3,539 reputation
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bio website blueraja.com/blog
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visits member for 3 years, 7 months
seen 4 hours ago

Sep
30
awarded  Explainer
Jul
28
awarded  Pundit
Jul
2
awarded  Curious
May
29
comment Will 1 in 4 American children grow up illiterate?
I disagree with the 'functional illiteracy' quote; just because functional literacy is difficult to define/measure doesn't mean we shouldn't attempt to define/measure it. Regardless, that quote does not provide an answer to the question asked.
May
29
comment Will 1 in 4 American children grow up illiterate?
They're likely talking about functional illiteracy.
May
27
comment Can standing in front of a microwave oven give you cancer?
"Microwave only allow a maximum leak amount of 5mW" - What your source actually says is "5mW per square centimeter". See also
May
27
awarded  Civic Duty
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
@JoeBlow: ..The helicopter is not grounded. There's a clamp connecting the worker to the helicopter so they all stay at the same electric potential, but if the helicopter were to become grounded, it would cause a short through the worker, likely killing him. You are correct that the terminology they use in that video is incorrect. If you have any more questions, please ask on the physics or EE stackexchanges, this is not the correct place to be discussing this.
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
@JoeBlow Voltage is a relative measurement; "absolute voltage" is called 'electric potential'. The helicopter/person have one potential, the wire has a different (average) potential. When there is a difference in potential, aka a voltage, electricity flows. This is what causes static shock. If the operator did not slowly equalize himself/the helicopter to the wire, he'd get an enormous shock when he touched the wire. It must happen to birds as well; the question is just how quickly (if their bodies have high enough resistance, it could happen slowly enough that they don't feel it).
Apr
13
accepted Are birds magnetically repelled from high-voltage power lines?
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
@JoeBlow Please plan what you want to say more carefully, your excessive comments are making it very hard to follow the conversation.
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
@JoeBlow Please see my video in the question. You do not need to touch two lines, and the shock is not small. You would need to touch two lines to have a continuous electrical flow, but the shock that occurs when neutralizing your voltage only requires touching one wire, and in HV lines, it can be very large.
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
This edit is better, I'll remove my -1. However, the statement "The birds also don't get electrocuted as they have no path to earth" is incorrect. They would shocked when they neutralize with the power-line, even if there is no path to ground; if they don't, their bodies must have exceptionally-high electrical resistance. See the link in the question, as well as my comment above and this link.
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
@JoeBlow I think you went overboard on the comments.. anyways, the statement "you have to touch both a positive and a negative to get a shock" is wrong in several ways. First of all, there is no positive/negative in AC. Secondly, you will get a shock if you touch an HV line, because at such high voltages the simplistic view of "electricity goes from hot to ground" breaks down. Electricity will flow because you, like all things, have a capacitance. That's why in the video I linked they need to neutralize before working. See here.
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
@EmanuelLandeholm: I would still consider 15kV as 'residential'. The lines I've always understood to be 'HV-lines' are the long-distance lines you see between cities of 100kV and up. Wikipedia calls them 'transmission lines'
Apr
13
comment Are birds magnetically repelled from high-voltage power lines?
Sorry, but I have to give this -1. The power lines shown in your google-search/picture are residential power lines, not high-voltage power lines. Also the claim that other animals (assuming that's what "made from the same stuff as birds" means..) cannot be repelled by strong magnetic fields is false. And your last paragraph is unsourced speculation.
Apr
12
asked Are birds magnetically repelled from high-voltage power lines?
Apr
11
comment Does chewing coffee grounds or beans give you more caffeine than drinking coffee?
@SpellingD: The difference is not just being pedantic about terminology, it completes changes the answer to the question. If the absorption amount is higher, the answer is "yes," but if only the absorption rate is higher, the answer is no.
Apr
9
comment Were the Egyptian pyramids wireless power stations?
"Wireless electricity" is a specific family of technologies. It does not refer to lightning or static electricity.
Apr
9
comment Does chewing coffee grounds or beans give you more caffeine than drinking coffee?
@SpellingD: Source? I've heard there's faster absorption to the bloodstream through the mucous-membranes, but not necessarily more absorption.