How would the network handle a sudden drop in hash rate?

[interfect]

How much of the current hashing power of the network could be lost overnight without compromising the usability of Bitcoin for transactions? If everyone but me left, for example, it would probably take me months to find each block, and many years to find enough blocks for the difficulty to update to a more reasonable level. In the interim, transactions would go unconfirmed for months on end.

The network would probably get by OK with half the current hash rate, with blocks coming about every 20 minutes. But would a block an hour be acceptable? It would take almost a business day for transactions to confirm.

[SomeoneWeird]

How much of the current hashing power of the network could be lost overnight without compromising the usability of Bitcoin for transactions? If everyone but me left, for example, it would probably take me months to find each block, and many years to find enough blocks for the difficulty to update to a more reasonable level. In the interim, transactions would go unconfirmed for months on end.

The network would probably get by OK with half the current hash rate, with blocks coming about every 20 minutes. But would a block an hour be acceptable? It would take almost a business day for transactions to confirm.

No, you would find block quicker as the difficulty adjusts itself accordingly.

[phillipsjk]

Hashing power dropping in half is not a sign of a healthy network.

If Bitcoin is still around in a year, I plan on investing in hardware that will only be used to mine in response to a drop in the network hash rate (most the time, it would be used for other things, or even sit idle).

If I write a nice script, other people may do the same thing

Edit: SomeoneWeird, difficulty takes 2 weeks to adjust.

[interfect]

No, you would find block quicker as the difficulty adjusts itself accordingly.

The difficulty adjusts itself after a certain number of blocks. If it takes me a year to find each block, the difficulty won't adjust for quite a while.

[MoonShadow]

Electronic transfers in the existing interbanking system takes longer than a day to confirm, whether or not your bank lets you see the new balance already or not.  If 90% of the miners dropped out, the system would be fine.  It would take a while for the difficulty to update, and there would be a finite amount of transactions that could get processed, but this would mostly be an annoyance than anything.  The average block is less than a tenth of the current max block size anyway.

[MoonShadow]

If Bitcoin is still around in a year, I plan on investing in hardware that will only be used to mine in response to a drop in the network hash rate (most the time, it would be used for other things, or even sit idle).

I plan on building a mining rack to put into my garage, and set it up with my thermostat to turn on and off the GPU miners based upon the heat demand in the fall and winter.  So I can have a warm car and still a change at catching a block every now and again.

[SomeoneWeird]

Hashing power dropping in half is not a sign of a healthy network.

If Bitcoin is still around in a year, I plan on investing in hardware that will only be used to mine in response to a drop in the network hash rate (most the time, it would be used for other things, or even sit idle).

If I write a nice script, other people may do the same thing

Edit: SomeoneWeird, difficulty takes 2 weeks to adjust.

Where did I say it would be immediate?