06 February 2009

Maths, Physics, Chemistry doubts

  1. There was a fire-emergency drill yesterday in my office and now I have a doubt, "What is the coldest possible flame? And how much heat does it produce and its temperature?" The flame froma welding equipment is definitely hotter than the flame from candle, So how to have a 1 square inch of visible flame with least amount of energy released. Will it be the material that can be ignited at a lowest temperature? hmm may be the material the material that would continue to burn in the lowest temperature... so what it is? How much is the temp?

  2. My roommate plays with Rubik cube a lot. And I saw an application that solves the rubik cube for your inputs. My question is what is the minimum no of faces required as input out of the total (9 x 6) 54 faces? Does the number change based on which faces?

  3. What is the largest number possible with two 9s? A question on a poster in my office.
  • 99
  • 9^9 (But isnt using operator allowed? But exponent can be written without operators as superscript i.e., 99)
  • 9!9! (But if you allow unary operators, I do not even need a second 9, i.e., ((9!)!)... == 9!!!!!!!!!!!!!
  • I think 99 could be the answer without any opertators, but I would say it is a number with base-googol or may be base-infinity ;) [In base-infinity 99 would mean 9*infinity+9]
Please tell me whatever you think could be the answer.


Nikanth Karthikesan said...

autoignition temperature or kindling point, Flame point, Fire point, Laminar flame, diffusion flame... quiet complex and interesting

karthik said...

I think there is not one largest number using two 9's but many.


Nikanth Karthikesan said...


There can only be 1 _largest_ number. If there are 2 largest numbers, the larger of the two is the only largest number.

karthik said...

yes right. the "largest" part was wrong. I think then the question becomes equivalent to "what is the largest number?" for which there is no answer:-)

probably irrelevant or nonsense...sometimes people do mention superlative degree in plural. "best minds of europe worked there.."

Nikanth Karthikesan said...

Even with your interpretation, the question is still the same.. answer could be different...

And with your interpretation of the question, i.e., "what is the largest number?", it still has an answer.

The question was suppose to mean using _only_ 2 9's and nothing else

karthik said...

"what is the largest number" have an answer? infinity?