Tag Archives: Physics

Converting Apollo State Vectors To Orbits

OK, another mathematical one. This is the fourth in a series of posts about the orbits followed by the Apollo spacecraft as they travelled to and from the moon—something I suppose is getting a little more topical now that NASA has finally got underway with its planned return to the lunar surface. I started with … Continue reading Converting Apollo State Vectors To Orbits

Ralph Bagnold: Two Memoirs

In the following pages I shall try to trace the unpremeditated steps by which a few army officers, with no initial thirst for exploration, and no desire to do anything unusual except to see the country they were in came gradually to break away from this conventional city outlook towards things outside; and how, beginning … Continue reading Ralph Bagnold: Two Memoirs

R.A.J. Matthews: Tumbling Toast, Murphy’s Law And The Fundamental Constants

Robert A.J. Matthews published this seminal bit of applied physics in 1995. The journal reference is European Journal of Physics 16(4): 172-6, and you can access the full paper at ResearchGate, here. For his efforts, he was awarded an Ig Nobel Prize in 1996.
Matthews was the first (but by no means the last) to use mathematical physics to explore the popular claim that “dropped toast always lands butter-side down”. The usual “explanation” invoked for this perceived rule is Murphy’s Law—“If anything can go wrong, it will”—but Matthews sought to show that there were sound physical principles underlying the phenomenon.

Relativistic Ringworlds

No matter how many times he considered it, Jophiel shivered with awe. It was obviously an artefact, a made thing two light years in diameter. A ring around a supermassive black hole. Stephen Baxter, Xeelee: Redemption (2018) I’ve written about rotating space habitats in the past, and I’ve written about relativistic starships, so I guess … Continue reading Relativistic Ringworlds

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The Myth Of The Starbow

Thus, with all Einstein numbers of flight [velocity as a proportion of the speed of light] greater than 0.37 a major dark spot will surround the take-off star, and a minor dark spot the target star. Between the two limiting circles of these spots, all stars visible in the sky are coloured in all the … Continue reading The Myth Of The Starbow

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