after hit.
Twitter can be a "cesspool" but I don't trust fb at all.
> Twitter is is ok to get info really fast, rarely goes down, you have access to all kind of views (from extreme left to extreme right).
Twitter was ok to get (and, equally important in my opinion, share) info really fast; now you need to have an account, be logged in, and be under your meager daily quota to even be allowed to see anything. And everyone you want to share info with needs to do the same. The recent changes have pretty severely undermined what made Twitter stand out among its larger competitors.
The quota is temporary. I agree with you that latest changes have been crazy,but it 's not the end of the world. I much rather prefer Twitter than give Zuckerberg more power.
Now, I see them winning if they go Twitter's route and nuke their content moderation guidelines but since that won't happen, I doubt you'll see mass migration from the freedom fighters, hehe.
Reality is they need each other. Conflict is what gets Twitter going. That and memes.
The only "extreme left" account I followed on Twitter (Chad Loder) was personally banned by Elon because his #1 priority post-Grimes breakup has been trying to become a made man so the internet fascists will let him into their gang.
There are certainly tankies on there, which is a kind of person that claims to be left but is actually a reactionary.
I think the vast majority of people don’t care much about what happens at the outer bounds of content moderation. Most people go to Twitter for pretty normal internet conversations, which are increasingly difficult to have there: the Blue buffoons being at the top of every thread with nothing worthwhile to say, the constant spotlight on Elon drama, rate limiting, huge jump in bugginess, etc.
FB allows a sufficiently diverse, extreme, and even toxic political environment on FB for most everyone. What kind of content would Threads forbid that is more crucial to Twitter users than a functional service?
Putting the content of people who have to pay for engagement above everyone else was one of the most heroically dumb product decisions I’ve ever heard. I was fine putting up with everything else but then the service just became legitimately not compelling because of that.
Pedantic but just for drive-by readers, there isn't really any nodejs dependency. You can use it to manage JS dependencies, or you can forgo it for "vendoring" with esbuild (or bun, etc).
Liveview itself has a small JS component that is mostly transparent (socket.connect() basically). You can of course add more JS too it.
Wow. This paper is _very_ well written. I am not an expert in neural networks, but the concepts were very well described and diagramed and I was able to follow along.
I would read a whole book about neural networks written in this style.
Normally, ML training is via back propagation, which is a synchronous technique. If you try to trivially parallelize, it doesn't work, for reasons (tm).
This lets you train a machine learning model of arbitrary size (bigger than can fit on a GPU, or even a multigpu node) using an actor-based distributed technique. There is a slight training cycles count penalty but it's way less than the cost of coordination.
I love Elixir and Phoenix/LiveView, but I have the same problem. I think it will need to gain the proverbial 10x improvement over React and JS frameworks in general before people consider it.
Sometimes you can come in the side door. I built a testbed reservation app for the GUI team I work with using Phoenix LiveView. The Product manager was surprised out fast I hammered it out. So far everyone is using it without a hitch. It's not product code, but it's still in active use with no problems.
not just this, but also no one knows elixir. Its a very niche language for very niche set of tasks, rewriting existing apps form react to elixir just to use liveview is a pointless overkill
I find it hard to drive through the Tenderloin without thinking “there is no fix for this”. Once someone has been homeless and into drugs for long enough, it’s going to be incredibly difficult to get them to fix their lives (if possible at all) for a good portion of them.
Beyond some massive investment in housing and recovery, it’s just going to continue not working. Prevention is the solution, we have to prevent it at all costs and do our best to ease the suffering of those who are stuck there now.
Unfortunately I think we’ll continue with half measures and the problem will remain unsolved.
As a cat owner who’s really bonded with his cat, this feels rather obvious to me. When he lays on my chest and stares into my eyes at the end of a day where I was gone a long time it’s pretty easy for me to feel like there’s more there.
