They do not like to talk about it too much in public these days, but Rocket Lab had somewhat shady beginnings. Once they moved past the semi-amateur phase, their first real project was weapons development on a DARPA…
It is uncontroversial among Dostoyevsky's scholars that his main focus is on Russian mysticism while the stories themselves are merely a setting for presenting author's theology. But that may be flying over the head of…
Marc Raibert was a student of Ivan Sutherland. Sutherland had a lot of pull at DARPA. This facilitated the unique prototyping work done at Boston Dynamics to get noticed and supported by DARPA. But as a flip side of…
Maybe it was a bit too colloquial. I am not sure if this is very important. A formal term would have been "full propellant load." The phrase "fill level" is also used in NASA documents. The question was whether during…
Correction: The first stage of New Glenn carries only about 260 tons of methane. The 1150 tons is the full propellent load, liquid oxygen and liquid methane combined. The heat from combustion of this amount would be…
The problem is that there is no standard meaning for the "full duration" in this context. Some reports say that this means "running all seven BE-4 engines at full thrust for up to 38 seconds". In flight the engines fire…
The TNT is relevant, because the atomic bomb energy output was defined in terms of TNT equivalent. Not the energy of the blast, but the total output. For Trinity this was 20 kt, or 20*4.2 TJ. This serves as a basis of…
You are talking about the energy of the blast. In my comment I was talking about the heat output. From the followup comments it seems I have not made it sufficiently clear. The energy of the detonation wave in rocket…
It is not clear what "full duration static fire" means, but if the stage was fully fueled, the fuel tank would have contained 1000 tons of methane. The heat of combustion of methane is 55 MJ/kg. TNT equivalent is…
Both SpaceX and NASA use LabView. NASA has a relatively detailed description of the engine test stands at Stannis: https://scholar.google.com/scholar?q=NASA+Data+Acquisition+S...…
Five years ago SpaceX reported that they had 30000 seconds of test firing time on the Raptor, over 567 engine starts. Since them the program accelerated dramatically. Well over one thousand engines had been produced,…
If we look at the venting from the propellant tank (around T+16:15) it looks thick white closer to the vent, becoming more transparent and blue as it expands. That's just sunlight scattering on the particles and density…
The views from Ship's engine bay looked rather ominous -- with the red glow visible in multiple places, and something venting furiously from the broken engine. It was a pleasant surprise that the ship did not explode…
There is an excellent three part documentary from Sandia National Labs: "Always/Never: The Quest for Safety, Control, and Survivability." (part 1) https://www.youtube.com/watch?v=DQEB3LJ5psk They cover both the…
Cleve Moler was one of the big names in numerical methods, and participated in creation of canonical FORTRAN libraries for solving linear equations, and matrix algorithms more generally. To teach this more conveniently…
They struggled with many things, often time the minutiae of accomplishing something conceptually rather simple. For example, making an explosive with a significantly slower detonation velocity turned out to be very…
There are different versions of the story. In one of them, somebody asked the question whether the atmosphere could ignite, and that was very quickly answered in the negative, but then Oppenheimer mentioned it to the…
Plutonium was compressed about two-fold by volume. There is a story about it. When they first brainstormed the ways to make the bomb, even before Los Alamos, in 1942, one of the several ideas was to use explosives to…
It is all true, but one needs to take into account that because of the different properties of the materials, the critical mass for uranium-235 is intrinsically much greater than that for plutonium-239. For a bare…
99% of all diamonds by mass are industrial diamonds. But they are so inexpensive that they only account for 3% or the revenue. The jewelry is the remaining 0.8% by mass, and it is split roughly equally between the…
I think one can extrapolate further. There will be two things intertwined together: 1. Thought will be liberated from the confines of mortal bodies. 2. Technology will be able to create and modify things on the…
The point is not that silicon is not suitable for extreme cold -- it is, with careful design. But the authors want to use a semiconductor which would operate at much higher temperatures than silicon can. And most of…
Exactly. In physics, when people measured things at 4K, there were many examples of active circuits built to measure or amplify things in situ at 4K, and only send the results out, often by the same wire that was used…
It was unintentional, but it is actually kind of true in his case. The guy is a founder and the CTO of two semiconductor companies.
In the "real" DRAM chip, there is a large array of very tiny capacitors, with the switches which allow to connect one row of the array at a time to the readout column wires. The capacitance of the wires themselves is…
They do not like to talk about it too much in public these days, but Rocket Lab had somewhat shady beginnings. Once they moved past the semi-amateur phase, their first real project was weapons development on a DARPA…
It is uncontroversial among Dostoyevsky's scholars that his main focus is on Russian mysticism while the stories themselves are merely a setting for presenting author's theology. But that may be flying over the head of…
Marc Raibert was a student of Ivan Sutherland. Sutherland had a lot of pull at DARPA. This facilitated the unique prototyping work done at Boston Dynamics to get noticed and supported by DARPA. But as a flip side of…
Maybe it was a bit too colloquial. I am not sure if this is very important. A formal term would have been "full propellant load." The phrase "fill level" is also used in NASA documents. The question was whether during…
Correction: The first stage of New Glenn carries only about 260 tons of methane. The 1150 tons is the full propellent load, liquid oxygen and liquid methane combined. The heat from combustion of this amount would be…
The problem is that there is no standard meaning for the "full duration" in this context. Some reports say that this means "running all seven BE-4 engines at full thrust for up to 38 seconds". In flight the engines fire…
The TNT is relevant, because the atomic bomb energy output was defined in terms of TNT equivalent. Not the energy of the blast, but the total output. For Trinity this was 20 kt, or 20*4.2 TJ. This serves as a basis of…
You are talking about the energy of the blast. In my comment I was talking about the heat output. From the followup comments it seems I have not made it sufficiently clear. The energy of the detonation wave in rocket…
It is not clear what "full duration static fire" means, but if the stage was fully fueled, the fuel tank would have contained 1000 tons of methane. The heat of combustion of methane is 55 MJ/kg. TNT equivalent is…
Both SpaceX and NASA use LabView. NASA has a relatively detailed description of the engine test stands at Stannis: https://scholar.google.com/scholar?q=NASA+Data+Acquisition+S...…
Five years ago SpaceX reported that they had 30000 seconds of test firing time on the Raptor, over 567 engine starts. Since them the program accelerated dramatically. Well over one thousand engines had been produced,…
If we look at the venting from the propellant tank (around T+16:15) it looks thick white closer to the vent, becoming more transparent and blue as it expands. That's just sunlight scattering on the particles and density…
The views from Ship's engine bay looked rather ominous -- with the red glow visible in multiple places, and something venting furiously from the broken engine. It was a pleasant surprise that the ship did not explode…
There is an excellent three part documentary from Sandia National Labs: "Always/Never: The Quest for Safety, Control, and Survivability." (part 1) https://www.youtube.com/watch?v=DQEB3LJ5psk They cover both the…
Cleve Moler was one of the big names in numerical methods, and participated in creation of canonical FORTRAN libraries for solving linear equations, and matrix algorithms more generally. To teach this more conveniently…
They struggled with many things, often time the minutiae of accomplishing something conceptually rather simple. For example, making an explosive with a significantly slower detonation velocity turned out to be very…
There are different versions of the story. In one of them, somebody asked the question whether the atmosphere could ignite, and that was very quickly answered in the negative, but then Oppenheimer mentioned it to the…
Plutonium was compressed about two-fold by volume. There is a story about it. When they first brainstormed the ways to make the bomb, even before Los Alamos, in 1942, one of the several ideas was to use explosives to…
It is all true, but one needs to take into account that because of the different properties of the materials, the critical mass for uranium-235 is intrinsically much greater than that for plutonium-239. For a bare…
99% of all diamonds by mass are industrial diamonds. But they are so inexpensive that they only account for 3% or the revenue. The jewelry is the remaining 0.8% by mass, and it is split roughly equally between the…
I think one can extrapolate further. There will be two things intertwined together: 1. Thought will be liberated from the confines of mortal bodies. 2. Technology will be able to create and modify things on the…
The point is not that silicon is not suitable for extreme cold -- it is, with careful design. But the authors want to use a semiconductor which would operate at much higher temperatures than silicon can. And most of…
Exactly. In physics, when people measured things at 4K, there were many examples of active circuits built to measure or amplify things in situ at 4K, and only send the results out, often by the same wire that was used…
It was unintentional, but it is actually kind of true in his case. The guy is a founder and the CTO of two semiconductor companies.
In the "real" DRAM chip, there is a large array of very tiny capacitors, with the switches which allow to connect one row of the array at a time to the readout column wires. The capacitance of the wires themselves is…