Monday, February 25, 2008

The High Ground


Army Air Corps veteran Gene Roddenberry made his Starship Enterprise a naval vessel. Owning the high ground allows victory over superior numbers. Control of the seas allowed the small nation of England to rule much of the world. After completion of a successful ISS construction mission, the week's biggest Space news is the shootdown of a spy satellite by the cruiser Lake Erie.

As the video begins we see the SM-3 missile launch and jettison its first stage. In the second half we see the satellite intercepted, leaving behind a debris cloud. Apparently the missile bulls-eyed the satellite right in the fuel tank. The interception sends an unmistakable message about the power of technology.

Ticonderoga-class cruisers like USS Lake Erie were originally designed to protect battle groups from hostile aircraft. In the photo below an Aegis cruiser is in the plane-guard position behind each carrier. With improvements to the Aegis system, they have found a new role defending from ballistic missiles. Unlike other missile defense systems, ships are mobile. In any future conflict, an Aegis cruiser in the harbour can provide a friendly nation with instant missile defense.

Rumour has it that India will get the carrier Kitty Hawk for free if India also buys American F/A-18's. For decades India has bought its fighter planes from the USSR. India has sunk a lot of rupees into acquiring a Russian carrier. The Admiral Gorshkov is a Kiev-class vessel of 44,000 tons designed for helicopters and VTOL aircraft. Converting it into a carrier means installation of catapults, arresting gear, a larger flight deck, new powerplants, and an unholy amount of money. The Kitty Hawk displaces 80,000 tons and comes fully loaded with catapults and arresting gear. India switching to US aircraft would mean many billions for Boeing and US industry.

(From my own experience, the F/A-18 is far superior to any Russian fighter. When I had the privilege of flying US Navy aircraft, pillots often flew 1V1 with MIG-29's courtesy of Germany. Using the right tactics, even the older F-14 could defeat a MIG-29 in combat. The F/A-18 is more maneuverable, easier to service, and has better thrust-weight ratio.)

One US presidential candidate is known for talking a good speech while avoiding specifics. He favours "postponing" the human spaceflight program for 5 or more years, in other words killing it. This would leave the initiative to other nations such as China. His opponent in the primaries desperately needs a win in Texas. The Space program is very popular with voters in Houston.

Many people have predicted that the US will lose its primacy among great powers to nations with larger populations. Control of technology and the high ground of Space would allow the US and allied nations to continue their leadership position. Continued support of science will mean breakthroughs in energy production. If they cede the high ground, someone else will take it.

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3 Comments:

Blogger mark said...

yes, Louise: politics, generally speaking, is fairly depressing, isn't it?

4:56 AM  
Blogger Parvulus said...

Hi Louise,

again not the right thread to post this, but I hope you will bear me!

You probably saw that I derived your variable c law from a non-Copernican, Special-Relativity expanding sphere model.

I've just seen that it can also be derived from non-Copernican, General-Relativity expanding fluid spheres.

It is well known that the radius of a fluid sphere must observe some relationships with its Schwarzschild radius (2GM/c**2) to be physically acceptable. That is not restricted to the Schwarzschild interior metric, as shown in
http://arxiv.org/PS_cache/gr-qc/pdf/0306/0306038v1.pdf

Let's specify the condition as:
2GM / Rc**2 <= constant_1

(constant_1 = 8/9 for a static sphere)

This can be expressed as:

c**2 >= constant_2 GM / R

(constant_2 = 9/4 for a static sphere)

For a specific model, you have specific constant_1_m and constant_2_m that satisfy the physical acceptability conditions and

c**2 = constant_2_m GM / R

Now take the case of an expanding sphere, with radial speed proportional to radius (to have a "Hubble" flow, keeping comoving distances constant). This can be described by metric expansion of space, so that you have

R(t) = a(t) R(to)

where R(to) is the comoving radius of the sphere, when a(to) = 1

Now, it is:

c**2 = constant_2_m GM / R(t)

c**2 = constant_2_m GM / a(t) R(to)

If the properties of the universe are time-invariant with respect to comoving coordinates, then c**2
must be c(t)**2.

Note that in this non-Copernican models comoving coordinates are not those whose view of the universe is isotropic, but those whose view of the universe has a constant degree of anisotropy over time (for the origin, that degree of anisotropy is zero).

Note that, as in my CIFRES Version 1 model, your variable c arises in the context of a non-Copernican model: a finite expanding sphere, whose center is the only point from which the universe is isotropous.

I feel quite comfortable with such a model. Some people may not.

Best regards...
P.

6:23 AM  
Blogger L. Riofrio said...

Hang in there, mark.

For parvulus: Your work on this is most appreciated. There are many ways to derive the GM=tc^3 equation. It applies to a variety of mass distributions, which can also be seen as co-expanding sections of a larger sphere.

6:59 AM  

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