The human heart shows signs of ageing after just a month in space

126 pointsposted a year ago
by gnabgib
(nature.com)

89 Comments

rafram

a year ago

Absolutely insane and cool that it’s possible to grow part of a heart in a lab, put it on a dish, blast it off into space, and study its behavior. So much in our modern world would’ve been a sci-fi dream only a few decades ago.

Andrex

a year ago

I wonder if there will ever be a legalized market for synthetic human meat.

Zigurd

a year ago

The Kardashians will license their DNA under the brand Eat the Rich.

jajko

a year ago

Now who would eat that garbage junk food, I hope people have higher moral standards... oh wait

amelius

a year ago

Probably a bad idea. Research tells us that prion diseases existed more among cannibal groups.

JumpCrisscross

a year ago

> prion diseases existed more among cannibal groups

Presumably one would exclude protein classes prone to prionic misfolding from the synthetic meat. Personally, I have no moral qualms with someone sampling lab-grown human flesh, though I’d probably pass.

jajko

a year ago

Aren't prions nerve cells + something something? Muscle cells are not that different from muscle cells of animals we eat regularly.

wizzwizz4

a year ago

Prions are misfolded proteins that act as enzymes to turn healthy proteins into more of themselves. The scary ones destroy the nervous system, but that's not an inherent part of being a prion.

dredmorbius

a year ago

Large-scale meat synthesis is a bacteriological outbreak nightmare even falling far short of that, but yeah.

owenpalmer

a year ago

Meat for eating? Hopefully not. Meat for organ and tissue replacement? Hopefully so.

Hammershaft

a year ago

Why hopefully not? As long as it's safe I don't see any ethical grounds for criminalization. Lab grown meats might open the door to all kinds of chimeric meats flavors we can't even dream of right now, all without animal suffering, deforestation, or the ingestion of bioaccumulated toxins.

__MatrixMan__

a year ago

It would be a little unsettling to run across somebody who was successfully creating foods which resembled meat who had chosen "resembles human" as the direction that they'd like to pursue.

TeMPOraL

a year ago

If there's a demand (or it can be induced), it's called "entrepreneurship".

hackernewds

a year ago

We could sustainably eat dog meat as well, but we don't. Same for humans.

TeMPOraL

a year ago

AFAIK in some countries people do eat dogs just fine.

In the western sphere, people don't, but that's a combination of an ick factor and there being plenty of alternatives far more efficient/sustainable (and I guess, tastier) than dogs.

And then, if you paid the right person enough (which may be very little, if you choose your supplier right), you could still get dog meat if you really wanted. Much like life, and for the same reasons, the market finds a way.

Zigurd

a year ago

Some prominent people assert they do.

ben_w

a year ago

Only when everyone else isn't so disgusted by the idea that they dismiss it out of hand.

I could give four examples that are already available synthetically but not acceptable to payment processors due to widespread disgust, but I suspect it's unwise to knowingly suggest here things that trigger most people's disgust reflexes.

iwontberude

a year ago

Hey I stick to organic payment processors, like maple syrup. Decent inflation, can be prone to blight or other natural disaster but none of that synthetic stuff.

ben_w

a year ago

Great, but I have yet to meet a landlord which accepts maple syrup as rent for the space in which to put a commercial food-grade bioreactor lab.

TeMPOraL

a year ago

Go deep enough into the woods on some remote place on Earth, and I bet you'll find them. Bring your own electricity though, they likely don't have any.

ben_w

a year ago

"If you go down in the woods today, you're sure of a big surprise." etc.?

TeMPOraL

a year ago

More like "find some local village leader from a society a step above the Sentinelese on the development ladder", but I was struggling to find a way to phrase it in a way that wouldn't be accidentally offensive to someone.

Point being, such a "landlord" will happily take your maple syrup and let you do approximately whatever on the land you lease from their tribe. They won't mind a "commercial food-grade bioreactor lab" because they have neither a reference point for it, nor a use for one, but because of that you'll also need to provide your own infrastructure and supplies somehow.

(Also first time around, I read it as "food-grade bioreactor" without the "lab" bit, so I imagined setting up a shed with some fancy biotech equipment; now I see you probably meant a manufacturing plant.)

ben_w

a year ago

Ah, I see. That might work.

My reference point for this kind of thing would be the Quorn factories.

Zigurd

a year ago

> Only when everyone else isn't so disgusted by the idea...

BNPL? Worldcoin? Flow? Juul?

ben_w

a year ago

> BNPL

By Now Pay Later? I don't see how that will help…

Likewise I have no idea what you mean by "Flow": https://en.wikipedia.org/wiki/Flow

Worldcoin might be an example of this, hard to tell from here how much of its issues are fundamental vs. implementation.

Juul, the e-cigarette company, almost certainly isn't — too many people smoke for that to be the case, even with the way they were advertised at teens.

owenpalmer

a year ago

Getting lots of people to acquire a taste for human flesh is a bad idea. Also, my monkey brain says "Ew".

hackernewds

a year ago

You seem to have an intense curiosity about this topic. Any reasons?

Hammershaft

a year ago

In this case the behavior we're discussing (eating ethically sourced lab grown human meat) doesn't infringe on consent, cause suffering, create negative externalities, or anything of the like. unqualified emotional reactions don't pass muster as a basis for criminalizing victimless behaviors.

qwertox

a year ago

Huge market for influencers. "Be like me."

DaoVeles

a year ago

This is no surprise. Look up how Scott Kelly described his experience coming back after a year on the ISS.

https://www.snexplores.org/article/how-year-space-affected-s...

vavooom

a year ago

"The researchers tested Scott again after six months back on land. Roughly 91 percent of the genes that had changed activity in space were now back to normal. The rest stayed in space mode. His immune system, for instance, remained on high alert. DNA-repair genes were still overly active and some of his chromosomes were still topsy-turvy. What’s more, Scott’s mental abilities had declined from preflight levels. He was slower and less accurate on short-term memory and logic tests."

tirant

a year ago

What that study does not take into account is that Scott was traveling around the world for 6 months giving interviews. I would have also expected a decline in that context.

Also his mental abilities recovered back to baseline some time after.

piyh

a year ago

His vision didn't

hackernewds

a year ago

that doesn't explain the changes in genetics

datameta

a year ago

I need to look through the study more, but what was done to control for the isolation that a year on the ISS brings?

hackernewds

a year ago

You could easily control for it by comparison with a cohort who has just discovered DoTA

suprjami

a year ago

I don't think that's a factor. The ISS is anything but lonely. Astronauts have internet up there and are regularly in touch with their family. I think it's also reasonable to say they know what they're getting into when they go up, so physical separation is unlikely to affect astronauts as badly as the general population. Many of these people are ex-military and have regularly been on long deployments away from home.

datameta

a year ago

I'll have to disagree based on my reading of Endurance by Scott Kelly. It is more the profound isolation away from everyone on earth, not the lack of communication. He struggled with saying goodbye to everyone who came up to the station with him, as he watched the missions rotate. It becomes different when you're doing a whole year vs 3-6 months.

pvaldes

a year ago

Substitute "human heart" by "a culture of isolated cells of human heart growing on a petri dish". Not the same thing.

hackernewds

a year ago

Fair means of testing

pvaldes

a year ago

How can we study a valve ageing or a worn cartilage if we don't even have a valve or a cartilage to watch?

Is ageing here defined as: "nutrients in my Petri dish are going exhaust so I will go pop"?

Aldipower

a year ago

Does it aged just one month?

RecycledEle

a year ago

I had hoped Robert Heinlein's hypothesis (in his fiction books) about zero-G lessening the demands on the hyman body and therefore increasing out lifespans would pan out.

Maybe science will come up with something.

wongarsu

a year ago

If the simple version of that hypothesis is true, then why is exercise so beneficial? Even in 1g our lifespan suffers if we don't regularly stress our body.

Maybe in 0g it is possible to find a better balance with lower baseline stress, with regular high-stress periods. But any ideas on how to even reach earth-equivalent levels of healthiness require much better space stations than what we have or build today

devmor

a year ago

The problem with that idea is that the human body exists via evolutionary fitness for gravitational stress.

Imagine a mechanical arm whose purpose is to put constant hydraulic pressure against a platform that is putting pressure towards the arm. Now imagine what happens when you take away the platform - the arm would likely damage itself unless specifically designed to handle the lack of pressure.

wileydragonfly

a year ago

Permanently screws up your vision, too

tomwiddles

a year ago

In what way? This is news to me

wileydragonfly

a year ago

Body is evolved to have fluid under pressure to resist gravity. You get rid of gravity and we aren’t built for it. I was peripherally involved in a research study where they were going to strap people to beds for three months with their heads below their torsos. Every so often they would be wheeled into a centrifuge to see if it would counter act the damage. It’s so risky you can’t do it in America so we had to use human subjects in Germany which was… on brand.

lifeinthevoid

a year ago

Next to all the other difficult problems to solve when sending people to Mars, this one looks particularly nasty.

user

a year ago

[deleted]

dan-robertson

a year ago

Perhaps we could learn more about space if we diverted a bit more money towards telescopes and probes and rovers and suchlike, and a little less money towards figuring out life-support for primates in LEO. But then I write this as someone who’s taxes do not go towards NASA, nor indeed towards any notable space exploration.

yapyap

a year ago

Man the astronauts reading this must be stressing rn

JoeAltmaier

a year ago

The health hazards of space may be entirely treatable or preventable, with enough research. By no means in the human body any kind of barrier to exploring space!

There have been so very few space denizens, the science is in its infancy.

Space travel itself could be changed. For instance, a rocket to Mars may swing the habitat in a circle at the end of a miles-long wire to create artificial gravity. To those that claim 'acceleration is different from gravity', take your physics course again.

And people can be changed. It took a special kind of person to live at high altitude, and on an island with periodic feast-and-famine, and on a 2000 calorie rice diet, and in a crowded city, and on a submarine.

We can imagine (and often have in science fiction) a person built to crew long space missions. And we can imagine space missions designed for humans. Right now it's all in early days.

pdonis

a year ago

> create artificial gravity. To those that claim 'acceleration is different from gravity', take your physics course again.

The physics course, at least if it includes General Relativity, will tell you that what the human body is used to is not gravity but acceleration. The astronauts in free fall in the ISS are fully responding to Earth's gravity; the difference between them and the rest of us stuck here on the Earth's surface is that we are feeling acceleration, because the Earth's surface is pushing upward on us, and they are not.

The potential issue with having a spaceship habitat swinging in a circle to create acceleration is the Coriolis effect; that would make it feel at least somewhat different from being on the Earth's surface, even if the magnitude of the acceleration were 1 g. That might cause something like motion sickness in some people--but then again, so does free fall. (I myself don't even like roller coasters, so I would probably be a very poor candidate for being a free-fall astronaut.)

nine_k

a year ago

AFAICT, the equivalence of gravitational and inertial masses is not a completely solved problem in modern physics.

Earth also rotates, and thus the Coriolis effect is present. It's not as noticeable as in a fast-rotating habitat in space, but air navigation, naval navigation, and artillery all make adjustments for it, among other factors, especially at high latitudes.

pdonis

a year ago

>* the equivalence of gravitational and inertial masses is not a completely solved problem in modern physics.*

I'm not sure what you mean. In GR the two are equivalent, period. There is no open issue there.

> Earth also rotates, and thus the Coriolis effect is present.

Yes, but on the scale of a human it is far, far too tiny to be detectable. So it doesn't make a difference to what humans experience on Earth, even though, as you note, there are scenarios in which it has to be taken into account.

In a space habitat swinging around to provide artificial acceleration, however, I think the Coriolis effect on a human would be large enough to be detectable by the human. At least unless you made the length of the cable it was swinging on of the same order as the radius of the Earth, i.e., thousands of kilometers, which is not likely to be practical.

nine_k

a year ago

In GR, the equivalence of inertial and gravitational masses is assumed, not proven in any way [1]. GR, of course, holds exceptionally well during the last 100+ years of experiments.

Indeed, in a small enough rotating habitat, jumping straight up would reveal the direction of rotation, and jumping "forward" and "backward" would have noticeably different results.

There's hoping though that the mechanisms which under zero g make the bones lose calcium, make tissues with a lot of small blood vessels swell, etc, won't be as seriously affected by the small variations introduced by the Coriolis effect as they are affected by the lack of weight and the pressure resulting from the weight. Solving 100.00% of a problem would be wonderful, but solving roughly 90% would already be highly beneficial.

[1]: https://en.wikipedia.org/wiki/Equivalence_principle#Einstein...

pdonis

a year ago

> In GR, the equivalence of inertial and gravitational masses is assumed

No, it's not, it's a necessary part of the way GR models gravity as spacetime curvature with the metric being the only "field" associated with gravity. You can't do that and have inertial and gravitational masses being different. I guess you could call modeling gravity as spacetime curvature with the metric being the only "field" associated with gravity an assumption, but it's an assumption that has a lot more consequences than just the equivalence of inertial and gravitational mass. So the latter is not usefully viewed as an "assumption" in GR by itself. It's one of many consequences of a much broader assumption that is the entire basis of the theory.

It is true that there are other theories of gravity that use spacetime curvature, but they all have additional fields besides the spacetime metric that are associated with gravity. And all of them known so far are ruled out by experiment, or at least the only region of their parameter spaces that are compatible with experiment make the extra fields observationally meaningless and the theories become equivalent to GR in all their predictions.

fouc

a year ago

There is a gravity gradient in the centrifuge, for a 2m tall person, if the radius is only 10m, gravity gradient ranges from 20% to 100% from head to toe, meaning it's quite noticeable. But at 100m radius it's only 2%, and presumed to not be noticeable (I'm not sure if they've actually put that to the test).

https://ntrs.nasa.gov/api/citations/20070001008/downloads/20...

pdonis

a year ago

> a gravity gradient

More precisely an acceleration gradient, at least in the terminology I was using in my previous post. Yes, this is a good point.

JoeAltmaier

a year ago

So use a 1km tether. Lots of room in space.

tptacek

a year ago

By a lot of means is the human body a kind of barrier to exploring space, so many and with such intensity as to call into question the whole exercise. Maybe it'll all work out, but it seems unreasonable to literally dismiss the question.

SoftTalker

a year ago

I think it's unlikely. Humans (and all other life on Earth) evolved to live on Earth. I think it's very doubtful that humans can live long-term anywhere else.

JoeAltmaier

a year ago

That supposition is not altogether clear - seeds of life may have been asteroid/meteorite provided, in which case life on earth was evolved for different places entirely.

Anyway, the Cambrian explosion shows how life can fill any ecological niche from ocean-bottom sulfur vents to mountaintops, from the stratosphere to mudpots in Yellowstone.

We don't have to wait for that. Lots of science fiction about making people to fit the world. An obvious solution, and already we're gaining the tools to do it.

kibwen

a year ago

Sure, but once you engineer a creature capable of living in 0g, it seems likely that the biological difference will be great enough that we'll be calling it something other than "human". And it almost certainly won't be capable of living on Earth without life support.

AStonesThrow

a year ago

All we need to do is compare the extent to which Man has explored space (and oceans and volcanoes etc.) vs. the extent that robots have been sent on our behalf, with quite resounding success, and the barriers are self-evident.

Not to mention the liability and really bad P.R. when human lives are lost in that pursuit.

JoeAltmaier

a year ago

Eyesight issues? Bone issues? Null-gravity related. Solutions are clear there, and not even hard

Radiation, that one is difficult. Water barrier? Magentic bottle? harder.

What other issues? The 'submarine' one has been largely solved, for, you know, submarine crews.

tptacek

a year ago

It seems you take my point. :)

JoeAltmaier

a year ago

And I presume you take mine - that smarter people than us will be highly motivated to solve the problem. :)

tptacek

a year ago

I don't agree, but past "this is a question worth taking seriously" I don't feel committed to litigating it; reasonable people can disagree!

jwells89

a year ago

Yes, there's clearly hurdles on the path but I think they're well worth figuring out how to clear.

There's multiple reasons why but one that stands out in my mind is the sheer difference in trajectories between a species that embraces spacefaring and comes to live on multiple worlds compared to a species that remains confined to its point of origin. In the long term, the former of those two will eventually fan out to other star systems and explore countless more modes of existence, structuring of societies, ways of expression, avenues of science, etc than the latter can ever hope to. Staying put stymies potential to an extent that's difficult to even comprehend.

Marsymars

a year ago

In the long term, with the distances in space, the former of the two probably isn't a single species, so the scenario isn't really "a multi-planet species", it's "multiple single-planet species with a common ancestor".

jajko

a year ago

You are mixing few different things here - yes AFAIK sherpas / tibetans have genes preselected to cope better with altitude, but there is absolutely 0 zilch nothing of such about 'crowded city or a submarine'.

WTF would that actually even be, submarines have cca surface pressure, maybe you meant adaptation to generally shitty soulless draining more stresful environments? Again, nothing like that out there in gene pool, city folks generally love running away to the nature as much as they can, at least those who already experienced how healing and recharging it can be and can afford it.

JoeAltmaier

a year ago

Yet they screen successfully for submariners and get a good crew. Their genes came from somewhere.

And every human in existence has been adapted over the last 50K years for tribal, village and city conditions. Early hominids were very different - hairier, loners, more fractious, used more calories, communicated less.

AMH (anatomically modern humans) have co-evolved with crowded conditions, to live in groups and tolerate each other without killing one another. So maybe three modifiers on that was hyperbole.

jajko

a year ago

Man you are all over the place and mixing stuff that doesn't make sense.

Evolution of some trait as adaptation to environment vs selecting by test from general population with variable levels of traits are completely different things.

The other points are in same vein, no point wasting more time.

c420

a year ago

>And every human in existence has been adapted over the last 50K years

50k years is a blink in the context of evolution. You're looking exclusively at cultural adaptations in this timeframe.

JoeAltmaier

a year ago

Not an evolutionary biologist? Read up on it.

Humans have evolved more in the last 50K years than in the 1M preceeding that. I'm talking about biological adaptation, though you bring up a reasonable point that cultural adaptation is another tool to help bring success.

user

a year ago

[deleted]