Which Is Higher? Atlantic Ocean Or Pacific Ocean?

[KrazyHorse]

The pressure difference is due to gravity drop.

[KrazyHorse]

let d be the density of water, h be the difference in height, g be the acceleration due to gravity and P be the pressure difference. with no drag due to turbulence or friction with walls,

P = ghd

[TCO]

Yeah...I already got that, you are trying to think about this like dropping balls off of a window.

Yes the gravity causes the pressure head difference. but that does not dictate velocity limiters on the fluid as it moves in a pipe between the two tanks (oceans). The acceleration happens at the mouth of the pipe and in the "near-mouth" region. Water is incompressible so the speed as it moves within the pipe is constant. (if area of pipe is constant). So why think about graviational acceleration anyway? I mean if this were in space and you had the same pressure difference, for instance? Surely you agree that it is the head loss (pressure drop from friction) that limits flow rate?

I do need to think about open channel though.

[DanS]

I like it better than the laser launching system which requires a beam that stays on target (and does not spread) over 1000 bounces and planetary distances or whatever...)

Actually, I was going to make a thread about this, but I'll ask here.

Assuming a high power solid state laser (1 MW - 10 MW range), what would the diameter of the beam be at interplanetary distances? Assume a power satellite in GEO (i.e., no atmospheric impact).

[TCO]

I think the 50% power contained area would expand to miles wide (this is using FHA analysis).

[DanS]

A power collector miles wide? Wow. Possible using short-term conceivable technology, but not at high efficiency.

Thanks for order of magnitude calculation. Very useful in comparing with space nuclear reactors.

I guess we would seek to combine multiple lasers.

[BlackCat]

Besides the rotational force there are also gravitational forces that give differences.

http://www.npagroup.co.uk/imagery/rs_intro/global.htm

The strength of the earth's gravitational field at its surface varies according to the ocean depth and the density of local rocks. Dense rocks and shallow ocean, such as along the Mid-Atlantic Ridge (shown in red in the image), creates a higher local gravitational force which causes a greater 'pull' on the surrounding ocean water and thus results in a higher local sea level. Satellites orbiting in very precisely determined orbits are able to measure the sea level to an accuracy of a few centimetres by using Radar Altimeters which transmit microwave pulses and time their return. This measurement of the results of gravitational variations gives us a better picture and understanding of the geological structure of the sea floor. From the time variation of the returned signal Altimeters can also build up a model of ocean wave heights, which relate to surface wind speed. Radar Altimeters therefore also provide valuable data useful in meteorological forecasting.

Apparently it isn't only at "left side" of continents there are buildups. Midatlantic is at a higher level than at the European and American coast.

[Lul Thyme]

Which all goes to show, there are many small scale phenomenon going on, just like with tides in general, which depend a lot on local geography...
If we are talking about a couple meters, the general "
sea level is sea level" is not true...

[KrazyHorse]

Originally posted by BlackCat
Besides the rotational force there are also gravitational forces that give differences.

Again, this does not make a difference as far as the difference in "height" is concerned.

Variations in local gravity might make the surface of the ocean further away from the earth's centre at some points rather than others, but they will maintain the surface of the ocean as an equipotential. You can't slide down the tidal bulge, or the equatorial bulge or the variations in local gravity. Without dynamic forces (winds, currents, vibrations, etc.) the surface of the earth would be exactly an equipotential.

[KrazyHorse]

I just spent the last 13 hours of my life doing this

http://www.pha.jhu.edu/~mmcevoy/hw7.pdf

Great.

[KrazyHorse]

Originally posted by TCO
I think the 50% power contained area would expand to miles wide (this is using FHA analysis).

WTF is FHA analysis?

[Lul Thyme]

Fourier Harmonic Analysis is my guess?

[TCO]

Originally posted by KrazyHorse


WTF is FHA analysis?

consulting term. "from Henry's ass"

[KrazyHorse]

Originally posted by Lul Thyme
Fourier Harmonic Analysis is my guess?

I thought that, but he added in another "analysis

Like PIN number...

[GePap]

Originally posted by TCO


I don't understand you. It's just a channel cut through the country. A thin extension of the Pacific ocean into the land (or of the Atlantic into the land). I'm assuming that we use the dam as a bridge for traffice. So we would want to be on one of the coasts.

No, the Panama Canal is NOT just a channel. As I said before, the water in the canal is fresh water provided by the Chagres river, which while short has a very heavy volume due to the heavy tropical rainfall. The bulk of the Canal is at a higher elevation than BOTH oceans, which is why locks have to raise ships on both sides to get them into the Canal. In theory then you could place a damn on BOTH sides, with power generated by the waters of the Chagres of the artificial Gatun lake falling into both oceans.