I'm not a huge fan of side chains yet, but Bitcoin's Grandfather (Adam Back) and a couple of other notables participating in this thread have done a lot to convince me they won't be the end of the world and may ameliorate pressure to adopt Gavin's Bloatchain proposal.

Doc's economic attack via free options still worries me, but I have faith antifragility win out in the end.

OTOH, 20MB blocks would destroy TOR, etc. compatibility and poke holes in our beautifully small (defensible/diffuse/resilient) network, which is the vehicle for BTC's antifragility.

Sorry I can't be more specific and impressively techie!   

What's your take on the matter, old bean?

$400 seems a reasonable short term target.

I can think of a big one. You cannot use Proof of Work on a sidechain. Therefore you accept security and/or counterparty risk. It will up to the sidechain user to determine how much risk to accept.

proof of work wont make it to the mainstream.
1billion^TM people will never benefit from it ~directly.
its insane. they just need ~apps.

ETFs, sidechains, offchains, blythechains.. whatever.

yes, it looks toppish to me, weekly chart with gold overlay attached below:



Do you think further move of dollar at such pace is sustainable? You say half way through, do you really expect to see 120? Do you know what consequences it would have for global economies?

Ps. don't need more lols, let's talk arguments and charts.

I don't see how selling at the tops is immoral.  If anything it is praiseworthy, since selling at the top and buying at the bottom will smoothen out BTC's price, resulting in lower volatility and greater usability for commerce, store-of-value etc. .  

Selling at the top gives you the ammo needed to buy at the bottom.  
By buying at the bottom you are showing your faith in the continued existence of bitcoin, and stop a feedback loop of declining prices leading to less interest and a smaller network.  

You just can't stop it ;

http://www.cityam.com/211436/new-report-goldman-sachs-shows-why-bitcoin-here-stay

300 coming right up.

 Once we get through it, we should see a nice pop. 

Those are neither 'economic' disadvantages, especially from Bitcoin's perspective, nor are they meaningful or true.

Firstly, there is a strong incentive on the parts of the Blocksteam folks to design out counter-party risk, and as engineering problems go it is little or no more difficult than doing so in Satoshi's Bitcoin.  At least as long as Satoshi's Bitcoin itself can be relied upon in this respect.

Secondly, note that if one has a backing such as Bitcoin or gold, one does not need to rely on POW for this function.  One could use POW to a much lesser degree to shore up internal bookeeping to keep away the ankle-biters, but that's a secondary design issue and not terribly important.  The backing currency is the ONE system which actually NEEDS absolute security and Bitcoin has ONLY POW to achieve this.  Alts don't have this advantage since they tend to try to occupy the same place as Bitcoin.  Bitcoin can transfer it's security to other solutions with no net loss.  Just the opposite, really, because the more solutions relying on Bitcoin (and likely supporting native Bitcoin in some manner in most sidechains designs I would guess), the better.

The main thing that a user of a backing needs is for that backing to be solid and usable.  For gold this would mean some combination of physical security and transparency.  Gold was not discontinued as a backing currency because these things were impossibly to achieve, but rather because there was a desire by TPTB to get away from a non-inflationary base currency because they wanted an inflationary monetary system.  Achieving transparency and security for Gold would be, while possible, very much less efficient than with Bitcoin.

I think people lose sight of the value of POW in Bitcoin also.  Say you have a speeding semi truck that you wish to stop.  You build a wall of reinforced concrete which is 100' thick.  (Today's sha256.)  How much value is there to making the wall 200' thick?  Twice?  Nope.  There are other ways to attack the wall which will be explored, and a defender would be well advised to try to anticipate these and defend against them accordingly.

As nonsensical as it is to assign a simplistic linear value function in wall thickness as above, it is even more silly to reject any wall for any purpose simply because it isn't as strong as the massively over-spec'd wall for stopping the speeding semi truck.

As long as I have a reliable store of wealth in native Bitcoin, I care very little about the relatively less security of a sidechain (if it is even that much different.)  My uses of the two solutions will be entirely different.  True, in a sidechain failure I might get stung paying native Bitcoin transaction fees to get my money out upon a sidechain failure, but it's not an event that would be common but rather just a hypothetical issue which would give me confidence to use the solution and lessen the incentive for people to run bogus sidechains for the purposes of ripping people off (like some alts for instance.)

I do see it as rational to exclude some people from the highest echelons of monetary security (e.g., native Bitcoin.)  When I was younger I was sometimes lucky to have enough money in my bank account to pay my car insurance or buy a bag of weed.  Did I have some God-given right or entitlement to have my $25 balance secured in a Swiss vault on someone else's dime?  Absolutely not, and I never dreamed to ask for it.  My money, even if it represented half  of my life's savings was never at significant risk in part because if was only $25 on not worth the bother to steal.