the explanation is people are just too lazy to actually go and carry out the experiment (looking at you ). So they just assume the claim is true.

I don't believe it is.

They stood up many eggs on the kitchen table, and even posted a picture as proof. Good for them!

Then they went on to say that doing this is easier during the equinox, and goes into an explanation about "diallel gravitational lines". Never heard of that. Nevermind.

The thing I noted is, they never actually carried out any experiment to show that it's easier to do so during the equinox. They just said it. Where are the numbers? I'll prefer a double blind experiment, perhaps involving people who do not believe that it's easier to stand up eggs during the equinox.

And their "equinox time" theory flatly contracts what frankzane hears, where it's only possible to stand up eggs during a completely different time of the year.

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Added on February 9, 2012, 8:29 amYou tried it on the day before, the day itself, and the day after?

And you visited your non-Chinese neighbour (who have never heard of this theory before) and watch him trying to do this on those 3 days?

This isn't double blind, but I'll settle for single-blind.

This post has been edited by dkk: Feb 9 2012, 08:29 AM

I don't see what the equinox have to do with anything. But during a solar eclipse, the sun, moon, and earth is in a line. The earth is pulling you down, while the sun and moon is pulling you up. Sort of cancelling part of the gravitational effect of the earth. So you might weigh less, as will the egg. If it weigh less, it might be easier to balance.

But how much gravitational force does the sun and moon exert on something on the surface of the earth, compared to the gravitational force exerted by the earth itself.

F = Gm/r2

G = 6.6742 x 10^-11
earth: radius = 6.371 x 10^6 m, mass = 5.9736 x 10^24 kg
moon: distance (perigee) = 3.564 x 10^8 m, mass = 7.3477 x 10^22 kg
sun: distance (perihelion) = 1.471 x 10^11 m, mass = 1.9891 x 10^30 kg

gravitational force on someone standing on the surface of the earth from ...
earth
= 6.6742 x 10^-11 * 5.9736 x 10^24 / ( 6.371 x 10^6 ) ^ 2
= 9.822 m/s/s
moon
= 6.6742 x 10^-11 * 7.3477 x 10^22 / ( 3.564 x 10^8 ) ^ 2
= 0.0000386 m/s/s
sun
= 6.6742 x 10^-11 * 1.9891 x 10^ 30 / ( 1.471 x 10^11 ) ^ 2
= 0.006135 m/s/s

I would say the moon's effect is too miniscule to matter. The sun's effect is two magnitudes bigger, but then is still probably too small to make any difference, compared to 9.8 m/s/s.

0.0000386 m/s/s is equivalent to the reduction in earth's gravitational force if you were to climb up a tower 125m high. That's about 30 floors or one-third up the Petronas Twin Towers.

0.006135 m/s/s is equivalent to the reduction in earth's gravitational force if you were to climb up a distance of 20km. The top of Everest is 8.8km above sea level. Mauna Kea is 10.2km from base to top. OTOH, the earth's equatorial bulge is 42.72km (a spot on the equator like KL, is 42km further away from the center of the earth than the north/south pole is).

One line summary: go to the summit of Chimborazo in Ecuador, and wait until the sun is directly overhead.

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Added on February 11, 2012, 7:53 pmAs far as I can tell, eggs are not ferromagnetic.

This post has been edited by dkk: Feb 11 2012, 07:54 PM

But that does not make the egg ferromagnetic.

Yes it does make a difference. I would love to see someone balance an egg on the pointed end.

I was replying to marasista who mentioned the earth's magnetic field.

Are you sure. I don't see it. Looks to me like they're balancing the eggs on the rounded end rather than the pointed end.

That's amazing. I would have thought it impossible. Same as the author of the website himself.

Never mind one month. Getting it to stand for 1 minute on the pointed end is amazing in itself.

As for one month, perhaps they covered it with a transparent box. Or there are just a few extra tables that students do not sit at (like I observe in most school labs), especially those at the side of the room.

The eggs look all white. And the shape is not like the chicken eggs we normally see. Perhaps they're using duck eggs intead of chicken eggs. But it could be just the whitebalance on the camera.

There's still the possibility of cheating. I might try it myself later.

I've tried it. It took about 5 minutes.

I cannot get the egg to balance on the pointed end *AT ALL*.

But I don't really have the patience to do this. Not even on the round end. I took that pix after I gave up. But how do you explain the pic? Guess how I cheated.

This post has been edited by dkk: Feb 14 2012, 10:29 PM


Attached thumbnail(s)

No. The egg was unmodified. It is a normal chicken egg.

The kitchen top is as old as my house, around 30 years old. There are tiny imperfections. Small "holes", less than 0.5mm in diameter, many times less than that in depth. They're so small as to be only visible when seen from about 5cm away.

I place the egg on top of one of these. It was still very difficult to balance. But do-able.

My kitchen top was simply too smooth and slippery. On a different, less slippery surface, it'll probably be easier to balance the egg.