# Sensei

Senior Members

6331

14

1. ## Solve this if you can !

But you never showed it in spoiler.. Or I am missing something? Where? In your head? It doesn't count. I have already showed you algorithm in post #24, when you asked.
2. ## How close is too close?

2 mln k of what? Meters? Kilometers? Astronomic Unit? C?
3. ## Solve this if you can !

tar, simply write [spoiler ] ..... [/spoiler ]
4. ## Solve this if you can !

Binary-search is basically divide to half, and compare. http://en.wikipedia.org/wiki/Binary_search_algorithm Suppose so we have array of strings, and want to find correct one matching input (or whether it exists), you have length of array, so divide length by 2, and compare input string with entry that has index=length/2 if it's lower then you know that string you're searching for has index < length/2 otherwise it has index > length/2. Repeat it in loop, dividing remaining length/2 each time, and appropriately add/subtract center position, and you have ultra fast algorithm find
5. ## Why (and how) do foods stick to a pan?

That's why typical western housewife/househusband is using Teflon pan. http://en.wikipedia.org/wiki/Polytetrafluoroethylene
6. ## Solve this if you can !

Almost like on roulette in casino (1 from 37). Once I saw that guy put maximum money (we have limits) on single number (and surrounding it pairs, corners etc. if you're not familiar with roulette hard to explain quickly), then croupier hit exactly that number, and guy earned ~40,000. And he leaved coins on the same number. Croupier hit it again, same number in a row! 80,000 earned in 3 minutes or so.
7. ## Logic and god

Job is good thing. Thinking is even better thing. But job where you're thinking is the best thing*.. *) thinking about things good for human kind, like science.. So banker etc. kind of people, thinking how to screw up other people, excluded.
8. ## Solve this if you can !

I didn't read other solutions, so maybe somebody already used this technique: It's slightly modified binary-search algorithm. At best it'll find ball in 3 weighting (7.7%) At worst it'll find ball in 6 weighting (46.15%), and 5 weighting (46.15% cases).
9. ## Logic and god

When people don't have other jobs to do, they are starting thinking..
10. ## Port forwarding

Yet another thing that has absolutely nothing to do with port forwarding.. Port forwarding happens at very low TCP/IP level. While DNS looking up happens inside of gethostbyname() function. You don't need to have any human readable DNS domain name, for port forwarding to work..
11. ## Three German students surprise a homeless guy

When I am returning from shop, and meeting "garbage-diver", I am giving them bun. One of them asked me whether it's for birds (he though it's one day, not fresh anymore). I answered it's for you for breakfast. He touched it, and "ohhh, it's still hot"... Other time, old women wanted from me "money for bread". I went to shop and bought bread, and gave her. She was upset! And started screaming on me, that she wanted money, not bread..
12. ## Three German students surprise a homeless guy

Three German students surprise a homeless guy See Buy bread to some homeless today..
13. ## Give your Opinion !

Actually I have made such experiment in reality. Put magnets (Neodymium) inside of test tube (so they couldn't rotate), NS-SN (magnets levitated on another without touching anything). And placed everything on weighting scale. I will later make photo, if I find some unbroken test tube..

Emission of photons by hot material.
15. ## How far can light go?

Energy must be conserved, so photon goes until being absorbed by some other particle. See inverse-square law in context of the Sun. http://en.wikipedia.org/wiki/Inverse-square_law Sun emits 3.86*1026 J energy per second. At 1 AMU we're receiving 1367 W/m2 At 1000 AMU we would be receiving 0.001367 W/m2 At 1000000 AMU we would be receiving 1.367*10-9 W/m2 Go on, and on, and we will reach situation with just one photon per unit of area at some large distance..
16. ## Can more ships and boats and submarines cause the sea level to rise?

Why don't you use math to calculate it? Volume = Area * Average Height so Volume of all seas = area of all seas * average depth Then mass of all seas = volume * density Find size of submarine (almost capsule figure) Pretty easy, as it's volume of tube + sphere. Then make graph in Excel/SpreadSheet with y axis increase of height, and x axis quantity of submarines and show us your results..
17. ## How close is too close?

Orbit would be unstable. One or both planets would be ejected from star system, sooner or later. Distance is not the only parameter. It's important what is their mass. They can be also have different angular momentum, and different ecliptic. There is couple star system simulators on the net. See this one for example https://phet.colorado.edu/sims/my-solar-system/my-solar-system_en.html Pick up preset Slingshot. Planet is ejected from such system.
18. ## Density Word Problem

Right, there is 1.3% difference between these two values. Either $\frac{p_0}{p_1}=\frac{101325}{100000}=1.01325 = 1.3\% difference$ and $\frac{m_0}{m_1}=\frac{1.2922}{1.2754}=1.01317 = 1.3\% difference$ So I don't know what for somebody is giving me negative??
19. ## Density Word Problem

I used this website as reference: http://en.wikipedia.org/wiki/Density_of_air And it has 1.2922 g/L at 0 C, 101.325 kPa In any case, it's 15-30% higher than OP value 1 g/L.
20. ## Density Word Problem

Cubic ton is different unit than the rest mentioned http://en.wikipedia.org/wiki/Cubic_ton g/mL is simply equal to g/cm3 Air has approximately 1.29 g/L at STP not 1 g/L So you should start from unification of units.
21. ## Port forwarding

By "host file" do you mean host file mentioned by wikipedia? http://en.wikipedia.org/wiki/Hosts_%28file%29
22. ## Port forwarding

No. Host file is just private DNS lookup table. Port forwarding you set in Firewall advanced controls. For instance this guy is setting up port forwarding without using any router in Windows XP:
23. ## Port forwarding

Any Windows computer (not to mention Unix/Linux) can be router. WinXP is fine for this task. It will just have to be running all the time. You will need two Ethernet cards plugged. Currently almost every machine has 1 built-in Ethernet, so you just need to buy one PCI card (\$10 or so). Connect modem to 1st Ethernet card, and 2nd Ethernet card to switch to spread net to other machines. I have been using it this way for 12+ years. Do you know where in Windows set port forwarding.. ?
24. ## Port forwarding

NoIP doesn't copy any single file.... Software installed to update, is using gethostbyname() function (to look up www.noip.com), which is calling DNS, like any other Internet application. Then logging in service, with login & password, IP is already in TCP/IP packet data. ps. Stop talking about things you have no idea about.. The whole point of dynamic IP updating DNS service is to have DNS record to point to right IP address (no matter if it's static or dynamic). The whole point of forwarding IP & port is to have service=daemon at private IP host. Thanks to forwarding
25. ## Port forwarding

There are dynamic updating IP services like f.e. NoIP. I have been using it for several years when I had ISP that was giving me dynamic IP, not static IP. User has to install app that's connecting to service. And whenever ISP is changing our IP that software is sending information to service about change and new IP address. And DNS is updated to always point to our dynamic IP address. It costs almost nothing (as much computer-server will consume energy for 24h/7d running). It's completely unrelated subject from OP question.
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