It is interesting to watch SpaceX continue to massively expand, with the goal of going from 61 launches last year to 100 launches this year.

SpaceX’s old record for a month was 7 launches, but in March they completed 8 launches, and almost did 9 but their latest launch had technical difficulties, and the closest they got to launch during the past two days was an abort with 2 seconds to go. They will try a 3rd time to launch this rocket tomorrow.

If SpaceX could do 9 launches/month, that would be 9 12 = 108 launches/year, or enough to meet their goal of 100 launches.

With Starlink now being profitable, they have a big incentive to launch as often as possible. The more they launch, the more they make!

SpaceX is now scheduled to launch a batch of 10 communications and missile tracking satellites on the Tranche 0 Flight 1 mission for the Space Development Agency (SDA) on Saturday, April 1, 2023. A first attempt on Thursday was aborted at T-3 seconds.

The flight will take off from launch site SLC-4E at Vandenberg Space Force Base in California. The satellites will be placed into a 1,000 km orbit, inclined 80 degrees.

The Falcon 9 launch vehicle will use booster B1075-2, which previously launched the Starlink 2–4 mission. After separating from the second stage, the booster will return to Landing Zone 4 at the launch site. The Falcon 9 second stage will be deorbited south of South Africa a couple of hours after the launch.

face_with_colon_three year 2022.

AdS/CFT Proves Its Usefulness

One of the first uses of AdS/CFT had to do with understanding black holes. Theoreticians had long been grappling with a paradox thrown up by these enigmatic cosmic objects. In the 1970s Stephen Hawking showed that black holes emit thermal radiation, in the form of particles, because of quantum mechanical effects near the event horizon. In the absence of infalling matter, this “Hawking” radiation would cause a black hole to eventually evaporate. This idea posed a problem. What happens to the information contained in the matter that formed the black hole? Is the information lost forever? Such a loss would go against the laws of quantum mechanics, which say that information cannot be destroyed.

A key theoretical work that helped tackle this question came in 2006, when Shinsei Ryu and Tadashi Takayanagi used the AdS/CFT duality to establish a connection between two numbers, one in each theory. One pertains to a special type of surface in the volume of spacetime described by AdS. Say there’s a black hole in the AdS theory. It has a surface, called an extremal surface, which is the boundary around the black hole where spacetime makes the transition from weak to strong curvature (this surface may or may not lie inside the black hole’s event horizon). The other number, which pertains to the quantum system being described by the CFT, is called entanglement entropy and is a measure of how much one part of the quantum system is entangled with the rest. The Ryu-Takayanagi result showed that the area of the extremal surface of a black hole in the AdS is related to the entanglement entropy of the quantum system in the CFT.

That means that these two people will say that the state of reality is different – they’d have different facts about where the particle is.

There are may other oddities about quantum mechanics, too. Particles can be entangled in a way that enables them to somehow share information instantaneously even if they’re light years apart, for example. This challenges another common intution: that objects need a physical mediator to interact.

Physicists have therefore long debated how to interpret quantum mechanics. Is it a true and objective description of reality? If so, what happens to all the possible outcomes that we don’t measure? The many worlds interpretation argues they do happen – but in parallel universes.