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Human running speed of 35-40 mph may be biologically possible

blog.smu.edu

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Re: Human running speed of 35-40 mph may be biologically possible

#21

Post by jcrites »

crystaln wrote: post #20
recursive wrote: post #17

Earlier quoted context omitted.

No. The runner still has the same mass, so accelerating takes the same amount of energy as 1x gravity. It's like shifting to a higher gear on your bike.

Not exactly. Horizontal acceleration takes the same amount of energy. The mass of the body must also be supported upon landing, which obviously takes more energy with more gravity.

Interesting. So it will feel like your normal weight in the horizontal dimension, but it will feel like wearing a 100-pound backpack in the vertical dimension.

Your ultimate running speed then depends on how strong you are. That 100 pound "backpack" will push you into the ground and give you far more acceleration than your normal weight would allow: it will feel like you have ultra-traction. But when you push to the side and accelerate your body, you're only accelerating your normal body weight.

Marathon times will likely suffer, but perhaps some short sprints will be faster in gravity over 1g.

Re: Human running speed of 35-40 mph may be biologically possible

#22

Post by pwr22 »

ars wrote: post #8
arjie wrote: post #3

Title had me confused for a bit. The article says that it was previously thought that the amount of force a limb can apply to the ground was the limiting factor in speed. However, it turns out that the actual limiting factor is how fast the muscles can apply that force. If muscles could apply the full force in the fraction of time that feet touch the ground, then that person would achieve those speeds. Interesting re…

> If muscles could apply the full force in the fraction of time that feet touch the ground Or if they could touch the ground for longer. We need human mounted wings to provide some downforce :) Or more realistically an elastic belt strapped to the runner, and running on a track underneath them.

Maybe some form of spoiler :P?

Re: Human running speed of 35-40 mph may be biologically possible

#23

Post by furyg3 »

IvyMike wrote: post #10

I've always been curious: in an enclosed stadium on the moon, would humans run the 100 yard dash faster or slower? I think the first reaction people have is "faster, since you weigh less". But I think the answer is slower, because you would actually be near-floating and contact the ground less. I got into a fight with people on ask.metafilter when I asked this same question, so I had to let it go. But still I hope so…

is the solution stairs?

It would be interesting if you could achieve a faster speed on the moon running up a flight of stairs than running on a level lunar surface.

Alternatively you could 'angle' the stairs on a level surface (think saw-tooth pattern) and translate that upward energy into forward energy.

Re: Human running speed of 35-40 mph may be biologically possible

#24

Post by maxerickson »

ck2 wrote: post #19

Wind resistance has to be a factor after 25mph, I mean it is on my electric bicycle. And holy cow, even 25mph is crazy fast, 35? If you tripped and fell at 35-40mph you could seriously injure yourself. I think I have a good question for the xkcd q&a site: how fast could Usain Bolt run on the moon (ignoring the oxygen problem). Ah I see someone beat me to the moon problem. Here's another thought, without strong gravit…

This analysis says Usain Bolt expends >90% of his energy on drag:

http://iopscience.iop.org/0143-0807/34/5/1227/article

(That is, yes, you are correct.)

Answering my own question, he took 41 steps when he set the world record.

Re: Human running speed of 35-40 mph may be biologically possible

#25

Post by jimmcslim »

IvyMike wrote: post #10

I've always been curious: in an enclosed stadium on the moon, would humans run the 100 yard dash faster or slower? I think the first reaction people have is "faster, since you weigh less". But I think the answer is slower, because you would actually be near-floating and contact the ground less. I got into a fight with people on ask.metafilter when I asked this same question, so I had to let it go. But still I hope so…

Olympics on the Moon? Maybe in 2020 according to one futurist of the past...

http://usbornepublishing.tumblr.com/post/60362087283/it-is-t...

(Scroll to the end specifically for the Olympics.)

Re: Human running speed of 35-40 mph may be biologically possible

#26

Post by ajuc »

ars wrote: post #8
arjie wrote: post #3

Title had me confused for a bit. The article says that it was previously thought that the amount of force a limb can apply to the ground was the limiting factor in speed. However, it turns out that the actual limiting factor is how fast the muscles can apply that force. If muscles could apply the full force in the fraction of time that feet touch the ground, then that person would achieve those speeds. Interesting re…

> If muscles could apply the full force in the fraction of time that feet touch the ground Or if they could touch the ground for longer. We need human mounted wings to provide some downforce :) Or more realistically an elastic belt strapped to the runner, and running on a track underneath them.

So, we need longer feet. Or longer shoes.

Re: Human running speed of 35-40 mph may be biologically possible

#28

Post by garganitan »

ars wrote: post #8
arjie wrote: post #3

Title had me confused for a bit. The article says that it was previously thought that the amount of force a limb can apply to the ground was the limiting factor in speed. However, it turns out that the actual limiting factor is how fast the muscles can apply that force. If muscles could apply the full force in the fraction of time that feet touch the ground, then that person would achieve those speeds. Interesting re…

> If muscles could apply the full force in the fraction of time that feet touch the ground Or if they could touch the ground for longer. We need human mounted wings to provide some downforce :) Or more realistically an elastic belt strapped to the runner, and running on a track underneath them.

Interestingly, you've hit upon the popular hypothesis that flight actually evolved via the wings providing downforce enabling faster/vertical running up trees.

Re: Human running speed of 35-40 mph may be biologically possible

#29

Post by agumonkey »

IvyMike wrote: post #10

I've always been curious: in an enclosed stadium on the moon, would humans run the 100 yard dash faster or slower? I think the first reaction people have is "faster, since you weigh less". But I think the answer is slower, because you would actually be near-floating and contact the ground less. I got into a fight with people on ask.metafilter when I asked this same question, so I had to let it go. But still I hope so…

In my amateur runner mind, that's where I spend the most time on technique. Balancing the effort waves ensuring everything goes forward and not up nor down. Faster means inertia, means lighter if not done appropriately, which require to tweak your approach.

Re: Human running speed of 35-40 mph may be biologically possible

#30

Post by agumonkey »

Silhouette wrote: post #2

[2010], but fascinating all the same. If you'd asked me how fast an elite sprinter could run today, I would probably have thought of running 100m in a little under 10s, but I don't think I would have connected that mentally with the idea that Usain Bolt runs almost as fast as a car on our 30mph streets, albeit very briefly.

I'm as astonished to think that marathon runners can sustain 20 km/h for 2 hours. 20 km/h is my average speed on bike ...
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