Recent content by eachus

I kept expecting someone here to point out that all of this only applies if your spaceship is not too near a black hole. With GR there is a last stable orbit beyond that, your spaceship will have to be constantly thrusting so it doesn't fall into the black hole. In reality, there is no such...

Just some circumstantial evidence that swabbing is unnecessary. I am what phlebotomists call a "hard draw," in fact a very hard draw. I was in the hospital for a week recently, and on several occasions had two different drugs flowing into the back of my hands. They kept taking blood for...

Don't let others get you wrapped around the axle. Choose an asteroid suitable for your project, say Apophis, and go with it. Assuming you are building a space elevator, there are three options. First build up and down at the same time, and part of the engineering will be to keep the orbit...

That's why I mentioned the kilonova. The collision and subsequent explosion will form lots of proton and neutron collections that are not gravitationally bound. They will rapidly decay down to (somewhat) stable particles very quickly. Trying to put a limit on the number of nucleons in an...

I believe that the idea that the R-process occurs in supernovas was falsified by the "kilonova" collision of two neutron stars. If the R-process is the decay of neutron stars, then your question is meaningless--the heaviest nucleus becomes two neutron stars at the point of collision (several...

There is a much simpler, and more likely to work solution. Get Malaysia and Indonesia to limit exports to current levels. It would likely require some money as quid pro quo, but the importing countries could afford to pay for it by taxing imports. ;-) If you prefer, just do the import...

There is one way the core can transfer heat directly to the corona, via neutrinos. That certainly occurs but is a trivial component of the heating. A more interesting question is whether neutrinos collide with atoms in the upper layers of the sun, and produce muons. These can directly heat...

Just a post to defend (real) statistics. Computing the mortality of an epidemic by computing deaths/number of cases is wrong. Especially early in an outbreak, deaths will trail confirmed cases significantly. There are two ways to compute a reasonable estimator. If you have good data on...

Globular cluster - Wikipedia The typical distance between stars in a globular cluster is about 1 light year, but at its core, the separation is comparable to the size of the Solar System (100 to 1000 times closer than stars near the Solar System). Globular clusters are not thought to be...

There is one scenario that can result in a magnitude 10 earthquake. A caldera like Yellowstone but located near a plate boundary--lots of them in the Pacific near or even part of the ring of fire. Think of a VEI 8 eruption as firing a really big gun upwards. (Gigatons of ash will reach the...

I've been thinking about solutions, not problems. I definitely think that you are asking for less than the minimum flow in hot weather, and anyway the inlet temperature is probably above 20 degrees C anyway. There are tanks sold for water expansion in hot water heating systems. One of these...

I don't want to get stuck in the politics of this issue, but... I'm a statistician, and I was first asked to look at this issue back in the 1970s. Then the concern was about falling global temperatures. Two things jumped out. The first was the shift from turbojets to turbofans. The net...

There are two contributions to spotting the football. Let's assume we have a football with an IoT tag that can be placed accurately to within a fraction of an inch, and the officials not only have the necessary tools to place the ball, but the needed training with the tools so they can do it...

Lots more landslide caused tsunamis, including a man-made one at Vajont Dam in Italy in 1963, which killed almost 2000 people, one that many of us watched on TV: Spirit Lake was mostly filled by the (sideways) eruption of Mount St. Helens. The man-made one? . There have been small ice-slide...

I'm a bit confused. I used Ada and needed an Ada library to interface with a BLAS written in Fortran. I declared several types with pragma Convention (Fortran, T_...); the T to indicate Transposed. The parameters of the BLAS routines used these types, and I provided functions to convert from...