[Seany (OP)]

I was just curious about this. Because if you drop an ant from shoulder height, or a 2-story high place, I'm pretty sure that the ant still lives. But it would seriously injure us humans, because of our mass, etc. But what if you drop an ant from an airplane or somewhere really high?

Just a curiosity..

[another_someone]

I suspect the limiting factor is the relatively high surface area (because of the small size) of the ant will mean there is a very limited terminal velocity, and the ant would (I guess) have reached that terminal velocity even when falling from a two storey building.  Humans are bigger and heavier, so the ratio of surface area to mass is much smaller for humans than for ants, and so we have a higher terminal velocity.

[paul.fr]

don't some species of ants have the ability to fly? well, not exactly fly like a bird does but they can control their descent when falling from trees.

[Seany (OP)]

Yeah, that makes sense, so the ant would still not die when it is dropped from the airplane? Or will the pressure applied to the ant have killed it before reaching the airplane? But I understand that the terminal velocity of an ant is relatively small compared to us, as they have a smaller surface area etc. But surely if must do SOME harm to an ant? Because, if we fall with the speed of terminal velocity, we would most definitely die. Even if the speed of terminal velocity of an ant is small, wouldn't it affect its small body?

[DrDick]

Ah, but we're squishy.  Ants have armor plating.

Some ants do indeed have wings, and they do fly, like other flying insects.  Several years ago, the building I lived in had an ant problem, and in the spring, these ants went into a flying form.  At first, we thought we were seeing flies, but we finally realized that they were flying ants.  This lasted for about a month or two, until they finally reverted back into a nonflying form (or died off or whatever).

Dick

[another_someone]

Ah, but we're squishy.  Ants have armor plating.

Some ants do indeed have wings, and they do fly, like other flying insects.  Several years ago, the building I lived in had an ant problem, and in the spring, these ants went into a flying form.  At first, we thought we were seeing flies, but we finally realized that they were flying ants.  This lasted for about a month or two, until they finally reverted back into a nonflying form (or died off or whatever).

Dick

I believe that ants fly when they are mating, but lose the ability to fly when they have nested (don't know if this is equally true of all species of ant).

[another_someone]

Yeah, that makes sense, so the ant would still not die when it is dropped from the airplane? Or will the pressure applied to the ant have killed it before reaching the airplane? But I understand that the terminal velocity of an ant is relatively small compared to us, as they have a smaller surface area etc. But surely if must do SOME harm to an ant? Because, if we fall with the speed of terminal velocity, we would most definitely die. Even if the speed of terminal velocity of an ant is small, wouldn't it affect its small body?

It you take it up high enough, it may have problems with the cold.

The ants body is small, but it is relatively strong for its small size (again a function of compactness - you drop an elepjant from an even lower height, it would probably die even where a human would survive).

[paul.fr]

Ah, but we're squishy.  Ants have armor plating.

Some ants do indeed have wings, and they do fly, like other flying insects.  Several years ago, the building I lived in had an ant problem, and in the spring, these ants went into a flying form.  At first, we thought we were seeing flies, but we finally realized that they were flying ants.  This lasted for about a month or two, until they finally reverted back into a nonflying form (or died off or whatever).

Dick

i forgot about flying ants in the UK, i meant ants in tropical rain forests that have evolved to fly. they use the ability to stop them landing way down on the floor of the rain forest and either getting lost or having to climb all the way back up.

if they fall they sort of parachute or glide back on to the tree, or something like that....the answer is on a NS podcast somewhere...ok now i am off

[Seany (OP)]

Yeah, that makes sense, so the ant would still not die when it is dropped from the airplane? Or will the pressure applied to the ant have killed it before reaching the airplane? But I understand that the terminal velocity of an ant is relatively small compared to us, as they have a smaller surface area etc. But surely if must do SOME harm to an ant? Because, if we fall with the speed of terminal velocity, we would most definitely die. Even if the speed of terminal velocity of an ant is small, wouldn't it affect its small body?

It you take it up high enough, it may have problems with the cold.

The ants body is small, but it is relatively strong for its small size (again a function of compactness - you drop an elepjant from an even lower height, it would probably die even where a human would survive).

Yeah, ants are capable of lifting stones which are like 10x heavier than their mass. And, I guess elephants will die where we will live aswell, i suppose.

[Bored chemist]

It's to do with the effect of viscosity. When you drop yourself or the ant out of the plane you start to accelerate downwards because of the force of gravity acting on you. As you pick up speed the air rushing past causes a dragforce which tends to slow you down. When these two effects cancel out the force of gravity is the same as the drag force, at this point you stop accelerating. For a human it's about 120MPH. For an ant it will be a lot smaller.


If you model the person and the ant as spheres with equal density and radii in the ratio 1000 to 1 falling through air at normal temperature and pressure, then you are probably a physicist and know about the Stokes Einstein equation.

[paul.fr]

http://www.canopyants.com/glide_intro.html


What are gliding ants? 
Some species of ants that live in the tropical rain forest canopy use a form of gliding (or "controlled aerial descent") to return to their home tree trunk when they fall from branches.  When a gliding ant falls, jumps or is brushed off of a tree branch (e.g., by a passing monkey), it drops straight down for a few meters, then makes a rapid adjustment in orientation such that its abdomen is pointed toward the tree trunk.  This alignment consistently directs the path of the falling ant through the air in a steep glide ending at the trunk.

[Seany (OP)]

It's to do with the effect of viscosity. When you drop yourself or the ant out of the plane you start to accelerate downwards because of the force of gravity acting on you. As you pick up speed the air rushing past causes a dragforce which tends to slow you down. When these two effects cancel out the force of gravity is the same as the drag force, at this point you stop accelerating. For a human it's about 120MPH. For an ant it will be a lot smaller.


If you model the person and the ant as spheres with equal density and radii in the ratio 1000 to 1 falling through air at normal temperature and pressure, then you are probably a physicist and know about the Stokes Einstein equation.

Yes. For a human, lets say the terminal velocity is 120MPH. In which case, we would most definitely die.

For an ant. Ok, it wound be relatively SMALLER than a human. But wouldn't it still be the same ratio? Therefore, still having a massive impact on such a little guy?

[neilep]

I was just curious about this. Because if you drop an ant from shoulder height, or a 2-story high place, I'm pretty sure that the ant still lives. But it would seriously injure us humans, because of our mass, etc. But what if you drop an ant from an airplane or somewhere really high?

Just a curiosity..

If the airplane is still on the ground  parked then there's a real good chance you'll survive !!

As a firm believer in empirical study I found an ant and made an airplane from some paper and put the ant on the plane then gently flicked it off. The ant survived but I think it had a headache.

Glad I could help.

[another_someone]

Yes. For a human, lets say the terminal velocity is 120MPH. In which case, we would most definitely die.

For an ant. Ok, it wound be relatively SMALLER than a human. But wouldn't it still be the same ratio? Therefore, still having a massive impact on such a little guy?

Don't know that it would be pro-rata (things like Reynolds numbers come into it - that is the answer to the puzzle why bumble bees can fly despite the fact that a scaled up bumble bee would never fly).

If one assumes for simplicity that it is pro-rata, then an ant is about 5mm long, while a human being is about 2 metres tall, that is a ratio of 500:1.  If the terminal velocity of a human is 120mph, then a 500:1 ratio would mean 0.24mph - I think it would seem preposterous to assume an ant would be harmed by an impact of ¹/₄ of 1mph.

The above assumes that the terminal velocity is pro-rata, and I doubt that the calculation is anywhere near as simple as that, so I don't think that is the actual right answer, but it does show that it is quite easy for the terminal velocity to be perfectly within tolerable levels for an ant.

[Seany (OP)]

Yes. For a human, lets say the terminal velocity is 120MPH. In which case, we would most definitely die.

For an ant. Ok, it wound be relatively SMALLER than a human. But wouldn't it still be the same ratio? Therefore, still having a massive impact on such a little guy?

Don't know that it would be pro-rata (things like Reynolds numbers come into it - that is the answer to the puzzle why bumble bees can fly despite the fact that a scaled up bumble bee would never fly).

If one assumes for simplicity that it is pro-rata, then an ant is about 5mm long, while a human being is about 2 metres tall, that is a ratio of 500:1.  If the terminal velocity of a human is 120mph, then a 500:1 ratio would mean 0.24mph - I think it would seem preposterous to assume an ant would be harmed by an impact of ¹/₄ of 1mph.

The above assumes that the terminal velocity is pro-rata, and I doubt that the calculation is anywhere near as simple as that, so I don't think that is the actual right answer, but it does show that it is quite easy for the terminal velocity to be perfectly within tolerable levels for an ant.

Yes, but 1/4 mph might still be a huge impact on a fly? Just like 120mph for us is? We cannot just assume that since 1/4mph is slow for us and not damaging, that it will be the same for flies?

[another_someone]

Yes, but 1/4 mph might still be a huge impact on a fly? Just like 120mph for us is? We cannot just assume that since 1/4mph is slow for us and not damaging, that it will be the same for flies?

The reason why I think that ¹/₄ cannot cause harm to an ant is because so many natural events in the environment occur at much higher speeds than that.

Aside from ants, any flying insect will regularly suffer impacts greater than this (just gently swat a fly or a bee, and you are exceeding that speed - a heavy swat may harm them, but a gentle one will not - even their own flying speed will exceed that speed).

I would expect that that even falling from table height would allow an ant to reach terminal velocity, yet this kind of fall would not be that uncommon for an ant.

[BillJx]

You've seen rocks floating in the air.  Very small rocks, with a lot of surface area in proportion to their mass.  They are called dust.

I think an insect of any kind would fall slowly enough to land safely.

[Seany (OP)]

Yes, but 1/4 mph might still be a huge impact on a fly? Just like 120mph for us is? We cannot just assume that since 1/4mph is slow for us and not damaging, that it will be the same for flies?

The reason why I think that ¹/₄ cannot cause harm to an ant is because so many natural events in the environment occur at much higher speeds than that.

Aside from ants, any flying insect will regularly suffer impacts greater than this (just gently swat a fly or a bee, and you are exceeding that speed - a heavy swat may harm them, but a gentle one will not - even their own flying speed will exceed that speed).

I would expect that that even falling from table height would allow an ant to reach terminal velocity, yet this kind of fall would not be that uncommon for an ant.

Yup, I think I'm getting to believe you now.. Because even when I squash an ant with my food (Meh..) it still squirms around, but doesn't die!

[Seany (OP)]

You've seen rocks floating in the air.  Very small rocks, with a lot of surface area in proportion to their mass.  They are called dust.

I think an insect of any kind would fall slowly enough to land safely.

That's a working theory too. I should try []

[another_someone]

You've seen rocks floating in the air.  Very small rocks, with a lot of surface area in proportion to their mass.  They are called dust.

Dust only appears to be floating from our perspective - the dust is in fact falling through the air (albeit, as you say, very slowly), but small pockets of air air rising, and the dust is sometimes falling slower than the pocket of air it is in rises, so the nett effect from our point of view is to see the dust itself rise.

Even humans can do this - in a tornado - it is just that to a small spec of dust, even the ordinary turbulence of warm air will feel like lots of tornadoes blowing about.