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Myth or truth?


qwerty_steve

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Hi guys,

I'm writing a guide on Australian tourist destinations and have come across the claim that Mt. Warning on Australia's east coast is the first point to be hit by sunlight each morning. Google it and you will see that many websites, news articles etc have taken this as a given.

I have heard a rumor that Point Lookout in the New England National Park could actually take this title, as it is higher, but not so close to the coast by about 70km due west.

Mt. Warning (1,156 m or 3,793 ft)

Point Lookout (1,564 m or 5,131 ft)

I'm not educated enough to calculate the curvature of the earth to determine if this is correct or indeed false. Can anyone help?

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One would also need the latitude and longditude of these two locations. Time of year could also impact on the result. It would take me two days flat out to reteach myself the limited amount of mathematics necessary to make the calculation, so we'll have to wait for someone smarter than both of us.

 

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True Area54. I have used Google Maps to provide the following:

Point Lookout:-30.488330, 152.410255

Mt. Warning: -28.398097, 153.271908

Good point regarding time of year also.

P.S. I don't think I would be able to teach myself the mathematics involved at all!

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It's actually Point Lookout in NSW StringJunky, not to be confused with Point Lookout in QLD.

Willy Weather doesn't take into consideration the Altitude of each lookout, which is a key factor in which lookout receives sunlight first.

I've never noticed 'first light' on a weather service before, thanks for the info

Edited by qwerty_steve
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1 hour ago, qwerty_steve said:

It's actually Point Lookout in NSW StringJunky, not to be confused with Point Lookout in QLD.

Willy Weather doesn't take into consideration the Altitude of each lookout, which is a key factor in which lookout receives sunlight first.

I've never noticed 'first light' on a weather service before, thanks for the info

Ah right. OK. I'm too busy now for a while to look but you could could cross reference several such sites and see what sort of times and differences come up until someone comes along and does the down and dirty maths. :)

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  • 2 weeks later...
On 8/15/2017 at 9:14 PM, qwerty_steve said:

Hi guys,

I'm writing a guide on Australian tourist destinations and have come across the claim that Mt. Warning on Australia's east coast is the first point to be hit by sunlight each morning. Google it and you will see that many websites, news articles etc have taken this as a given.

I have heard a rumor that Point Lookout in the New England National Park could actually take this title, as it is higher, but not so close to the coast by about 70km due west.

Mt. Warning (1,156 m or 3,793 ft)

Point Lookout (1,564 m or 5,131 ft)

I'm not educated enough to calculate the curvature of the earth to determine if this is correct or indeed false. Can anyone help?

It may be the first point to be hit by sunlight in Australia, but not in the world.  It really depends on the time of year you are talking about because of Earth's 23.5° tilt.  On Summer Solstice the very first landmass to be hit by sunlight is Semisopochnoi Island located at 51° 57' 05" North by 179° 36' 03" East.  Semisopochnoi Island is one of the Rat Islands in the Aleutian Island chain in Alaska.

https://en.wikipedia.org/wiki/Semisopochnoi_Island

Even New Zealand, at 41° 17' South by 174° 27' East, gets the morning sunlight before Australia.  FYI, Semisopochnoi Island is in the New Zealand Time Zone, but just slightly further east.

 

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That's a fair enough statement. I meant to say in Australia only, not the world, but my question is a little ambiguous so I'll give you that :)

I've decided to work this out in layman's terms i.e. a rough estimation.

Based on the following:

http://mathcentral.uregina.ca/QQ/database/QQ.09.02/shirley3.html

It appears that the curvature of the earth results in a drop of 8 inches every 1 mile. I live in Australia, so I'm more comfortable with metric which equates to 20 cm over 1.6 km

Using Google Earth with the two points visible on my screen and a ruler, I have estimated that these two locations are approximately 85 km apart in LONGITUDE.

So over 85km, the math equals 85 / 1.6 x 20 = 106.25 meters drop due to the earth's curvature

Due to the tangent of line of sight, this figure needs to be doubled, so 212.50m

So which receives light first?

Mt. Warning (1,156 m or 3,793 ft)

Point Lookout (1,564 m or 5,131 ft)

With an elevation difference of 408 metres, even with time of year differences, Point Lookout is clearly the first point of Australia to receive sunlight each day! So there you go, a common misconception down here in oz.

p.s. the other math in the link is beyond me, but close enough I think. The difference in elevation is pretty big.

Edited by qwerty_steve
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9 minutes ago, qwerty_steve said:

It appears that the curvature of the earth results in a drop of 8 inches every 1 mile. I live in Australia, so I'm more comfortable with metric which equates to 20 cm over 1.6 km

No it doesn't, it is non linear. This make a huge difference as the distance gets larger than about 10km.

A good approximation, used by surveyors, for sightable distances (It won't work for a quarter circle) is

Difference between a circular curve and a straight line tangent = (Length of sight)2 / 2R

where R is the radius of the Earth.

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You beat me to it Studiot! I was in the process of updating my post. I needed to double the figure due to the tangent of the earth.

Point Lookout is still the first point to receive sunlight taking this into account.

Edited by qwerty_steve
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I'll leave the geography of Oz to those who know much much more about it than I do.

 

:)

Edit I see our cricket team has reverted to type after an uncharacteristic lapse when they actually won something.

Edited by studiot
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