Can a clear glass bottle shatter from the heat of the sun on a hot day?

Factual Questions
1

A few days ago, I was at a local recreation center, picking up my darling daughter after her soccer practice.

As we were gathering her things, we heard the sound of a glass bottle shattering from impact (or so I thought) on the nearby stairs.

I immediately went up the stairs to the terrace above and confronted the kids there demanding that the kid who threw the glass bottle down onto the stairs come clean and take responsibility for his/her action.

They all played dumb and insisted that nobody did such a thing.

I called BS on it at the time, but on second thought, I want to know if it’s possible that a clear glass bottle, sitting in the hot sun, could explode by itself.

FYI: It was about 85 degrees F on that day (29 degrees or so Celsius).

Anyone?

2

What were the contents of the bottle and was it sealed? If the contents of the bottle expanded too much, it could have shattered that way. Do you remember the splash pattern of both the contents and the glass? If the bottle had been dropped, the glass fragments would have been widely spread, not so in the case of a burst from a non-carbonated fluid content, and probably not from a bottle of carbonated fluid.

3

I should have specified … it was an empty glass bottle.

I had other things on my mind at the time (such as a glass shard hitting my daughter’s friend’s leg), so I didn’t examine the shatter pattern.

4

I’d say there’s a chance if the bottle was sealed, and virtually no chance if it wasn’t.

IANA physicist or glass blower or a bottler.

5

I’m not saying it’s completely impossible for an open glass bottle to spontaneously shatter, but in weighing the chances of it happening against the chances of children lying about tossing a bottle down stairs, I’m inclined pretty heavily towards the second possibility.

6

I don’t think it’s possible. Glass and ceramics can break from thermal stress - when one part is at a significantly different temperature than another. The classic example is pouring boiling water into a cold cup - the inside of the cup heats up and wants to expand, but the outside is still cold and doesn’t want to expand, so the cup cracks. But a glass bottle left in the sun wouldn’t change temperature quickly enough for thermal stress to occur. It would heat up slowly enough that it wouldn’t have much of a thermal gradient across the material.

Sealed - still don’t see it. Say it started at room temperature, 70 F = 294 kelvin. Let it heat to 120 degrees f = 322 degrees K. PV=nrT, so you get an pressure increase of about 8% - not enough to break a sealed glass container - they can hold much higher pressures than that.

Plus, what Quercus said.

7

I have been told that it’s possible - the light from the sun focuses like a magnifying glass, heating up the surface on which the bottle is resting and that heating results in the breaking glass. Supposedly, this most often happens early in the day when the glass is still cold.

I don’t believe it, though. Anyone who has spent as much of his youth as me burning ants with a magnifying glass knows that it’s hard to get that much energy concentrated when you’re trying to do it on purpose, let alone by accident. Furthermore, I’ve only seen glass shatter due to rapid changes of around a hundred degrees in temperature.

8

I’d go with Quercus.

9

Thanks for all the replies, everyone.

I’ll take “Kids are Jerks” for $500, Alex.

10

Perhaps the Mythbusters could look into this one.

11

I had a lead crystal ashtray that I inherited from my dad that was sitting outside. It fractured spontaneously when transitioning from a cold night to a hot day. Bummed me out.

12

If there was something wrong with the bottle - perhaps some manufacturing flaw involving weak spots and/or unevenly distributed internal stresses - it doesn’t seem utterly, utterly impossible, but it would be a pretty freakish occurrence,

13

If 85° was all it took to shatter a glass bottle, we’d all have to use plastic from March to November.

14

I do not have a definitive answer, but based on the following reasoning, I believe it does not happen:

  1. There are millions of said bottles out there
  2. If some were to have burst there is bound to be people who would sue over it.
  3. The media would have a field day: Do glass bottles pose a risk to your child? Tune in at 10 to find out.
  4. Since we have never heard of it happening, I don’t think it does happen.

Note that this could not be called science in even a loose sense of the word, so I am only saying that IMO, it does not happen.

15

BS - your error is that you asked who “threw” the bottle. Nobody did. Now, maybe somebody “knocked the bottle over” or “pushed” the bottle" or even “tossed the bottle” but they were probably all outraged (outraged I say!) that you would suggest they would “throw” a bottle. Kids are natural sea lawyers.