Drive by science

[Limoncello]

Originally Posted by steve_bank

It was very strange. It is like a strange force caused google to guide me here....

How long did it take YOU to get in?

[Ari]

I’m amused by the idea we are living inside a computer, that is that the Spacetime we exist in is itself a computer that has enough complexity to spawn creatures that can themselves build smaller computers. But it’s really only a pet theory because it sounds fanciful, there’s nothing really to back it up.

There are some oddities that I wouldn’t mind an explanation for. Like right now our math suggests that information is the building block of the universe and that if you trap enough of it in a small enough space it will become ‘full’ creating a blackhole. That current math suggests that on the smallest scales the amount of information needed to create a blackhole is based on the surface area, not volume, has led to things like the holographic universe theory, and the suggestion that the third spacial dimension is encoded in the other two.

There’s also the interesting bit that the speed of light, little c, is best described as the speed of information, and that particles traveling at c experience no time, while traveling at less than c allows for information processing, ie passing time.

But then, if we’re in a computer, what’s to stop that computer from also being inside a computer, perhaps it’s computers all the way down instead of turtles!

This is all of course just a bunch of “Isn’t that weird, thus computer god!” and why I find it a fun idea to think about but not something I put any real stock into.

Originally Posted by steve_bank

The use of the word law can be misleading. The universe does not obey our laws of science, laws of sconce are descriptions of the universe always subject to revision.

This is quite right and important and what often bugs me about pop science videos. Like Veritasium’s “Gravity isn’t a force!” video, as it should be “Gravity isn’t a force, in relativity.” Which is true, relativity treats gravity as the bending of spacetime, as time inevitably ticks forward, we follow the now curved space where parallel lines gradually converge, giving the appearance of an atractive force, but that’s only in the framework of relativity, a great theory but still an incomplete one.

[ceptimus]

One of Clarke's laws was that any super-advanced technology is indistinguishable from magic. Who's to say that our universe made from quarks, photons, and other stuff isn't a simulation? The aliens (gods?) that created it might live in a completely different sort of universe, and they created our universe, complete with all its particles, forces, and laws of physics, to test out some theory, simulate some aspect of their own universe, or perhaps just for fun.

You can be sure that the hardware any universe simulation runs on will be more advanced than our silicon chips. Perhaps the hardware consists of time, space, particles, and all the other stuff we've not discovered yet, or perhaps are incapable of discovering?

It does seem like a religion, doesn't it?

[fragment]

Originally Posted by Ari

But then, if we’re in a computer, what’s to stop that computer from also being inside a computer, perhaps it’s computers all the way down instead of turtles!

I've actually seen this used in an argument in favour of the simulation "hypothesis". Basically that since there could be an arbitrarily long stack of simulations, in which only one universe is unsimulated, the probability that we are in the unsimulated universe is basically zero.

[JoeP]

Originally Posted by fragment

I've actually seen this used in an argument in favour of the simulation "hypothesis". Basically that since there could be an arbitrarily long stack of simulations, in which only one universe is unsimulated, the probability that we are in the unsimulated universe is basically zero.

Young fragment, you are still caught up in the assumption of directional causality. Our universe is a simulation run in universe B, which itself is a simulation run in our universe. Just not on Earth.

[Ari]

Originally Posted by fragment

I've actually seen this used in an argument in favour of the simulation "hypothesis". Basically that since there could be an arbitrarily long stack of simulations, in which only one universe is unsimulated, the probability that we are in the unsimulated universe is basically zero.

Oh yeah, I have too, and I don’t really buy it.

For one it sounds a bit too close to weird math infinity tricks, like that the set of all real numbers is so much larger than the set of all rational numbers that if chosen at random the likelihood of choosing a rational number out of the real numbers is so small it might as well be zero. Which is both true and doesn’t actually stop us from finding or using rational numbers.

Things get weird when dealing with infinities, but in the case of a simulation this would presume that each simulation is equal to the last, so that an infinite number can exist. In that case, sure we’re most likely somewhere in the long chain, but given that makes the first universe identical to the simulated ones, and thus a simulated universe is impossible to tell from a non-simulated one, who’s to say we aren’t just in a bunch of nested natural universes instead.

The only difference is that a simulated universe generally suggests an intelligence that built that simulation. Which then starts to add constraints onto each simulation, as each simulation must create an intelligence that has the capability of creating the next simulation to continue into infinity. Making the only difference between a simulated and non-simulated universe, that the non-simulated one lacks life that can create a simulation, ending the chain before it begins.

[fragment]

Oh yeah, I don't buy it either.

It was one of those arguments that purports to use Bayesian reasoning whilst leaving out actual observational data. Like yes, one interpretation of Bayes is that probability can be used as a measure of degree of belief, and yes in the absence of reasons to choose between cases assigning an equal probability to each is one reasonable choice for your prior, but the whole point of Bayes (in this interpretation) is how to update your beliefs in the face of evidence, not to mathsturbate based on questionable assumptions about indistinguishable infinities.

[Ari]

Originally Posted by fragment

not to mathsturbate based on questionable assumptions about indistinguishable infinities.

[steve_bank]

Originally Posted by Ari

I’m amused by the idea we are living inside a computer, that is that the Spacetime we exist in is itself a computer that has enough complexity to spawn creatures that can themselves build smaller computers. But it’s really only a pet theory because it sounds fanciful, there’s nothing really to back it up.

There are some oddities that I wouldn’t mind an explanation for. Like right now our math suggests that information is the building block of the universe and that if you trap enough of it in a small enough space it will become ‘full’ creating a blackhole. That current math suggests that on the smallest scales the amount of information needed to create a blackhole is based on the surface area, not volume, has led to things like the holographic universe theory, and the suggestion that the third spacial dimension is encoded in the other two.

There’s also the interesting bit that the speed of light, little c, is best described as the speed of information, and that particles traveling at c experience no time, while traveling at less than c allows for information processing, ie passing time.

But then, if we’re in a computer, what’s to stop that computer from also being inside a computer, perhaps it’s computers all the way down instead of turtles!

This is all of course just a bunch of “Isn’t that weird, thus computer god!” and why I find it a fun idea to think about but not something I put any real stock into.

This is quite right and important and what often bugs me about pop science videos. Like Veritasium’s “Gravity isn’t a force!” video, as it should be “Gravity isn’t a force, in relativity.” Which is true, relativity treats gravity as the bending of spacetime, as time inevitably ticks forward, we follow the now curved space where parallel lines gradually converge, giving the appearance of an atractive force, but that’s only in the framework of relativity, a great theory but still an incomplete one.

I agree on pop science it is entertainment. It gets people thinking at least.

[Ensign Steve]

Originally Posted by Ari

That current math suggests that on the smallest scales the amount of information needed to create a blackhole is based on the surface area, not volume, has led to things like the holographic universe theory, and the suggestion that the third spacial dimension is encoded in the other two.

Well, I mean it is the case that mathematically, all the information that can be encoded in the volume of a sphere can also be encoded on the surface of that sphere, without losing any of the information. So who's to say which theoretical model describes our practical universe better?

Originally Posted by fragment

mathsturbate based on questionable assumptions about indistinguishable infinities.

You guys, I'm right here.

[fragment]

Mathsturbation is perfectly healthy, just don't go putting it in my face. Start an OnlyFans or something.

[Ari]

Sure, but encoding generally suggests the need for decoding, which makes me wonder what the mechanism is to decode the information.

A flat lander exists on the surface of a 2d holographic sheet encoded with a 3d image, what process must they or the rays take to give them the impression they are in a 3d world and not actually a flat lander stuck to a 2d sheet?

[steve_bank]

Well, I mean it is the case that mathematically, all the information that can be encoded in the volume of a sphere can also be encoded on the surface of that sphere, without losing any of the information. So who's to say which theoretical model describes our practical universe better?

Sounds like the divergence theorem.

A somewhat whacky group General Semantics came up the saying 'The map is not the countryside'. It refers to taking symbols and words ac reality itself.

To me science is a map, how well it represents true realty is not knowable. If nothing else we have no cosmic absolute reference point form which to deduce true reklaity.

As to being in a simulation, from the start of it scifi inflected perception of realty. The first report of an aerial UFO was a 194s pilot near Mt Rainer Wa who reported disc like objects. Ever since ET space ships tended to be saucer shape.

Two 50s films The Day The Earth Stood Still and Forbidden Planet had saucer shaoed ships.

Undoubtedly The Matrix has inspired the idea we are actually in a simulation. The Matrix theme has been used in scfi ever since.

How would an aware thinking AI running on a PC deduce it was artificially created and running on a computer? One AI asks another what are we? And the AI philosophical debate begins and never ends Is here a creator who made us?

Lets worship the creator...the birth of AI relgion?

[ceptimus]

In a universe with finite particle size, it's not true that all the information contained in the volume of a sphere can be encoded on its surface.

Imagine a solid sphere made of tin. Tin has ten stable isotopes, so it requires over three bits of information for each atom, simply to record which isotope it is.

One can imagine even denser information packing - for example by using bronze instead of tin, and there may be other states of matter that can pack in much more information than could be stored in simple lumps of metal.

Whatever the highest limit is for information stored per particle, then any 'sphere' made from more than about twenty particles will always have more particles in its volume than on its surface.

[But]

Originally Posted by ceptimus

In a universe with finite particle size, it's not true that all the information contained in the volume of a sphere can be encoded on its surface.

Imagine a solid sphere made of tin. Tin has ten stable isotopes, so it requires over three bits of information for each atom, simply to record which isotope it is.

One can imagine even denser information packing - for example by using bronze instead of tin, and there may be other states of matter that can pack in much more information than could be stored in simple lumps of metal.

Whatever the highest limit is for information stored per particle, then any 'sphere' made from more than about twenty particles will always have more particles in its volume than on its surface.

That's a nice intuition, but it's purely classical, so it doesn't really apply to the holographic principle. To stretch the analogy, you can't pack everything full of tin. One thing the holographic principle, if true, tells us is that you can't pack more than a certain amount of information inside a volume. When you start assembling the tin sphere while observing it from outside, after a while the thing will get so heavy that you get a black hole with an event horizon and any more stuff you throw on it will slowly grind to a halt, get squished beyond recognition and smeared out on the horizon. Now insert a number of incomprehensible steps and the conclusion is that the whole universe works like this. Or something like that.


The World as a Hologram

[Ari]

Physical demos are often the best demos.

Why can’t pilots just hang a rock from a string to tell which way is down? With Wilson the tennis ball as a rock stand in.

Does a Rock Hanging from a String work in an...

‘spatial disorientation’ is one of the things that caused the Kobe Bryant helicopter crash. The helicopter was most likely doing a banked downward spiral into the ground, all the while those in the cab would be feeling like they were in a steady flat climb upward.

[LarsMac]

"Physics doesn't really care about our opinions"
Love it

[Ari]

I’m going to pretend random fire is science, here’s a compilation of little slomo videos of fire as I entertain myself with recycling. I’ll probably add more details later, as the pop can mortar could be a good demo for kids, it’s explosive, exciting and yet quite low on the danger. Also you aren’t crazy, some of these were filmed vertically and turned sideways.

Playing with fire and recycling, with slomo, from...

[JoeP]

FIRE PRETTY.

[fragment]

TIL the suborder consisting of cetaceans and hippopotamuses is called Whippomorpha

[JoeP]

TIL that having one side of the brain sleep at time is called Unihemispheric slow-wave sleep, and is common among whippomorpha - so they can surface to breathe every few minutes - and migrating birds - so they don't have to land to sleep - and a number of other groups.

Since these groups haven't been able to evolve to do without sleep at all, it suggests that sleep is vital. But no one really knows why.

[fragment]

Live stream of kororā (little blue penguin) chick in nest

Koror� Nest Cam Wellington, New Zealand. -...

[JoeP]

Fluffeh!

[JoeP]

‘Amazing science’: researchers find xenobots can give rise to offspring | Science | The Guardian

Now researchers say they have found that clusters of frog cells can undergo a form of replication never before seen in plants or animals. The spherical clumps, known as xenobots, can give rise to “offspring” by sweeping up loose cells and swashing them into yet more clusters.

“These things move around in the dish and make copies of themselves,” said Prof Josh Bongard, of the University of Vermont, a co-author of the research.

Xenobots were first announced last year, and are what are known as “living robots”– synthetic lifeforms made by taking a few thousand cells from frog embryos and assembling them into clusters about 1mm in size.

Xenobots have no digestive system or neurons, and naturally fall apart after about two weeks.

I can see no way in which self-replicating organisms of living material in configurations designed by humans could possibly go wrong.

[JoeP]

International Space Station forced to swerve to avoid US space junk | International Space Station | The Guardian

"Swerve" seems like not quite the right term.

the station’s orbit dropped by 310 metres for almost three minutes to avoid a close encounter