had a phone with a camera?

They could start using /. instead.

It's almost like a virus.

I was at a physics conference a while back and someone worked out that a very large percentage of the people in our subfield have Erdos numbers between 3 and 5. It turns out one of my colleagues also did semi-amateur acting and has an Erdos/Bacon number of 7 - the same as Carl Sagan and Natalie Portman. It's a fun thing to do over beers, but not much more than that.

You should write this up with a proof - this sounds like Fields Medal material!

The best part is that the editors can't even figure out that this site (still!) doesn't do unicode.

I've been thinking about this too and you are absolutely correct - a clock measures 1 second in your local gravitation potential without you having to correct for that value. Gravitational time dilation applies to everything in your local gravitational potential - there is no correction. Interestingly, even the metrologists who do this for a living use wording that can trip you (well me at least) up. In the 2002 Metrologia paper describing the NIST fountain clock the following is in the abstract:

Systematic frequency biases for which corrections are made – second-order Zeeman shift, black-body radiation shift, gravitational red shift and spin-exchange shift – are discussed in detail.

It sounds like they are correcting for local gravity. When you read deeper in the paper, that correction is only for when they compare to other clocks in other locations.

Up front admission - I know nothing about manned spaceflight procedures. I do know a little about NASA's satellite procedures. Every component has to go through extensive review of how it's made, how it's stored and how it's shipped with estimates of the amount and type of contamination caused in each step. They wouldn't be smearing petroleum goo over the parts I've heard about. Of course those parts were much smaller and easier to ship with climate control.

Sorry if I wasn't clear. You are right, there is no SI definition of terrestrial time, only the second. The SI definition of the second says "the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom". The word unperturbed means these clocks need to be corrected for gravitational, magnetic, and other effects that would change the transistion frequency. The people building and studying these clocks have have been correcting for local gravity since at least the 1970's. It's interesting that these clocks are getting so good that they are becoming the best way to measure local gravity.

I think the SI definition accounts for this. This is the kind of problem metrologists love to solve.

Because it has a 13" screen. Their other models are a Framework 12 and a Framework 16.

get April Fools' Day and Tax Day confused?

Agreed. Although It would been more fun if NASA had distributed 8 billion ape masks to everyone else.

It was discussed by a bunch of people in the slashdot duplicate story 2 days ago - https://science.slashdot.org/s....

The upshot is that each annihilation makes about 2 GeV (similar to a lowish energy cosmic ray). If you add it all up and convert to more everyday scale units the total is around 30 nano Joules - so not very much. I bet some high energy gamma rays will escape the equipment though.

Yup - Calma is where gdsii came from. Still in use today. The term for release to manufacturing - tapeout - comes from sending a 9-track tape with the gdsii file to the reticle house.

Why do I still read slashdot? People here used to actually know things.

In fact, even OFC (oxygen free copper) or the more commonly used OFHC (oxygen free high conductivity) have oxygen in them. The purest I've ever heard of has an oxygen concentration of around 0.1 ppm. There is no copper in solid form you can get on earth that is oxygen free. The material they used in their Penning trap just has a lot less oxygen than the copper used for more mundane things like wiring. OFHC has been used industrially for at least 100 years (vacuum tubes, magnetrons for WW2 radar, nearly every vacuum system used in semiconductor manufacturing).

In typical slashdot fashion, someone assumes that the entire scientific field knows less than they do. This isn't hard to find, oxygen free copper even has it's own wikipedia page!