TIL 1:

Movement in the galaxy and mass extinctions

mass extinctions. There are various theories about what has caused this.

I came across one of these recently.

orientation of the galactic plane. There is a difference in the two

orientations in other words. Sometimes it's in the galactic plane, and

at times it's "above" or "below".

bursts originating in the galaxy than when it's not. The period of

rotation is the Galactic year and is about 225 million years

long.

radiation has effects on life on Earth. There seems to be a correlation

between these events - gamma ray exposure and extinctions - though there

is no certainty that this is so. Extinctions may have multiple causes,

so the relationship cannot be simple.

to find out more.

TIL 1: Links

Extinction event

Galactic plane

Galactic year

Stackexchange: What angle does our Solar System make with The Milky

Way?

Shiva hypothesis

Journal of Astrobiology: The galactic cycle of

extinction

TIL 2: Which is correct -

ml or mL?

Cooking

metric. Often it's something like 540 mL can of tomatoes.

abbreviated form of millilitre is ml, but today I

learnt that mixed case mL is also permitted and is preferred in

the USA, Canada and Australia, while Europe prefers lower case

ml.

Litre such as dl and dL for decilitre and

even for quettalitre (1030 litres) - Ql and

QL.

TIL 2: Links

Friends Cooking

SI prefixes applied to the litre

TIL 3: Meibomium glands

glands in general produce secretions to protect the skin and hair. On

the skin they are part of the hair follicle and produce an oily

substance called sebum (from the Latin word for tallow

used to make candles).

to the eyelashes. The oily substance they produce helps to prevent the

eye surface from drying out by mixing with the tears. It also helps the

eyelids to make an airtight seal when the eyes are closed. There are

many functions.

as a student, but didn't know very much about their function.

physician and scholar.

reduce with age, or the glands can can be blocked, leading to MGD

(Meibomium Gland Dysfunction). I might have this according to

my Optometrist.

meibum.

TIL 3: Links

Meibomium gland

Heinrich Meibom

Meibomium Gland Dysfunction