This is where it starts to get exciting. Up to this point in human history, we have had no firm evidence of life on another world even though speculation runs rife. It is always just beyond our reach to detect it, but we may soon collect enough bio-signatures to infer its existence with reasonable confidence.
Life on K2-18 b is still pretty unlikely. Or at least what we would call life… There have been signs of Dimethyl sulfide, which would be one of those bio markers.
Salad is good for you, generally speaking, so growing fresh greens in orbit seems like a winning way for space farers to stay healthy. New research suggests that as nutritious as space salad might be, it could pose something of a risk to astronauts.
The problem is growing leafy plants like lettuce and spinach in space can come with a side dish of bacteria, according to a new study from a team at the University of Delaware. In tests on plants grown in simulated microgravity, they were shown to actually be more susceptible than normal to the Salmonella enterica pathogen.
Sounds like not a big problem at all. Seems like they'll just have to use appropriate cleaning methods. Even in the worst case scenario they would probably just have to use food irradiation.
Man, lots of people in this thread seem happy to accept any wild, physics-breaking idea rather than accept that there’s just a bunch of matter we can’t see.
I think it goes beyond not being able to “see” it and goes to we can’t detect it at all. Doesn’t dark matter just fill in the mathemagical holes with some numbers to make it all work?
We can detect its gravitational influence, as it interacts via gravity. The issue being that gravity is a weak force, and so there’s a lot of room for speculation.
But there is a lot of evidence backing up dark matter existing. But it’s not definitive yet.
I get that but it still sounds woo-woo since we can’t directly detect it. I’m not naysaying since I realize it’s the best we have and I’m not smart enough to come up with anything better.
I mean, I guess it depends on what you mean by “directly detect”. We measure neutrinos by having photoreceptors in huge tanks of very pure water deep under old salt mines… which hardly seems more direct than looking at where galaxies and stars are moving and calculating the gravitational pull and noticing that something is missing…
Dark matter is matter that we infir to exist only on its gravitational effects. We’ve observed its existence by the fact that it seems to clump up in the middle of two massive super-solar structures following a collision.
We can indirectly detect dark matter thru gravitational lensing. That is how NASA created this map showing the actual locations of dark matter in tinted blue.
Or the effect we see on gravitational lensing that is accounted for by “dark matter”? I don’t see how that could be explained by “light losing energy”…
Not an astronomer but if I read the article correctly the observations gathered about galaxies rotating and colliding would be explained instead by regional changes in what were previously assumed universal constants, which would be very interesting if true but 1 paper isn’t consensus yet
The team’s measurements even suggest that the supernovae that virtually cleared the bubble of space in which the Milky Way resides was born in a cluster of stars within the Radcliffe Wave.
Wait, the Milky Way is inside of a bubble generated by novae which were inside a cluster which is inside the Radcliffe Wave which is… itself… inside the Milky Way?
The Radcliffe Wave formation is a bunch of gas that is apparently, wiggling, in incredibly huge time and distance scales, like a sinusoidal wave.
So, imagine very, very long ago, before the Milky Way formed, you have a particular dense gaseous region/formation.
Dense gaseous regions tend to give birth to new stars. This region did so, and then one of them supernova’d.
Next, the Milky Way ended up forming in the void created by this supernova.
Then, this dense gaseous region was basically incorporated into the Milky Way (seems like one of its spiral arms) over another absurdly long period of time.
But, for some reason, it is wiggling, in a manner that dense gaseous regions have not been observed to behave in.
Thats the best I can do here, I am not an astrophysicist, though I did take two quarters of intro level astronomy in college lol.
Probably worthwhile to note that the article says that their data ‘suggests’ not ‘shows’ or ‘proves’ the bit about the supernova clearing the Milky Way void.
To actually prove that would encompass, among many other things, running the clock backward on star orbits/trajectories over billions of years using extremely complicated models and mountains of data I am absolutely not qualified to comment on.
Im just trying to very broadly explain the chain of events here if this supernova really did cause the void the Milky Way formed in.
Anyway, other fun fact: Our Milky Way Galaxy is not actually a pure spiral Galaxy as it has so often been depicted for quite a long time.
It is actually a barred spiral galaxy. Basically, instead of just swirly arms, there are actually short, more or less straight parts to the arms as they emanate out from the center, which then begin to curve into spirally arms.
Between that or blimps on Mars and other planets, it's almost a given to have something with any new exploration. Just like rovers are so much better than a fixed location for a one-shot deal.
Based on the gradient of pressures from the “surface” to the core, it’s entirely feasible. I’ve read about ideas for blimp colonies on Jupiter as well as Venus!
If that photo was taken right before impact, none of the continents will remain continents because it’s all about to melt and we might have another moon when everything settles down and we evolve back from scratch over the next several billion years.
All this time? What like less than 100 years looking only? That’s a blip on the cosmic scale. 100 lightyear sphere of our galaxy is what, less than 1%? With all the theories and possibilities of what’s going on out there, it’s way too rash to start theorizing like this in my opinion.
If dark matter is fully explained by such black holes, their most likely mass, according to some theories, would range from 10^17^ to 10^23^ grams—or about that of a large asteroid.
In case this doesn’t tell you a lot, 10^17^g is half the weight of Mount Everest, and 10^23^g is 4x the weight of the Antarctic ice shield.
The earth is estimated to “weigh” 13,170,000,000,000,000,000,000,000 pounds. (That is weird when you think about it. The weight of the earth being based on what something weighs on earth, I mean.)
Mt. Everest is only about 357,000,000,000,000 pounds and is just a tiny fraction of the mass of the earth.
So. My point is that we need a better way to portray scale of things in the universe. AUs work to a point but then we have to quickly move to parsecs. Parsecs quickly give way to light years. (Or vice-versa, depending on how you visualize things better.) Light years kinda work, but only for between 14-26 billion years. Even after all of that, I can hardly still fathom the size of Mt. Everest. (This was a rant, but not an angry rant.)
Weight in pounds isn’t the right unit here. Weight varies depending on the strength of the gravitational field you’re in, whereas mass does not. A kilogram here on earth weighs 2.2lbs but on the moon it only weighs 0.36lbs.
In the English Engineering System, the unit of mass is 1 pound mass (lbm), and is equivalent to the amount of matter that weighs 1lb at 1G. I won’t argue that EES is a good system, but it does at least have a kludged unit for mass. It has an equally kludged unit for force, too, called pounds force (lbf).
I cannot fathom the size of anything on an astronomical scale. I have seen the videos that zoom out and show Earth at scale with the Sun and then the Sun at scale with other stars. No matter how many times I view the facts it will be incomprehensibly large.
astronomy
Ważne
Magazyn ze zdalnego serwera może być niekompletny. Zobacz więcej na oryginalnej instancji.