HN Explorer

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e12e
Does this account for number of people and trains/boat etc?

[ed: on mobile so can't launch the app]

mtmail
It doesn't. Flights/airports only.
mplanchard
You can add an airport multiple times to account for multiple people coming from the same place.
glaucon
When I do that it doesn't make any difference to the Total CO2. I just did Glasgow/London and then added an extra Glasgow and the total didn't change. In any case, as I've mentioned elsewhere, the CO2 seems to be based on the entire aircraft rather than per passenger, whether or not this is a good idea depends on the intention of the person looking at the tool.
kushie
why cant i view on mobile
furyofantares
How many times is it acceptable to post the same Show HN? (Genuine question)
[deleted]
(comment deleted)
schemescape
> You can post a new release as a Show HN only if the new version is significantly different. It shouldn't just be an incremental upgrade. If you do repost, add a comment linking to the previous Show HN and explaining what is different from last time. This should probably only happen once or twice a year—more starts to be excessive.

It’s in the “Show HN” -> Tips link: https://news.ycombinator.com/item?id=22336638

Of course, this and many other submissions just seem to have resubmitted until getting traction. I don’t know what to say about that

iso8859-1
Isn't it better to meet in a place where one of the people is already located? Then one less person has to fly, and they can use their saved time to work and offset the CO2 spent by the additional time traveled by the others.
wolrah
> Isn't it better to meet in a place where one of the people is already located? Then one less person has to fly, and they can use their saved time to work and offset the CO2 spent by the additional time traveled by the others.

I'm not sure if the tool specifically accounts for that or if the math just ends up working out, but I was testing with various combinations of my family and it always ended up at someone's home airport.

capableweb
> I'm not sure if the tool specifically accounts for that or if the math just ends up working out, but I was testing with various combinations of my family and it always ended up at someone's home airport.

Not sure. But if you put the two locations of Caracas, VE and San Francisco, US, they suggest meeting in Houston, US.

Does it make sense? Is it more environmental friendly for two people to meet in the middle rather than having one person staying and the other going there? My gut says the latter should be more environmental friendly.

kortilla
Better for one to travel. A disproportionate amount of a flight’s fuel is in takeoff and climb. Meeting in Houston is far worse because you’ve doubled the required takeoff rolls.
jamilton
The tool claims to take that into account, it breaks it down in the "show report" button. Liftoff is 3 tons of CO2.
gabrielhidasy
Unless it's accounting for no direct flights between Caracas and San Francisco, which would mean either the Caracas person needs to fly to SF connecting in Houston, or both go to Houston in a direct flight, meet there and go back. It's the same 4 takeoffs.

(Disclaimer, I have no idea if there are direct flights from Caracas to SF, but from Brazil I always need to stop by in a hub)

kortilla
Even with a layover, it’s better for one to do it because it’s one less hotel room, airport transport, etc.
jameshart
It's certainly not always the case.

In planar Euclidean geometry, for any three points, if the triangle formed by those three points has all its angles less than 120 degrees, then the sum of the distances from the three points to certain points inside the triangle will be smaller than the sum of the shortest two sides. Only if one of the angles exceeds 120 degrees will one of the three points always have the shortest total travel distance.

The relevant concept is the 'Fermat point', which is the point that minimizes total distance from the vertices of a triangle.

In spherical geometry, it gets more complicated, but the same logic applies to spherical triangles that aren't too large. You can definitely find sets of three points on a sphere, such that points inside the triangle are the one which minimizes travel distance.

Kwpolska
Does this still hold if you count the flown distance twice, because the meeting participants would probably like to get back home after it ends?
winnit
Of course, the lengths are just doubled. If someone travels twice as far to get to someone’s home they also have to travel twice as far back. If the two met in the middle instead there would be four journeys but each would be half as long (2+2=1+1+1+1).
wiml
The carbon cost of a flight isn't a linear function of its distance, though — takeoff is much more expensive than cruise, and on long flights there's the cost of hauling the fuel itself, rocket-equation style. (Presumably the data underlying this website accounts for all that.)
seabass-labrax
Indeed; furthermore, some air traffic control regions have adopted a direct routing strategy, replacing the conventional routing strategy of published airways. This means that a flight from, say, Prague to Bucharest should be ever so slightly more efficient than the equivalent distance from London to Venice because of the direct routing.
jameshart
All of which complexity just means that air travel carbon costs are a slightly more complex noneuclidean metric than just ‘spherical geometry’.

But you should still be able to define a metric over the graph of airports which is based on costs.

And what Fermat points tell us is that even in well behaved metric spaces like the plane there can be cases where minimizing distance means going to a node other than one of the starting point. So in more complex spaces it seems likely that that remains the case.

Which was all the op was asking.

abdullahkhalids
I would expect that aircraft emissions have a fixed cost + a distance dependent variable cost. Coupled with the fact that we are optimizing over a discrete set of locations, it is very possible that the optimal location is at one of the corners of the triangle.
jameshart
… sure, but also possible that it won’t always be.
akira2501
They have variable costs that aren't dependent on the distance. Some planes take off in 10 minutes, some planes have to sit for 45 before they can take off.

This all also assumes that you will always be able to fly directly to your destination on the selected day. If you end up diverting or getting delayed, or if certain routes make that _more_ likely, then this wouldn't be a win at all.

dheera
I guess if you're optimizing on the other metrics, yes, but if you're optimizing for CO2 only the best solution may not necessarily be where someone is already located.

However, I did try putting in e.g. 10 x Boston, 1 x London, 1 x Paris, and it did in fact suggest Boston as the meeting point.

Realistically, it is often also the case that the announced location of a meeting influences who attends it, as compared to travelling for a conference (flights + lodging + meals), the costs are much, much lower for people who already live in that city, who need to only buy the entry ticket.

So if you announce a conference in Paris instead of Boston you might expect a bunch of people who already live in Paris to suddenly want to attend. This effect is hard to account for.

bagels
If you enter two locations, it picks one of the two as the meeting place.
jamilton
Not necessarily. San Francisco and New York give me Chicago.
Eric_WVGG
Agreed. If > 50% of the attendees are already in a central-ish location, that changes the calculation by quite a lot.

Fun and well-designed tool, though.

wolrah
This is a really neat tool, but I'm having a hard time imagining situations where it'd be all that useful, where people from substantially different locations all need to meet in person, but don't care where they're meeting. How often does that happen?

Am I missing something?

jameshart
Remote-first companies encounter this problem all the time.
ytdytvhxgydvhh
Do they? I feel like remote-first companies seem to enjoy having an excuse to travel to exciting destinations as a recruitment/retention perk. “We’re meeting in Kansas City because that minimizes emissions” likely doesn’t spark joy in the same way that “we’re meeting in the Bahamas because we’re cool and fun!” would.
micromacrofoot
I refuse to fly to corporate meetings due to climate impact, and I have a few colleagues that do the same, so I don’t think this is universally true. I would respect a company that didn’t.
chroma
Depending on how you measure it, aircraft account for 1.9-3.5% of greenhouse gas emissions.[1] The biggest source is electricity and heating, followed by ground transportation.[2] Compared to almost all other sources, air travel is a rounding error.

1. https://ourworldindata.org/co2-emissions-from-aviation

2. https://ourworldindata.org/emissions-by-sector

micromacrofoot
I also produce more electricity than I use with solar panels (including heat) and drive an ev less than 2500 miles a year… so I’m an extreme case. This isn’t realistic for everyone because of how the world is built, but the hardest part was saving for the upfront investment (I’ll start generating profit from solar once I’m 7 years in, probably less now because I haven’t recalculated faster than expected inflation).

While not everyone can manage this due to upfront costs, a lot more people could do this, but simply don’t.

jsharf
I think for academic conferences, they typically choose a venue that changes every year. This could be used to aid in selecting a venue.
Jolter
They won’t know who’s attending then they book the venue. It works the other way around, usually.

And of course, if you don’t know who’s attending…

cagenut
there is a small but growing cohort of people who both a.) work in all or predominantly remote orgs and b.) understand the carbon cost of flying.

if your team meets those critera then this is the only way to make these decisions.

even if your team doesn't entirely agree on b, those of us who do can use this to inform our votes on where to meet.

wolrah
My emphasis for that sort of scenario would be on the *need* to meet in person aspect. I've been working remote exclusive for over a decade at this point and even though we're all in the same part of a single US state the last time more than two of us occupied the same building at the same time was years ago.

The more people or travel groups you add to the equation the less likely it is in my mind that you actually needed to physically meet unless you're meeting to do something in the real world which usually can't be done absolutely anywhere. If you're not meeting somewhere specific to do a thing in that place why couldn't the meeting have been done virtually?

Someone else suggested conferences, and I guess that could make sense in the case of small conferences where any random major airport hotel can handle their needs and a substantial portion of the attendees can be expected to vote, but it doesn't scale.

nottathrowaway3
Because it's designed to optimize fuel efficiency, the use case is basically corporate greenwashing.

HR: "our company meetup allows authentic inclusive in-person interactions, all while helping save the environment, by only releasing 1M tons of CO2 rather than 1.03M tons."

The most environmentally friendly meeting is obviously one that happens online. In-person meetups increase retention but -- until teleportation is invented -- that retention comes at an environmental cost.

A similar tool could be designed to minimize something else (cost, flight time, etc.) which would have a better use case outside corporate ESG politics.

cagenut
first off thank you, anything even remotely down this road is the right direction.

as a UI bug, when I typed "ewr" or even "newark" it shows zero search results. strangely if i back off just one character on either then it does show newark liberty international airport. for some reason the search is penalizing you for finishing the string.

a second one, the show report button didnt work at all.

product suggestion: make the results a unique url that can be shared amongst coworkers planning an event. they should be able to edit it like a google doc to collaboratively update how many people are flying from what locations, and then everyone can reference the shared url to see the calculated result.

last thing, can you share some of the tech details behind how you made the globe/flight-visualizations?

SECProto
It doesn't work well (graphically) if you choose eg, something in australia and something in the US. Shows the Australia flight travelling West across all of africa (when it actually travels northeast, across the ocean)
zenlf
It would be funny if it redirects to Zoom.
capableweb
As funny as if you have a "ATM Locator" application that redirects you to the bank mobile application. What if I actually want cash in hand?
andai
Any reason this wouldn't work as a mobile app?
tbabej
Europe has quite a few high-quality, high-speed rail connections. If I may suggest a feature, in order for the tool is to be faithful to its mission, alternative mods of transport could be supported as well.

Personally, I am more than happy to take an overnight train than a short-flight, given the additional overhead of travelling to/from the airport. An overnight train can take you pretty far within continental Europe.

melx
That's what I'm going to do this August with my 3yr old as we'll be visiting friends and family etc.

I'd be taking a train to London (about 3h), then EuroStar to Paris (2h 15), then to Berlin (about 8h). Total time ~13 hours.

Flight time for me to Berlin is ~4h, but to get to Airport and the wait for boarding brings it probably close to 8h, but then I can't visit the relatives in Paris that easy.

Actually I don't like flying that much these days (the eco reasons aside).

riedel
This is the ideal case. However, I have been involved in quite a bit of European projects and it is not that easy. Last meeting was in Poznan and I could have used the train via Berlin from south Germany, but somehow I have not been able to book any night trains lately and traveling over the day would have taken a whole day of my work week instead of half. Next trip is the other direction to The Hague. I will take the train but last time I had to replan my trip 3 times while traveling due to cancellations and delays. I don't want to fly but I am always totally stressed after long train trips. To a typical meeting people from like 10 countries come in a European research project. Traveling from Germany to Spain or even Greece is not really feasible by train until we get better night train connections (only Austrian rail is actually operating them, but there seems currently no chance to book them)
throwaway049
Do you have the option to use the train seat as a work space? That way daytime train travel is still useful.
melx
I don't travel for work by train but for fun, so my experience is probably different to yours.

Some EU countries (Greece, Poland, Portugal) still have terrible, slow trains. Paris-Berlin takes 8h (fastest one) for about 877 km. Berlin-Gdansk takes 8h for about 400 km (!!).

I last traveled by night train about 20 years ago throughout Germany and Poland. It was terrible experience. But great if I was looking for a companion to beer, or surprise sex with random folk.

Also night trains are non-existent in some countries. For example in the UK, most trains run from 6am onwards on week days. Forget if you need to travel from York and be in London for 8am. We have some night services[0] that go out of London to Scotland/Cornwall but I see them more like touristic offer than for any economic reason.

[0] https://www.nationalrail.co.uk/on-the-train/sleeper-trains/

chroma
Considering the size of the cities and how close they are, I'm surprised train transportation is so slow. Paris has 11 million people (comparable to Los Angeles). Berlin has 6 million people (comparable to Philadelphia). As the crow flies, they are 545 miles apart. By road the distance is 650 miles. Assuming you average 60mph, that's 11 hours by car. And when you get to your destination you have a car, so you can easily travel outside the main city. Using a car also means you don't have to worry about transportation to/from the train stations, nor do you have to do anything special to transport bulky items such as bicycles.

Some of my friends have greatly praised European trains, so I thought they'd be far more compelling.

nicoburns
Europe's train network is often excellent within a country, but lacking when it comes to crossing country borders. That's starting to be addressed now, but it will take some time for the effects to be seen.
makestuff
I was working on an app as a side project similar to this. Basically each traveler would fill out a form saying I live in X and I have access to car/train/etc. transportation. The idea was to match people and then find a central location for remote teams to meet up. For example, 2 people live in Chicago, 3 in NYC, and one in SF. Where is the best city to meet up; however, I was optimizing on cost.

It turns out several people on HN had similar ideas (Villagers app was one but it seems to be offline now https://news.ycombinator.com/item?id=33344734). I stopped working on it after reading this HN thread where several people linked to various articles like https://blog.garrytan.com/travel-planning-software-the-most-....

bagels
Interested, but not enough to do the research, if the data takes in to account the fact that you won't find direct flights to most of the places it chooses as the meeting spot.
jedberg
It seems like once you have a few points in North America and Europe, the answer is always Iceland, no matter how many other cities you add.

I guess this makes sense, but it's interesting to see visualized.

outside1234
Strange that it doesn't choose one of the locations people are in.

For example, for me it chose Toronto for an international meeting even tho one of the folks attending was from New York City. Why not NYC to prevent one person from traveling.

Also, you need weighting, as often there are multiple people from a location.

mplanchard
You can add an airport multiple times to weight for multiple people
msla
Does this only work on locations in Europe?
cristiioan
I find the idea great, but there are a few issues with it.

The biggest ones I have found is that when there are multiple people flying from the same airport, it won't redo the math to try to find a better location.

Also it is more fuel efficient for just one to fly than two when there are only two people.

capableweb
> The biggest ones I have found is that when there are multiple people flying from the same airport, it won't redo the math to try to find a better location.

Yeah, I saw this too. I started by choosing three locations in Russia, which put the meeting point somewhere in the middle of Russia. Then I added 10-15 departures in Europe. Realistically, the meeting point should be somewhere in Europe/Eastern Europe at that point, as there is only three departures from Russia. But the meeting point remained in middle/center Russia.

abeppu
I entered the 3 US airports I use most frequently, and I was told to meet at an airforce base.
blumomo
It’s not the one time meetings that are a problem. It’s a problem when it becomes a habit to fly super regularly, on a daily or weekly basis. Picking climate friendly locations for a one off meeting has close to zero impact.
e12e
I agree with the general sentiment (fix harmful habits first, exceptions later) - but if we set the ideal at no flights - then even a few mid-distance flights come out as pretty bad.
switchbak
Agreed. I've met a bunch of people that literally commute via airplane. That's just crazy to me.

A one off meeting isn't going to move the needle as compared to that.

1270018080
It would be cool to see the non-euclidean paths. Still very nice.
someweirdperson
The cheapest place to meet at is usually some destination for tourists, ouside of vacation season of couse.
jeffbee
I like the way this instantly produces PDFs. Very slick.

I'm not sold on the math because it doesn't seem to take into account connecting flights. At least, it does not seem clear that me in SFO and my colleague in KEF should meet in Yellowknife, NT, Canada. It's an airport neither of us could reach directly on commercial flights. Considering they would need to fly the wrong way to FRA first, it seems like MSP or YUL make way more sense.