TIL: Today I Learned

[Michkov]

Could they launch all the garbage into the sun?

With how orbital mechanics works that is a terribly expensive solution. First you have to schlep the garbage out of the gravity well of the Earth and then you need to slow it down enough so it falls towards the sun. Might as well burn it here and get some energy out of it.

 

[Zkribbler]

Well, there are techniques for sailing in a zig-zag against regular wind.

Yes, one tacks against the resistance of the water. But there's no ocean in outer space.

 

[Synobun]

Yes, one tacks against the resistance of the water. But there's no ocean in outer space.

How would you know?

 

[Chukchi Husky]

Could they launch all the garbage into the sun?

You need to create another ball of garbage of the same mass and density to hit the garbage into the sun. The second ball will be sent on a trajectory where it will return in a thousand years, but that's for the people of future to solve.

 

[Imaus]

I suppose a space elevator is still just science fiction?

A space elevator is fiction on Earth. We're a high-g, big rocky world.

On the Moon, on Mars, even Venus, we can construct one. But earth is just so big and dense (we're a very dense world) that it's a miracle we were able to launch off at all. Any bigger than this and we would be seeing rockets launched from super-heavy jet bombers/jetliners.

 

[aimeeandbeatles]

A space elevator is fiction on Earth. We're a high-g, big rocky world.

On the Moon, on Mars, even Venus, we can construct one. But earth is just so big and dense (we're a very dense world) that it's a miracle we were able to launch off at all. Any bigger than this and we would be seeing rockets launched from super-heavy jet bombers/jetliners.

Actually, that makes me wonder how the elcor from Mass Effect were able to achieve spaceflight. Their home planet is super high-gravity.

 

[hobbsyoyo]

I suppose a space elevator is still just science fiction?

Yes, and probably will remain so for another century or two at the very least. It would also be exceedingly dangerous should it collapse and so it would require a ton of additional margin on top of the already painfully-high baseline strength.

Could they launch all the garbage into the sun?

I don't think launch costs will ever get that cheap. Even with a space elevator, we'd likely end up using all of it's capacity sending useful stuff up and down.

I was thinking that you could use a solar sail, because if it's garbage anyway, you don't need it to get there fast. But can a solar sail carry something towards the sun?

Pretty sure you can but it's not easy. Going to the sun is never easy to begin with. But space is big enough that you don't have to actually send stuff to it - just launch it to a suitably stable point in the void and be done with it.

A space elevator is fiction on Earth. We're a high-g, big rocky world.

On the Moon, on Mars, even Venus, we can construct one. But earth is just so big and dense (we're a very dense world) that it's a miracle we were able to launch off at all. Any bigger than this and we would be seeing rockets launched from super-heavy jet bombers/jetliners.

Pretty sure a space elevator won't work on Venus since it rotates so slowly. A space elevator requires you put an anchor mass at geostationary orbit and for Venus, the rotational speed is so low that 'geostationary' distance would be super far out there.

Ok I googled and this turned up on a Wikipedia page about terraforming Venus

Venus' extremely slow rotation means that space elevators would be very difficult to construct because the planet's geostationary orbit lies an impractical distance above the surface,

Also, Venus has 90% of the gravity of Earth so I don't think it would be easy to build an elevator even without the rotation issue.

Actually, that makes me wonder how the elcor from Mass Effect were able to achieve spaceflight. Their home planet is super high-gravity.

Based on the book I just read on exoplanet formation, I'm not even sure any life could arise on planets much bigger than Earth. We're sort of at the upper end of the habitability scale because as gravity increases, the processes that drive our weather and make the Earth livable break down.

 

[aimeeandbeatles]

Based on the book I just read on exoplanet formation, I'm not even sure any life could arise on planets much bigger than Earth. We're sort of at the upper end of the habitability scale because as gravity increases, the processes that drive our weather and make the Earth livable break down.

Oh wow.

If I'm not mistaken, some of the random planets in the first Mass Effect game are composed of elements that would react violently when put together. I guess they didn't do all their research.

 

[Imaus]

Yes, and probably will remain so for another century or two at the very least. It would also be exceedingly dangerous should it collapse and so it would require a ton of additional margin on top of the already painfully-high baseline strength.

I don't think launch costs will ever get that cheap. Even with a space elevator, we'd likely end up using all of it's capacity sending useful stuff up and down.

Pretty sure you can but it's not easy. Going to the sun is never easy to begin with. But space is big enough that you don't have to actually send stuff to it - just launch it to a suitably stable point in the void and be done with it.

Pretty sure a space elevator won't work on Venus since it rotates so slowly. A space elevator requires you put an anchor mass at geostationary orbit and for Venus, the rotational speed is so low that 'geostationary' distance would be super far out there.

Ok I googled and this turned up on a Wikipedia page about terraforming Venus


Also, Venus has 90% of the gravity of Earth so I don't think it would be easy to build an elevator even without the rotation issue.


Based on the book I just read on exoplanet formation, I'm not even sure any life could arise on planets much bigger than Earth. We're sort of at the upper end of the habitability scale because as gravity increases, the processes that drive our weather and make the Earth livable break down.

Oh wow.

If I'm not mistaken, some of the random planets in the first Mass Effect game are composed of elements that would react violently when put together. I guess they didn't do all their research.

This also means that Humans are the giants/high G race.Use that for your settings, people! Everything else is low-G. The Expanse sort of plays with this, how a Terran could beat up a cargohold of Belters and a room of Martians if they bodybuild just because the Belters and Martians are just weaker.

 

[Takhisis]

TIL that Ukrainian President Volodymyr Zelensky starred in a sitcom where he played a high-school teacher who unexpectedly gets elected President of Ukraine.

WTH is going on ? Are the gods just mocking us ?

I'll just reply ‘You're fired!’.

 

[Takhisis]

Wow, that looks like the Dave Garrowunway Show from MAD magazine.

 

[hobbsyoyo]

I watched a documentary on birds and learned that avian brains tend to be more densely packed with neurons than mammal brains. Then I did some googling and it turns out that the early research into bird brains was heavily skewed by a flawed interpretation of how evolution works. Basically, a leading bird brain scientist thought that evolution worked in a straight line from less complexity to more complexity. And from this he drew very bad conclusions on how bird brains were structured - they aren't a whole lot like mammal brains and he took this to mean they were less complex. He then went on to give names to regions of bird brains that were somewhat derogatory (basically, he gave them prefixes that makes them seem more primitive) and these misconceptions and nomenclature went on to tilt the whole field of study until fairly recently. In other words, many birds are a lot smarter than we give them credit for.

And this has me thinking how far back in time these trends extend? I mean I don't think that a stegosaurus with a body mass of a bull elephant and a brain the size of a peanut could have been smart, but I wonder if it could have been significantly less dumb than we'd think it based on brain size alone.

 

[Hrothbern]

I watched a documentary on birds and learned that avian brains tend to be more densely packed with neurons than mammal brains. Then I did some googling and it turns out that the early research into bird brains was heavily skewed by a flawed interpretation of how evolution works. Basically, a leading bird brain scientist thought that evolution worked in a straight line from less complexity to more complexity. And from this he drew very bad conclusions on how bird brains were structured - they aren't a whole lot like mammal brains and he took this to mean they were less complex. He then went on to give names to regions of bird brains that were somewhat derogatory (basically, he gave them prefixes that makes them seem more primitive) and these misconceptions and nomenclature went on to tilt the whole field of study until fairly recently. In other words, many birds are a lot smarter than we give them credit for.

And this has me thinking how far back in time these trends extend? I mean I don't think that a stegosaurus with a body mass of a bull elephant and a brain the size of a peanut could have been smart, but I wonder if it could have been significantly less dumb than we'd think it based on brain size alone.

Why would some dinosaurs not be intelligent ?
Some (or many ?) did take care of their offspring. Some did live in herds. Some could have lived in wolfpacks for hunting.
All that is greatly helped with social group development.
Brains help.
The weight issues of birds, they must fly, not only pushing for lighter bones, but also for more densely packed neurons ? Why not ?


I guess also that we tend to overemphasise the value of brains for succes in evolution because that fits so comfortably well with our grandstanding as human being.

Let's see how ants and scorpions comment on that in case we succeed in making a nuclear dessert out of our Earth.


Brains have high metabolic energy cost and are I guess basically limited in size to "fit for purpose" or worded better "fit for needed"
That can, I guess again, be substantially larger than the "rational engineering" minimum, because so many animals spend on reality so much resources (and survival potential) in courting each other !!!
Courting as process for species internal competition, but also courting to pinpoint that you have sex with the specific subspecies you are !
(many species can have viable offspring with species closely related but not the same)/

Especially birds spend a lot of their resources on precision match courting. The color of the feathers, impractical bodily features, the dancing, the singing...
All needing energy and lessening of "fighting" abilities.

Has that purpose ?
I don't think so !
I guess the principle of evolution is not purpose or "the best fit" becoming "better all the time... but more "the viable fit".
If a species CAN exist... it DOES exist.

With birds again, I can imagine that they had an "easy" advantage to survive after the dinosaur collapse compared to many crawling animals. They were warmblooded, had a nice "fur"... and could fly away from danger !
The (now assumed) lack of food after the meteorite has been I guess to the advantage of small animals that could also have a good meal from insects and small organism living in the earth like worms etc.
Lots of evolutionary habitat room for many kinds of birds to "can exist" even in dire times.
Lots of room for social interactions in less dire times.

 

[Traitorfish]

bird brain scientist

heehee.

 

[hobbsyoyo]

Why would some dinosaurs not be intelligent ?
Some (or many ?) did take care of their offspring. Some did live in herds. Some could have lived in wolfpacks for hunting.
All that is greatly helped with social group development.
Brains help.
The weight issues of birds, they must fly, not only pushing for lighter bones, but also for more densely packed neurons ? Why not ?


I guess also that we tend to overemphasise the value of brains for succes in evolution because that fits so comfortably well with our grandstanding as human being.

Let's see how ants and scorpions comment on that in case we succeed in making a nuclear dessert out of our Earth.


Brains have high metabolic energy cost and are I guess basically limited in size to "fit for purpose" or worded better "fit for needed"
That can, I guess again, be substantially larger than the "rational engineering" minimum, because so many animals spend on reality so much resources (and survival potential) in courting each other !!!
Courting as process for species internal competition, but also courting to pinpoint that you have sex with the specific subspecies you are !
(many species can have viable offspring with species closely related but not the same)/

Especially birds spend a lot of their resources on precision match courting. The color of the feathers, impractical bodily features, the dancing, the singing...
All needing energy and lessening of "fighting" abilities.

Has that purpose ?
I don't think so !
I guess the principle of evolution is not purpose or "the best fit" becoming "better all the time... but more "the viable fit".
If a species CAN exist... it DOES exist.

With birds again, I can imagine that they had an "easy" advantage to survive after the dinosaur collapse compared to many crawling animals. They were warmblooded, had a nice "fur"... and could fly away from danger !
The (now assumed) lack of food after the meteorite has been I guess to the advantage of small animals that could also have a good meal from insects and small organism living in the earth like worms etc.
Lots of evolutionary habitat room for many kinds of birds to "can exist" even in dire times.
Lots of room for social interactions in less dire times.

I was specifically talking about Stegosaurs but by extension could have been talking about some of the other large-bodied and small-brained plant eaters. Although those dinosaurs did not lead to birds, they have more in common with them than with mammals and I would suspect they had broadly similar brains.

I know that many of the theropods (avian dinosaurs) had large brains and were smart. However, many of the big plant eaters had comically small brains, especially when factoring in that brain size scales with body mass, at least in mammals. This is necessary just to provide enough computational power to take in and process all of the nerve inputs of such a large body. Like I said, some dinosaurs like stegosaurs had brains the size of walnuts or peanut pods. No matter how neuron-dense their brain were, they would not have been very smart animals. They did have nerve bundles near their hips, which likely would have done some of the nerve-signal processing but were not true brains.

And I'm also emphatically not placing any premium on brain sizes or 'smartness'. I'm not making any value judgement on the things, just commenting on what I've recently learned and how that interplays with other things I previously learned. I'm not saying stegosaurs were bad for being dumb, or that crows are good because they are smart, just stating these things as fact. You read too much into my previous post. I simply wonder if some dinosaurs - notably the ones with massive bodies and tiny brains - might have been a bit smarter than we might otherwise assume in light of the fact that bird brains are more neuron-dense than mammals.

 

[Hrothbern]

I was specifically talking about Stegosaurs but by extension could have been talking about some of the other large-bodied and small-brained plant eaters. Although those dinosaurs did not lead to birds, they have more in common with them than with mammals and I would suspect they had broadly similar brains.

I know that many of the theropods (avian dinosaurs) had large brains and were smart. However, many of the big plant eaters had comically small brains, especially when factoring in that brain size scales with body mass, at least in mammals. This is necessary just to provide enough computational power to take in and process all of the nerve inputs of such a large body. Like I said, some dinosaurs like stegosaurs had brains the size of walnuts or peanut pods. No matter how neuron-dense their brain were, they would not have been very smart animals. They did have nerve bundles near their hips, which likely would have done some of the nerve-signal processing but were not true brains.

And I'm also emphatically not placing any premium on brain sizes or 'smartness'. I'm not making any value judgement on the things, just commenting on what I've recently learned and how that interplays with other things I previously learned. I'm not saying stegosaurs were bad for being dumb, or that crows are good because they are smart, just stating these things as fact. You read too much into my previous post. I simply wonder if some dinosaurs - notably the ones with massive bodies and tiny brains - might have been a bit smarter than we might otherwise assume in light of the fact that bird brains are more neuron-dense than mammals.

Too late in the evening now to answer more comprehensive...

Consider for that stegosaurus
A lot of our human brain is dedicated for rather non-intellectual features:
our thumb, as handy animal, has relatively to the size of our thumb a lot of brain neurons dedicated to it. Our tongue as speaking animal similar.
The other thing is that in general both brain size as amount neurons are in general relatively much higher for smaller animals (smaller in body weight).
A small fish, a small mouse having relatively enormous brains compared to humans or horses, and even more compared to an elephant. With insects the effect is even much bigger.

Looks to me that there is a base need of neurons to handle base motorique and base sensor (eyes, etc) handling.
The bone structure, the amount of musles, etc more or less the same for a mouse or an elephant... why would that part need to be handled by an elephant by so much more brain neurons than that of a mouse ?
ok... a mouse needs more for its fingers and toes because more "handy" than an elephant or hoofed animals.
Scaling up from a mouse to a rat... that's a very clever animal in the way we measure intelligence compared to a horse (rather stupid animal) or so many other far bigger animals.

To put it provokingly: why is the brain of a stegosaurus so much bigger than that of a rat ?

 

[Lemon Merchant]

The size of the brain does not always correlate with intelligence. If you factor out autonomous nervous control and instincts that occupy a fair bit of the brain, the actual amount left over for "thinking" is variable, depending on the animal. Humans have one of the most developed brains on the planet, followed by apes and dolphins/whales. I suspect, though, that the more we learn about the brain, we will learn that more animals are actually "intelligent" by a rudimentary measure. But back to my original point: You can have a large brain and limited intelligence. We see this even in humans. The average median IQ is around 90 to 110 (the top of the bell curve) and I forget the actual percentage of people that fall into this category, but it is large. Then you have outliers, people with IQ's below 25 or above 180 which should not be factored in as they skew the data. We can safely say that the human race is intelligent in that 90 to 110 is a perfectly functional IQ, and that those people are intelligent enough to live and care for themselves and function completely well in society. Yet those persons have a brain that is the same size as someone with an IQ of 150 or higher. How is it that the brain of a person with an IQ of 150+ is apparently more intelligent? The brain is the same size and has the same functional capability but seems to work better/faster (It's actually just better at solving puzzles) than a median brain. Why?

This is what we do not understand yet, and probably won't for a while. The same logic can be applied to dogs. Some dogs are very intelligent. Some are stupid as posts. Some of these dogs have the same brain size. What makes them different with respect to intelligence? My cat knows what time I get up and feed him in the morning, but he knows to let me sleep in on weekends. How does he know this? Yes, it's a learned behaviour, but how did he figure this out on his own, if he is not intelligent? How does he tell time? He wakes me up five minutes before my alarm rings every weekday morning, I can set a watch by him. How does he know to do this if he isn't capable of some kind of conscious thought? His brain is smaller than a human's, but it functions as well as someone with a low IQ. He understands some basic English words. Yes, his brain is largely taken up by instinct and autonomous nerve responses, but there has to be a layer of "thinking" there, just like humans have. It's just not as developed as ours, but I would still call him intelligent.

I'll just bet that stegosauruses were smarter than we give them credit for. We'll never see examples of machinery or architecture from them, but I doubt that they were complete dolts.

 

[hobbsyoyo]

I used to think we are smarter than dolphins and whales but I'm not of the opinion if they had opposable thumbs, we'd probably be the by-catch of their factory-hunting operations rather than the other way around.

It's quite troubling for me when I think of our ability to ever communicate with ET when we are so unable to do that with cetaceans. Though in our defense, I don't think we spend much resources on the cetacean-communication effort.

To put it provokingly: why is the brain of a stegosaurus so much bigger than that of a rat ?

Because even putting aside the nuances of muscle and limb structure, they have several orders of magnitude of surface area over the rats. Presumably, this means they have a lot more sensory nerves on their skin and around their bodies which produce inputs that must be processed and responded to. That they are so large means that to some extent, temperature regulation comes automatically which would lessen that burden a bit. But I have to guess that if you stuck a hot poker in its backside you'd still get a kick! That takes some level of processing power to accomplish, only it applies not just to where you've stabbed your hot poker but all over their massive bodies. This is going to drive them to have a larger brain than the rat even if it it's not big enough to make them smarter than the rat by any metric.

 

[Hrothbern]

I used to think we are smarter than dolphins and whales but I'm not of the opinion if they had opposable thumbs, we'd probably be the by-catch of their factory-hunting operations rather than the other way around.

It's quite troubling for me when I think of our ability to ever communicate with ET when we are so unable to do that with cetaceans. Though in our defense, I don't think we spend much resources on the cetacean-communication effort.


Because even putting aside the nuances of muscle and limb structure, they have several orders of magnitude of surface area over the rats. Presumably, this means they have a lot more sensory nerves on their skin and around their bodies which produce inputs that must be processed and responded to. That they are so large means that to some extent, temperature regulation comes automatically which would lessen that burden a bit. But I have to guess that if you stuck a hot poker in its backside you'd still get a kick! That takes some level of processing power to accomplish, only it applies not just to where you've stabbed your hot poker but all over their massive bodies. This is going to drive them to have a larger brain than the rat even if it it's not big enough to make them smarter than the rat by any metric.

Good point that more sensory input because of for example higher surface skin.
But
Body surface goes with the second power and body weight with the third power. An animal twice the lenght, at similar shape has 4/8, has only need for 50% handling of body skin sensorial inputs.
The other thing is that the amount of nerves varies great per square cm over our body. IIRC the difference is big between your fingertips or your buttocks. Factor 10 ?
Our evolution made choices there.

Perhaps part of the explanation is of a very banal nature.
Brain tissue needs really high metabolic resourcing (IRRC our 1,5 kilo brain, ~2% of body weight, consumes 25% or so of our oxygen consumption during rest).
A 10% more effective brain would save 2.5% energy. That does matter in evolution during the ever recurrent famine-starvation periods.
An animal with ten times the weight of us, with for example a brain the size of a human, would consume during rest only 2.5% of total oxygen/energy consumption.
A 10% more effective brain would save only 0.25% energy. A no-issue evolutionary factor.
Slack in bigger animals ?

And out of the blue for dinosaurs.
Our dry weight brain is something 10% (animal) omega-3.
Not that much available in food ! And vegetable omega-3 must be converted in animal omega-3.
Perhaps omega-3 was low in vegetable food in dinosaur period. Perhaps the metabolic pathways were in dinosaurs not that advanced as modern animals.
Who knows ?
Sea fish have always enough omega-3 from plankton. Carnivores have always enough omega-3 because they eat the brains of herbivores. The relatively enormous brains of insects ensured that insect eating birds, avian dinosaurs got enough.
And yes... some Papua tribes, in traditional cannibalism, eat the bodies of war victims, but the brains were for the pregnant and breast-feeding women. A female body metabolism will "borrow" omega-3 from the brain of the mother to grow the brain of the foetus/baby.
=> perhaps the herbivore dinosaurs could not build up bigger brains.

The issue I see is that we know so damned little !

And by lack of that we must try to understand from morphological data, from some eggs for parental care or not, etc.
What you need is also the big library of metabolic pathways that "we" gathered during the evolution.
Much on that is in going now, because we can put rough dates on enzymes currently in animals because we can estimate from the number of (DNA) mutations of that enzyme in various existing organisms how old that enzyme is.

Vit D is, evolutionary seen, for example a very very old metabolite. And no wonder that there are currently estimates that Vit D influences our metabolism in several thousands of ways !
A lot more than that one-dimensional "feature" to prevent rickets.
How "old" are our advanced metabolisms in absorbing and converting omega-3 ? When did the differentation emerge that females can convert twice as effectively as male ? And why was it advantageous for males not to pick up that metabolic improvement ?
And that's still hardware.

Everything to do with the software, the perception-decision features of our brain... how can we find back data on that ?

 

[Bugfatty300]

I used to think we are smarter than dolphins and whales but I'm not of the opinion if they had opposable thumbs, we'd probably be the by-catch of their factory-hunting operations rather than the other way around.

It's quite troubling for me when I think of our ability to ever communicate with ET when we are so unable to do that with cetaceans. Though in our defense, I don't think we spend much resources on the cetacean-communication effort.

There were serious attempts at it in the 60s and 70s. The results were fairly predictable:

Going back to the ocean was their biggest mistake. Good luck discovering fire while underwater, thumbs or no thumbs.