askscience

Candelestine , in Would it be possible to comfortable survive 10 Gs if the acceleration was slow enough?

So, this is a basic misunderstanding of gravity and acceleration. The measure of Gs is the exact measure of how fast the acceleration is.

This is just like asking if it would be comfortable to survive 100 C if the temperature was cold enough.

There is no difference between acceleration and gravity. If locked into an elevator, you wouldn’t be able to tell with certainty if the elevator started going up, or someone had just turned the gravity of the planet up to make you heavier somehow. If the elevator suddenly dropped in freefall, you would not be able to tell if it was the elevator moving down, or someone had simply turned gravity off somehow. This is part of Einstein’s Special Relativity.

Telodzrum ,

While you’re right, I think it’s pretty clear that the OP meant the change in acceleration or “jerk .”

mrcleanup ,

I don’t think we can assume that. This reads like a speed question to me too. But who can ever really know the unknowable mind of OP?

Emperor , in How good (or bad) is sunflower oil for cooking?
@Emperor@feddit.uk avatar

I use extra virgin olive oil for marinades and salad dressing (and an olive oil spread instead of butter or margarine) and rapeseed oil (usually just labelled as vegetable oil here in the UK) for frying. The latter has a high smoke point, is lower in saturated fat compared to sunflower oil (also higher in monounsaturated and lower in polyunsaturated fats, a bit like olive oil although that has even better proportions of the two) and has better levels of Omega 3.

Here’s a bit of a review.

And why you might want to avoid sunflower oil:

vegetable fats can change during the cooking process, breaking down into harmful chemicals, including aldehydes.

The stability of the oil is important too: some oils, like sunflower oil, are more likely to oxidise when heated – or combine with oxygen in the air – producing harmful compounds in greater quantities. A 2012 study by researchers at Spain’s University of the Basque Country reported that aldehydes can react with our hormones and enzymes.

With the issues with sunflower oil after the invasion of Ukraine the UK’s Food Standards Agency drew up a report about the substitution of other oils, which has plenty of data.

A switch away from sunflower oil should reduce levels of heart disease, following this paper:

Zatonski et al. [25] examined trends of mortality due to coronary heart disease (CHD) and fat consumption in eleven Eastern and Central European countries from 1990 until 2002. They observed that, in countries where sunflower oil remained the primary oil (such as Russia, Ukraine, Romania, and Bulgaria), the rate of CHD remained stable from 1990 onward. Meanwhile, in countries such as Poland, Czech Republic, Estonia, Latvia and Lithuania, which started to use rapeseed oil, a strong decline in CHD mortality was observed. This finding is confirmed in our study. Although both oils are rich in PUFAs, rapeseed oil contains more α-linoleic acid (ALA, C18:3), an omega-3 fatty acid with atheroprotective properties. Moreover, ALA is partly converted to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which may protect against CHD and cerebrovascular diseases [26, 27].

Ganondorf , in Would it be possible to comfortable survive 10 Gs if the acceleration was slow enough?
@Ganondorf@kbin.social avatar

Yes it is possible because it has happened. I'm not an expert, but I believe survival rates are connected more to duration than G force. If the body becomes unable to circulate blood and regulate itself for a long enough period of time, it dies.

WHYAREWEALLCAPS ,

That's exactly what happens. The human body cannot withstand more than 2-3 G for a prolonged period. Above that, the heart just can't pump blood and you die if you stay there too long. For instance, Stapp, the world record holder only withstood 46.2 Gs for a brief instant. Normally your blood weighs about 8-10% of your total body weight, so for the instant he was at 46.2 G, he weighed about 7700 lbs and his blood weighed between 616 lbs and 770 lbs.

ShaunaTheDead , in Blackhole Warfare Strategy
@ShaunaTheDead@kbin.social avatar

Time moving slower inside a black hole's gravitational field would have the opposite effect from what you're thinking. Like in the movie Interstellar, when they go down to the water planet they say "one hour on this planet is equivalent to 7 years on Earth".

So any civilization within a black hole's gravity well would actually be at a huge disadvantage and have considerably less time to prepare.

tkohldesac OP ,
@tkohldesac@kbin.social avatar

Sorry - just saw this now.

I think you're right, I'm thinking about it exactly opposite. That was a good example, thank you!

toasteranimation , in Okay, but how actually do mirrors reflect light?
@toasteranimation@lemmy.world avatar

light is also a wave, and don’t forget, some wavelengths will go right through the mirror and not reflect at all

en.wikipedia.org/wiki/Wave–particle_duality

Tomassci OP ,
@Tomassci@kbin.social avatar

That is indeed true, but how do you redirect a wave with what is just a bunch of atoms? Do you reradiate it?

toasteranimation ,
@toasteranimation@lemmy.world avatar

No, the wave is just bouncing off the atoms in the mirror, same as sound would

Tomassci OP ,
@Tomassci@kbin.social avatar

How does that work?

toasteranimation ,
@toasteranimation@lemmy.world avatar

See Newton’s Laws

Tomassci OP ,
@Tomassci@kbin.social avatar

I don't that's how it works, after all it's a different scale and quantum mechanical

exohuman , in Drug-resistant fungi are thriving in even the most remote regions on Earth, finds new study
@exohuman@kbin.social avatar

Great. The Last of Us minus the violence. Just what climate change ordered.

ShaunaTheDead , in If photons don’t ‘experience time’ how do they experience space?
@ShaunaTheDead@kbin.social avatar

It's a bit more easily understood if you look at a space-time diagram, but essentially it kind of boils down to the speed of an object through space and the speed of an object through time are related and they must add up to 1. So if you're traveling at 50% the speed of light through space, then you're traveling at 50% the speed through time compared to an object at rest. So if you're traveling at 100% the speed of light through space, you're traveling at 0% through time, or not at all.

Moogly OP ,

I’ve read about this but it kind of loses me since it’s such an abstract model of what’s going on. It treats each dimension as equal but like, time certainly seems distinct from the 3 spatial dimensions too.

I know it’s legit and a proper way of understanding it though just nitpicking since it leaves me with a sense of fuzziness like, maybe a gross oversimplification?

Granted I know it’s only meant to explain what’s happening in a predictable way not actually address the nature of these values which I guess is what I naturally lead into wondering about

ShaunaTheDead ,
@ShaunaTheDead@kbin.social avatar

I found this channel (Science Asylum) really helpful in explaining things very simply. He uses space-time diagrams in this video to explain how gravity is an emergent property of time and how the two are linked together.

FlowVoid , in If photons don’t ‘experience time’ how do they experience space?

Redshift depends on the observer, so photons do not “experience” redshift until they are detected in an ordinary reference frame.

Furthermore, I’m not sure there is a good way to define the “experience” of a photon. Photons simply move through space until they interact with matter, and matter is never in the same reference frame as light.

Moogly OP ,

Yeah I figure “experience” is sort of ambiguous and pop science-y, but it’s how I’ve usually had it explained.

That redshift depends on the observer is obvious now that you point it out and profound too since yeah, I suppose they’re not developing across space in the way I imagined.

This makes me wonder about a potential universe with nothing except photons/radiation in it. They’d just.. never change? Even though they could do things like affect spacetime they pass through or interfere with eachother?

tal , in Why do we associate nuclear radiation with a green glow?
@tal@kbin.social avatar

Some possible factors, from reading similar discussions:

muftiboy ,

since 1) and 3) are things that maybe 10 people in the world even know about, it's probably the Simpsons yeah

tal ,
@tal@kbin.social avatar

In 2023, yeah, but remember that it isn't in 2023 that the association was made.

Tritium watches used to be a much bigger deal some decades back, as you could actually use the thing in the dark. Subsequent to that, battery-powered digital watches with a light became common, and then a lot of people just moved to using a cell phone to know the time.

As the linked WP article details, uranium glass also used to be more-common prior to the government locking up a lot of supplies of uranium. I've only seen uranium glass in person in museums, and in general, plastic has displaced a lot of glassware today.

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