Jump to content


Photo
- - - - -

which occurs first lightning or thunder?


  • Please log in to reply
44 replies to this topic

#1 fluid

fluid

    Lepton

  • Members
  • 5 posts

Posted 4 January 2017 - 06:00 PM

which is which?


  • 0

#2 swansont

swansont

    Evil Liar (or so I'm told)

  • Moderators
  • 36,417 posts
  • LocationWashington DC region

Posted 4 January 2017 - 06:01 PM

Thunder is the result of lightning. Lightning happens (or at least starts) first.


  • 1

Minutus cantorum, minutus balorum, minutus carborata descendum pantorum          To go to the fortress of ultimate darkness, click the up arrow ^

I am not a minimum-wage government shill.             Forget it, Jake — it's Crackpottown.

My SFN blog: Swans on Tea                                                           

 

 

                                                                                                                     

 

 


#3 Sensei

Sensei

    Scientist

  • Senior Members
  • 3,230 posts

Posted 4 January 2017 - 07:51 PM

Sound travels approximately 340 m/s in air.
So if you see lightning and start counting seconds,
divide them by 3,
and you have distance to lightning in kilometers.

Suppose so you counted seconds to 5

d = v*t
d = 340 m/s * 5s = 1700 meters
  • 0

#4 EdEarl

EdEarl

    Scientist

  • Senior Members
  • 3,024 posts
  • LocationTexas, USA

Posted 4 January 2017 - 08:23 PM

Lightening is a spark, like when you touch a door knob after walking across a carpet, and you get shocked. The sound and spark occur at the same time. However, sound travels slower than light, so at a distance you see the lightening and later hear the thunder.


  • 0

Be kind whenever possible. It is always possible. -- Tenzin Gyatso, the 14th Dalai Lama.

Anyone who isn't confused really doesn't understand the situation. -- Edward R. Murrow

If there is a god, he is addicted to dice.

 


#5 zztop

zztop

    Baryon

  • Banned
  • 180 posts

Posted 4 January 2017 - 08:40 PM

which is which?

Thunder occurs a few fractions of a second after lightning but arrives a few seconds later due to the difference in speed propagation between light and sound. See: https://en.wikipedia...lating_distance


Edited by zztop, 4 January 2017 - 08:40 PM.


#6 swansont

swansont

    Evil Liar (or so I'm told)

  • Moderators
  • 36,417 posts
  • LocationWashington DC region

Posted 4 January 2017 - 10:14 PM

Lightening is a spark, like when you touch a door knob after walking across a carpet, and you get shocked. The sound and spark occur at the same time. However, sound travels slower than light, so at a distance you see the lightening and later hear the thunder.


But the spark causes the sound. It has to happen first.
  • 0

Minutus cantorum, minutus balorum, minutus carborata descendum pantorum          To go to the fortress of ultimate darkness, click the up arrow ^

I am not a minimum-wage government shill.             Forget it, Jake — it's Crackpottown.

My SFN blog: Swans on Tea                                                           

 

 

                                                                                                                     

 

 


#7 Daecon

Daecon

    Formerly Transdecimal

  • Senior Members
  • 1,464 posts
  • LocationNew Zealand

Posted 4 January 2017 - 10:21 PM

Is thunder like a sonic boom?
  • 0
Cast your influence, cast your might.

#8 EdEarl

EdEarl

    Scientist

  • Senior Members
  • 3,024 posts
  • LocationTexas, USA

Posted 4 January 2017 - 11:38 PM

But the spark causes the sound. It has to happen first.

Perhaps, but in a vacuum there is neither spark nor sound, merely subatomic particles moving. The spark is ionized molecules, which must be moved by a charge. The sound is movement of molecules. I don't know if anyone has investigated what happens in the first nanoseconds of a spark. It is an interesting question.


  • 0

Be kind whenever possible. It is always possible. -- Tenzin Gyatso, the 14th Dalai Lama.

Anyone who isn't confused really doesn't understand the situation. -- Edward R. Murrow

If there is a god, he is addicted to dice.

 


#9 iNow

iNow

    SuperNerd

  • Senior Members
  • 17,246 posts
  • LocationAustin, Texas

Posted 5 January 2017 - 01:42 AM

Lightning and thunder don't occur in a vacuum.
  • 0

#10 Acme

Acme

    Primate

  • Senior Members
  • 2,357 posts

Posted 5 January 2017 - 03:59 AM

Is thunder like a sonic boom?


Yes.

Thunder

Thunder is the sound caused by lightning. Depending on the distance and nature of the lightning, thunder can range from a sharp, loud crack to a long, low rumble (brontide). The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within a bolt of lightning. In turn, this expansion of air creates a sonic shock wave, similar to a sonic boom, which produces the sound of thunder, often referred to as a clap, crack, peal of thunder, or boom. ...


  • 0

#11 Externet

Externet

    Molecule

  • Senior Members
  • 1,525 posts
  • LocationMideast U.S.

Posted 5 January 2017 - 05:31 AM

Lightning heats air.

Heated air expands.

Expansion of air produces a sonic wavefront.


  • 0
Abolish the deciBel !

#12 StringJunky

StringJunky

    Genius

  • Senior Members
  • 6,262 posts
  • LocationUK

Posted 5 January 2017 - 06:59 AM

Perhaps, but in a vacuum there is neither spark nor sound, merely subatomic particles moving. The spark is ionized molecules, which must be moved by a charge. The sound is movement of molecules. I don't know if anyone has investigated what happens in the first nanoseconds of a spark. It is an interesting question.

Photons move in a vacuum. They are produced by the excited electrons of  the ionised molecules as they drop back down to their resting level..


Edited by StringJunky, 5 January 2017 - 08:35 AM.

  • 0

 Education, like life, is a journey not a destination


#13 EdEarl

EdEarl

    Scientist

  • Senior Members
  • 3,024 posts
  • LocationTexas, USA

Posted 5 January 2017 - 10:50 AM

Photons move in a vacuum. They are produced by the excited electrons of  the ionised molecules as they drop back down to their resting level..

True, I didn't fully expound during my previous statement.

 

A potential difference in a vacuum moves electrons between two conductors (anode and cathode), but no spark is produced. I don't think other subatomic particles would move between them, nor photons. But, there is no such thing as a perfect vacuum, so some atoms will exist and can become ionized. They would emit photons. Electrons hitting the anode would cause heat, and at some point atoms from the anode would be released into the vacuum, probably as ions. Eventually enough anode material would be in the vacuum to cause a spark. Often cathodes are heated to allow electrons to flow more freely. Atoms might escape from the cathode, too.

 

This isn't on-topic, but is a more complete explanation of a potential difference in a vacuum. I'm not sure it's all correct.


Edited by EdEarl, 5 January 2017 - 11:21 AM.

  • 0

Be kind whenever possible. It is always possible. -- Tenzin Gyatso, the 14th Dalai Lama.

Anyone who isn't confused really doesn't understand the situation. -- Edward R. Murrow

If there is a god, he is addicted to dice.

 


#14 StringJunky

StringJunky

    Genius

  • Senior Members
  • 6,262 posts
  • LocationUK

Posted 5 January 2017 - 10:57 AM

True, and maybe dark matter particles.

I was responding to this:

 

 

Perhaps, but in a vacuum there is neither spark nor sound, merely subatomic particles moving.


Edited by StringJunky, 5 January 2017 - 10:57 AM.

  • 0

 Education, like life, is a journey not a destination


#15 studiot

studiot

    Genius

  • Senior Members
  • 6,623 posts
  • LocationSomerset, England

Posted 5 January 2017 - 11:08 AM

Perhaps, but in a vacuum there is neither spark nor sound, merely subatomic particles moving. The spark is ionized molecules, which must be moved by a charge. The sound is movement of molecules. I don't know if anyone has investigated what happens in the first nanoseconds of a spark. It is an interesting question.

 

Was the negative vote here a mistake?

 

This could certainly have been better phrased, but deserving of a negative vote?

 

I have added +1


  • 0

#16 StringJunky

StringJunky

    Genius

  • Senior Members
  • 6,262 posts
  • LocationUK

Posted 5 January 2017 - 11:16 AM

 

Was the negative vote here a mistake?

 

This could certainly have been better phrased, but deserving of a negative vote?

 

I have added +1

I never saw the neg but if there was it was unwarranted. There is a possibility as I passed my cursor to move to another part of the page it hit a red; that's happened before. I use a touchpad which can inexplicably do things I don't want it to do.


  • 0

 Education, like life, is a journey not a destination


#17 EdEarl

EdEarl

    Scientist

  • Senior Members
  • 3,024 posts
  • LocationTexas, USA

Posted 5 January 2017 - 11:27 AM

I edited the mention of dark matter particles out of my post, and expounded on, "Perhaps, but in a vacuum there is neither spark nor sound, merely subatomic particles moving," and probably said too much with additional omissions of other relevant info.


Edited by EdEarl, 5 January 2017 - 11:29 AM.

  • 0

Be kind whenever possible. It is always possible. -- Tenzin Gyatso, the 14th Dalai Lama.

Anyone who isn't confused really doesn't understand the situation. -- Edward R. Murrow

If there is a god, he is addicted to dice.

 


#18 Sriman Dutta

Sriman Dutta

    Molecule

  • Senior Members
  • 576 posts
  • LocationKolkata, India

Posted 5 January 2017 - 11:47 AM

Lightning occurs first. It's an electric spark across a very high potential difference.


  • 0
We are what we repeatedly do.
Excellence is then not an act but a habit.
-Aristotle

#19 AshBox

AshBox

    Quark

  • Senior Members
  • 43 posts

Posted 10 January 2017 - 07:22 AM

They happen at the same time. But since light travels faster than sound, you see the lightning before you hear the thunder.


  • 0

#20 swansont

swansont

    Evil Liar (or so I'm told)

  • Moderators
  • 36,417 posts
  • LocationWashington DC region

Posted 10 January 2017 - 11:45 AM

They happen at the same time. But since light travels faster than sound, you see the lightning before you hear the thunder.

 

 

What causes the thunder, then?  


  • 0

Minutus cantorum, minutus balorum, minutus carborata descendum pantorum          To go to the fortress of ultimate darkness, click the up arrow ^

I am not a minimum-wage government shill.             Forget it, Jake — it's Crackpottown.

My SFN blog: Swans on Tea                                                           

 

 

                                                                                                                     

 

 





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users