Paul Simeon

I study the origin of cosmic rays, especially the ultra-high-energy variety. I like physics, astronomy, and teaching.

[Paul Simeon @PESimeon]

@melialfp @shai_machnes @DavidDeutschOxf You may appreciate the academic conversation regarding the classification of endonyms and exonyms. Here is one paper mentioning the decades of literature on the subject.

https://t.co/dFa3PnbDmW

[Paul Simeon @PESimeon]

@melialfp @shai_machnes @DavidDeutschOxf This sounds like a distinction that is not widely accepted. I just checked Wikipedia and grok.

Turkey, Italy, and Spain all seem to be regularly called exonyms.

And it’s odd to request another language to adopt a spelling containing diacritics that don’t exist in the language.

[Paul Simeon @PESimeon]

@Whachutryin2say @rodrimot_ @Sagiel_X @CuriosityonX The black hole’s size, measured by its event horizon, is about 1% of a light year. It’s within a much larger gas cloud that is larger than our Galaxy.

[Paul Simeon @PESimeon]

@Austen Just be sure to wash strawberries because they grow on the ground.

I got dysentery from freshly picked strawberries at a friend’s house. I didn’t know they were unwashed.

[Paul Simeon @PESimeon]

Fusion won’t make energy much cheaper than it is today.

There will always be large costs for capital, construction, maintenance, financing, and regulation.

[Paul Simeon @PESimeon]

@FamedCelebrity @skdh This incorrect framing has bugged me for a long time. Is there a name for it?

[Paul Simeon @PESimeon]

@cosmicfibretion Was that just his criterion to convince himself, or something else?

I think most physicists were already convinced there’s a problem with LCDM.

[Paul Simeon @PESimeon]

@FangYi11101 @Metathea11 @sporadica I once heard “on the east coast” and kept following up until they named it.

[Paul Simeon @PESimeon]

@MarkovMagnifico @samlakig For over a decade I’ve thought about a Diablo-like game where you unlock new skills based on the 4 forces by passing real physics tests. Big incentive to learn physics.

[Paul Simeon @PESimeon]

@Strav9 @HProggy @demystifysci Yes
https://t.co/xEBFNpuJ3y

[Paul Simeon @PESimeon]

@martinmbauer ! → 'bang'
'power tower'
'kissing number'
'Killing vector'
'Hairy ball theorem'

[Paul Simeon @PESimeon]

@DNA101X @martinmbauer Two-photon interactions can even happen at lower energies. It’s just very weak.

[Paul Simeon @PESimeon]

@rprobst @martinmbauer Sorry, I didn’t make the figure or cutoff the caption. This is the attenuation length of photons, protons, and iron as a function of energy. The one that drops the most is photons interacting with the CMB.

[Paul Simeon @PESimeon]

@rprobst @martinmbauer There’s a pretty sharp cutoff around 100 TeV

[Paul Simeon @PESimeon]

@ChloubaTomas @HProggy @demystifysci The interaction probability does drop with increasing energy, but it's still not that small, especially when you have the whole atmosphere as the target.

We need big detectors because the particle showers are large AND because the flux is so low.

[Paul Simeon @PESimeon]

@tabulla_rassa @HProggy @demystifysci Grok is partially wrong here. We’ve detected photons over 1 PeV.

[Paul Simeon @PESimeon]

@ChloubaTomas @HProggy @demystifysci That’s right. The key idea is that no matter what wavelength the photon has, it can still interact with protons, electrons, or even the microwave background (other photons).

[Paul Simeon @PESimeon]

@WKCosmo designed to appeal to illiterate investors…

[Paul Simeon @PESimeon]

@arpitrage I’d love to see a similar study about chronic pain among PhD students. I predict a similar trend.