Galileo was observing Venus in 1610; his telescope was enough to see the phases of Venus but probably not high resolution or quality enough to see someone waving Semaphore flags or lighting a bonfire. Astronauts in Low Earth Orbit can't see the Great Wall of China with the naked eye.
What scale of 'device a way to signal back visually' could done with 1600's era manufacturing and technology?
I'm basing what I said on the comment I was replying to which said that they _already_ figured out that they have neighbors. Given the level of scientific understanding in the 1600s, it seems highly likely that they'd have to have pretty definitive visual proof in order to know they have neighbors, which implies they can see at least some of what's going on over on the other planet. While you're right that they probably wouldn't be able to see someONE waving semaphore flags or lighting A bonfire, there must be a way to have multiple someones doing such in sync so that it'd be visible. Or more likely, a system of simple machines arranged in an array, with the ability to show either a white or black stretch of fabric. It probably wouldn't need to cover the entire area between machines.
I'll admit, it'd take a lot of effort/money to communicate and it'd be pretty slow, but it's not impossible to happen just decades (or perhaps even within a decade) of when its figured out that they had neighbors. Not hundreds of years.
Isaac Arthur on YouTube makes videos on sci-fi ideas that we might be able to do within the laws of physics, albeit not with today's technology. He did a video on Colonizing Venus some years ago, and an updated one a few months ago, and some others around colonisation and teraforming of the planets in the Solar System:
> "there is only one multi-geared commercially available unicycle hub, and it only has 2 gears, and costs $1500 (Schlumpf drive)"
The Kwiggle folding bike in Germany[1] took over manufacturing of the Schlumpf drive in 2023[2] and uses it for their 6-speed option. It's in the bottom bracket and shifts by hitting the axle left/right with the heels. (costs ~€2000 and surely the front gear is not three quarters of that?).
[2] https://www.drive-mobility.com/en "We, KwiggleBike GmbH, have been managing the business of Haberstock Mobility GmbH since 01.04.2024. We have been manufacturing all Schlumpfdrives since mid-2023"
There are 2 schlumpf drives; there is a bottom bracket-compatible one like you describe. That is used for recumbent bikes and a few niche things like Kiwgglebikes. However, they still power the wheel with a chain. The unicycle hubs, which are the same as shown in the cyclauto, have no chain; the hub is also the center of all the spokes on the wheel. But yes, they are basically the same thing.
I'm sure it doesn't cost $1500 to produce, that's just the cost to consumers. My point wasn't that it's ridiculously expensive (which it is), but that this seems like a really high hurdle to produce the cyclauto; no other company is currently producing the unicycle version, and even if they can manufacture them for, say $500, that's still astronomical compared to if they used the cruzbike model.
> "So, you have a lot of people commenting here that this is obvious common sense"
You have this about everything, everywhere. It's a pet peeve how much stuff people will attribute to "common sense" so they can do the internet "I'm superior" thing.
"Wear sunscreen, it's just common sense". No it isn't. We evolved on Earth under the sun, we feel good when going out in the sun, it's bright and beautiful. Rubbing petrochemical distillate or industrially processed plant extract on your skin so the invisible light discovered in 1801 doesn't denature the invisible DNA discovered in 1869 is not common sense it's learned behaviour. Nothing much about Science is common sense, it took thousands of years from the dawn of Civilization until the Enlightenment era and still people can go through years of education and then choose to believe what we want to believe instead of what the evidence shows.
'Common Sense' is that the world is simple, designed for a purpose by a human-like mind one or two levels up from us on the power scale, and inhabited by life-like energies and spirits, some of them malevolent. Common Sense is that things which didn't happen today or yesterday will probably never happen. Common Sense is that things which happen together cause each other; if the relative comes to town and the crop fails then they are bad luck, if the relative comes to town and the baby is born healthy then they are good luck.
Why would it be any kind of 'common sense' - 'sound judgement not based on any specialised knowledge' - that glucose (1747) response differs for the same meal if you need a continuous glucose monitor (FDA approved in 1999) to find that out?!
You are using one particular "definition" of the phrase common sense. It does appear when I search as well. But so do others.
knowledge, judgement, and taste which is more or less universal and which is held more or less without reflection or argument. As such, it is often considered to represent the basic level of sound practical judgement or knowledge of basic facts that any adult human being ought to possess.
Now with that definition some of what you said very definitely would no longer be the case as the above definition would seem to automatically "adjust with the times" so to speak in that what we might expect most adults to know and understand changes over the years, decades and definitely centuries.
To be fair, what I quoted said "any", so I guess they mean closer to 99.99% but I'm with you on "unfortunately common sense seems to not be quite as common as one might wish for" ;)
And this isn’t even universally true. It’s tied to skin color. Sunscreen won’t do much for someone with extremely dark skin. In medical lit, “common” often refers to “white persons.”
Because that's conceptually simple. With your idea, you cannot clone the domain 'gmail.com' so one of these must happen:
- one company gets control of gmail.com and the other has to register a new domain nobody has ever heard of.
- the companies share control of gmail.com and users see no changes.
Anyone who must upend their digital life (email, contacts, Android login, YouTube login, analytics, 'login with Google' around the web, payment data, etc. etc.) has a problem, the company which gets the domain has a massive advantage. If they share it how are they competing with each other, which one can change the Gmail experience or pricing scheme?
Similar with GCP, which split gets to run a big customer's services? The customer isn't going to pay twice for them to be cloned. Does the customer have to update all their logins and API keys and contracts and payment details?
Who owns all the Exabytes of pre-existing YouTube data and what happens to all the ISP peering and CDN server hosting contracts which run it?
What happens to the legal contracts, tax deals to have offices in certain countries, employee visas, paying the datacenter maintenance bills or office cleaning bills? If the employees sit next to each other and now one works for Google_A and keeps everything the same, the other works for Google_1 and has to move to a new office which hasn't been built yet... same problem as Gmail but internally, one company gets a big advantage the other gets a big disruption.
What happens when you algorithmically split employees 'to avoid chaos' but one company ends up with no senior people who have access to a certain system?
Since we didn't ask for our accounts to be copied to Google1, do hundreds of millions of us have send Google1 a 'delete my account' request to get rid of them? If I delete my account from GoogleA do they have access and legal right to delete the copy from Google1 as well? If they don't, does my deleted login to GoogleA still work backed by the copy of my account on Google1, because there is only one GMail.com domain and it has to keep working?
It's conceptually easier to say maps.google.com is under control of a new company, not subsidised by Google Advertising income, and it needs to compete with other map providers, even if technically it's hard to extract the accounts and data from Google's server infrastructure.
The Lake Peigneur diaster in 1980, drilling for oil in a lake bed in Louisiana they accidentally drilled down into a salt mine and drained the freshwater lake into it. That disolved the salt pillars supporting the mine's roof and created a 65 acre sink hole and backfilled the whole area from the saltwater bay.
Like the startups which try to make solar systems to condense drinking water from the air. They demonstrate it in wet climates where the idea works but the solar panels don't because it's cloudy and cool. Those environments don't need drinking water because they are rainy. Then they try it in deserts where the water is needed and the solar panel bit works, but the whole thing doesn't work because there's no water in the air - that's why the water is needed there(!).
ThunderF00t Busted! videos on scammy startups keeping on raising money for this fundamentally unworkable idea:
This dietician blog on the British Heart Foundation website suggests it's wrong but partly right[0], saying "although having low levels of vitamin D is associated with increased risk of cardiovascular disease, the low vitamin D is a result of lifestyle factors that increase your risk of heart disease and stroke, rather than the cause of increased risk.".
The leading causes of death in the UK[1] are heart disease, lung cancer, influenza, dementia, vascular disease (stroke?) and lower respiratory disease. Skin cancer is 1% of cancer deaths, and for melanoma the peak of diagnosis is people 85-89 years old[2]. Considering average life expectancy, people are generally diagnosed with skin cancer a few years after they die.
The partial claim "refrain from going outside which in turn .. is way worse than potential UV induced cancer risks" could be right. Avoiding exercise and increasing your heart disease risk, in the hope that you'll avoid one of the more treatable and less fatal cancers in very late life, is probably the wrong tradeoff. Not to do with Vitamin D or covering up or suncream though. Still, why not do both - cover up and go out, lower heart disease risk and lower your chances of skin cancer diagnosis in late life.
> "That is one bus, even a tiny city will need more than 100 buses to just provide bad service, and would need 5-10 times as many just to give good service"
You say that as if it's an unthinkable impossibility. As of 2017 London had 8,600 busses carrying 6.5M passengers every day. Yes a big city needs a lot of buses, so they have a lot of buses. No problem. What would it cost if there were no buses and 6.5M more car journeys every day? And the roads and parking spaces for - what - 1M+ more cars to account for that?
What financial cost to the city for roads and infrastructure and traffic lights and signs and maintenance, what financial cost to the people needing cars, what time cost of humans stuck in traffic, what health cost of less exercise, what health cost of pollution, what accident cost?
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