
Lunar Eclipse: An Email to a Daughter and Son-in-Law - susam
https://groups.google.com/d/msg/b-a-s/9rcz9MbC5p8/2Q8txQgGBAAJ
======
hluska
In May, my three year old daughter and I flew out to Vancouver Island, Canada
to spend a couple of weeks with my Dad. It was my daughter’s second time out
to the island, though the first time was for my Grandma’s funeral when she was
six months old.

This email from a father to a child reminds me of the emails my Dad sent us in
the lead up to our trip. I’ve never seen my Dad so excited for anything. The
day of the flight, he was awake at 1am his local time to start watching the
flight schedule and the weather. He wrote lots of reminders, to make sure that
I packed Lauren’s identification, Pull Ups and wipes. And he wanted to make
sure that Lauren had a window seat where she wouldn’t just stare out at a
wing. No no no, his only granddaughter was going to have a view. (Strangely,
the day of the flight was cloudy as hell until we got to the mountains, then
we flew over the Rockies with barely a cloud in sight. It was as if Grandpa
put in his order for weather that would give his granddaughter the best view
imaginable).

I was pretty scared in the lead up. I hate flying at the best of times and
this was my first solo flight with a three year old. Shit, I’m hardly
qualified to deal with Webpack when it has a tantrum. This is a bloody human
life in a plane.

The flight was amazing and reading my Dad’s dispatches every ten minutes added
to our excitement. When we landed, my Dad and stepmother were visibly excited.
My daughter ran to them and the three of them had a wonderful moment.

My Dad’s emails were purely about his excitement. And this dad’s email makes
him sound just as excited as my Dad was. I am only going to have one child and
I pray that one day, I get to be that excited about my little girl hopping on
a flight to visit me. If my excited message happens to go public and it
contains some factual issues, I hope to hell that the people who read it
recognize it for what it is...I’ll just be a really excited dad who is doing
whatever I can to pass the time before I get to see someone I love more than
life! :)

~~~
cheez
Love it.

------
bnegreve
> Solar Eclipses are Virtual. They really do not exist. [..] Lunar Eclipses
> are real. They are actually happening of an event on the moon.

During a lunar eclipse, the earth projects its shadow on the moon. During a
Solar Eclipse, the moon projects its shadow on the earth. Only the shadow is
smaller. I'm not sure what makes lunar eclipses more real.

~~~
svat
This has been discussed in another thread, but to repeat myself in different
words:

\- During a solar eclipse, something appears to change with the sun, but
appearances are deceptive: all that a so-called "solar" eclipse means is that
the _observer_ happens to be in a small region a few miles across on earth;
one can easily drive to a different place and see that the sun is unaffected
and continues to shine as usual. Despite the name, a solar eclipse is really
an event about a small patch of earth.

\- During a lunar eclipse, something appears to change with the moon, and this
is right! The moon really does fall under shadow, something that's true
wherever the observer may be. A lunar eclipse really corresponds to something
happening on the moon.

Of course if you define away the difference by saying that eclipses are only
about a specific observer at a specific point on earth, there is no
difference, but that's not the point being made.

~~~
lisper
There really is a difference, but the words "real" and "virtual" are not the
correct characterization of that difference. Solar eclipses are every bit as
real as lunar ones. "Global" and "local" are more appropriate adjectives to
describe the difference.

~~~
svat
Well, this is where we get into shades of meanings of words like “eclipse”,
and what connotations those words carry to you. If you think of an eclipse as
purely a visual phenomenon in the sky as seen from earth—if that's all the
connotation that the word carries to you—then of course solar eclipses are
every bit as real as lunar ones; as anyone can plainly see. It is similar if
you think of the astronomical phenomena as simply “ _some_ body casts its
shadow on _some_ body”, and the terms “solar” and “lunar” are merely
conventional labels attached to distinguish the different kinds.

But it's possibly cultural what you think of as an “eclipse”. In Indian
languages, the word from Sanskrit used is _grahaṇa_ , which is from the verb
for seizing, holding, catching, capturing, etc. So “solar eclipse” and “lunar
eclipse” are literally “sun-capture” and “moon-capture”. Now from a very
literal reading, neither of those is real: neither the sun nor the moon is
really seized or captured anyway.

But based on the connotation that I think most people have, we can say:

* During a solar eclipse, you may think something's happening to the sun, but that's not real; that's only virtual.

* During a lunar eclipse, you may think something's happening to the moon, and that's real.

So I hope we can agree that there is _something_ that's “real” during a lunar
eclipse and not during a solar eclipse (namely, the corresponding named body
being physically affected in some way); whether the word “eclipse” carries
that connotation to you is of course something for only you to say.

~~~
lisper
> So I hope we can agree that there is something that's “real” during a lunar
> eclipse and not during a solar eclipse

No. I understand what you're saying, but it is simply not true that nothing is
happening to the sun during a solar eclipse. Something _is_ happening to the
sun: it is being blocked from your view by the moon. It is perfectly analogous
to what happening to the moon during a lunar eclipse: it is being blocked from
the sun's view by the earth. The situations are exactly the same except for
two things: the scope, and the perspective of an earth-bound observer. But
IMHO those differences are not nearly enough to warrant labeling one of those
"real" and the other one "virtual". They are both equally real.

~~~
svat
I edited my previous comment to include the word "physically" in "physically
affected". I think we're going in circles now -- how would _you_ describe the
fact that really some less light falls on the moon (so an observer on the moon
can tell when a lunar eclipse is going on), while nothing changes on the sun
(an observer on the sun cannot tell, at least not easily / in any significant
way, when a solar eclipse going on in Europe?). If you will not grant that in
one case there's a physical ("real") change happening on the moon/sun and in
the other not, what words or phrases would you use to describe it? And is it
inconceivable that someone's conception of an eclipse may care about whatever
that difference is?

At this point we're just debating the meanings of words and phrases like
"something is happening to the sun" and whether being blocked from the view of
someone on earth counts as something happening to the sun; one can very well
argue whether shadows are real ("of course it's real, you see it right there"
versus "no a shadow has no physical existence, it just looks like there's a
dark object on the ground") and so on. At some point one ought to grant that
others attach subtly different connotations to words.

~~~
lisper
> an observer on the sun cannot tell, at least not easily / in any significant
> way, when a solar eclipse going on in Europe

But that is simply not true. An observer on the sun _can_ tell, and the
observation is both easy and significant: it would look like a transit of the
moon across earth that passes over Europe.

~~~
svat
During a lunar eclipse, the surface temperature on the moon drops by about 150
to 250 degrees Celsius in a few minutes. The whole "day" side of the moon—an
immense region about seven million square miles in area—is plunged into
darkness. For anyone on (that half of) the moon “outdoors”, it would be
impossible to miss: one would not even have to look at the sky to see the sun
being blotted out by the earth; one could tell from the surrounding light and
the temperature. The moon is physically affected in a significant way. Even if
someone on the moon did not care about the earth, they would care about the
time of the lunar eclipse. All this lines up somewhat (at least matches the
timeline) with our apparent perception from earth.

During a solar eclipse, someone on the sun would hardly notice. The surface
temperature does not change; the brightness does not change; the earth is
about a 100 million miles away and occupies less than 10^-7% of the sun's sky
(18 arc seconds; compare with the ~30 arc minutes that the sun or moon occupy
in earth's sky). An observer on the sun would need to have very good optical
instruments to take note of the entire earth in the first place; let alone the
patch of earth a few miles across that is experiencing a total solar eclipse.
Unless they were looking for it, they would not be aware of (what the
earthlings call) a solar eclipse taking place.

(During a solar eclipse, we people on the _earth_ do notice. The sun is hugely
significant to the earth physically even though the earth is barely
significant to the sun; the temperature can fall by maybe 15 degrees Celsius;
people in the affected area of earth are plunged into darkness, etc.)

As a physically significant phenomenon, what's real during a solar eclipse (in
somewhat the same way as a lunar eclipse) is happening on _earth_ ; if we
called it a terrestrial eclipse it would be fairly real, but is the _sun_
significantly affected? I'd say not really.

\---

Now, as this is my last post, there are a few philosophical issues this
conversation has brought up:

\- One is a question of ontology: What is "real"? I think people can differ in
the level of how physical/material their ontology is; certainly everyone would
agree about a visual spectacle taking place, but some would consider more
"physical" phenomena more real (as in my earlier remark about whether shadows
are “real”), and a brightness-and-temperature difference over half the entire
moon is surely a physically more significant event (to the moon) than some
faraway object casting a shadow on another faraway object would be to the sun.

\- The second is a question of semantics: What connotations does the word
"eclipse" carry? To some people, it carries connotations (e.g. "X-adj
eclipse"="X experiencing a seizure") such that, for instance, a "solar
eclipse"="sun being darkened" is only appearance not reality, while "lunar
eclipse"="moon being darkened" is both appearance and reality.

\- The third is a question of interpretation/hermeneutics. When I read
something, I'm trying to see: "Is there some interpretation under which what
I'm reading is correct?" The question of "Is there some interpretation under
which the author of the above email is wrong, and solar eclipses are similar
to lunar eclipses?" is not very interesting; of course the answer is yes, and
in my earlier comments I've mentioned at least three interpretations under
which the author is wrong. Certainly, it's not the language I'd use: before
reading the post I'd never have described lunar eclipses as real and solar
eclipses as virtual, and I probably still won't. Maintaining that the author
is wrong does not challenge my perspective or contribute anything new to my
life. I feel secure in my understanding of eclipses, and if someone has a
different perspective, it does not feel like my perspective is being
questioned; it's just an opportunity. On the other hand, "Is there an
interpretation under which the author is right?" (the principle of charity) is
more interesting, and having newly experienced this perspective I've been
defending an answer of "yes": yes, not only is there a combination of
connotations of "solar eclipse" and "real" under which a so-called solar
eclipse is not a "solar-ly" significant event (thus not "real" in that sense),
but also it's quite a fresh way of looking at things and appreciating how,
even though both appear the same to us, one (which we call a "sun-seizure") is
an event of significance only to us puny humans on earth and the sun is
unaffected, while the other is truly, improbably, a case where the earth (our
home!) has an unmissable effect on the moon, a case where our visual
perception, of the moon falling into shadow, is actually correct, something
contrary to our perception being so frequently wrong in the astronomical
domain where for instance the sun and moon and stars appear to rotate around
us every day and night but reality is different.

~~~
lisper
> During a solar eclipse, someone on the sun would hardly notice.

That doesn't make the event any less real. An event doesn't have to be
dramatic to be real.

~~~
svat
I tried to use many words, so let me try using fewer:

• “solar eclipse = sun gets darkened” is only appearance, not reality.

• “lunar eclipse = moon gets darkened” is both appearance and reality.

(I can guess what the response is going to be: either “that's not what
‘eclipse’ means”/“why care about that?”, or “but the sun _does_ get darkened,
as viewed from earth”. Thus the conversation goes in circles. Really I should
stop; I've said all this already.)

~~~
lisper
No, my response would be that when something "gets darkened" the mechanisms by
which that can happen depend on whether the thing "getting darkened" is a
source of light like the sun, or merely a reflector, like the moon. But both
phenomena are fully fledged components of reality.

------
jmkd
Well, BA119 took off about an hour late which should give the passengers more
time at greater altitude to see the red moon from this evening's partial
eclipse.
[https://www.flightradar24.com/data/flights/ba119#214ec914](https://www.flightradar24.com/data/flights/ba119#214ec914)

The discussions about the subjective nature of a solar eclipse vs the
objective nature of a lunar eclipse are especially relevant if you find
yourself in an aircraft travelling at 550mph, as no advantage will be given in
terms of duration for this particular celestial event.

Compare to solar eclipses where strategically flown aircraft can extend
totality by some margin: [https://www.space.com/42768-total-solar-eclipse-
july-2019-ai...](https://www.space.com/42768-total-solar-eclipse-
july-2019-airplane-flight-plan.html)

------
jonnydubowsky
A possible place to start: if your dad is still alive, give him a call. Ask
him to read the letter before the call. Then ask him if there was ever an
event or phenomena that he wishes he could have prepared you for, to give you
the gift of enjoying the wonder of the world we live in. You'll probably be
surprised and happy at his answer.

~~~
starsrider
This sounds like the end of an email forward from grandpa, not going to lie.
I've been close enough to my dad that I read with enthusiasm as he wrote
emails to his surgeons' professional group, and this is such a trite way to do
things.

~~~
jacobush
I don't understand this comment at all, genuinely. What is trite? And what is
an and of an email forward? Will you stop forwarding emails from him? Don't
get it. Maybe my reading comprehension dropped sharply recently.

~~~
constmu
I don't understand that comment either. Perhaps that comment meant that its
parent comment looks like the end of early 2000-era email forwards that would
end with sentimental messages. But I don't know what is being referred to as
trite.

------
DoreenMichele
In case this doesn't quite click for people, this is about tomorrow's lunar
eclipse.

Fun factoids:

Eclipses typically occur in pairs, one solar and one lunar. They occur two
weeks apart. (Sometimes there is a third one.)

Eclipses occur every six months, but most are partial. Total eclipses are much
less common.

Photos taken during a total solar eclipse proved Einstein's Theory of
Relativity and helped make him famous overnight.

~~~
s_gourichon
Make him famous overnight... eclipse... haha, good one. Oh, sorry. ;-)

------
Whatitat90
Having to log in to Google just to read a message on a mailing list always
creeps me out. Every time I see it it looks like a phishing attempt :-/

~~~
jankotek
Could you explain? Google groups do not require login, just opened in private
window.

~~~
Whatitat90
If you've already signed to Google but your session is stale it automatically
redirects to login screen.

In private window it just works but still I consider the design of checking
login on a page that doesn't require it quite bad.

------
ggm
I pre-checked a campsite I was visiting with my son using lat/long and
heavens-above website, and there was a mag -4 satellite transit there. So.. at
the right time I said "look up" THE WIZARDING IS STRONG WITH THIS ONE...

But yea, doing this on a public list.. creepy.

~~~
spraak
> But yea, doing this on a public list.. creepy.

I guess I don't see how it's all that different from you sharing your story
here.

~~~
danielparks
Context.

It is normal to post an anecdote related to the link.

It is weird to post a message like this to a public mailing list out of
nowhere, i.e. without related context.

(I have not actually checked if the message was out of the blue.)

------
shmerl
How is one more real than another? Shadow from the Moon falls on Earth - you
get solar eclipse. Shadow from Earth falls on the Moon - you get lunar
eclipse. It's all relative (consider for example observer on the Moon).

~~~
lutorm
Exactly. An observer in space can see a solar eclipse on the surface of the
Earth just like we can see lunar eclipses. Like
[https://youtu.be/rwNc5aK3dBk](https://youtu.be/rwNc5aK3dBk)

~~~
nosianu
No, not "exactly". You and OP completely ignore the point the author makes.

In a lunar eclipse the moon actually really _does_ get dark - no light falls
on it any more. There is no point anywhere from which you will be able to see
a moon that receives any light from the sun, because it doesn't.

During a solar eclipse on the other hand there is no change whatsoever to the
sun, it continues to shine just the same. Only those under the shadow of the
moon see a change.

Just to clarify, I'm merely relaying the point of the author. I have nothing
to say about the use of language, he chose the words that he did and some may
find them confusing and some may not. The way he expressed it is separate from
the point made though, and OPs comment ignored that point.

~~~
shmerl
The point wasn't very relevant though, regardless of the confusing language of
"real". Obviously eclipse is measured relative to the observer, so how is it
relevant that "the sun continues to shine just the same"? It's not relevant to
the concept of _eclipse_ , and doesn't make it any less real.

~~~
svat
What the author of the email is pointing out is that:

* A (total) solar eclipse is merely a statement that you, the observer, happen to be present in a small region of a few miles' radius, wherever the moon's shadow happens to be. If you imagine yourself flying around in space (or even just driving around in a car), you can very easily get out of this region and see that the sun continues to shine, etc.

* A (total) lunar eclipse is a statement that the earth's shadow falls on the moon. No matter where you are in space, this is a statement about the amount of light reaching the moon's surface, independent of where the observer happens to be.

You may not care about this, deciding that your vantage point as an observer
is all that matters (whether _your_ view of the sun or moon changes,
respectively) by saying "Obviously eclipse is measured relative to the
observer", but the author cares, and it's an interesting point. Obviously he's
not claiming that a solar eclipse isn't "real" in the sense that you can't see
it; only that it doesn't correspond to any astronomical event that is
observer-independent (and relevant to more than a small region of the earth).

Edit: Another way of saying this is that despite the name, a "solar" eclipse
is a statement about (a small region of) the _earth_ \-- that's the part that
gets less light; the sun is unaffected by a solar eclipse. On the other hand,
a lunar eclipse is really a statement about the moon; the moon really does get
less light during a lunar eclipse, as the moon is what is in shadow.

------
benj111
On one level you can tell this guy is intelligent, his love of the subject
material draws you in. But then his statements about lunar v solar eclipses, I
just disagree with completely.

It's good sometimes to be reminded that differences of opinion aren't always
down to stupidity.

~~~
morekozhambu
யொவ் யார் வெனா யார வெனுமுன்னா stupid சொல்லலாம். அப்படி சொன்னா அது உண்மை ஆகாது.

Most often difference of opinion arises due to understanding or rather
misunderstanding. And misunderstanding arises due to the language or
linguistic barrier.

It takes intelligence to see through the language barrier and to understand
someone. Just disagreeing and calling someone stupid shows one's own
intellectual deficiency.

~~~
yellowflash
True, it's just he loosened the notion of real and virtual to an extent that's
unfamiliar to people.

Anyway nice profile name. :D

------
gfaure
Is "mt" as an abbreviation for minute, or "sc" for second common in India?
First time I've seen this.

~~~
plibither8
No. Like everywhere else, minute is abbreviated to 'min' second to 'sec'.

------
cjsawyer
I agree that the sentiment is really sweet but I don’t like the idea of this
info being public.

~~~
spraak
Which information specifically? To my reading an average Facebook post is just
as or more revealing of personal details.

------
ulisesrmzroche
Why y’all weirded out about a family email being public? Ever read history
books?

~~~
edflsafoiewq
The availability of the private correspondences of famous persons has always
weirded me out too.

~~~
ulisesrmzroche
Why? Just because?

~~~
edflsafoiewq
It seems voyeuristic I guess.

~~~
ulisesrmzroche
Cool. So what? What’s wrong with that?

------
hanoz
It doesn't seem quite right to pick apart a private family email from an
obviously enthusiastic father, and I stand to be corrected as only a casual
observer myself, but a lot of his message seems pretty misleading.

Apart from the unobstructed view and the fun factor, I don't think being on a
plane bestows any great advantage to the casual observer versus being on the
ground.

The last full lunar eclipse we had here I heard many people comment on how 3D
- "marble like" \- it looked, that's not something that's going to be any
better from a plane, nor is it an effect which "pops" out at you, in my
experience.

Also, due to its atmosphere, the Earth's shadow is certainly not "sharply
edged", far from it, and you won't be seeing its edge climbing mountains and
valleys, nor be able to calibrate your watch to the second from the start of
it. Again, being on a plane won't make any difference on this front.
Ironically, for great views of sharp edged shadows its a partial moon you want
to observe.

Finally, if my use of [https://staratlas.com/](https://staratlas.com/) is
correct, I don't think the moon is going to be at a straight though the window
level as it begins for them over Oman unfortunately, but rather at 45 degrees
up, so some neck craning is going to be needed after all unfortunately.

~~~
Neil44
He's creating excitement, giving the experience a sense of magic and being
special for his children. If you believe something is special then it is.

~~~
hanoz
I've no wish to intrude on that, but as a father eager to instill a sense of
magic in the night sky in my own children, I am conscious that it is possible
to spoil an experience by raising unrealistic expectations. It would also be a
shame if anyone reading this seemingly authoritative post on an astronomical
society forum was left with the impression this was an experience they could
"never have from the earth's surface".

