What is Gravity?

[IWMP]

Congrats.

[IWMP]

There is a charming quality to childhood science theories. I remember in grade school a friend and I thought we would try and make a rocket. That was long enough ago the possibility of satellites was new. We purchased sheet metal for a body and started plans for an engine. My friend ,a year older than I and having an enthusiasm for chemistry , had a plan for the engine and drew it carefully out. We found that our fabrication abilities with sheet metal were inadequate so the body and engine never got built. Becoming more mature my friends interests led him to become a chemical engineer. He started work far away and we lost touch. I do not know what his career found.

It was quite a few years later when the movie Back to the Future came out. It is fun but I was impressed by the realization that the flux capacitor that enabled the time travel was the design my friend created for our grade school rocket. Perhaps he will suddenly come from the future and stop at my house to say hi.

I think the nostalgia helps.

I once designed a TV. This was before smart TVs. I was a kid. I drew it all out. It was to be a frameless TV but with a computer built in so you could choose your own frames like a foreground and connect to the internet on your TV.

[IWMP]

What is the significance of Valo posting that link a few minutes after I had just watched a clip of that interview?

Aww lost what I said.

I wrote:

Maybe one of you is psychic lol

When I was a kid, I dreampt I was standing in my history teachers livingroom. I saw his cat and grandchildren. The next day I told him (I knew nothing about him, I was in my own world and barely spoke to anyone) and described the room colour and he said that his room was like that and he does have a cat that lays on the windowsill and his grandchildren visit and play on the floor, like in my dream. I've had lots of observation dreams and dreams that happen but that was crazy.

[Res Ipsa]

There is a charming quality to childhood science theories. I remember in grade school a friend and I thought we would try and make a rocket. That was long enough ago the possibility of satellites was new. We purchased sheet metal for a body and started plans for an engine. My friend ,a year older than I and having an enthusiasm for chemistry , had a plan for the engine and drew it carefully out. We found that our fabrication abilities with sheet metal were inadequate so the body and engine never got built. Becoming more mature my friends interests led him to become a chemical engineer. He started work far away and we lost touch. I do not know what his career found.

It was quite a few years later when the movie Back to the Future came out. It is fun but I was impressed by the realization that the flux capacitor that enabled the time travel was the design my friend created for our grade school rocket. Perhaps he will suddenly come from the future and stop at my house to say hi.

I think the nostalgia helps.

I once designed a TV. This was before smart TVs. I was a kid. I drew it all out. It was to be a frameless TV but with a computer built in so you could choose your own frames like a foreground and connect to the internet on your TV.

Cool!

[High Spy]

What is the significance of Valo posting that link a few minutes after I had just watched a clip of that interview?

Effective algorithms most likely, but have faith hoping for more and miracles will occur if your aim is righteous, and you wish to discover God’s purpose for your life. It wouldn’t hurt to brush up on the subject of Gematria and tuples too, which is a word in certain contexts.

(Gravity isn’t a force, but rather an accelerant)

Acceleration isn’t something easily visualized, and a bit like the wind that also can’t be seen.

Its presence can be felt, and causes objects to behave in predictable ways.

Sometimes math makes too much sense.

[Physics Guy]

(Gravity isn’t a force, but rather an accelerant)

This might sound like more mumbo-jumbo but it's actually a true and important point that High Spy is expressing with a non-standard word. Or at least, there is a true and important point which somebody might well express in this way, so it only takes minimal charity to assume that this is what High Spy meant.

In Newtonian theory gravitational force on an object is proportional to the mass of the object, and so in F = m a the mass m cancels out, and everything gets the same acceleration a. This is different from all other forces, which give quite different accelerations to objects with different masses.

In Newtonian theory the gravitational force just happens to be proportional to mass, by postulate, with no further story behind the coincidence. In General Relativity it isn't a coincidence any more.

[Chap]

In Newtonian theory the gravitational force just happens to be proportional to mass, by postulate, with no further story behind the coincidence. In General Relativity it isn't a coincidence any more.

Very neatly put!

[Physics Guy]

One of my brothers and I once built a trebuchet on a sandy beach using a middling-sized tree trunk as the throwing arm and a washtub full of rocks and wet sand as the weight. Our fulcrum was a steel crowbar—the longer and straight true crowbar rather than the shorter S-shaped wrecking bar—supported by tripods of logs lashed together. Our missile was an embarrassingly small rock for the size of the trebuchet. Once we got the thing working we had pretty decent range but no accuracy. We never managed to hit our target sandcastle even though we had observed the fall of shot before we built the sandcastle and placed it in the middle of our beaten zone.

With every shot the whole trebuchet violently shook. We took to burying its tripod supports in the sand, but after two or three shots they would always kick loose and we would have to straighten everything up and dig them back in again. In our quest for stability we ultimately resorted to driving big spikes into the ends of the tripod logs and piling big rocks on the spikes to keep them from jerking up out of the sand. Once we had the thing solidly rigid, we fired again—and the throwing arm broke. Turned out that kicking loose from the sand had been absorbing a lot of impact energy. We had improved our contraption to death.

We looked at each other and went in for supper. I've told the story as a metaphor for various things. I may already have told it here. It's one of my yarns.

[Res Ipsa]

One of my brothers and I once built a trebuchet on a sandy beach using a middling-sized tree trunk as the throwing arm and a washtub full of rocks and wet sand as the weight. Our fulcrum was a steel crowbar—the longer and straight true crowbar rather than the shorter S-shaped wrecking bar—supported by tripods of logs lashed together. Our missile was an embarrassingly small rock for the size of the trebuchet. Once we got the thing working we had pretty decent range but no accuracy. We never managed to hit our target sandcastle even though we had observed the fall of shot before we built the sandcastle and placed it in the middle of our beaten zone.

With every shot the whole trebuchet violently shook. We took to burying its tripod supports in the sand, but after two or three shots they would always kick loose and we would have to straighten everything up and dig them back in again. In our quest for stability we ultimately resorted to driving big spikes into the ends of the tripod logs and piling big rocks on the spikes to keep them from jerking up out of the sand. Once we had the thing solidly rigid, we fired again—and the throwing arm broke. Turned out that kicking loose from the sand had been absorbing a lot of impact energy. We had improved our contraption to death.

We looked at each other and went in for supper. I've told the story as a metaphor for various things. I may already have told it here. It's one of my yarns.

One of my kids built a trebuchet for a school project. It had the same problem with violent shaking. It finally shook itself to pieces. He had fun, though.

[High Spy]

One of my brothers and I once built a trebuchet on a sandy beach using a middling-sized tree trunk as the throwing arm and a washtub full of rocks and wet sand as the weight. Our fulcrum was a steel crowbar—the longer and straight true crowbar rather than the shorter S-shaped wrecking bar—supported by tripods of logs lashed together. Our missile was an embarrassingly small rock for the size of the trebuchet. Once we got the thing working we had pretty decent range but no accuracy. We never managed to hit our target sandcastle even though we had observed the fall of shot before we built the sandcastle and placed it in the middle of our beaten zone.

With every shot the whole trebuchet violently shook. We took to burying its tripod supports in the sand, but after two or three shots they would always kick loose and we would have to straighten everything up and dig them back in again. In our quest for stability we ultimately resorted to driving big spikes into the ends of the tripod logs and piling big rocks on the spikes to keep them from jerking up out of the sand. Once we had the thing solidly rigid, we fired again—and the throwing arm broke. Turned out that kicking loose from the sand had been absorbing a lot of impact energy. We had improved our contraption to death.

We looked at each other and went in for supper. I've told the story as a metaphor for various things. I may already have told it here. It's one of my yarns.

One of my kids built a trebuchet for a school project. It had the same problem with violent shaking. It finally shook itself to pieces. He had fun, though.

Launcher 1.0 was actually preceded by a couple failed designs that bent the hell out of the throwing arm. The trick is to stop the falling weight without shocking the throwing arm. Using a heavy bag with straps decouples the arm from the weight when it hits the carpeted base.