To date the series has made an unprecedented effort to use real science and concepts of spacetravel, having featured things like finding lime for the air-processing systems, correct use of aerobraking and gravity slingshots, as well as accurate use of terms like delta-v and thrust-to-weight ratio, and even newer phrases such as 'goldilocks zone' and 'comet-catcher' and correct suggestion of tidally locked planets around a Red Dwarf. It’s even handled depressurization well. They even seem to have given some detail to the ‘countdown clock’ in the background, to make it fit with the dialogue in scenes it appears in.
While ancient texts in stargate have long used a simple symbol-substitution code, they can’t generally be presumed to be valid in-universe information because it doesn’t fit with the dialogue. The actual spoken Ancient language is not English. I think this clock can be considered valid because of how accurately it fits the dialogue, with the clock showing a modern sexagesimal number system, except its last column that appears to show centiseconds.
Some time-skips appear to happen in 'Air' between even tense scenes, but whenever the clock is shown and someone speaks about it, the dialogue roughly matches the Ancient number shown. Therefore, it seems that the clock displays Hours:Minutes:Seconds:Centiseconds.
What's the relevance of this? In episode 5 'Light,' Destiny enters a Red Dwarf star to restore her power reserves, while part of the crew take her shuttle to a planet identified as (marginally) inhabitable to avoid the apparent death of this action. When Destiny leaves the star, her engines come on and she accellerates past this inhabitable planet. As she leaves the star, the countdown activates, indicating the ship intends to go to FTL again.
In these last two shots, they've caught up with the shuttle, which has passed the habitable planet, and are preparing to dock.
In a long-shot shortly before Destiny passes into the photosphere, she seems to cover her own length against the background of the photosphere below about seven times per second by my estimation (I've seen no scalings, and will wait to see if a clearer image of her scale appears, but I'm assuming she's no more than three or so kilometers long) therefore that this speed is less than twenty kilometers per second.
Of course, this information isn't much use unless we can tell how far away the planet is. Which, interestingly, we can. The Red Dwarf Gliese 581 has been studied in reality because of the possibility that some of its exoplanets may be habitable. Science Daily article
(Image from Science Daily article)
Now, using 0.13 AU as the basis of our stargate planet's minimum orbit (it's much likely further out, as due to its lack of greenhouse gases, it's very cold, but I'm aiming for a lower-limit figure here) because this is within the minimum orbit of both models, we can estimate its lower end accelleration.
d = ut+(0.5*a)t²
d = Distance Displacement = 0.13 AU = 19,447,723,190 meters =~ 19,000,000,000 m
u = Initial velocity =~ 20,000 m/s
t = Time taken = 2:59:57-06:39 = 2:53:18 =10,398 seconds =~ 10,000 sec
a = ?
Therefore, using the two-significant-figure figures:
19,000,000,000=20,000*10000+0.5a*100,000,000
Which simplifies to
19000000000 = 200000000 + 50000000a
Which solves to
a = 376 m/s/s low end
This is distinctly unimpressive, compared to other Stargate accelerations (though impressive enough given the realistic feel of this show so far) which are often thousands of Gs or more, but it's been suggested elsewhere that the ship intended to allow the shuttle to return, which makes sense given its seemingly AI (if not sapient) computer systems. I've also preferred low-end figures wherever possible for this number.
