General Question

simone54's avatar

How fast would you have to go to see a never ending sunset?

Asked by simone54 (7629points) September 3rd, 2010
12 responses
“Great Question” (10points)

Say you had a helicopter and you really liked sunsets. You wanted to the sunset to last for ever. You hop in your chopper and fly west. How fast would you have go to keep the sun right on the horizon forever?

Observing members: 0
Composing members: 0


JubalHarshaw's avatar

It depends on your altitude above sea level and the latitude of your location. At the equator and at sea level, you would have to be traveling slightly over 1000 miles per hour or about Mach 1.4. This is obviously beyond the capability of helicopters.

iamthemob's avatar

@JubalHarshaw is totally right. That’s the speed of the earth’s rotation (approximately) at the equator.

You would have to take into account the earth’s axis though…since the earth is on a tilt, you would have to fly over different latitudes at different speeds (e.g., you’d probably have to dip between the Tropic of Cancer and the Tropic of Capricorn and then back again. As you increase in latitude, you’d recalculate the drop in speed necessary to travel along that latitude (which would be less), but this might not decrease if the additional distance you are required to travel to get to the new latitude offset the drop in speed required to keep up with rotation at that latitude. Plus, the headwinds.

Math is fun.

Response moderated (Unhelpful)
JubalHarshaw's avatar

@iamthemob I bow to a superior navigator :^)

Thammuz's avatar

You’d have to maintain the same angular velocity of the earth, plus you’d have to factor in the fact that the day, as in not night, isn’t always long the same, so assuming a constant height the speed would be a sinusoid ranging from a minimum on the summer solstice to a maximum on the winter solstice. that is assuming you’re above the northern hemisphere.

I don’t know if this would be true if you flied in a straight line above the equator, now that i think of it.

cazzie's avatar

Theoretically, you’d find the sunset point, and simply counter the speed of the earth’s spin around that point. But with the earth’s axis at 23.5 degrees, even at the equator, there will be small seasonal variations.

The closer you are to the equator, the more even the days are, regardless of the season. The equator is 0. This is the longest latitudinal line on the planet, so it would take the longest to get around. The speed at which the earth spins varies upon your latitudinal location on the planet. If you’re standing at the north pole, the speed is almost zero but at the equator, where the circumference of the earth is greatest, the speed is about 1,038 miles per hour (1,670 kph). But, helicopters can’t fly that fast, so you’d have to choose a higher latitude to follow….....but even the mid latitudes spin at 700 to 900 mph (1125 to 1450 kph), so you’d be stuck in the higher latitudes, where seasonal fluctuations are most dramatic.

‘Helicopters by their nature tend to be much less efficient long-range vehicles than fixed-wing aircraft. As a result, the record for maximum range is far lower and there has been little effort to break it for decades. The current official record belongs to Robert Ferry who flew a prototype YOH-6 Cayuse on a cross-country flight from California to Florida on 6 April 1966. The distance covered on the journey was 1,923.08 nm (3,561.55 km).’

Fixed wing aircraft might be a better option perhaps, for both speed and distance.

GeorgeGee's avatar

It depends on where you are. Some of these answers assume you’re at the equator, which most people are not. If you’d like to visit Alaska in autumn, you can hang out in dusk/dawn for a month or so without flying at all.

simone54's avatar

Okay then….

Let’s say, I’m starting 500 ft above San Diego, CA on September 10th 2010. I have a brand new Harrier Aircraft that has a max speed of 2000 mph.

Winters's avatar

@simone54 uh, a Harrier has a max speed of around 700 mph. Now the SR 71 Blackbird has a max speed of around 2200 mph, give or take a little since it would depend on which of the 30 (or was it 32?) that were made you’re flying.

LuckyGuy's avatar

Assuming the Earth is 40,000 km in diameter
A day is 24 hour
You know your latitude (L) and are near the surface.
V= cos(L) x 40000 km/hr/ 24
If you live near the equator Cos (90)= 1, you need to travel at 1667 km/hr.
If you live near NY City Lat 42 deg .Cos (42)= .7431 x 1666.6= 1238.57 km/hr

LuckyGuy's avatar

For San Diego, latitude 33 deg, Cos (33)= 0.83867
So 1397.8 km/hr or 869 mph
Have a wonderful trip.

cazzie's avatar

(Hey! My figures weren’t too far off!)

Answer this question




to answer.

Mobile | Desktop

Send Feedback