# Unusual technical support request

## Our technical support department received the following question about dropping eggs:

I have been searching your web pages trying to find out how I can  drop a regular raw egg off a roof without it breaking. Years ago I did this in a physics class, but cannot remember what I did. There is nothing in your web pages regarding this. My seven year old grandson and I would like to do it. Could you help?

Normally we can only answer questions related to our products, but we felt this question deserved a reply. To get a broad range of replies we asked the readers of our email newsletter for help.

1. Get an egg-eating snake, give it the egg and wait until the egg is about half way down the snake, then fit the snake with tail flights (like a dart), then drop said snake plus egg from bridge, etc. The front of the snake will act as a crumple zone, thereby protecting the egg (makes a mess of the snake, but that is outside the parameters of the experiment) Then cut open the snake and remove the egg (snake already deceased, so this is no longer an ethical problem)

2. It's really quite simple — can’t imagine how he’s forgotten that he dropped it while it was still inside the hen! Just make sure it’s not a hen with clipped wings-specially if the roof is high…

3. Theory has it that, given sufficient height, aerodynamics will cause the egg to align itself to land on the blunter of the two ends. The egg is remarkably strong in this orientation. As long as it falls onto a reasonably forgiving surface, a lawn maybe, it won’t break — sometimes!

Safer bet is for Grandad to drop a hard boiled one and palm his stunned Grandson a raw one.

4. I recently dropped an egg from a rooftop and was able to achieve a drop of some 15 metres without the egg breaking. How? The roof was 16 metres from the ground. It was that last metre that always did the damage.

5.

1. Hold the egg carefully in your hands and jump off the roof.
2. Put the egg in the middle of a 1 foot square styrofoam block.
3. Take the roof off, sit it on the ground and roll the egg of the edge of the roof next to the ground.
4. Immerse the egg in liquid nitrogen first
5. Fit the egg with a parachute.

6. It’s really very simple, the clue is to spread all the force during the retardation phase (landing) on the COMPLETE surface of the egg. In this way, the resulting (vector) forces will be zero. In other words: The forces will “become a pressure” instead. And, since the egg may be compared to a pressure vessel (the surface is curved and can thus take really a lot of pressure before breaking) the egg will not break if you put it in a strong bottle filled with water before dropping it!

This is the classical solution to the problem. I have never worked it out myself but it should work as long as the bottle itself is strong enough (do a test by dropping the bottle filled with just water before doing the test in front of an audience).

7.

1. Center the egg in a nylon stocking.
2. Stretch stocking tight from each end.
3. Pinch off stocking several inches from each end of egg with rubber bands (so egg can slide a bit if impact is in axis of stocking).
4. Attach stretched ends of stocking to opposing diagonal corners of a large cardboard box.
5. Close box with tape and drop.

8. Just jump off with the egg. Land on your feet. No tall roofs.

9. Well, on a pedantic front you’ve got:

• A doll's house roof… (not far to go)
• A houseboat roof (into water — wouldn’t break)
• If the wind speed was extremely high the egg would fly and never hit the ground.
• If the house was on a comet or meteoroid with very low gravity it would hit the ground very slowly and not break.

On the stupid front:

• What if the raw egg was still inside the chicken?
• What about encasing it in concrete or a solid lump of metal — you wouldn’t be able to get at it, but it wouldn’t break.

And finally:

• How about putting the egg in a balloon full of water. I remember seeing a demo: put an egg in a jar and shake it and it breaks, fill the jar with water and shake and the egg doesn't break. Along similar lines— you must be able to put it inside something inflatable (like people in those giant Zorb things) — that should protect it.

10. Well, you could enclose it in a football-sized piece of foam… or modify the building to place the roof 1 inch above ground level… or you could place a pillow on the ground… or you could plough the ground up into soft loam? Or you could arrange for the entire yard to fall toward the centre of the earth until the relative velocities matched? At 9.8 m/s/s, this may leave a large hole in the yard…

11. If you shape a block of ordinary packing polystyrene to fit around the egg snugly with at least a few inches of extra styrene surrounding the egg. Best if you make two halves and glue them together.

12. To do this you must hold the egg pointed end uppermost before dropping it, and make sure you drop it on grass (ie something soft) not concrete. When the egg hits the ground the forces of the impact are distributed around the shell so it does not break. I have tried this myself in the past and it does work.

13. Hope that this helps your reader. Here are some simple (and some stupid) ways to protect the egg from a messy end:

• Wrap the egg in bubble paper very loosely (several layers) and seal with loosely applied tape.
• Place egg inside one balloon and then place this inside another bigger balloon. Inflate the inner balloon a bit and the outer one a until it is tightly stretched. You need to get a balloon floating within a balloon and the egg is bouncing inside the two balloons. Spin the balloon when you throw it!
• Make a simple box-shaped cradle for the egg out of a wire coat hanger and suspend the egg in the middle of the cradle using rubber bands so that it hangs in the middle of the cradle well away from the edges.
• Coat egg in expanding foam and shape the foam into a pyramid.
• The hardest way is to ensure that the egg hits the ground point first; try some tail fins!
• It is theoretically possible to spin the egg along its long axis at such a high speed that it will actually slow the descent. As long as the shell doesn’t fly apart with the forces involved!
• Are parachutes cheating?
• Are smaller paper gliders allowed?
• Can the grandson catch it?
• Find a new hobby!

14. It’s been a long time, but I think the egg was placed in a couple of styrofoam cups. The idea being that the cups, one within the other, slide together and absorb the shock.

15. My uni class did a project of dropping eggs from a roof. The basic criteria were you had to save a raw egg (at least 55 g) from damage whilst being dropped from a great height. The only materials to be used were as much PVA glue as you wanted and as many standard match sticks as you wanted. There was also a limit on the overall height and width of the finished object / device i.e approx 500 mm each way. An open mind and all manner of solutions will appear with varying degrees of success. Have fun.

16. Your reader asks how to drop an egg from a roof without it breaking? Don’t worry, the roof will not break.

Seriously, the reason the egg shatters is simple physics. Large deceleration with a small area of contact equals a massive force. To stop the egg breaking, suspend a linen sheet above ground on the drop zone. The result is that the deceleration time for the egg to change its velocity to zero is fairly long, and the sheet applies the force over a large area of the shell.

17. I noticed your query about dropping raw eggs from the roof. I guess that one would classify this as a smartass reply, but someone has to do it…

There is no trouble about dropping the egg. It won't break until it hits something hard like the ground. So what we have here is simply a case of a poorly identified problem. As for how you stop it breaking on hitting the ground, I really don't know for sure. It seems to be a matter of decelerating it slowly. Possibly spinning the eggabout its long axis and dropping it with the long axis horizontal into a water bath would do it: who knows?

18. I remember that the New Scientist ran an article, and I think a series of follow-up snippets, on this very topic. It’s something to do with getting the pointed end at a certain angle to the ground — which was grass, not concrete. The articles must have been around the 1960’s I would guess, but their archivist should be able to locate them.

19. Try to put the egg into vinegar to soften the egg.

20. The answer to the above question is simple. Put the egg inside a tin can that is larger than the egg (5 times in height) and fill the can with salt water. Add salt so that the egg will float in the solution. Now the salt water will behave like a shock absorber and the friction of the salt water and the egg will dump the movement after the hit.

It can work very well up to 14 meter drop with a regular can. At greater heights you should use stronger can.

21. You must wear slippers, preferably fluffy ones with a soft felt sole, then tiptoe along the roof, raising your knees deliberately into the air with each step. I find that, unless the roof is very very thin, it won’t break.

22. Why not try the method used by stuntmen when dropping off high buildings?

• Make a large bag out of thin material, fill it with air and make flaps on the bag that will let the air out in a controlled way when the egg hits the bag. Experiment with these vents to get the best result.
• Soak the egg in araldite and/or fill it with rubber solution.

23. When I was in engineering school, we had a similar contest. The winning entry used “Rice Krispies” breakfast cereal in sandwich bags to enclose their egg.

24.

• RULE NO 1: YOUR EGG MUST BE RAW

The filming took place at a school somewhere up north, the exact location I can’t remember, I’m going back to about 1969/70. Most of the school turned out and there seemed to be an unlimited supply of eggs. It quickly became apparent that eggs do not bounce on tarmac or concrete but only on grass. So…

• RULE NO 2: DO IT IN A FIELD!

Technique is all important and lobbing the egg underarm gave the lowest failure rate. The experiment progressed from the playing field to the 1st, 2nd and 3rd floors of the school and, although the mean time between failures decreased, we still had bouncing eggs.

• RULE NO 3: DEVELOP A GOOD LOBBING TECHNIQUE

So! How to beat the dreaded ovum? An egg beater? Yes! A big giant one! Enter the cavalry, or, rather, the Air Force — the American Air Force at that! The helicopter landed at the school and duly took off again with a full complement of “dozens” of eggs. Guess what? Provided that they were thrown, er — lobbed — as far out as possible from the downdraught, some still actually bounced!!
This 16 mm black and white film is probably hidden away somewhere in Auntie BBC”s archives? A phone call perhaps?

• RULE NO 4: DEVELOP A TASTE FOR OMELETTES/PANCAKES/SCRAMBLED EGGS, ETC.

Pico Technology does not accept any responsibility for damaged caused to any eggs, chickens, humans, snakes, roofs, etc. while trying these experiments.