[csswg-drafts] [css-egg] Note about astronomical units doesn't match physical reality

SelenIT has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-egg] Note about astronomical units doesn't match physical reality ==
In the 'Astronomical units' section, the parsec unit (`pc`) is defined as the absolute unit equal to 3.086E18 `cm`, and there is the following note:
> This specification does not address relativistic effects of scrolling or animations and transitions at (or beyond) the speed of light.

However, all browsers I tested don't preserve this proportion. Instead, they render 1 parsec as something about 0.38 to 0.4 `cm` (see JSfiddle example: https://jsfiddle.net/oxqoqkxh/1/).

The only explanation to this phenomenon I can come up with is that, according to the Special Relativity theory, "traditional" units and astronomical units are measured in the different reference frames: the Lorentz factor of the reference frame where "traditional" absolute units are measured is extremely lower that that of the reference frame used for astronomical units. While the Lorentz factor of the former is usually below 2 (e.g., on iPhone and iPad mini `1in` at 100% scale is about 0.59 physical inches), the latter is several orders of magnitude higher. And the fact that in all browsers the proportion of the "static" centimeter and the "Lorentz transformed" parsec is nearly the same, I suppose that the speed rate of these two reference frames must be a fundamental constant.

I haven't calculated which speed does the Lorentz factor used for astronomical units correspond, but given that the CSS EGG spec has many connection to CERN, I guess that this speed has something to do with the LHC (maybe it's the speed of the proton beam on its maximum energy?).

Technically, this speed is not "the speed of light or beyond", so I can't say that the Note in the spec is _absolutely_ wrong. But because it's 1) very close to it and 2) its Lorentz factor is _in constant proportion_ to that of other physical units in all browsers, I believe this fact is also worth noting in the spec!

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/2491 using your GitHub account

Received on Sunday, 1 April 2018 10:41:56 UTC