Hi there! Looks like you linked to a Lemmy community using a URL instead of its name, which doesn’t work well for people on different instances. Try fixing it like this: !reisen)
I think reposts from reddit could be really beneficial for lemmy , cause part what made reddit great was that it was basically a content libary, that had the answers to a lot of questions and in turn drove people to the side. On lemmy we still have to build that libary
Why would anyone want that? I always thought that was just an addiction trap for commercial sites to trick you in to browsing for longer - we’ve broken free from that kind of BS here haven’t we?
What was your intention? Your comment seems like a direct value judgement, and you made no obvious effort to answer the question. Weren’t you basically telling OP “you shouldn’t want that”?
I thought I was jovially expressing confusion but that clearly didn’t come across (and admittedly re-reading it, I agree, I misjudged the tone, it’s not my best comment).
I really didn’t realise that anyone actually liked infinite scrolling and hoped that somebody would explain it to me.
Honestly that sounds cheap. The professor probably earns more per hour than that.
How much time would it probably cost him to teach the student, to get his grades straight? 10-20 hours? Double that worth his salary and maybe it will be worth for him. Lets say he would normally earn 25€/h x 10-20 x 2 = 500-1000€
Yeah but the Cesar’s app let’s you play without paying. You can, but it’s not necessary. Besides some of the games are fun to play without spending any money
Roche limit is not really relevant here. That’s for orbiting bodies, like a satellite around a Jupiter-like planet whose orbit spirals inward due to tidal forces, and eventually crosses the Roche limit, whereby the moon disintegrates into a cloud of rocks that spreads out and forms a ring. Yes, the hyperbolic orbit of the collision trajectory here is a “type” of orbit, but really the video is about the collision itself. There is not enough time for the planet to meaningfully disintegrate under the neutron star’s gravity. “What’s that? The ground is kinda shaking. Could that be the tidal force from that neutron st-ACK!!!”.
In the video you can see the surface of the Earth bulge out towards the star under its gravity in the last second, but most of the kinetic energy of the explosion is imparted by direct physical interaction (i.e. electromagnetic) between the matter of the earth and the matter of the star, and in particular between the matter of the earth that has already been accelerated and the matter of the earth lying farther out.
Or at least it would be if the impactor really was just a chunk of iron with the density slider cranked up. This fluid simulator can’t imagine anything else of course, but you are right that it remains a question of whether a neutron star or a black hole could impart any kinetic energy onto the greater earth at all. Maybe it will just pass through and leave a circular hole, sweeping the material in front of it onto itself. The tunnel would immediately collapse, and the crust would be messed up from tidal sloshing, but maybe the ball of the earth itself will remain intact.
The hard x-rays I believe is a reference to thermal radiation of infalling matter. Just like a bullet that hits a wall while staying intact is hot to the touch because its kinetic energy got 100% converted into heat, or a meteoroid that hits the Moon creates a flash of light visible from Earth because for a second the cloud of collision debris is as hot as the filament of a lamp, the earth material impacting the surface of the star gets really hot. The impact velocity is at minimum the escape velocity of the star, which is thousands of km/s, which means the peak of thermal radiation is in the x-ray range.
<pre style="background-color:#ffffff;">
<span style="color:#323232;">E = 3/2 k_B T
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Say we imagine that the entire kinetic energy of bulk material from Earth (let’s say iron) impacting the star at 10000km/s is converted into thermal kinetic energy of individual iron atoms (atomic weight 56).
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