You can use a pinhole to project an image of the sun onto a sheet of paper but not directly as glasses. Look up a ‘pinhole projector’ you can make a pretty good one with an Amazon box.
I can’t see it anyway from my part of the world :( I was just curious because it doesn’t seem like it would be safe, but it was literally taught to me in elementary school.
Are you so deeply entrenched in modern technology that you cannot fathom that a human could comprehend and map future astronomical patterns?
Humans have been doing this since early records of humankind on earth. Loooooong before computers existed. Computers have only been around the last few decades.
IANAP, but isn’t universal expansion understood to be accelerating? How would “weakening forces of nature” account for that? Assuming this energy could be “lost” (breaking an even longer standing and well tested principle of physics), that loss wouldn’t accelerate anything. At best the speed would remain neutral.
The tired light theory is an alternative explanation to the red shift of distant light that says it’s not because distant objects are all moving away from us but instead that the light somehow loses energy as it travels, which lowers its frequency.
There was another alternate theory that suggested everything was shrinking instead of the universe expanding (thus wavelengths seem longer by the time they get to us).
Personally, I’m more “open to the idea” than “sold” for the idea of the universe’s accelerated expansion. I like theories that eliminate the need for dark matter or energy, especially given that the current ones requiring them assume that they make up 95% of everything. It just seems more likely that we don’t understand things as well as we do than to assume we’re right about everything we think but just need to add 19 times what’s already here to balance it all out.
This thing is just a mosaic of ordinary CCDs. I’m sure the name has something to do with it’s specific scientific goals, but that’s not explained at all in this article. They didn’t even attempt to make any kind of connection between the veil and dark energy. Or even between supernovae and dark energy.
It feels like the title should be “uninhabited”. Life on earth doesn’t survive because we continue to be bombarded with nutrient carrying asteroids, it just needed them to kick it off. That few nutrients are likely to make it from the surface to the ocean means the genesis is unlikely to occur, but it doesn’t seem to make a decision about whether an unlikely genesis could survive, even if only in a small pocket of the ocean.
I don’t know all of the details of this mission, but it seems like they’ve just lowered the lowest point in its orbit - called periapsis - until it sits low enough in the atmosphere to get enough drag that the orbit slowly decays over a decade.
The lowest part of the orbit would only drop a little bit, but the highest part of the orbit woukd reduce more with each orbit. If you do it slowly enough, the orbit would circularise and then it would begin to decay more evenly. As it falls deeper into the atmosphere the orbit would decay faster and faster until it can no longer sustain orbit, and then it falls deeper into the atmosphere and burns up in just a few minutes.
The reason for this I can only guess at - it wouldn’t take a whole lot more fuel to just deorbit all at once. My best guess is that it has something to do with reentering at the lowest possible speed. If you fall from a high orbit and reenter, you have a lot more speed and have to dissipate more energy all at once. It’s possible this increases the risk that the satellite will fail to deobrit, and break up and send pieces off in less predictable orbits. If it breaks up from a low circular orbit, there’s no chance of any parts escaping back into orbit.
Starlink is causing problems, but it seems to me that this image was made in bad faith to oversell the case. The caption says it’s a combination of 29 separate exposures, but if those exposures were combined properly, you wouldn’t see the satellites (median combination does wonders, and there are more sophisticated techniques which do even better). Some streaks start at one chip edge and extend to another chip edge, without continuity across the focal plane. So it’s not at all clear just how this image was created. And why on earth is it not flat-fielded? Maybe this is just really sloppy image processing, but even amateurs can do far better than this, leaving the final combination with no satellites at all.
astronomy
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