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SorteKanin , in Given a writing speed of one logical symbol per planck time, would the amount of time it takes to write Rayo's Number exceed Rayo's Number?
@SorteKanin@feddit.dk avatar

Write it how? Seeing as Rayo’s number is defined as the smallest number bigger than what can be written in first order set theory with a googol symbols, you could probably write down the number with, say, googol+1 symbols. Or let’s just say 2*googol symbols, that should certainly be enough. It would not take Rayo’s number amount of seconds to write down 2 * googol symbols.

TL;DR: No.

Sims , in How do different body parts (specifically shape) emerge from our genes?

how cells form into specific shapes for arms, hands, organs, etc.

Not really qualified to answer, but Michael Levin have done some very interesting work on bioelectricity and growth of bodyparts. He is beginning to control the cell/formation of bodyparts, and other fascinating stuff. There’s some fine interviews on yt.

(Just for fun!)

Oh, just noticed that. Anyway, you seem interested in the subject, so you should check him out anyway ;)

remotelove OP ,

I am totally interested in this stuff, so thanks! I’ll absolutely check that out.

Oh, this is my version of “fun” and it’s not for work or any kind of project for a school. ;)

MightBeAlpharius , (edited ) in What mechanism is the source for Earth's Nitrogen?

I’m not a scientist, but one could argue that it’s likely that all three planets had nitrogen, but only Earth still has it.

I don’t know much about Venus, but I know that part of why we have way more atmosphere than Mars is due to Earth’s magnetic field. Earth has a much stronger magnetic field than Mars, and it does a pretty good job of shielding us from the solar wind; meanwhile Mars has been slowly trickling atmosphere into the void for ages because it lacks that shielding.

Given that CO2 is actually super heavy, it makes sense that Mars would lose almost everything else first. You mentioned H2, but it’s also almost twice as heavy as N2 - because of this, nitrogen would concentrate at higher altitudes, eventually becoming exposed to the solar wind as lighter gases were stripped away.

As for Venus… Again, I’m not an expert, but a quick search suggests that it has a weak magnetic field as well. With a primarily CO2 atmosphere and a weak magnetic field, one could infer that Venus is in a similar position to Mars, and any significant nitrogen that may have been in its atmosphere has simply been stripped away by the solar wind.

sneezycat ,
@sneezycat@sopuli.xyz avatar

You mentioned H2, but it’s also almost twice as heavy as N2

Nope, H2 is ~2g/mol while N2 is ~28g/mol. Nitrogen is a heavier element and nitrogen gas is therefore heavier as well.

I like your hypothesis otherwise!

MightBeAlpharius ,

Sorry, I think my phrasing might have been kind of weird - I was referring to the weights of H2 and N2 relative to CO2, which weighs a whopping 44 grams per mol.

…Although, I just did some quick estimates last night, and “almost twice as heavy” was still pretty far off. CO2 is much closer to 1.5x the weight of N2 than double the weight of N2.

sneezycat ,
@sneezycat@sopuli.xyz avatar

Oh yeah, that makes much more sense, I thought you might’ve meant that. Confusion cleared!

JoBo , in What's the equivalent of physics constants for social studies?

You reminded me of this exchange between Robert Cousins and Andrew Gelman:

Our [particle physicists’] problems and the way we approach them are quite different from some other fields of science, especially social science. As one example, I think I recall reading that you do not mind adding a parameter to your model, whereas adding (certain) parameters to our models means adding a new force of nature (!) and a Nobel Prize if true. As another example, a number of statistics papers talk about how silly it is to claim a 10^{⁻4} departure from 0.5 for a binomial parameter (ESP examples, etc), using it as a classic example of the difference between nominal (probably mismeasured) statistical significance and practical significance. In contrast, when I was a grad student, a famous experiment in our field measured a 10^{⁻4} departure from 0.5 with an uncertainty of 10% of itself, i.e., with an uncertainty of 10^{⁻5}. (Yes, the order or 10^10 Bernoulli trials—counting electrons being scattered left or right.) This led quickly to a Nobel Prize for Steven Weinberg et al., whose model (now “Standard”) had predicted the effect.

I replied:

This interests me in part because I am a former physicist myself. I have done work in physics and in statistics, and I think the principles of statistics that I have applied to social science, also apply to physical sciences. Regarding the discussion of Bem’s experiment, what I said was not that an effect of 0.0001 is unimportant, but rather that if you were to really believe Bem’s claims, there could be effects of +0.0001 in some settings, -0.002 in others, etc. If this is interesting, fine: I’m not a psychologist. One of the key mistakes of Bem and others like him is to suppose that, even if they happen to have discovered an effect in some scenario, there is no reason to suppose this represents some sort of universal truth. Humans differ from each other in a way that elementary particles to not.

And Cousins replied:

Indeed in the binomial experiment I mentioned, controlling unknown systematic effects to the level of 10^{-5}, so that what they were measuring (a constant of nature called the Weinberg angle, now called the weak mixing angle) was what they intended to measure, was a heroic effort by the experimentalists.

souperk OP ,
@souperk@reddthat.com avatar

Really interesting discussion, thanks for sharing 🙏

DickFiasco , in Utility of Arc Furnace Versus Other Heat Sources

Coal and lime probably don’t have a high enough inductance to be heated by induction. Induction furnaces are limited to metals as far as I know. Also, the temperature required for this process is almost 4000°F, which is difficult to obtain by combustion. Thus, electric arc is about the only way to go.

e_t_ OP ,

But the process does just require heat, right? So if you had a magical furnace that could reach that temperature, it would work as well? Or does the electric arc itself do anything to the chemistry?

cecilkorik ,
@cecilkorik@lemmy.ca avatar

Yes, you could probably use a laser furnace if it was cost-effective at those power levels. But it’s not even close. Arcs are and very practical in almost every sense and ridiculously cheap besides the power they consume. And a laser would consume more.

MalReynolds , in Hard Science Futurism: What types of theoretical prefabricated materials would the first stellar generation ship carry to construct an O'Neil cylinder upon arrival?
@MalReynolds@slrpnk.net avatar

Why ship pieces instead of shipping manufacturing capability (nano 3D printing etc) and use resources at the end point? By then presumably we’ve got asteroid mining down, no?

j4k3 OP ,
@j4k3@lemmy.world avatar

I think it would likely be similar to engineering materials today. The highest performing materials are very difficult to manufacture and we are talking about pushing them near their limits. I think a lot of the substructure will be made in-situ, but I think the most stressed parts of the main structure will require the largest scales of manufacturing. Like Sam Zeloof made a chip fab in a garage, so why doesn’t he start producing the next Nvidia GPU. It is that kind of difference here. A lot can be done there, but nothing like what can be done on the cutting edge of what humans are capable of making at out largest and most advanced facilities.

MalReynolds ,
@MalReynolds@slrpnk.net avatar

Fair cop.

Kit , in Is there any scientific study about where should the bed be facing?

It’s safest to keep your bed against an interior wall instead of a window, in case of earthquakes or other natural disasters. Or even someone crashing their car into your house, bombs dropping, etc.

linucs OP ,

Source? :)

Anyolduser ,

Source is that cars usually crash into houses from the outside and not out from the inside.

A secondary source is that broken glass comes from windows and not walls that don’t have windows.

It’s a bed. You’re overthinking this.

WhyAUsername_1 ,

Hahaha I laughed so hard at this one.

Kit ,

Broken glass hurts.

Witchfire , in Is there any scientific study about where should the bed be facing?
@Witchfire@lemmy.world avatar

North-facing bed in a south-facing room, so the morning light comes in behind you. Reverse this in the southern hemisphere.

fiat_lux , in Can placebo effect really help you heal faster and cure physical illness ? If so won't someone who works out too little but believes in himself too much get jacked beyond comprehension ?

Getting jacked is a physical process that requires mechanical damage and healing to individual muscle fibres all over the body in every muscle (unless targeting specific groups only).

Placebo effect is possibly the result of people actively influencing their hormone levels and balance to encourage hormones that promote healing. Specifically increasing serotonin, that we know plays a big role in sleeping, which is where you do most of your healing. Serotonin also makes your entire food to energy pipeline function. More energy allows more energy to be dedicated to healing. Serotonin is also used to create ATP, which activates the muscle fibres.

So I would guess that you could probably increase the speed of getting jacked via placebo effect because your chemical balance is altered to promote serotonin. But you couldn't be sedentary and get jacked. And you could maybe not outpace someone else getting jacked if they're spending more time exercizing than you.

Disclaimer: I am not medically trained, I'm just someone who has been forced by circumstance to learn about the endocrine system and its tyrannical rule over organisms.

ericxjo ,

Uh, what’s the story behind the disclaimer if I may ask!?

fiat_lux ,

I rolled a natural 1 for END(ocrine function) in the womb and ended up with one of the comorbidities they didn't predict would be unfortunate with covid.

Unfortunately doctors know very little about hormones overall, which ironically makes it pretty easy to cover as a topic when researching possible ways to make your body do... the whole being alive thing. Serotonin happens to be one of the main hormones I'm tinkering with to try to partially unfuck what covid did to my brain.

dependencyinjection , in Can placebo effect really help you heal faster and cure physical illness ? If so won't someone who works out too little but believes in himself too much get jacked beyond comprehension ?

There is a great long video on this on YouTube from Medlife Crisis who is a doctor at a London university hospital. Well worth a watch.

Link

xkforce , in Has a vaccuum chamber ever been used for desalination?

You could but the reality is that using a semipermeable membrane and a difference in pressure is more energy efficient.

peto , in Would a mechanical counter pressure suit make you poop?

Probably not? I think the suit would have to hold all of you together to work otherwise you would risk parts of you following the waste.

I’m also pretty sure the vacuum doesn’t even top the list of things you need a space suit to protect you from. Eva suits do a lot of work.

CanadaPlus ,

In terms of engineering, it does. Micro meteorite protection and heat management can both be provided by normal garments. UV protection is obviously easy enough too. Breathing gas is a bit less convenient, but still not as tricky as making a suit that’s both rigid enough to reliably hold several PSI in and flexible enough to comfortably work in. That’s why the elastic suits are being researched like they are.

AmalgamatedIllusions , in Potential energy created by same poles of magnets

Yes, he’s right that bringing the poles of two magnets together puts the system in a state of higher potential energy. And, yes, you could use this as an explanation for “why” the magnets repel by invoking the principle of minimum energy. You can even show that this results in a force, as a gradient in the potential energy is mathematically equivalent to a conservative force. I do think, though, that you can give further justification for the principle of minimum energy than he gives in the video, as it follows from the second law of thermodynamics (see Wikipedia article). Regarding the exchange of virtual photons and using this to explain how the electromagnetic force arises: I would avoid this entirely.

One side nitpick though: I wouldn’t say that the energy came from “the chemical bonds in the food [you ate]”, but rather the formation of new bonds as you digest the food. Chemical bonds are states of lower potential energy, so breaking them in the sense of separating the constituent atoms requires energy. It’s just that different bonds can have even lower potential energy and therefore release energy when they’re formed.

CanadaPlus , (edited ) in Why are we so concerned with oxygen production yet we never hear about nitrogen production, though we actually need 78% nitrogen vs 21% oxygen to survive?

Atmospheric nitrogen is useless to most life, as it’s extremely hard to break down into other nitrogen compounds. Certain bacteria are the exception, and they’re very important both to ecology and human agriculture (although less so since the Haber process was invented and artificial fertilisers became available). The other natural source of nitrogen compounds is lightning strikes.

Oxygen is completely the opposite. It’s unstable in an Earth-like environment (which is why fires happen), and if you find it in such an environment there must be something special producing it continuously. It’s not the only biomarker astronomers look for, either. There was a planet with insane amounts of a chemical called DMS found recently, and that’s just as eye-catching, if weirder.

Deep sea divers also use a nitrogen mix (nitrox) to stay alive and help prevent the bends

You’ve actually got that somewhat backwards. To go really deep you switch to heliox or similar. Nitrox is for intermediate depths where you need less oxygen than in the normal nitrogen-oxygen atmosphere, but nitrogen narcosis isn’t an issue yet.

OpenTheSeaLegs , in Why are we so concerned with oxygen production yet we never hear about nitrogen production, though we actually need 78% nitrogen vs 21% oxygen to survive?

When scuba diving recreationaly, Nitrox tanks actually have higher concentrations of oxygen, leaving less “space” for nitrogen and other gases.

Normal air tanks are filled at 21% oxygen. A nitrox tank will have more than 21%. The ones I use have 32% oxygen, wich helps when being at depths between ~20m and ~40m

I know that technical divers do use other gas concentrations, and they even change the nitrogen in the tanks for other inert gasses. But I’ve no idea of which gasses they use.

dylanmorgan ,

The most famous is Heliox, 98% helium and 2% oxygen iirc.

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