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Title: No new block for more than an hour Post by: zaradoz on April 24, 2014, 05:27:53 PM Just noticed that there is no new block for more than an hour, I don't know the Bitcoin protocol that good, is it normal for a block to take so long?
Title: Re: No new block for more than an hour Post by: kendog77 on April 24, 2014, 05:34:59 PM Just noticed that there is no new block for more than an hour, I don't know the Bitcoin protocol that good, is it normal for a block to take so long? It's called variance. On average, the Bitcoin network will solve a block every 10 minutes, but variance can cause some blocks to take much longer to solve. Title: Re: No new block for more than an hour Post by: zaradoz on April 24, 2014, 05:50:10 PM Just noticed that there is no new block for more than an hour, I don't know the Bitcoin protocol that good, is it normal for a block to take so long? It's called variance. On average, the Bitcoin network will solve a block every 10 minutes, but variance can cause some blocks to take much longer to solve. I understand the variance concept, but it's the first time I see block takes so long to solve. It is solved now thou. Title: Re: No new block for more than an hour Post by: DannyHamilton on April 24, 2014, 08:00:16 PM I'm not sure if its the longest time between blocks so far, but I think there was 7741 seconds (2 hours and 9 minutes) between block 270193 and 270194.
The early blocks (when there weren't enough people mining yet to averate a block every 10 minutes at difficulty 1) probably had even more time between them. Title: Re: No new block for more than an hour Post by: Chris_Sabian on April 25, 2014, 01:12:48 AM I'm not sure if its the longest time between blocks so far, but I think there was 7741 seconds (2 hours and 9 minutes) between block 270193 and 270194. The early blocks (when there weren't enough people mining yet to averate a block every 10 minutes at difficulty 1) probably had even more time between them. There were some longer ones in 2009 when the network was really young: Block 27: 2009-01-10 06:56:13 Block 28: 2009-01-10 15:30:57 Block 168: 2009-01-11 23:39:41 Block 169: 2009-01-12 03:22:03 Block 74637: 2010-08-15 17:02:43 Block 74638: 2010-08-15 23:53:59 Title: Re: No new block for more than an hour Post by: deepceleron on April 25, 2014, 08:33:07 AM I'll just consolidate some old quotes of mine here
These two statements appear to be in dissonance, but are both true:
Obviously easy to confuse the two when calculating things. So the chance a block won't be found after 10, 20 minutes, etc. (and the 1 in x chance) Code: >>> for x in range(10,131,10) : 20 13.53353% 7.39 30 4.97871% 20.09 40 1.83156% 54.60 50 0.67379% 148.41 60 0.24788% 403.43 70 0.09119% 1096.63 80 0.03355% 2980.96 90 0.01234% 8103.08 100 0.00454% 22026.47 110 0.00167% 59874.14 120 0.00061% 162754.79 130 0.00023% 442413.39 And after how many minutes will half of blocks, 25% of the blocks, etc. not be solved: Code: >>> for x in [ 10*math.log(2), 10*math.log(4), 10*math.log(8), 10*math.log(16), 10*math.log(32), 10*math.log(64)]: 6.9314718056 50.00000% 2.00 (median block length) 13.8629436112 25.00000% 4.00 20.7944154168 12.50000% 8.00 27.7258872224 6.25000% 16.00 34.657359028 3.12500% 32.00 41.5888308336 1.56250% 64.00 And every day we can reasonably expect a block longer than 49 minutes, every week one longer than 69 minutes, every month 83 minutes: Code: >>> for x in [ 10*math.log(144), 10*math.log(144*7), 10*math.log(144*365.25/12)]: 49.6981329958 0.69444% 144.00 69.1572344863 0.09921% 1008.00 83.8548870042 0.02282% 4383.00 Note the "long tail" on the chance of not finding a block after x time: ...the probability density function of an exponential distribution (http://en.wikipedia.org/wiki/Exponential_distribution) looks like this: http://upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Median_exp.svg/374px-Median_exp.svg.png Note that the average block time is 10 minutes (1/λ), but 50% of the blocks are less than 6.93 minutes (the median ln(2)/λ). Most long blocks came early in Bitcoin, here's 212 blocks with over 100 minutes since last block timestamp. Note that the block timestamp is based on the mining computer's time, there are more blocks than this with a negative time. 15324 (http://blockexplorer.com/b/15324) 1508.9 16564 (http://blockexplorer.com/b/16564) 1506.5 15 (http://blockexplorer.com/b/15) 1452.6 16592 (http://blockexplorer.com/b/16592) 1229.7 20189 (http://blockexplorer.com/b/20189) 1003.4 19724 (http://blockexplorer.com/b/19724) 785.5 21438 (http://blockexplorer.com/b/21438) 637.0 19722 (http://blockexplorer.com/b/19722) 625.6 28 (http://blockexplorer.com/b/28) 514.7 16490 (http://blockexplorer.com/b/16490) 511.4 20432 (http://blockexplorer.com/b/20432) 507.1 20364 (http://blockexplorer.com/b/20364) 500.2 20349 (http://blockexplorer.com/b/20349) 488.8 21389 (http://blockexplorer.com/b/21389) 468.7 19565 (http://blockexplorer.com/b/19565) 433.3 15048 (http://blockexplorer.com/b/15048) 422.9 19726 (http://blockexplorer.com/b/19726) 415.1 74638 (http://blockexplorer.com/b/74638) 411.3 21446 (http://blockexplorer.com/b/21446) 392.9 21527 (http://blockexplorer.com/b/21527) 384.7 21466 (http://blockexplorer.com/b/21466) 384.2 16468 (http://blockexplorer.com/b/16468) 380.7 26242 (http://blockexplorer.com/b/26242) 368.3 21359 (http://blockexplorer.com/b/21359) 357.8 21449 (http://blockexplorer.com/b/21449) 342.3 21463 (http://blockexplorer.com/b/21463) 330.1 21382 (http://blockexplorer.com/b/21382) 327.1 21376 (http://blockexplorer.com/b/21376) 321.3 21383 (http://blockexplorer.com/b/21383) 308.6 23418 (http://blockexplorer.com/b/23418) 305.4 21585 (http://blockexplorer.com/b/21585) 302.0 23434 (http://blockexplorer.com/b/23434) 300.7 20384 (http://blockexplorer.com/b/20384) 299.6 16215 (http://blockexplorer.com/b/16215) 294.8 15424 (http://blockexplorer.com/b/15424) 285.1 23433 (http://blockexplorer.com/b/23433) 277.6 21442 (http://blockexplorer.com/b/21442) 263.8 16286 (http://blockexplorer.com/b/16286) 263.8 21464 (http://blockexplorer.com/b/21464) 261.6 22945 (http://blockexplorer.com/b/22945) 260.1 22527 (http://blockexplorer.com/b/22527) 259.3 20325 (http://blockexplorer.com/b/20325) 248.2 21458 (http://blockexplorer.com/b/21458) 238.0 21374 (http://blockexplorer.com/b/21374) 234.9 19725 (http://blockexplorer.com/b/19725) 234.2 21418 (http://blockexplorer.com/b/21418) 232.2 21444 (http://blockexplorer.com/b/21444) 230.8 28705 (http://blockexplorer.com/b/28705) 226.3 21440 (http://blockexplorer.com/b/21440) 225.9 21348 (http://blockexplorer.com/b/21348) 225.1 1390 (http://blockexplorer.com/b/1390) 224.3 11964 (http://blockexplorer.com/b/11964) 223.8 169 (http://blockexplorer.com/b/169) 222.4 21462 (http://blockexplorer.com/b/21462) 220.2 21403 (http://blockexplorer.com/b/21403) 217.6 21331 (http://blockexplorer.com/b/21331) 217.3 20435 (http://blockexplorer.com/b/20435) 216.1 8231 (http://blockexplorer.com/b/8231) 214.7 20439 (http://blockexplorer.com/b/20439) 211.4 1398 (http://blockexplorer.com/b/1398) 211.2 32647 (http://blockexplorer.com/b/32647) 208.9 13889 (http://blockexplorer.com/b/13889) 208.9 20190 (http://blockexplorer.com/b/20190) 205.3 16271 (http://blockexplorer.com/b/16271) 202.3 20187 (http://blockexplorer.com/b/20187) 198.4 21361 (http://blockexplorer.com/b/21361) 196.8 13898 (http://blockexplorer.com/b/13898) 196.4 1917 (http://blockexplorer.com/b/1917) 196.1 21340 (http://blockexplorer.com/b/21340) 195.0 25788 (http://blockexplorer.com/b/25788) 194.1 26237 (http://blockexplorer.com/b/26237) 191.6 20405 (http://blockexplorer.com/b/20405) 190.9 8211 (http://blockexplorer.com/b/8211) 190.7 20357 (http://blockexplorer.com/b/20357) 190.7 1296 (http://blockexplorer.com/b/1296) 188.3 21385 (http://blockexplorer.com/b/21385) 188.2 11966 (http://blockexplorer.com/b/11966) 186.9 32629 (http://blockexplorer.com/b/32629) 186.3 15228 (http://blockexplorer.com/b/15228) 186.1 21393 (http://blockexplorer.com/b/21393) 179.2 21459 (http://blockexplorer.com/b/21459) 178.8 20344 (http://blockexplorer.com/b/20344) 175.6 8226 (http://blockexplorer.com/b/8226) 175.2 20008 (http://blockexplorer.com/b/20008) 174.9 163 (http://blockexplorer.com/b/163) 174.2 21428 (http://blockexplorer.com/b/21428) 172.7 20361 (http://blockexplorer.com/b/20361) 170.8 20343 (http://blockexplorer.com/b/20343) 170.4 18030 (http://blockexplorer.com/b/18030) 166.6 79 (http://blockexplorer.com/b/79) 165.9 20339 (http://blockexplorer.com/b/20339) 163.7 23425 (http://blockexplorer.com/b/23425) 163.0 21380 (http://blockexplorer.com/b/21380) 162.4 20436 (http://blockexplorer.com/b/20436) 161.9 21584 (http://blockexplorer.com/b/21584) 161.5 20418 (http://blockexplorer.com/b/20418) 160.8 21345 (http://blockexplorer.com/b/21345) 160.1 25740 (http://blockexplorer.com/b/25740) 158.1 20417 (http://blockexplorer.com/b/20417) 157.4 20351 (http://blockexplorer.com/b/20351) 157.3 21581 (http://blockexplorer.com/b/21581) 156.5 21443 (http://blockexplorer.com/b/21443) 155.1 1916 (http://blockexplorer.com/b/1916) 155.1 20308 (http://blockexplorer.com/b/20308) 155.0 28742 (http://blockexplorer.com/b/28742) 154.3 16588 (http://blockexplorer.com/b/16588) 154.0 21447 (http://blockexplorer.com/b/21447) 150.8 20427 (http://blockexplorer.com/b/20427) 150.4 23426 (http://blockexplorer.com/b/23426) 148.7 22950 (http://blockexplorer.com/b/22950) 147.5 13082 (http://blockexplorer.com/b/13082) 146.9 21441 (http://blockexplorer.com/b/21441) 146.5 21332 (http://blockexplorer.com/b/21332) 146.5 15331 (http://blockexplorer.com/b/15331) 146.3 20390 (http://blockexplorer.com/b/20390) 145.0 155290 (http://blockexplorer.com/b/155290) 144.8 1389 (http://blockexplorer.com/b/1389) 143.5 149098 (http://blockexplorer.com/b/149098) 141.0 20310 (http://blockexplorer.com/b/20310) 140.0 20356 (http://blockexplorer.com/b/20356) 137.2 70718 (http://blockexplorer.com/b/70718) 135.9 21423 (http://blockexplorer.com/b/21423) 134.5 70665 (http://blockexplorer.com/b/70665) 133.2 20304 (http://blockexplorer.com/b/20304) 132.8 15818 (http://blockexplorer.com/b/15818) 132.8 21369 (http://blockexplorer.com/b/21369) 132.2 20333 (http://blockexplorer.com/b/20333) 132.0 20376 (http://blockexplorer.com/b/20376) 129.3 20188 (http://blockexplorer.com/b/20188) 128.7 17149 (http://blockexplorer.com/b/17149) 127.9 21325 (http://blockexplorer.com/b/21325) 127.5 20438 (http://blockexplorer.com/b/20438) 126.2 20421 (http://blockexplorer.com/b/20421) 124.4 22018 (http://blockexplorer.com/b/22018) 123.0 32527 (http://blockexplorer.com/b/32527) 122.1 25132 (http://blockexplorer.com/b/25132) 122.0 15222 (http://blockexplorer.com/b/15222) 121.8 69515 (http://blockexplorer.com/b/69515) 121.4 20203 (http://blockexplorer.com/b/20203) 121.3 76594 (http://blockexplorer.com/b/76594) 121.2 26275 (http://blockexplorer.com/b/26275) 121.0 20191 (http://blockexplorer.com/b/20191) 120.9 26236 (http://blockexplorer.com/b/26236) 120.6 105909 (http://blockexplorer.com/b/105909) 120.5 25889 (http://blockexplorer.com/b/25889) 120.3 28702 (http://blockexplorer.com/b/28702) 120.2 23421 (http://blockexplorer.com/b/23421) 120.1 156113 (http://blockexplorer.com/b/156113) 119.6 154185 (http://blockexplorer.com/b/154185) 119.4 19951 (http://blockexplorer.com/b/19951) 117.8 20411 (http://blockexplorer.com/b/20411) 116.4 21586 (http://blockexplorer.com/b/21586) 116.2 21360 (http://blockexplorer.com/b/21360) 115.9 16590 (http://blockexplorer.com/b/16590) 115.6 24419 (http://blockexplorer.com/b/24419) 115.4 16565 (http://blockexplorer.com/b/16565) 115.3 20359 (http://blockexplorer.com/b/20359) 115.3 26843 (http://blockexplorer.com/b/26843) 114.6 24956 (http://blockexplorer.com/b/24956) 114.4 163966 (http://blockexplorer.com/b/163966) 114.0 21323 (http://blockexplorer.com/b/21323) 113.4 26873 (http://blockexplorer.com/b/26873) 113.2 24415 (http://blockexplorer.com/b/24415) 112.8 24494 (http://blockexplorer.com/b/24494) 112.7 21422 (http://blockexplorer.com/b/21422) 112.5 23430 (http://blockexplorer.com/b/23430) 112.3 207497 (http://blockexplorer.com/b/207497) 112.2 26249 (http://blockexplorer.com/b/26249) 112.1 26201 (http://blockexplorer.com/b/26201) 112.0 26190 (http://blockexplorer.com/b/26190) 111.6 87107 (http://blockexplorer.com/b/87107) 111.2 175720 (http://blockexplorer.com/b/175720) 110.5 26212 (http://blockexplorer.com/b/26212) 110.1 20327 (http://blockexplorer.com/b/20327) 109.6 21451 (http://blockexplorer.com/b/21451) 109.5 18253 (http://blockexplorer.com/b/18253) 109.4 28731 (http://blockexplorer.com/b/28731) 108.2 21334 (http://blockexplorer.com/b/21334) 108.0 26104 (http://blockexplorer.com/b/26104) 107.5 8223 (http://blockexplorer.com/b/8223) 107.0 205771 (http://blockexplorer.com/b/205771) 106.5 22158 (http://blockexplorer.com/b/22158) 106.3 21461 (http://blockexplorer.com/b/21461) 106.2 32632 (http://blockexplorer.com/b/32632) 105.9 13892 (http://blockexplorer.com/b/13892) 105.7 21433 (http://blockexplorer.com/b/21433) 105.7 25130 (http://blockexplorer.com/b/25130) 105.5 206669 (http://blockexplorer.com/b/206669) 105.4 28697 (http://blockexplorer.com/b/28697) 105.3 152996 (http://blockexplorer.com/b/152996) 104.7 204798 (http://blockexplorer.com/b/204798) 104.4 20347 (http://blockexplorer.com/b/20347) 104.3 18265 (http://blockexplorer.com/b/18265) 104.3 25033 (http://blockexplorer.com/b/25033) 104.3 20334 (http://blockexplorer.com/b/20334) 104.2 20381 (http://blockexplorer.com/b/20381) 103.8 21408 (http://blockexplorer.com/b/21408) 103.5 28771 (http://blockexplorer.com/b/28771) 103.5 8227 (http://blockexplorer.com/b/8227) 103.1 26260 (http://blockexplorer.com/b/26260) 102.9 21597 (http://blockexplorer.com/b/21597) 102.3 154346 (http://blockexplorer.com/b/154346) 102.2 28749 (http://blockexplorer.com/b/28749) 102.1 19977 (http://blockexplorer.com/b/19977) 102.0 25117 (http://blockexplorer.com/b/25117) 101.9 24263 (http://blockexplorer.com/b/24263) 101.8 21373 (http://blockexplorer.com/b/21373) 101.5 26126 (http://blockexplorer.com/b/26126) 101.3 15230 (http://blockexplorer.com/b/15230) 101.0 25147 (http://blockexplorer.com/b/25147) 100.2 26251 (http://blockexplorer.com/b/26251) 100.1 Deepceleron's razor #17: If something is worth saying to a noob, deepceleron has probably already said it. |
