lqg

The question:

A triple stellar system, showing a parallax of 0.01 arcsecond, is composed of a binary system,

with a distance between the two stars of 0.2 AU, and a third star, at a distance of 90 AU from

the binary. This system is observed in the optical (wavelength of 55000 Angstram) with a 1 meter telescope.

a. What is the distance of this system ?

b. How many stars will actually be seen when using a space-based telescope ?

c. How many stars will be seen when using a ground-based telescope, where the typical seeing

is 1 arcsecond ?

My attempt at solution

a. Well,[latex]\theta=0.01[arcseconds][/latex]

,[latex]D=\frac{\lambda}{\theta}[/latex] where lambda is the wavelenghth given in the brackets, and D is the distance of this stellar system from earth.

Don't know how to do b. and c., any advice?

Thanks in advance.

x'y' + xy = (xy' +x'y)'

x'z + xy = x'y'z + yz + xy

if (xy'+x'y)=1

then either xy'=1 x'y=0 or xy'=1 x'y=0 or xy'=xy'=1

1) xy'=1 x'y=0 then x=y'=1,

obviously x'y'=0 and xy=0 cause y=0 and x'=0. and (xy'+x'y)'=0 so we have an equality.

this way you prove for the other two cases and for the case where (xy'+x'y)=0 which is another three cases.

i might not be an astronomer but isn't the centre of our solar system is the sun itself? (regarding your first question).

according to my dictionary (an oxford one).

grime<=>dirt.

this is why i asked what i asked.

your last name is really 'grime'?

i'm not the expert, but that seems to me to be invalid.

yes that is what you typed now, not what you first wrote, and the tree's interpretation of either string of characters is strictly correct, it does equate to 1/1, because you have not braced off the subscripts. Sure, the correct meaning is clear if you stare at it ifor a while but you shouldn't have to do that.

sorry but i prefer to talk about the maths and not about the means to convey it via the internet.

i guess i should work it out by my own, as allways.

what i have typed is:

lim a_n+1-a_n/b_n+1-b_n=G

what about the first question, any tips there?

so far, youv'e encrypted it very well.

i don't have time to learn latex, if i had you bet your money i would post by latex.

here iv'e got another four questions, any pointers or hints would be appreciated.

in the attached doc file.

I have four questions about limits.doc

okay, forgot to look on monotonic series, thanks for the tip.

1) let a1,b1>0 b_n+1=sqrt(a_n*b_n) a_n+1=(a_n+b_n)/2

prove the existence of lim an as n->inf and lim bn as n->inf, and prove that they are equal?

i figure i need to use epsilon ofcourse but the problem is with N, what its quantity should be with regard to epsilon and the variables here.

thanks in advance.

i know of devcc++, but i think it will suffice.

i need to get on with progress and not think of the past, thank you.

no, it isn't.

but i appreciate the effort.

does someone know where may i download it from?

my question is still remains open, someone?

i appreciate the help if you can hand in some.

thanks.

can someone help me with the second one?

i hope that someone could help me with my q's here:

http://www.physicsforums.com/showthread.php?t=97985

anyone?

are there other tough newtonian & relativity mechanics books besides daniel kleppner's intro to mechanics and french's two volumes of mit series?

i mean with respect to the problems.

are the books of penrose's as rigorous as cartan's books?

bacause if they are, i think it's better to buy them bacause of the rigorous treatment with the physical examples as well.

The definitive classic is The Theory of Spinors by Cartan.

 

http://www.amazon.com/exec/obidos/tg/detail/-/0486640701/qid=1118280520/sr=1-1/ref=sr_1_1/102-4889131-5900916?v=glance&s=books

tom, what about roger penrose's two volumes about spinors and space time, isnt there also a rigorous treat to spinors besdies the physical one?

They most definitely are not.

 

However' date=' 0^0 should be strictly speaking undefined, as the proof by notation that works for x^0 where x =! 0 doesn't hold if x = 0.[/quote']

why not?

 

0/0 is like 0^a/0^a=0^(a-a)=0^0

 

now why this is wrong?

 

 

wait a minute perhaps it's not the same because zero can be represented in infinite state of powers:

0^a/0^2a=0^(a-2a)

0^0 is undefined. like division by 0 is undefined

because they are the same:

0/0=0^0

but what is the condition of e so that it loses mga of energy each bounce

because the collision with the stairs isnt absolutely elastic nor is it plastic the one that lasts is non elastic in this case e is between 0 and 1: 0<e<1