How-do-birds-sit-on-high-voltage-power-lines-without-getting-electrocuted

[jtd (Jude T Dsouza)]

@Paramveer

If we hold direct current and we are not in contact with the ground or any other thing that can complete the path we won’t get electrocuted. We can hold 220 volt “Direct current” and not get electrocuted. But in the case of alternating current which we have at our homes we get electrocuted because of an effect known as capacitance.

DC or AC makes no difference to getting a shock. However DC will have a much higher chance of killing you.
Anyone knows why?
What is the difference between DC and AC?

[jtd (Jude T Dsouza)]

@Paramveer

Also birds cannot sit on extremely high voltage wires they can sit on phase wires we receive at our houses

440000VAC

[Paramveer]

Low-frequency (50–60 Hz) alternating currents can be more dangerous than similar levels of DC since the alternating fluctuations can cause the heart to lose coordination, inducing ventricular fibrillation, a deadly heart rhythm that must be corrected immediately

Source https://www.physicsforums.com/threads/why-dc-is-said-to-be-more-dangerous-than-ac.563362/

[jtd (Jude T Dsouza)]

@Paramveer

Source Why DC is said to be more dangerous than AC? | Physics Forums

The link is quite far from being factual or authoritative.
An AC voltage passes through a zero potential point. At that instant your contracted muscles suddenly relax. Depending on which muscles remain contracted and which are not, you will stagger in some direction, ideally away from the electrical contact point. Also it is not the type of electrical energy - ac or dc- but the quantum of current and path through the body for heart failure.

Here is a useful link
https://bjanaesthesia.org/article/S0007-0912(17)45702-3/pdf

[abhayanshu (Abhayanshu singh)]

Birds have hallow bones for the currents don’t flow

[abhayanshu (Abhayanshu singh)]

Electricity flows along the path of least resistance. Birds don’t get shocked** when they sit on electrical wires because they are not good conductors of electricity. Their cells and tissues do not offer electrons an easier route than the copper wire they’re already traveling along.

[jtd (Jude T Dsouza)]

@abhayanshu

Birds have hallow bones for the currents don’t flow

What is in the center of bones of mammals?
OR the legs of ostrich, a bird that can run very fast?
Or Cassowary or Emu which too can run very fast?

[jtd (Jude T Dsouza)]

@abhayanshu

Birds don’t get shocked** when they sit on electrical wires because they are not good conductors of electricity.

Nope.

@abhayanshu

Their cells and tissues do not offer electrons an easier route than the copper wire they’re already traveling along.

Correct.
The term “good conductor” is a very relative term.

[abhayanshu (Abhayanshu singh)]

Thank you sir for telling the correct answer

[dialecticalbiologist (dilecticalbiologist)]

It makes some sense.
However, Any reference?

[dialecticalbiologist (dilecticalbiologist)]

@jtd

The conductor points between the crow’s two feet also have a minute potential difference. However the crows body resistance is orders of magnitude higher than the wire between it’s feet. Consequently the current flowing is orders of magnitude lower. Therefore birds - or other living creatures like lizards - don’t get shocked when they sit on electrical wires because they are not good conductors of electricity relative to the conductance of the wire between their feet.

This makes eminent sense! Now, however, suppose the bird is wet in rains, do you think it makes a difference and why? @jtd @bivasnag @Mandar

[dialecticalbiologist (dilecticalbiologist)]

@jtd

If one were to to cut the wire between the crows feet and place a resistance comparable to the value of resistance of the crows body as measured between it’s feet, the crow would get a nasty shock.

This @jude is eminently good for a cartoon, to understand many things in Electricity, I suppose!
Can we take out a booklet to introduce elementary aspects of Electricity with such cartoons? Filling the concept gaps are soooo important!

[dialecticalbiologist (dilecticalbiologist)]

@bivasnag

There are other perils for our feathered friends, Sun points out. “The wood pole supporting the wires is buried deep in the ground,” she says, “so it would also be dangerous for a bird to sit on the pole and touch a wire.”

Why should this a worry for the bird, since the wood is a poor conductor, even if it is touching the ground, unless the wood is wet, right? Again, is there a way of drawing it? @jtd @bivas @gnowgi @Mandar

[dialecticalbiologist (dilecticalbiologist)]

@bivasnag

Our bodies turn out to be excellent conductors of electricity, and the electrical current will happily use them to complete a closed path to flow from high potential (the wire) to low potential (the ground). ZAP!

So all our talk about body of birds are poor conductors are bunkum?!!

[dialecticalbiologist (dilecticalbiologist)]

@jtd

However it assumes that the wire resistance is very low relative to the body resistance of the bird.

And if the bird is wet,dripping with rain water, what is the implication? @jtd

[dialecticalbiologist (dilecticalbiologist)]

@Paramveer

Humans get electrocuted because their feet are on the ground which completes the path of electricity.

What do you mean by “…ground which completes the path of electricity”? Why is it so? What is special about “ground”? @Paramveer @jtd @bivasnag @gnowgi @Mandar

[dialecticalbiologist (dilecticalbiologist)]

@Paramveer

an effect known as capacitance.

What is that?

[dialecticalbiologist (dilecticalbiologist)]

@Paramveer

Also birds cannot sit on extremely high voltage wires

So would railway wires be dangerous for birds? @Paramveer @jtd

[dialecticalbiologist (dilecticalbiologist)]

Here is a Wikipedia reference @Paramveer gave with cross references:
War of the currents - Wikipedia “Low-frequency (50–60 Hz) alternating currents can be more dangerous than similar levels of DC since the alternating fluctuations can cause the heart to lose coordination, inducing ventricular fibrillation, a deadly heart rhythm that must be corrected immediately.[14] However, any practical distribution system will use voltage levels quite sufficient for a dangerous amount of current to flow, whether it uses alternating or direct current. As precautions against electrocution are similar for both AC and DC, the technical and economic advantages of AC power transmission outweighed this theoretical risk, and it was eventually adopted as the standard worldwide.”

Source https://www.physicsforums.com/threads/why-dc-is-said-to-be-more-dangerous-than-ac.563362/

What do you say about it? @jtd

[dialecticalbiologist (dilecticalbiologist)]

@abhayanshu

Birds have hallow bones for the currents don’t flow

Really?! @abhayanshu