Doctor Who 9x10 - Heaven Sent (spoilers!)

[Batman]

The sky will look different if you're on the wrong damned hemisphere but I'm supposed to believe the Doctor will know what the sky whill look like from any point within a 2 lightyear sphere when he doesn't even know in which direction he's looking. WITH access to the TARDIS? Probably effortlessly. By just looking at the sky?

[Bedlam]

Something to question would be the skulls in the water, they're all the doctors, presumably and they don't get reset each time. After 2 billion years how many of those were there? Say each cycle is a month (might be longer might be shorter) so 24 billion skulls by the end, how much space do they take up? Would they fill the entire sea by then?

[EnterpriseSovereign]

I recall the doctor mentioning that it's the rooms that get reset- clearly that cannot extend to the exterior of the building. When we see the whole thing from a distance it's portrayed as an island in the middle of a vast ocean. Of course, if all the skulls fall in the same spot we have to assume that ocean currents are what's responsible for them ending up as they do, else they'd form a massive pile.

I too did wonder about the wall, I just rewatched it to check the dialog- the Doctor said it was "Azbantium. 400 times harder than diamond". Compared to that, eroding the rocks of the Grand Canyon is childs play. Unless that wall was really made of many small pieces of the stuff instead of one contiguous mass, the doctor won't even put a scratch in it- no matter how many times he punches.

EDIT: unless I'm very much mistaken, in the sky you can clearly see the constellation of Orion. I don't know enough about the constituent stars to say how they would move over time.

[Broomstick]

The sky will look different if you're on the wrong damned hemisphere but I'm supposed to believe the Doctor will know what the sky whill look like from any point within a 2 lightyear sphere when he doesn't even know in which direction he's looking. WITH access to the TARDIS? Probably effortlessly. By just looking at the sky?

Mere humans can learn to recognize the different stars of the different hemispheres on earth, in fact, it used to be a key part of global navigation. This is not the impossible feat you seem to think it is.

[SpottedKitty]

Mere humans can learn to recognize the different stars of the different hemispheres on earth, in fact, it used to be a key part of global navigation. This is not the impossible feat you seem to think it is.

A supplement to this that just occurred to me — in past episodes, we've seen the Doctor able to pay such close attention to something that he can notice tiny movements a normal human wouldn't. Would just a few minutes observation be long enough for him to see which way round the sky is rotating, and so (if he's still assuming the teleport was fairly short on a galactic scale) very roughly where he is, if he's still on Earth?

Note, this isn't quite as ridiculous as it sounds; I used to use a small spyglass for astronomy, and if I fixed it to a good solid mounting, I could see the Moon slowly but steadily move across the field of view.

[Prometheus Unbound]

Mere humans can learn to recognize the different stars of the different hemispheres on earth, in fact, it used to be a key part of global navigation. This is not the impossible feat you seem to think it is.

A supplement to this that just occurred to me — in past episodes, we've seen the Doctor able to pay such close attention to something that he can notice tiny movements a normal human wouldn't. Would just a few minutes observation be long enough for him to see which way round the sky is rotating, and so (if he's still assuming the teleport was fairly short on a galactic scale) very roughly where he is, if he's still on Earth?

Note, this isn't quite as ridiculous as it sounds; I used to use a small spyglass for astronomy, and if I fixed it to a good solid mounting, I could see the Moon slowly but steadily move across the field of view.

try it with a full blown telescope... mine could do 400x zoom (I think) but didnt have the hookup to the laptop to control the motion - if I tried to look at the moon at maximum zoom, if I spotted something neat and tried to show someone, by the time they got to the telescope and looked it was out of frame ><

[Eternal_Freedom]

The sky will look different if you're on the wrong damned hemisphere but I'm supposed to believe the Doctor will know what the sky whill look like from any point within a 2 lightyear sphere when he doesn't even know in which direction he's looking. WITH access to the TARDIS? Probably effortlessly. By just looking at the sky?

Actually from what I can recall one light year will make virtually no difference to the constellations as seen from Earth. Even if you're around Alpha Centauri, the only difference will be Alpha Centauri itself isn't in Centaurus (obviously) and Sol will appear as a bright yellow star in Cassiopeia. That's the only difference. One light-year from Earth? (Note, he said he can't be more than a light-year, so that's an upper bound) You'd be hard-pressed to notice any differences unless you really knew the night sky.

Yes, the sky will look different if you're in "the wrong damn hemisphere." Different as in, "Huh, Orion is upside down, I must be south of the equator." It really isn't as bad as you seem to think. But hey, Batman spends his time in a cave so what do you know about the night sky?

As for why he can recognise Earth's constellations so easily? Well it has been his favourite planet for the best part of two thousand years, and he was exiled here for a while in his third incarnation. With no TARDIS to fly around in, he needed something to keep him busy.

[SpottedKitty]

Even if you're around Alpha Centauri, the only difference will be Alpha Centauri itself isn't in Centaurus (obviously) and Sol will appear as a bright yellow star in Cassiopeia.

Not really all that bright; the Sun's Absolute Magnitude (at a standard distance of 10 parsecs) is only about +4 which is going to be quite dim unless seeing conditions are very good. Remember, +6 is about the limit of naked-eye visibility. Even if you come in to about one light year, the Sun would still be far from the brightest visible star.

[Eternal_Freedom]

Oh certainly it wouldn't be the brightest, that'll still be Sirius, but some quick number crunching remembered from my university days says the Sun would be magnitude 0.4 or so from Alpha Centauri, and it'd make the W of Cassiopeia a zig-zag. So it'll be big, bright and noticeable as a difference.

The same number crunching tells me that at one light year the Sun should be about -8 magnitude, so it would still be the brightest visible star.

[SpottedKitty]

Ah, OK, I must have dropped a decimal point or two on the floor somewhere.

[Captain Seafort]

Except for why the pocket universe in the confession dial would have Earth constellations, that was never explained.

As E_F said, he has had a particular interest in the place for quite a while, and dumping him on our particular rock has been part of his punishment by the Time Lords before.

[Batman]

Something to question would be the skulls in the water, they're all the doctors, presumably and they don't get reset each time. After 2 billion years how many of those were there? Say each cycle is a month (might be longer might be shorter) so 24 billion skulls by the end, how much space do they take up? Would they fill the entire sea by then?

Assuming your month, 24 billion skulls assuming a volume of a cubic foot each (a good bit larger than the average human skull but close enough) gives us 64.8 cubic kilometres worth of skulls so at least for the immediate surroundings of the tower, that would work.

[NecronLord]

Something to question would be the skulls in the water, they're all the doctors, presumably and they don't get reset each time. After 2 billion years how many of those were there? Say each cycle is a month (might be longer might be shorter) so 24 billion skulls by the end, how much space do they take up? Would they fill the entire sea by then?

I was actually waiting for a shot of the castle amidst an enormous pile of skulls, but someone probably pointed out that eventually the Doctor would start going 'splat' on them.

[SpottedKitty]

I was actually waiting for a shot of the castle amidst an enormous pile of skulls, but someone probably pointed out that eventually the Doctor would start going 'splat' on them.

Heh, that's exactly what I was thinking halfway through the multiple repeats at the end. After all, we don't know how deep the water was to begin with.

Although, considering the whole thing was a created scenario inside the Confession Dial, maybe the pile never did get any deeper.

[jwl]

Of course, over two billion years the skulls would break down into limestone or something, which would take up quite a bit less volume.

Also, did anyone else notice that two skulls rise to the surface outside the tower when the doctor is standing outside and the tower moves around. It looks like something might be moving the skulls from the inside of the tower to the outside, I don't know how that works though.

[Broomstick]

I too did wonder about the wall, I just rewatched it to check the dialog- the Doctor said it was "Azbantium. 400 times harder than diamond". Compared to that, eroding the rocks of the Grand Canyon is childs play. Unless that wall was really made of many small pieces of the stuff instead of one contiguous mass, the doctor won't even put a scratch in it- no matter how many times he punches.

I recently re-watched that episode - the wall of azbantium is NOT one crystal, it's clearly a disordered jumble of crystals smooshed together and formed into a wall, you can see fracture lines and inclusions in it. Yes, it's hard. It's harder than a similar wall formed of diamond crystals smooshed together, but not being all one crystal it should be possible to get through it. Eventually.

[madd0ct0r]

Of course, over two billion years the skulls would break down into limestone or something, which would take up quite a bit less volume.

Also, did anyone else notice that two skulls rise to the surface outside the tower when the doctor is standing outside and the tower moves around. It looks like something might be moving the skulls from the inside of the tower to the outside, I don't know how that works though.

Skulls are light and round and smooth. Pouring sand onto a table gets you a 45degree cone that cannot get taller without building its base first. Skulls in water would be almost flat by comparison. The stack would spread very very far without the pile getting much taller.

[EnterpriseSovereign]

I too did wonder about the wall, I just rewatched it to check the dialog- the Doctor said it was "Azbantium. 400 times harder than diamond". Compared to that, eroding the rocks of the Grand Canyon is childs play. Unless that wall was really made of many small pieces of the stuff instead of one contiguous mass, the doctor won't even put a scratch in it- no matter how many times he punches.

I recently re-watched that episode - the wall of azbantium is NOT one crystal, it's clearly a disordered jumble of crystals smooshed together and formed into a wall, you can see fracture lines and inclusions in it. Yes, it's hard. It's harder than a similar wall formed of diamond crystals smooshed together, but not being all one crystal it should be possible to get through it. Eventually.

That's what I thought, and there's plenty of unknowns- most noticeably the density of the Azbantium, both at the atomic/molecular level and the size of and how the crystals are packed together. Looking back at it, it would be more powerful if perhaps if the Doctor had found a pickaxe/sledgehammer- though didn't he have to use a shovel to dig that grave? I could imagine him using that to bash at the wall.

Skulls are light and round and smooth. Pouring sand onto a table gets you a 45degree cone that cannot get taller without building its base first. Skulls in water would be almost flat by comparison. The stack would spread very very far without the pile getting much taller.

The only comparable scene I can think of is in ROTK with that skull avalanche- however without knowing Time Lord bone density we cannot determine the mass of each skull.