[HN Gopher] The key to a successful egg drop experiment? Drop it...
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The key to a successful egg drop experiment? Drop it on its side
Author : samizdis
Score : 30 points
Date : 2025-05-27 07:55 UTC (2 days ago)
(HTM) web link (arstechnica.com)
(TXT) w3m dump (arstechnica.com)
| Apes wrote:
| > They dropped 60 eggs each from three different heights (8, 9,
| and 10 millimeters)
|
| Based on the photos, they measured this as the distance from the
| surface of the edge to the surface they were dropping it onto.
|
| But for the vertical egg drop, the center of mass is several
| millimeters higher than for the horizontal drop, a pretty
| significant difference when you're only dropping 10mm at the
| most.
|
| Maybe I'm missing something, but based on how they set up the
| experiment, maybe they're not measuring how resistant the egg is
| in certain positions, but instead just measuring that higher
| potential energy is more likely to break an egg?
| nojs wrote:
| > over half of the eggs broke when dropped vertically from an
| 8-millimeter (31-inch) height
|
| Something went wrong with the units I think
| tbrownaw wrote:
| 8mm is a bit under a third of an inch (25.4mm), so someone
| dropped the decimal point.
| haiku2077 wrote:
| https://xkcd.com/3065
| rawgabbit wrote:
| I think they meant 8 meters as they showed someone dropping
| eggs from a bucket truck.
| tbrownaw wrote:
| They mention the eggs cracking a middling fraction of the
| time.
|
| Just now, dropping an egg about a finger-width onto
| whatever my kitchen counter is made of did indeed leave a
| small crack, so part is an inch is about right.
| meatmanek wrote:
| Unless the egg rotates significantly during the fall, the
| distance from the floor to the bottom surface of the egg
| determines the potential energy that could go into falling
| speed before the egg hits the floor. In order to fall further,
| the egg either needs to have already cracked or to roll once
| hitting the floor (unlikely to cause cracking if the initial
| impact didn't).
| divbzero wrote:
| > _They dropped 60 eggs each from three different heights (8, 9,
| and 10 millimeters) onto a hard surface in three different
| orientations: horizontal, vertical on the sharp end, and vertical
| on the blunt end._
|
| I find it hard to extrapolate from this experimental setup to an
| egg drop competition. A ~1cm drop onto a hard surface is quite
| different from a ~10m drop in protective packaging.
| hinkley wrote:
| However you try to pad it there will end up being a hot spot
| where either the force is maximal or the shell is thinnest. So
| I think it makes sense to do the unprotected tests to see what
| the failure mode is for the egg and then design for that.
|
| The neck is the weak point in a car crash. So we design cars
| and airbags and child seats to account for that.
| javman wrote:
| I wonder if someone made a mistake with unit conversions... The
| next paragraph says:
|
| > The results: over half of the eggs broke when dropped
| vertically from an 8-millimeter (31-inch) height
|
| 31 inches is 0.8m, not 8mm. Maybe they meant to say 0.8, 0.9,
| 1.0 meters? Strange.
| SamBam wrote:
| Yet the image ("Experimental snapshots for vertical (top) and
| horizontal (bottom) egg drops.") definitely appears to show
| something closer to 8mm, assuming the black area is the
| table.
|
| Edit: Reading the paper [1] it's definitely 8mm. The
| ArsTechnica writer screwed up the conversion to inches.
| Should be 0.31".
|
| 1. https://www.nature.com/articles/s42005-025-02087-0
| plasma_beam wrote:
| In high school physics I procrastinated until the night before
| our egg drop competition to finally address what I was going to
| do. I got a medium/large size plastic tupperware container (rigid
| plastic body with a rigid lid). I took a bag of cotton balls,
| stuffed them in there as tight as I could, put an empty cardboard
| toilet paper roll vertically in the center, with more cotton
| balls designed to go in said cardboard below and above the egg.
| Taped the lid shut. People laughed at my concoction, especially
| those that went to great efforts to design theirs. I even tossed
| mine in the air beforehand to test it, which gave me extreme
| confidence going into the 30 ft drop that I'd be fine. I was. I
| do not recall what side it landed on but obviously it bounced
| several hard times after hitting the ground.
| broost3r wrote:
| i've done this experiment 2 years in a row with my youngest
| kiddo as a STEM challenge in elementary school. i thought we
| got pretty close this year with using heavy duty sponges, paper
| plates, and a parachute, but was always operating under the
| assumption that the egg needs to be vertical. i'm excited to
| try again next year after reading this.
|
| oh and at our school, they bring in a big bucket truck from the
| local power company and send the teachers up to the top with
| the devices and let them drop them :)
| slavik81 wrote:
| Get a block of styrofoam, slice it in two, and carve out a
| hole between the blocks exactly the size and shape of your
| egg. Tape the blocks together with the egg in the centre.
|
| It is incredibly effective to have a solid surface in contact
| with the whole shell. And, the outer styrofoam will absorb
| the worst of the landing. It's also very light, so it
| minimizes the energy that must be dissipated.
|
| Lesson learned from my failed attempt at the egg drop in high
| school. The guy with the styrofoam absolutely destroyed
| everyone at that challenge.
| dmonitor wrote:
| Even simpler: A barrel of water densified such that the egg
| floats in the middle
| slavik81 wrote:
| That was the solution employed in the ActionLabs video
| linked in another comment, but you'll note that their
| first attempt failed with that approach.
|
| It's difficult to prevent any container that heavy from
| breaking open when hitting concrete at terminal velocity.
| I'd bet that the styrofoam block could be dropped from
| any height and survive landing on any surface, no matter
| how unyielding.
| sdeframond wrote:
| How about soaking the egg into epoxy resin ?
| luhn wrote:
| Yeah, tight packing is simple and very effective. I had a
| successful drop with nothing but corn starch packing peanuts
| shoved into a cardboard box.
| Avshalom wrote:
| I put it in a half filled gallon ziploc of flour (on top of the
| flour).
| hinkley wrote:
| From an engineering standpoint it 'makes sense' to make the
| device radially symmetrical by standing the egg on one end. But
| it sounds like that causes the device to need to be better to
| achieve the same level of protection.
| tiffanyh wrote:
| Isn't this simply due to the fact that there's more surface area
| contact when an egg is on it's side vs vertically.
| vlovich123 wrote:
| I thought the key was to completely surround it with water & make
| sure it's not floating next to any side of the container to avoid
| incidental contact.
|
| https://www.youtube.com/watch?v=JBo9X2Hkw1s
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