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Comment by raldi | Hacker News Reader

I'm going to have to demand better evidence that you can't drop an iPhone (cased or naked) without breaking it.

The glass it's made of is not the same as, say, the kind you drink wine out of. Unfold a paper clip and try to scratch your iPhone. You'll fail miserably.

I know anecdotes are not the same as data, but I've heard so many "my iPhone is indestructible" stories like http://www.mac-forums.com/forums/switcher-hangout/237495-iph... that I'd love to see the results of an actual durability testing lab.

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Unfold a paper clip and try to scratch window glass. You'll fail miserably.

It's quite probable that iPhone glass is easier to scratch than window glass. Glass is harder than just about everything except for diamond, so adulterated glass, like the Gorilla Glass in your iPhone isn't as hard.

Normal glass is very brittle. Gorilla Glass isn't.

This isn't the case - the surface of Gorilla glass is under compression along its surface in such a way that it's incredibly scratch resistant in addition to being very flexible (see demos of people scratching car keys on it).

The primary weakness of Gorilla glass is that any actual incremental damage basically causes the glass to implode on itself and creates spiderwebs of cracks instead of a straight one reflecting where the structural integrity was breached. Think of how many times you've seen hairline cracks in windshields versus the disaster that someone's iPhone screen turns into if they happen to crack their screen.

The way Gorilla glass is manufactured it is by far the weakest around the edges (there's no compression depth-wise across the edge) and thus the iPhone 4 is somewhat more susceptible to damage than earlier models (due to the edge to edge glass on the front).

It's worth mentioning that there is a difference between "hardness" and "toughness" when dealing with glass and gems/minerals. Hardness is the material's resistance against scratching, while toughness is its resistance to breakage. The iPhone uses a synthetic sapphire I believe (much like in many eyeglasses made today) which has a hardness of 9 on the Mohs scale (Diamond is 10), so it is very resistant to scratches, since only materials with a hardness the same or above can scratch it; that doesn't correlate with it's resistance to breakage. Many very hard materials are also very brittle and will crack or shatter more easily than anticipated.

You can certainly drop an iPhone without breaking it - but I wouldn't be sure it would work every time.

Also, scratch-resistant and drop-resistant are not the same thing.

They definitely aren't indestructible - my sister's iPhone4 dropped out of her pocket onto a concrete floor (movie theater) - around a 3 ft drop, and hit the corner and the glass backing cracked from top to bottom.

I love the form and fit of my 4S, but when it's out of the snap case, I am very ginger with it.

They certainly aren't indestructible:

http://www.youtube.com/watch?v=elKxgsrJFhw

It's not that you can't drop it without breaking, but it'll break often enough that it's a really bad idea.

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