I already heard how our atmosphere causes the light to twinkle theory.
Is there other theories?
Like stars twinkle because photons coming from stars travel in waves. so sometimes more intense than others, so thus, it is twinkling.
or like stars are nuclear explosions, so explosions are in waves…
i mean besides atmosphere, any other ideas?
Why would you need any other explanation when the original one is right? Ask any astronaut…
The Hubble space telescope says that stars in space do not twinkle.
http://curious.astro.cornell.edu/question.php?number=114
http://www.casciencectr.org/Exhibits/AirAndSpace/StarsAndTelescopes/Hubble.php
If the stars twinkled because of photon or nuclear waves, then they’d twinkle for the Hubble, too.
Unfortunately all those therories are pretty much ruled out by observation. Go above the atmosphere and stars no longer twinkle. As for the specific theries:
The wave length of a photon is incredibly short, measured in nanometers (billionths of a meter) for visible light. There are waves but they are too fast to see.
Stars are not so much like explosions as they are like a continuously burning torch. There are minor fluctuations such as the solar flares from our own sun but these are too minute to be seen with the naked eye.
No, it’s the atmosphere. That’s why Hubble Telescope photographs are so razor-sharp, because it’s out in the near-vacuum of space. The “waves” that light are made up of are too small to see on a macroscopic scale.
Or you could simply look at the sun (not directly of course 
). Does the sun twinkle?
There’s something most people miss when explaining twinkling.
If you look at a star with only one eye, it seems to twinkle less. If you cross your eyes so that you see two images of one star, you’ll notice the images don’t change brightness in sync. This is because of the slightly different paths of the light to each eye. This slight difference is a major factor in the perception of twinkling.
Plenty of stars shine irregularly, and the irregularity can sometimes be noticed on a scale of days, or sometimes hours.
The only star that would appear to twinkle above the atmosphere would probably be a pulsar like the one in the Crab Nebula - some pulsars blink at a rate easily observed by the human eye, if you were close enough to see it…
Some years ago I read that people who live in some parts of the Mideast, on average, tend to see stars twinkling more often and more intensely than do most other people.
This is because, in addition to atmospheric distortions, the appearance of twinkling can be brought on be flaws and irregularities in the lens of the eyes. These, in turn, can be brought on by fine damage to the cornea caused by sand and grit blowing in the wind.
Stars appear to twinkle when seen from the Earth because when the light of distant stars passes through the layers of Earth’s atmosphere, the temperature differences in the atmospheric layers create a shimmery effect, much in the same way that a hot road seems to shimmer in the summertime.
[source: Don’t Know Much About the Universe, by Kenneth C. Davis, 2001]