20170418, 05:51  #34 
"Rashid Naimi"
Oct 2015
Remote to Here/There
2×7×139 Posts 
Never seen that before
Somehow it does make sense I can't get a number higher than 24, no matter what number I add? https://www.timecalculator.net/hours...nowcalculator 
20170418, 16:37  #35  
"Curtis"
Feb 2005
Riverside, CA
3^{2}·499 Posts 
Quote:
Try doing some reading really. Your ignorance is on full display in this thread. 

20170418, 21:45  #36  
"Jeppe"
Jan 2016
Denmark
10100010_{2} Posts 
Quote:
But where does that exponent come from? Why do you think it is particularly interesting? /JeppeSN 

20170418, 23:35  #37 
"Forget I exist"
Jul 2009
Dumbassville
20B1_{16} Posts 

20170419, 05:46  #38 
Romulan Interpreter
Jun 2011
Thailand
2^{2}×7×11×29 Posts 
Subscribing.
What do some people are smoking these days? speed of light? trillions of operations per second? do you mean like... let's see... kilo..., mega..., giga... tera... Teraflops? GIMPS can do a hundred of them and it is not optic. And speed of light... what the hack is that? Are you talking about that thing which I can nowadays measure extremely accurate with a 500 dollars (cheap) oscilloscope, using one LED, two photoresistors, a mirror placed at 30 centimeters away, and a caliper?*** (the caliper is to measure the distance to the mirror ) That is, by far, not "instant". You need better then that... Neither quantum computers can help you here... I think some people do not realize the magnitude of the numbers involved. Like it was already explained, by Curtis and others, GIMPS, with its hundreds of teraflops, can only test numbers with 78 digits at the exponent*. And these numbers have a very special form that makes them extremely easy to test for primality. Talking about random picks, we are not even able to test a number with an exponent of 6 digits** for primality. With ALL our planetary resources put together. See for example the quest to "find the smallest prime number with exactly a million digits". Imagine that all atomic particles that we have a name for (electrons, protons, etc), from the visible universe come up to a number with 2 digits at the exponent (yes, they are less than 10^100 all together). Then imagine that we (humanity) were not able in over half of a century to prove (or disprove) the Catalan conjecture, i.e. test if \(2^{2^{127}}1\) is prime. Or, how somebody would call it, MMMMM2... It goes like that: \(M2\) is \(2^21=3\), prime; \(M3=MM2\) is \(2^{M2}1=2^31=7\) prime; \(M7=MM3=MMM2\) is \(2^{M3}1=2^71=127\) prime; \(M127=MM7=MMM3=MMMM2\) is \(2^{M7}1=2^{127}1=17014...5727\) (39 digits) prime; So, is the next one, \(MM127=2^{39\ digits\ exponent}1\) prime? Here we only have a 39 digits exponent, and the number has a very special form which is extremely easy to test for primality. And we (humanity) were not able to do it in a hundred years. And you want to test a number with over a thousand digits in exponent? C'mon... You will need either some "superhyperquantum" stuff, or a lot of new mathematical breakthrough...  (*) (no, not 89, that is when the base is 2, we are talking about base 10) (**) (again, no, a number with a million digits does not have an exponent of 7 digits, because 10^one million is a number with onemillionandone digits, i.e. 10 times bigger; 10^999999+x for a small x is the prime we are looking for) (***) the light travels ~300000 km in a second, which would make a 300000 meters in a millisecond, equivalent with 300 meters in a microsecond, or 30 centimeters in a nanosecond. For an average oscilloscope with 0.5 nanoseconds time base, i.e. 0.1 ns per screen division, you will see a measurable delay between the direct light pulse and the pulse reflected in the mirror. You still need to rotate the mirror, and a light guide to switch which light goes to one of the two photoresistors, and which to the other, and measure in both ways, to eliminate circuitrelated delays, and you need to do few measurements with the mirror at intermediary distances, for interpolation purposes, but at the end you will get an accuracy better than worldtop scientists and scientific labs were able to do 60 years ago. Last fiddled with by LaurV on 20170419 at 06:37 
20170419, 14:02  #39 
Feb 2017
Nowhere
3×19×67 Posts 
I agree. It is conceivable that this could be done by finding a polynomial f(x) in Z[x] with an algebraic factorization in Z[x], for which f(10) = 10^n + 7 and neither algebraic factor evaluates to 1 or 1. Alas, I don't know any obvious candidates.

20170419, 15:52  #40  
"Rashid Naimi"
Oct 2015
Remote to Here/There
11110011010_{2} Posts 
There has been a lot of nonsense uttered in this thread by the "expert" members and I do not really like to resort to authoritative sources.
However, here is a quote from an organization which probably knows a thing or two about computers and again very likely has a PHD or two on their payroll. Quote:
The implication here that somehow conventional computers can perform factoring of large integers where Optical computers cannot is baseless nonsense, also. I'm just saying. 

20170419, 16:06  #41  
Banned
"Luigi"
Aug 2002
Team Italia
2^{2}×1,193 Posts 
Quote:
11 years vs 1 hour means a speedup factor of 100,000x while your requested check needs a time that probably surpasses 200x the actual age of the universe. Even applying a reduction of a factor 100,000 using hypothetical "optical computers", we need more than 27,6 million years to perform it. Not to mention tat the Universe has not enough atoms to store the digit for the computation... Can you see now why everyone is laughing at you? Last fiddled with by ET_ on 20170419 at 16:08 

20170419, 16:13  #42  
Undefined
"The unspeakable one"
Jun 2006
My evil lair
16F7_{16} Posts 
Quote:


20170419, 16:35  #43 
"Dana Jacobsen"
Feb 2011
Bangkok, TH
1110001010_{2} Posts 
Surely quantum computing would be better than mere optical computing.
But more seriously, postquantum methods using lightplane superpositions seems like the right solution for this. There's some good research in phase modulation of the planes as well, which shows a lot of promise. 
20170419, 19:41  #44 
Bamboozled!
"πΊππ·π·π"
May 2003
Down not across
3^{2}×11×103 Posts 
Not everyone is laughing. There appears to be at least two groups who are not. Those who do not understand the mathematics behind estimates based on established technology, and those who are now giving serious thoughts as to how the mathematics or technology or both can be improved to the point where the stated task becomes feasible.
I'm in the second category but I very much doubt that I will be able to make useful progress in either field of endeavour. 
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