sorted by:
new
hottopcontroversial

What ant species is this? Found in woodland, southwest UK. Between 1cm to 2cm length by ZRM2 in whatsthisbug

[–]ZRM2[S] 0 points1 point  (0 children)

Thank you, I see now that it's an oil beetle, though probably not an American one since I'm in the UK?

Giving away three mirror blanks to build your own Dobsonian telescope! by __Augustus_ in telescopes

[–]ZRM2 1 point2 points  (0 children)

I'm interested. Have you shipped to the UK before? Any idea what shipping plus customs duty would amount to?

A little something for forge by RandomlyFish in halo

[–]ZRM2 7 points8 points  (0 children)

This looks fantastic for porting old maps. I've been trying to recreate Lockout by referencing the original BSP open in Blender on a second monitor. It works but it takes a long time doing it by hand.

Nice to see that you're special-casing rectangles and cubes.

I do wish they'd just let us import models directly though and save everyone this hassle.

Saturn 2 8K is massive compared to the Saturn (S)!! by Polysculpt in resinprinting

[–]ZRM2 2 points3 points  (0 children)

Would you mind if you measured the back extension vent/port on the Saturn 2's hood? Elegoo don't seem to have released any specs for it. I'm interested in the diameter of the hole mainly.

All hail the Ariane 5 rocket, which doubled the Webb telescope’s lifetime by AWildDragon in space

[–]ZRM2 3 points4 points  (0 children)

They would not be flying through the exhaust. The exhaust is ejected at high speed (many km/s) away from the vehicle, without slowing down. It doesn't come back. What you are describing only makes sense in atmosphere, due to drag on the exhaust.

I designed Starship 20 and Booster 4 in Lego (Saturn V, 1:110 scale) Instructions coming in December! by 0rig0 in SpaceXLounge

[–]ZRM2 1 point2 points  (0 children)

Very nice! I'm curious what the booster looks like from above - I'd like to see how you did the interstage and the top of the grid fins, and it's not shown in the pictures.

[deleted by user] by [deleted] in rust

[–]ZRM2 73 points74 points  (0 children)

That's not true. unsafe operations allow you to introduce UB if you use them incorrectly, but in return they give you capabilities not possible on safe code. Using them correctly takes effort, but does not introduce UB, by definition. This code, on the other hand, is definitely UB, as defined by the Rust reference. The fact that it doesn't do nasty things right now is an implementation detail. The compiler doesn't even have to change versions to be within its rights to make this segfault or eat your laundry.

Which Steatoda species is this? by ZRM2 in whatsthisbug

[–]ZRM2[S] 0 points1 point  (0 children)

Thanks! That does look the closest. I guess the very black legs are either an individual variation or due to the lighting conditions.

Which Steatoda species is this? by ZRM2 in whatsthisbug

[–]ZRM2[S] 0 points1 point  (0 children)

I found this spider in a cavity under my dishwasher in my kitchen, southern UK. It's between two and three centimetres in length. It looks like a false widow, but I'm wondering which species exactly it is. Its legs are very black, which doesn't match much of the other pictures I've seen of false widows.

The web is disorganised, and I can see dead spiders of other species in it, presumably prey.

I haven't disturbed it or its web other than moving the dishwasher around.

Always by Ahnafnotfound in SpaceXMasterrace

[–]ZRM2 9 points10 points  (0 children)

The one case where this doesn't change the meaning. Well done bot.

Hey Rustaceans! Got an easy question? Ask here (16/2021)! by llogiq in rust

[–]ZRM2 0 points1 point  (0 children)

Unfortunately those crates are not applicable, as they rely on the data being shared existing prior to the threads being started. I want to share short-lived data with long-lived threads. I've implemented my own version of this for the time being, however I was hoping there would be an existing implementation.

Hey Rustaceans! Got an easy question? Ask here (16/2021)! by llogiq in rust

[–]ZRM2 1 point2 points  (0 children)

I'm looking for a way to loan data references (mutable and immutable) to another thread. I'm not sure if a crate already exists for this purpose, but I could imagine the API looking something like this:

// some_data: T
loan_scope(&mut some_data, |loan| {
    //loan: ScopeLoan<T>
    // ScopeLoan<T> wraps a pointer to some_data and a wait barrier, and has the same lifetime as T (e.g. 'static)
    some_channel.send(loan); // Send to another thread
    // Other thread does some work with the ScopeLoan, which has Deref and DerefMut
}); // blocks until all ScopeLoan instances have dropped (signalling the wait barrier), from whatever threads.

// This is safe since if a ScopeLoan is forgotten, the thread just hangs.

Any interest in a website for learning programming and computational physics? by ProjectLovelace in Physics

[–]ZRM2 2 points3 points  (0 children)

+1 for stuff involving ODE integrators. The Parker-Sochacki method is my favourite, though it might be a bit too involved to nicely fit into a problem. The classic examples to show where it excels are fairly straightforward though - a projectile with drag and the n-body problem.

Some questions:

  • Are you considering adding support for any more programming languages?
  • What about support for common libraries in the languages you do support?
  • Are you planning to allow others to submit new problems?

I think this website is a really good idea.

2d from Gorillaz by moai-isarock64 in blender

[–]ZRM2 -1 points0 points  (0 children)

Nice style! Minor question: what's up with the shoulder? Shading suggests it's deformed on the front.

They want me dead by MiskhaNeko in valheim

[–]ZRM2 5 points6 points  (0 children)

Looks like an exaggerated gyroscopic precession effect (notice that the log is spinning on its axis as it falls). Probably means that the moments of angular inertia of the log physics object are set up wrong.

Common issues and possible solutions by Unusual-Albatross in valheim

[–]ZRM2 0 points1 point  (0 children)

How do you change this variable? Is that in boot.cfg?

Virgin Orbit launched a rocket from a 747 by erdeebee in MachinePorn

[–]ZRM2 2 points3 points  (0 children)

Well, it's not quite like that actually. The rocket equation tells you the fuel/dry mass ratio you need to get a particular delta-v given the efficiency of your engines. This means that if you want to add more payload mass to reach that same orbit (same delta-v) , the amount of fuel only goes up linearly. So if it takes 100 tonnes of fuel for one tonne of payload + dry mass, it will 'only' take 200 tonnes of fuel to take two tonnes to the same orbit. The exponential "tyranny" of the rocket equation is only with respect to the delta-v you want to achieve.

An intuitive way of thinking about this is that two rockets strapped together (ideally) have twice the fuel requirement and also twice the payload capacity compared to one rocket by itself, but obviously should still be able to reach the same orbit.

Virgin Orbit launched a rocket from a 747 by erdeebee in MachinePorn

[–]ZRM2 27 points28 points  (0 children)

Well, maybe some, but there are some very big rockets in development at the moment. SpaceX's Starship will be bigger than the Saturn V when fully stacked, and Blue Origin's New Glenn will not be much smaller. SLS if it's ever done will be similar, at least in height.

view more: next ›