Talk:2027: Lightning Distance - Revision history

172.70.91.128: Whoops, not a forum/BBCode... ;)

2022-07-25T23:39:10Z

Whoops, not a forum/BBCode... ;)

172.70.85.13 at 23:37, 25 July 2022

2022-07-25T23:37:41Z

172.70.85.13 at 23:37, 25 July 2022

2022-07-25T23:37:02Z

Nitpicking at 20:02, 25 July 2022

2022-07-25T20:02:57Z

141.101.69.175: /* Actually... */ new section

2021-07-18T12:37:46Z

‎Actually...: new section

Dgbrt: Layout

2018-10-22T18:31:37Z

Layout

Redbelly98 at 01:05, 7 August 2018

2018-08-07T01:05:44Z

172.68.54.64: more comments

2018-08-06T15:01:53Z

more comments

188.114.103.95: scary

2018-08-06T12:12:42Z

scary

Redbelly98 at 02:18, 6 August 2018

2018-08-06T02:18:05Z

@@ Line 125: / Line 125: @@
 :::Keep in mind, if you're using radios (normal consumer receiver/amp/speaker setups) to pick up the radio-frequency emissions, and eyes the visible light, you have to add the speed of sound back into the equation, based on the distance between the speaker and your ear. Plus, there would inevitably be the delay for the circuitry in the radio, plus the delay in your perceptions. At the nanosecond scale, the difference in length between optic and auditory tracts in your cerebral innervation and brain would be more than enough to swamp any effect of the lightspeed variation. Thus: specialized equipment would be needed. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 20:02, 25 July 2022 (UTC)
-::::Unless you're listening to digital radio (with decoding delays, which is why you shouldn't depend upon DAB audio of [url=https://en.m.wikipedia.org/wiki/Greenwich_Time_Signal]"The Pips"[/url], but probably also won't reliably render the interference derived from the lightning) the circuitry in the radio won't significantly delay things. It's barely buffered by FM or AM being processed to extract the raw audio (original, or pseudo-original interpretation of the intergerence) and the wiring between components barely adds anything. 570 nanoseconds per 100m of wire (for a 1Mhz signal, lower frequencies can take longer, but not that much), is one estimate of wire-lenth delay, and you probably don't have that much length wrapped around inside your transistor radio. (Elsewhere, 75% of c is quoted, in saying that it's maybe a couple of tens of milliseconds delay across a distance between New York and Los Angeles, by a probably non-direct cable, after removing relay and protocol-processing delays.)
+::::Unless you're listening to digital radio (with decoding delays, which is why you shouldn't depend upon DAB audio of [https://en.m.wikipedia.org/wiki/Greenwich_Time_Signal "The Pips"], but probably also won't reliably render the interference derived from the lightning) the circuitry in the radio won't significantly delay things. It's barely buffered by FM or AM being processed to extract the raw audio (original, or pseudo-original interpretation of the intergerence) and the wiring between components barely adds anything. 570 nanoseconds per 100m of wire (for a 1Mhz signal, lower frequencies can take longer, but not that much), is one estimate of wire-lenth delay, and you probably don't have that much length wrapped around inside your transistor radio. (Elsewhere, 75% of c is quoted, in saying that it's maybe a couple of tens of milliseconds delay across a distance between New York and Los Angeles, by a probably non-direct cable, after removing relay and protocol-processing delays.)
 ::::Obviously when multiplying by 5 (or more) billion, the increased (or decreased) delay does become significantly more maladjusted (and significant) from the original premise, but that surely applies far more to the audio/perceptive/reactive delays, however you calculate those. [[Special:Contributions/172.70.85.13|172.70.85.13]] 23:37, 25 July 2022 (UTC)

@@ Line 126: / Line 126: @@
 ::::Unless you're listening to digital radio (with decoding delays, which is why you shouldn't depend upon DAB audio of [url=https://en.m.wikipedia.org/wiki/Greenwich_Time_Signal]"The Pips"[/url], but probably also won't reliably render the interference derived from the lightning) the circuitry in the radio won't significantly delay things. It's barely buffered by FM or AM being processed to extract the raw audio (original, or pseudo-original interpretation of the intergerence) and the wiring between components barely adds anything. 570 nanoseconds per 100m of wire (for a 1Mhz signal, lower frequencies can take longer, but not that much), is one estimate of wire-lenth delay, and you probably don't have that much length wrapped around inside your transistor radio. (Elsewhere, 75% of c is quoted, in saying that it's maybe a couple of tens of milliseconds delay across a distance between New York and Los Angeles, by a probably non-direct cable, after removing relay and protocol-processing delays.)
-:::::Obviously when multiplying by 5 (or more) billion, the increased (or decreased) delay does become significantly more maladjusted (and significant) from the original premise, but that surely applies far more to the audio/perceptive/reactive delays, however you calculate those. [[Special:Contributions/172.70.85.13|172.70.85.13]] 23:37, 25 July 2022 (UTC)
+::::Obviously when multiplying by 5 (or more) billion, the increased (or decreased) delay does become significantly more maladjusted (and significant) from the original premise, but that surely applies far more to the audio/perceptive/reactive delays, however you calculate those. [[Special:Contributions/172.70.85.13|172.70.85.13]] 23:37, 25 July 2022 (UTC)
 '''Whoops!'''

← Older revision		Revision as of 23:37, 25 July 2022
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	:::Keep in mind, if you're using radios (normal consumer receiver/amp/speaker setups) to pick up the radio-frequency emissions, and eyes the visible light, you have to add the speed of sound back into the equation, based on the distance between the speaker and your ear. Plus, there would inevitably be the delay for the circuitry in the radio, plus the delay in your perceptions. At the nanosecond scale, the difference in length between optic and auditory tracts in your cerebral innervation and brain would be more than enough to swamp any effect of the lightspeed variation. Thus: specialized equipment would be needed. [[User:Nitpicking\|Nitpicking]] ([[User talk:Nitpicking\|talk]]) 20:02, 25 July 2022 (UTC)		:::Keep in mind, if you're using radios (normal consumer receiver/amp/speaker setups) to pick up the radio-frequency emissions, and eyes the visible light, you have to add the speed of sound back into the equation, based on the distance between the speaker and your ear. Plus, there would inevitably be the delay for the circuitry in the radio, plus the delay in your perceptions. At the nanosecond scale, the difference in length between optic and auditory tracts in your cerebral innervation and brain would be more than enough to swamp any effect of the lightspeed variation. Thus: specialized equipment would be needed. [[User:Nitpicking\|Nitpicking]] ([[User talk:Nitpicking\|talk]]) 20:02, 25 July 2022 (UTC)
		+
		+	::::Unless you're listening to digital radio (with decoding delays, which is why you shouldn't depend upon DAB audio of [url=https://en.m.wikipedia.org/wiki/Greenwich_Time_Signal]"The Pips"[/url], but probably also won't reliably render the interference derived from the lightning) the circuitry in the radio won't significantly delay things. It's barely buffered by FM or AM being processed to extract the raw audio (original, or pseudo-original interpretation of the intergerence) and the wiring between components barely adds anything. 570 nanoseconds per 100m of wire (for a 1Mhz signal, lower frequencies can take longer, but not that much), is one estimate of wire-lenth delay, and you probably don't have that much length wrapped around inside your transistor radio. (Elsewhere, 75% of c is quoted, in saying that it's maybe a couple of tens of milliseconds delay across a distance between New York and Los Angeles, by a probably non-direct cable, after removing relay and protocol-processing delays.)
		+	:::::Obviously when multiplying by 5 (or more) billion, the increased (or decreased) delay does become significantly more maladjusted (and significant) from the original premise, but that surely applies far more to the audio/perceptive/reactive delays, however you calculate those. [[Special:Contributions/172.70.85.13\|172.70.85.13]] 23:37, 25 July 2022 (UTC)

	'''Whoops!'''		'''Whoops!'''

← Older revision		Revision as of 20:02, 25 July 2022
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	::Ehh... I see your point, but I'm not sure I'm really convinced. In my mind, a Gamma Ray Spectrometer is specialized equipment. People don't normally have them in their house or car. Radios are (or, at least, were) very common. But you're right, it says specialized instrument, not "rare" instrument. I'm not changing the explanation, just wanted to point out for those geeky enough to read the comments that for normal people, detecting the radio wave output lightning is doable without buying extra equipment one doesn't normally have in the home. Detecting the difference between the flash and the static on the radio is where it gets impractical. [[Special:Contributions/172.68.54.64\|172.68.54.64]] 15:01, 6 August 2018 (UTC) (newbie)		::Ehh... I see your point, but I'm not sure I'm really convinced. In my mind, a Gamma Ray Spectrometer is specialized equipment. People don't normally have them in their house or car. Radios are (or, at least, were) very common. But you're right, it says specialized instrument, not "rare" instrument. I'm not changing the explanation, just wanted to point out for those geeky enough to read the comments that for normal people, detecting the radio wave output lightning is doable without buying extra equipment one doesn't normally have in the home. Detecting the difference between the flash and the static on the radio is where it gets impractical. [[Special:Contributions/172.68.54.64\|172.68.54.64]] 15:01, 6 August 2018 (UTC) (newbie)
		+
		+	:::Keep in mind, if you're using radios (normal consumer receiver/amp/speaker setups) to pick up the radio-frequency emissions, and eyes the visible light, you have to add the speed of sound back into the equation, based on the distance between the speaker and your ear. Plus, there would inevitably be the delay for the circuitry in the radio, plus the delay in your perceptions. At the nanosecond scale, the difference in length between optic and auditory tracts in your cerebral innervation and brain would be more than enough to swamp any effect of the lightspeed variation. Thus: specialized equipment would be needed. [[User:Nitpicking\|Nitpicking]] ([[User talk:Nitpicking\|talk]]) 20:02, 25 July 2022 (UTC)

	'''Whoops!'''		'''Whoops!'''

← Older revision		Revision as of 12:37, 18 July 2021
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	:Storms just became 5 times more scary for you :) [[Special:Contributions/188.114.103.95\|188.114.103.95]] 12:12, 6 August 2018 (UTC)		:Storms just became 5 times more scary for you :) [[Special:Contributions/188.114.103.95\|188.114.103.95]] 12:12, 6 August 2018 (UTC)
		+
		+	== Actually... ==
		+
		+	There's a citizen science project called blitzortung.org that uses special radio receivers to sample the lightning 's signature, compare it with the other receivers and use gps time to triangulate its position!
		+	--[[Special:Contributions/141.101.69.175\|141.101.69.175]] 12:37, 18 July 2021 (UTC)

@@ Line 97: / Line 97: @@
 ::NOTE: Please ignore the linearly interpolated "13 C" above. It turns out ''n'' for radio waves is a highly nonlinear function of temperature. Plus the 1/Δ''n'' dependence -- where Δ''n'' changes by a factor of 7 or 8 -- makes the nonlinearity even worse. --[[User:Redbelly98|Redbelly98]] ([[User talk:Redbelly98|talk]]) 01:05, 7 August 2018 (UTC)
-== Assumptions on the medium properties sound? ==
+'''Assumptions on the medium properties sound?'''
 Refractive index of *dry* air might be pretty close to 1 for both light and RF EM waves, but:
@@ Line 123: / Line 123: @@
 ::Ehh... I see your point, but I'm not sure I'm *really* convinced.  In my mind, a Gamma Ray Spectrometer is specialized equipment.  People don't normally have them in their house or car.  Radios are (or, at least, *were*) very common.  But you're right, it says specialized instrument, not "rare" instrument.  I'm not changing the explanation, just wanted to point out for those geeky enough to read the comments that for normal people, *detecting* the radio wave output lightning is doable without buying extra equipment one doesn't normally have in the home. Detecting the difference between the flash and the static on the radio is where it gets impractical. [[Special:Contributions/172.68.54.64|172.68.54.64]] 15:01, 6 August 2018 (UTC) (newbie)
-== Whoops! ==
+'''Whoops!'''
 I always thought it was 1 second per mile. I didn't know about the 'divide by 5" part. [[User:These Are Not The Comments You Are Looking For|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For|talk]]) 01:23, 5 August 2018 (UTC)
 :Storms just became 5 times more scary for you :) [[Special:Contributions/188.114.103.95|188.114.103.95]] 12:12, 6 August 2018 (UTC)

@@ Line 93: / Line 93: @@
 :* ''n'' for air at 0 C, 1 atm, is closer to 1.000292, according to both {{w|List_of_refractive_indices|the Wikipedia link}} and also the "Simple Shop-floor Formula" given by NIST at [https://emtoolbox.nist.gov/wavelength/documentation.asp the bottom of this site]. This would give a <math>{\Delta n}</math> of 0.000023, and a time-to-distance conversion value of <math>\frac{c}{\Delta n} \approx 7.9\cdot10^9</math> mi/s.
 :* Thunderstorms rarely occur at 0 C. Using values for 30 C (86 F) instead, we have 1.000261 for air (from the simple NIST formula) and 1.000429 for radio waves (from Table 1, p. 8 of [https://www.fig.net/resources/proceedings/fig_proceedings/fig_2002/Js28/JS28_rueger.pdf the Rueger paper]). This gives a <math>{\Delta n}</math> of 0.000168, and a time-to-distance conversion value of <math>\frac{c}{\Delta n} \approx 1.1\cdot10^9</math> mi/s.
-:This suggests that the conversion value is the desired 5 billion for ''some'' temperature between 0 and 30 C. Linear interpolation of the above suggests this temperature is about 13 C or 55 F. More to the point, the conversion value varies too strongly with temperature for there to be a simple rule. That being said, I do like that the 5 billion figure ties in nicely with the familiar (in USA) ''divide by 5'' rule. [[User:Redbelly98|Redbelly98]] ([[User talk:Redbelly98|talk]]) 02:18, 6 August 2018 (UTC)
+:This suggests that the conversion value is the desired 5 billion for ''some'' temperature between 0 and 30 C. Linear interpolation of the above suggests this temperature is about 13 C or 55 F [EDIT: See note after this comment]. More to the point, the conversion value varies too strongly with temperature for there to be a simple rule. That being said, I do like that the 5 billion figure ties in nicely with the familiar (in USA) ''divide by 5'' rule. [[User:Redbelly98|Redbelly98]] ([[User talk:Redbelly98|talk]]) 02:18, 6 August 2018 (UTC)
 == Assumptions on the medium properties sound? ==

← Older revision		Revision as of 15:01, 6 August 2018
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	:But radios ARE specialized equipment. [[Special:Contributions/172.68.51.52\|172.68.51.52]] 10:35, 4 August 2018 (UTC)		:But radios ARE specialized equipment. [[Special:Contributions/172.68.51.52\|172.68.51.52]] 10:35, 4 August 2018 (UTC)
		+
		+	::Ehh... I see your point, but I'm not sure I'm really convinced. In my mind, a Gamma Ray Spectrometer is specialized equipment. People don't normally have them in their house or car. Radios are (or, at least, were) very common. But you're right, it says specialized instrument, not "rare" instrument. I'm not changing the explanation, just wanted to point out for those geeky enough to read the comments that for normal people, detecting the radio wave output lightning is doable without buying extra equipment one doesn't normally have in the home. Detecting the difference between the flash and the static on the radio is where it gets impractical. [[Special:Contributions/172.68.54.64\|172.68.54.64]] 15:01, 6 August 2018 (UTC) (newbie)

	== Whoops! ==		== Whoops! ==

← Older revision		Revision as of 12:12, 6 August 2018
Line 122:		Line 122:

	I always thought it was 1 second per mile. I didn't know about the 'divide by 5" part. [[User:These Are Not The Comments You Are Looking For\|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For\|talk]]) 01:23, 5 August 2018 (UTC)		I always thought it was 1 second per mile. I didn't know about the 'divide by 5" part. [[User:These Are Not The Comments You Are Looking For\|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For\|talk]]) 01:23, 5 August 2018 (UTC)
		+
		+	:Storms just became 5 times more scary for you :) [[Special:Contributions/188.114.103.95\|188.114.103.95]] 12:12, 6 August 2018 (UTC)

@@ Line 43: / Line 43: @@
 ::Just realized I also glossed-over the replacement of "divide" with "multiply."  The brain is a funny thing.[[Special:Contributions/172.68.54.142|172.68.54.142]] 20:07, 1 August 2018 (UTC)
 Do these account for the air pressure variability common in most thunderstorms?
@@ Line 87: / Line 89: @@
 :Nice one. I didn't think to use the refractive indicies directly. [[Special:Contributions/172.68.51.118|172.68.51.118]] 22:22, 2 August 2018 (UTC)
 == Assumptions on the medium properties sound? ==