 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Am 06.10.2015 um 01:05 schrieb David Given:
> And here's another one (yeah, yeah, I know you're sick of these by now);
No - actually, not at all.
> My procedural noise needs a *lot* of work,
I think the terrain looks gorgeous.
> and there's something very
> odd about the sea texture. As does the surface texture, for that matter.
Waves pattern?
Moiree effect, I'd guess.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
What exactly is causing those anomalies in Earth's gravity that cause
the ocean surface to be lower at some regions and higher at some other
regions (or similar effects on the dust on the moon)?
On 03.10.2015 06:28, Thomas de Groot wrote:
> On 3-10-2015 12:57, Stephen wrote:
>> On 10/3/2015 10:16 AM, clipka wrote:
>>>> This is also true for our own Earth in fact. Local variations of the
>>>> >gravitational field make the oceans' surface vary by several (tens of)
>>>> >meters, sometimes over quite short distances.
>
>>> I did know/that/ - but tens of meters is still quite a shot from a
>>> kilometre.
>>>
>>
>> It certainly is. Mind boggling actually.
>
> That is indeed true. Tells something about the composition of the Moon's
> interior.
>
>>
>>> But did you also know that fast-flowing rivers are higher in the middle
>>> than at the banks - sometimes by as much as half a meter?
>>>
>>
>> Not the value but I am sure you can see it, on some rivers.
>>
>>
>
> Ah yes. I don't remember exactly why that is: something to do with the
> drag along the border?
>
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 16-12-2015 13:01, Sven Littkowski wrote:
> What exactly is causing those anomalies in Earth's gravity that cause
> the ocean surface to be lower at some regions and higher at some other
> regions (or similar effects on the dust on the moon)?
>
That is because the Earth's density is not constant and varies quite a
lot. A mountain (and its roots) is a massive object for instance that
deviates gravity. A pendulum is thus attracted towards the mountain when
you are standing at its base. Very, very slightly of course. Those
differences describe the /geoid/, the "true" shape of the Earth. See for
instance this:
https://www.quora.com/If-you-were-to-measure-gravity-on-the-surface-of-the-ocean-over-the-deepest-place-in-the-world-would-it-be-9-81-ms-s2-Or-would-water-have-less-gravitational-pull-than-a-mass-of-rock
--
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 16-12-2015 13:01, Sven Littkowski wrote:
> What exactly is causing those anomalies in Earth's gravity that cause
> the ocean surface to be lower at some regions and higher at some other
> regions (or similar effects on the dust on the moon)?
>
That is because the Earth's density is not constant and varies quite a
lot. A mountain (and its roots) is a massive object for instance that
deviates gravity. A pendulum is thus attracted towards the mountain when
you are standing at its base. Very, very slightly of course. Those
differences describe the /geoid/, the "true" shape of the Earth. See for
instance this:
https://www.quora.com/If-you-were-to-measure-gravity-on-the-surface-of-the-ocean-over-the-deepest-place-in-the-world-would-it-be-9-81-ms-s2-Or-would-water-have-less-gravitational-pull-than-a-mass-of-rock
or:
https://en.wikipedia.org/wiki/Gravity_of_Earth
--
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
...and I just remembered the term mascon:
https://en.wikipedia.org/wiki/Mass_concentration_%28astronomy%29
--
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Sven Littkowski <jam### [at] yahoo com> wrote:
> What exactly is causing those anomalies in Earth's gravity that cause
> the ocean surface to be lower at some regions and higher at some other
> regions (or similar effects on the dust on the moon)?
Differences in material composition, with differences in density.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Thanks to both of you, Thomas and Clipka. Yes, I assumed it is the
amount of matter, like mountains or valley which have the one or another
influence. But I wonder, if also the TYPE OF MATTER has influence, too.
Example: I wonder, if a iron sphere of 10,000 km diameter produces the
same gravity as a styrofoam sphere of 10,000 km diameter. I believe, not
only the amount of matter matters, but the type of matter matters, too.
Am I right?
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Le 15-12-16 17:59, Sven Littkowski a écrit :
> Thanks to both of you, Thomas and Clipka. Yes, I assumed it is the
> amount of matter, like mountains or valley which have the one or another
> influence. But I wonder, if also the TYPE OF MATTER has influence, too.
> Example: I wonder, if a iron sphere of 10,000 km diameter produces the
> same gravity as a styrofoam sphere of 10,000 km diameter. I believe, not
> only the amount of matter matters, but the type of matter matters, too.
> Am I right?
>
As the sphere of iron is probably about 5 times as dense as your
styrofoam, even after it have collapsed from it's own mass a few Km
down, the iron sphere will have a much greater gravity than the styrene
one. It all depends on the average density of the planete, whitch
dictate it's total mass, whitch, with the radius, determine the surface
gravity.
A planet made entirely from water would be about 5 times larger than the
Earth to have about the same surface gravity, and an escape velocity
about 5 times higher.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Thanks for the answer, Alan. I think, the more an element is located at
the end of the elements table (all known elements), the more gravity it
is producing. I asked those previous questions, because I am working
there on some idea, but can't really speak yet about it.
Great subject, great group of people here. Big thanks to everyone!
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Sven Littkowski <jam### [at] yahoocom> wrote:
> Thanks for the answer, Alan. I think, the more an element is located at
> the end of the elements table (all known elements), the more gravity it
> is producing.
That's not how a scientist would put it, but yes -- the periodic table of
elements is sorted by the number of protons per atom, which coincides with a
sorting by mass per atom, and there is a general trend that "heavier" elements
(those with a higher mass per atom) are also denser (i.e. have higher ratio of
mass per atom vs. volume occupied per atom).
This is just a trend though; for instance, copper, at position 29 in the table
has a density of 8.92 g/cm^3, whereas radium, at position 88 in the table, has a
density of just 5 g/cm^3.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
