Such great writing! Especially because the topic isn't a main interest, yet I was fascinated. My inbox is getting cluttered with Substacks. I don't have time to read all the good essays so I leave them there until a Friday night, home with a cold, and give them the time they deserve. Bravo Gunnar!
This is brilliant! You made each topic so captivating. I think you’re beyond capable and smart even if things feel stagnant in life. I completely relate. Thanks for sharing!
even the earth, the solid, stable (read: stuck) earth is moving - these plates are floating on magma, on an object hurtling around the sun at 67,000 mph. humans are bound to earth but even then we are free ;)
You’ve scooped me again! Though my idea was to play with the discovery of a reliable way to determine longitude—as opposed to sharks and swifts—as a way of navigating that overlap of time and space and feeling stuck.
Also, I’m so curious how they know how much time swifts spend in the air during migration. Do you know how they (the Royal “they,” of course) observed that?
"putting clocks in planes that fly around the world in opposite directions results in a nanosecond-but-measurable time difference" - yes but each thinks the other is slower... When they meet again how do they reconcile that?
They were both compared to a stationary clock at the United States Naval Observatory. Also, and I admit I borrowed this from Wikipedia ;),
… a clock aboard the plane moving eastward, in the direction of the Earth's rotation, had a greater velocity (resulting in a relative time loss) than one that remained on the ground, while a clock aboard the plane moving westward, against the Earth's rotation, had a lower velocity than one on the ground.
You’re right, there is no absolutely stationary. The ground clock is called ‘stationary’ because the center of the earth provides an inertial frame of reference, unlike the moving planes.
I've puzzled over this for years. If you take the simplest symmetrical case: two spaceships move apart and then back together. Both should see the other as older.
Such great writing! Especially because the topic isn't a main interest, yet I was fascinated. My inbox is getting cluttered with Substacks. I don't have time to read all the good essays so I leave them there until a Friday night, home with a cold, and give them the time they deserve. Bravo Gunnar!
‘Not my main interest, yet fascinated’ is one of the finest compliments I can imagine. Thank you, Bettina! (and feel better soon)
I mean, sharks are cool of course! But physics and the hard sciences in general need a good personal hook to keep me reading.
Happy to have had you hooked. 😉
Loved this - elegantly done; and so interesting.
Thanks; I appreciate that!
This is brilliant! You made each topic so captivating. I think you’re beyond capable and smart even if things feel stagnant in life. I completely relate. Thanks for sharing!
Thanks, McKenna! I really appreciate that.
even the earth, the solid, stable (read: stuck) earth is moving - these plates are floating on magma, on an object hurtling around the sun at 67,000 mph. humans are bound to earth but even then we are free ;)
So hopeful, tracy!
You’ve scooped me again! Though my idea was to play with the discovery of a reliable way to determine longitude—as opposed to sharks and swifts—as a way of navigating that overlap of time and space and feeling stuck.
Also, I’m so curious how they know how much time swifts spend in the air during migration. Do you know how they (the Royal “they,” of course) observed that?
Like minds…
They designed a tiny backpack for the birds with an accelerometer and light sensor.
"putting clocks in planes that fly around the world in opposite directions results in a nanosecond-but-measurable time difference" - yes but each thinks the other is slower... When they meet again how do they reconcile that?
They were both compared to a stationary clock at the United States Naval Observatory. Also, and I admit I borrowed this from Wikipedia ;),
… a clock aboard the plane moving eastward, in the direction of the Earth's rotation, had a greater velocity (resulting in a relative time loss) than one that remained on the ground, while a clock aboard the plane moving westward, against the Earth's rotation, had a lower velocity than one on the ground.
The one that moved westward had a slower velocity than the ground clock so you can't call the ground clock stationary.
This assumes there's such a thing as "absolutely stationary", but maybe this is a special case cos it involved rotation.
You’re right, there is no absolutely stationary. The ground clock is called ‘stationary’ because the center of the earth provides an inertial frame of reference, unlike the moving planes.
I've puzzled over this for years. If you take the simplest symmetrical case: two spaceships move apart and then back together. Both should see the other as older.