Stars have a lot of mass. The Sun loses almost 5 billion tons of mass every second and has enough fuel to last another 4-5 billion years. Adding a single ton of anything would make no appreciable difference. If you were to drop Jupiter into the Sun, it would have an effect, but Jupiter is only 0.09% the Sun's mass, so the effect would be small.
Depending on how you define a star, you could smush ~13 Jupiters together and make something that is maybe a star. To make a definite star you need ~80 Jupiters. To make it the same size as our Sun you’d need almost 250 Jupiters.
The fact they spin and the bits interact gravitationally makes them symmetric. There are almost certainly some asymmetric galaxies as we know galaxies collide and they will be asymmetric for a bit afterwards, but the spinning and fiction of gravity will make them symmetric again fairly quickly on galactic time scales.
Your question made me realize I had never thought about this at all so I spent some time searching. If I am understanding this article correctly it essentially boils down to the factors that would cause rotational symmetry at a smaller scale ie spinning sand on a plate apply at the galaxy scale as well.
OP phrased it weirdly but what they mean is that trees have all growth happen at the surface, not in the middle.
which is actually the opposite of how our skin grows, skin cells grow at the bottom of the skin and are pushed upwards by the new growth and mature as they go, until they reach the surface and die so that they can protect us and easily be shed to make space for new cells.
which is why you’ll see hollow trees being perfectly happy and healthy, whereas a human with an empty space underneath their skin is going to be uncomfortable at best.
Yeah my question was wrongly put but I thought trees did what you described skin does: I thought new tree cells were created in the middle and the outermost layers were the oldest ones.
well i’d say that trees grow in both ways: the stem grows on the outside because it’s acting more like our bones, but the bark acts like our skin and indeed grows in the same way, new matter being created at the base and pushed outwards, hence why a lot of bark has tons of cracks in them from the stretching.
Generally in trees you have the xylem in the middle which transports water and minerals from the roots to the rest of the plant. You have the phloem on the outside, it transports photosynthetic products and nutrients to all parts of the plant. The cambium where growth happens sits between them, because there they get easy access to water minerals and nutrients. The xylem is a mix of living and dead cells. The tracheids and vessel elements in the xylem, which are responsible for water transport, are dead at maturity. So it’s probably too hard to move them to grow from the inside out for trees. This whole process of growing thicker is called secondary growth as opposed to primary growth at the tips of stems and roots.
Also if were the other way around and trees would grow from the inside out, you’d have to have vessels going from the leaves to the center of the stems to deliver nutrients, which just complicates everything. And the tree wanted to grow from the inside by 1cm, every “ring” in the xylem would have to grow one centimeter longer in circumference or crack. It’s much easier to just add a layer on the outside. Also having living layer around the tree probably helps it defend itself from pathogens. If all the mostly dead woody stuff was on the outside fungi etc would have an easier time invading, I think.
So, the inner rings are actually the oldest. I’m no botanist, but I know that with your average deciduous tree, you have a layer right between the bark and first wood layers, and that thin layer is where the cell division for growth is mostly occuring. So, it actually is the exterior, just right beneath the bark.
Other kinds of plants are probably different, and again, I’m no botanist. Just have some basic biology study.
Trees grow layers on the outside, just underneath the bark. This is the only part of a tree trunk that is actively growing and is part of the plant’s circulatory system. All the older wood toward the center of the tree is basically only structural support.
There’s a technique called “collaring” used to remove invasive trees, if you cut a shallow, 4 inch tall ring from the bark around eye level, everything above that ring will die, because you’ve severed the circulatory system between the roots and everything above the collar
Not a direct answer, but I want to point out that if you’re considering a technology that will help improve poor people’s lives, you must also consider that technology is prone to the same issues that caused the wealth disparity in the first place. Namely, that only rich people can afford new technologies. Suppose if we really are able to edit human genes to let people drink salt water. Would poor people (the people who may actually need this technology) be able to afford it? Or will it end up just becoming a gimmick for rich people?
As others have pointed out, there’s really no need to be able to drink salt water, since we already have the technology to desalinate water. It’s only that poorer areas don’t have the funding to build desalination plants. You can start to see that it’s the same issue as what I said above - there’s a new technology that would theoretically help poor areas, but then it ends up not benefiting poor people because they can’t afford the technology.
All of this is not to say that new technology is bad. It’s simply that we already have solutions for a lot of societal issues, and the reason we still have those problems is simply because we as a society don’t care enough to distribute the benefits of those solutions fairly
Great question. Since we evolved consuming “fresh”, non-salt, water our physiology revolves around certain set points for normal neurological, renal, and basic cellular function. Consuming salt water changes the osmolality of the blood, which then causes shifts of fluid to try and balance the change of osmolality which negatively effects neurological function since we evolved to function within a strict range of osmolality, sodium level, etc. The body manages this from the pituitary/ adrenal / and renal perspective to maintain neurological function. If you could create a situation where the normal isotonic function is reset to a more hypertonic environment then that would be the start. I’m only familiar with human physiology and pathology but perhaps someone who is familiar with fish physiology could comment on how fish stay “hydrated”.
You make it sound like drinking salt water would solve all of our humanitarian problems or something. Lack of resources is not our problem, lack of fair and reasonable distribution of resources is. Never forget that five or six men own as much as the rest of the world combined.
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