Google Earth In 4D

Rockgod writes to tell us about Google Earth's latest expansion. From the article: "Google skipped right past the third dimension and landed directly in the fourth (time) by offering historical maps on Google Earth. Now you can travel back in time — for example, I am looking at the globe of 1790. Don't expect detailed high resolution photography from days gone by, but it's still interesting to see old maps overlaid on the satellite imagery of today." I suppose a link to Earth4 would have been good.

Comments

Shows how old those damn satellites must be :-)

[cheros]

It's going to be interesting how the usual historical inaccuracies are dealt with, including moving river deltas and/or later removal of objects such as the British Echelon site, Menwith Hill :-)

well

[thejrwr]

wow, the dev team for google sure must be having fun, i mean come on, when you PAID to make new features when ever you want, no wonder working for google is a prized job (I'm only 10, if my grammer is bad, well oh well)

Re:today's maps will be historical

[c6gunner]

Won't happen. While there have been numerous hiccups on our way through history, human progression hasn't ever seen any massive reversion. Even if the US and most of the western world gets wiped out by Islamic savagery, their society would become more liberal eventualy, and in the meantime you'd have countries like China to pick up the slack. I know it's not much comfort to you, but even if our society dies out, many of our ideals and most of our technological accomplishments will live on in other nations.

Re:Pangea?

[Ingolfke]

Not all intelligent design people believe that that Earth is young. The basic premise of Intelligent Design is that the universe is too complex for it to just have happened... that doesn't speak to who or how it was created or how long it happened to take.

Either way though... they should probably have a checkbox for users to select which theory they believe in (young earth or old) and then if they select "young" they can get a nice error message.

Re:If it's not spatial it's not 4D

[chrisb33]

While I agree that 4D is being used more as a buzzword than anything else, time is in fact considered as a fourth dimension in physics. You can look at special relativity if you want to understand how time and the spatial dimensions can be "interchanged":

In the geometry of special relativity, a fourth dimension, time, is added, with units of c, so that the equation for the differential of distance becomes:
ds^2 = dx_1^2 + dx_2^2 + dx_3^2 - c^2 dt^2
If we wished to make the time coordinate look like the space coordinates, we could treat time as imaginary: x4 = ict . In this case the above equation becomes symmetric:
ds^2 = dx_1^2 + dx_2^2 + dx_3^2 + dx_4^2

Special relativity goes on to say that you can exchange time and spatial coordinates using the Lorentz transform, which preserves the length of the 4D position vector.

If the special relativity example seems too bizarre, just think in terms of locating an event. If I wanted you to come to my party, I would tell you 4 pieces of info - the x,y,z, and t coordinates of the party. Each of these degrees of freedom is a dimension.


What's much more annoying to me are the "4D" shows that are 3D plus some user interaction (getting water shot at you or something like this). That is a misuse of "4D".