Ah. But sorry, no. It's straight from "how to lie with charts".
How much energy is it going to take a human to cross 40000 km (circumnavigate the Earth)? A human on a jet will require around 2 tons of fuel and around 40 hours of time (fuel economy of about 4L per 100km of flight).
A human on a bicycle will roughly take about a year of travel (assuming a fairly reasonable 150km a day). In other words, about 1/50-th of a productive human life needlessly wasted that could have been used to improve the world.
Carbon footprint in the US is about 20 tons per year per person, so that's another way to look at a year of missed opportunity that you would spend by cycling instead of flying.
This aspect is almost completely ignored when people talk about bikes or public transit. Yes, they are efficient, but their efficiency comes at a cost of several wasted lifetimes of time every day for a large city.
Ok, now for the people using motor vehicles instead of their own muscle power, account for the time wasted at the gym for the equivalent exercise. Or for time at the hospital, due to their sedentary lifestyle. Then account for the various types of pollution and destruction caused by motor vehicles.
Or, you know, just appreciate this 2D chart for the two dimensions of factual information it is able to convey effectively.
The paper looks at energy expenditure for the purposes of travel. Of _course_ slower methods are more efficient. They didn't include ICBMs but those would be crazy expensive.
That's it, that's the whole story. Adding calories for the "other stuff" that happens while travel is occurring is not part of the story.
The first illustration has no legend or explanation of what the axes are (if you scroll it, you can find it), but if you scroll down, you're going to see it again. A bit annoying ¯\_(ツ)_/¯
Pure efficiency in locomotion is a terrible measure, is a person on a bicycle more efficient traversing a forest?
Trying to say that a dog is incredibly unefficient is misleading at best - especially when we're trying to make a statement about nature's most efficient traveller.
It's the classic physics issue - you are ignoring air resistance, but in this case you are ignoring everything other than a perfectly paved road.
They aren't saying that dogs are incredibly inefficient – looks like dogs are right where they "should" be based on their body weight. The point of course stands that bikes need a flat ground to be efficient, but this isn't some sort of competition or measure of moral worth. It's just an observation that given that we've already filled human-inhabited spaces with nice flat surfaces, cycling happens to be a really efficient form of locomotion. Fish also need to be in water to be able to move at all, but that's immaterial for the purposes of the chart.
> Pure efficiency in locomotion is a terrible measure, is a person on a bicycle more efficient traversing a forest?
Quite possibly. I would imagine it depends on the forest. I've been in forested areas on the mountain bike and you can cycle through these areas fine.
> It's the classic physics issue - you are ignoring air resistance, but in this case you are ignoring everything other than a perfectly paved road.
Rolling resistance is mainly down to the types of tyres used, how wide they are and how much they are inflated. Surface doesn't make that much of a difference IMO unless it is on a really lose surface e.g. loose gravel, mud or ice.
The biggest improvements to cycling efficiency is usually either being in a recumbent bicycle (less air resistance as you are led down) or by being in a more more Aero position with lycra on. But air resistance only becomes a big thing past 20mph or if you are wearing clothing that is really baggy.
Bicycles are the most efficient forms of transport in energy per mile. They are often the fastest in built up areas as well.
Given all the means by which one might get from A to B, what is the most efficient. It might be that not all means are available, but the "pure efficiency" analysis allows you to answer that question from the means that are available.
FWIW, the original version of this chart is what Steve Jobs was referring to when he first used his “Bicycle for the Mind” analogy. There’s a clip of him talking about it somewhere on YouTube at an early computer fair.
I'm curious about why helicopters are located where they are. A powered sailplane case study: pipistrel snius weighs 700 lbs and gets 47 mpg. A comparable weight helicopter (mosquito XE) gets about 7 mpg.
Seeing how this is related to physics I'm surprised they left out the Spherical Cow [1] since it would probably score high marks when it comes to efficiency.
Chartjunk. It took near-zero effort to find better ones all around this interesting and heavily researched topic, and their real papers too, per standard HN preference.
23 comments
[ 1.1 ms ] story [ 62.4 ms ] threadHow much energy is it going to take a human to cross 40000 km (circumnavigate the Earth)? A human on a jet will require around 2 tons of fuel and around 40 hours of time (fuel economy of about 4L per 100km of flight).
A human on a bicycle will roughly take about a year of travel (assuming a fairly reasonable 150km a day). In other words, about 1/50-th of a productive human life needlessly wasted that could have been used to improve the world.
Carbon footprint in the US is about 20 tons per year per person, so that's another way to look at a year of missed opportunity that you would spend by cycling instead of flying.
This aspect is almost completely ignored when people talk about bikes or public transit. Yes, they are efficient, but their efficiency comes at a cost of several wasted lifetimes of time every day for a large city.
Or, you know, just appreciate this 2D chart for the two dimensions of factual information it is able to convey effectively.
That's it, that's the whole story. Adding calories for the "other stuff" that happens while travel is occurring is not part of the story.
Why have they animated the chart? It adds nothing, as far as I can tell.
Why all the tiny points? Is each one a data point (seems unlikely)?
Why is there only one swimmer?
Why is there a walker/runner area to the left and below swimmers? What is in that area?
Is this article just shilling for Big Velomobile? ;0)
Trying to say that a dog is incredibly unefficient is misleading at best - especially when we're trying to make a statement about nature's most efficient traveller.
It's the classic physics issue - you are ignoring air resistance, but in this case you are ignoring everything other than a perfectly paved road.
Quite possibly. I would imagine it depends on the forest. I've been in forested areas on the mountain bike and you can cycle through these areas fine.
> It's the classic physics issue - you are ignoring air resistance, but in this case you are ignoring everything other than a perfectly paved road.
Rolling resistance is mainly down to the types of tyres used, how wide they are and how much they are inflated. Surface doesn't make that much of a difference IMO unless it is on a really lose surface e.g. loose gravel, mud or ice.
The biggest improvements to cycling efficiency is usually either being in a recumbent bicycle (less air resistance as you are led down) or by being in a more more Aero position with lycra on. But air resistance only becomes a big thing past 20mph or if you are wearing clothing that is really baggy.
Bicycles are the most efficient forms of transport in energy per mile. They are often the fastest in built up areas as well.
Don't overthink it.
https://youtu.be/npqD602G90o
[1] https://www.sphericalcowblog.com/spherical-cows
- https://www.zianet.com/wrucker/the%20energetic%20cost%20of%2...
- https://www.sciencedirect.com/science/article/pii/S258884042...
- https://www.nature.com/articles/ncomms1350