
When Hubble stared at nothing for 100 hours (2015) - hwayne
https://www.nationalgeographic.com/science/phenomena/2015/04/24/when-hubble-stared-at-nothing-for-100-hours/
======
short_sells_poo
"Bob was right, I was wrong. The use of that discretionary time was a
courageous thing,"

This is such a powerful statement from Rob Kirschner. It is science at it's
best. Someone (rightfully) opposing an experiment, being incorrect and
admitting, without reluctance, shame or regrets that they were wrong.

At the time, Bob's idea was by all available information questionable. But it
was right for him to persevere, it was right that he had to face and overcome
opposition and it is right that the opposition gracefully admits that Bob was
right :)

~~~
cflyingdutchman
This interview with Kirshner is a good read as well:
[https://www.aip.org/history-programs/niels-bohr-
library/oral...](https://www.aip.org/history-programs/niels-bohr-library/oral-
histories/32418) And a reminder that science is not generally moved forward by
strokes of brilliance, but by a whole bunch of people grinding at the fuzzy
edge until the picture becomes a little more clear.

~~~
bashinator
Spectacularly appropriate metaphor - thanks for that.

~~~
vlz
Kuhns distinction between normal and revolutionary science might be
interesting to you:
[https://en.wikipedia.org/wiki/Normal_Science](https://en.wikipedia.org/wiki/Normal_Science)

------
nabilhat
> _In 1995, astronomer Bob Williams wanted to point the Hubble Space Telescope
> at a patch of sky filled with absolutely nothing remarkable. For 100 hours.

It was a terrible idea, his colleagues told him, and a waste of valuable
telescope time. People would kill for that amount of time with the sharpest
tool in the shed_

And by 'Bob Williams', we mean the director of the Space Telescope Science
Institute, which operates Hubble. Williams chose to use some of the predefined
Director's Discretionary Time to explore the limits of the telescope and our
understanding of the universe.

[https://en.wikipedia.org/wiki/Robert_Williams_(astronomer)](https://en.wikipedia.org/wiki/Robert_Williams_\(astronomer\))

~~~
jostmey
Wow! The culture sounds very risk averse. I mean 100 hours is not much given
how long the telescope remained opertional

~~~
dheera
Exactly, this is exactly why I decided not to pursue academia.

Too many times I heard things along the lines of getting "low hanging fruit"
to get "published" and that "don't try that you won't ever graduate". Why is
graduating and publishing papers and tenure and theses the goal of academia,
instead of trying the highest possible risk things that even companies
wouldn't want to risk? Why isn't academia about doing the most utterly crazy
things possible in the name of advancing science for civilization?

~~~
Kalium
You're absolutely right. What's good for _civilization_ is to advance
scientific understanding and knowledge. To take risks, because sometimes they
pan out! So go on, pour resources into a thousand crazy ideas. Something will
work out eventually.

Yet, what's good for the academic? Each effort costs potentially years of your
life. A great discovery will catapult you to the stars, a small one will
advance your career, and a negative finding does nothing. You're not alone,
you have peers competing for the next round of funding, tenured position, or
residency. There are literally never enough to go around, and each will judge
applicants in part on their record of results.

I think you're describing a conflict between what's valuable for a system at
scale and what's valuable for individual actors within it.

~~~
db48x
If you want to find nothing without hurting your career, spend your time
reproducing other people's results. Lots of the time you will find what they
found, which doesn't help your career much. But sometimes you'll find frauds
or mistakes, and that will help your career and our civilization quite a lot.

~~~
bonoboTP
That's very optimistic. More likely you will be disliked by your peers for, in
their view, actively trying to demolish their reputation. There's a lot of
politics in academia and it's way better to just try to be friends and never
say bad words of other peoples works. Live and let live. Is this good for the
public and "Science" in capital letters? No. But it's how it is.

~~~
db48x
Perhaps it is, but you don't have to reproduce the work of your direct
colleagues.

~~~
bonoboTP
Specialties are usually small worlds where everyone knows everyone, reviews,
funding grants recommendations flow between them, as do postdocs and graduate
students. Stirring up as little water as possible and playing into the hands
of the others is incentivized.

------
fmakunbound
This and the later XDF (eXtreme Deep Field) surveys still raise the hairs on
the back of my neck every time I look at them. It really puts our human scale
and importance in perspective.

~~~
caiobegotti
This almost makes me dizzy: [https://en.wikipedia.org/wiki/Hubble_Ultra-
Deep_Field#/media...](https://en.wikipedia.org/wiki/Hubble_Ultra-
Deep_Field#/media/File:XDF-scale.jpg) (it's a picture of the night sky showing
what exactly Hubble was imaging with the Moon for scale)

I never really understood how XDF is only that tiny patch of the sky and yet
it has a godzillion of galaxies inside it!

~~~
ctdonath
TIL: Moon covers 0.5°.

~~~
brianpan
The Sun- also 0.5°

~~~
alejohausner
Wow, they're both the same size! What a cool coincidence! Just think what
would happen if the moon passed exactly in front of the sun! Has it ever
happened? Has anybody looked up at the sky when this happened? I wonder what
it looks like.

~~~
nojvek
Yeah full solar eclipses are a lot of fun. I had an experience in Seattle a
couple of years ago.

They perfectly align and all you see is a thin ring from the sun flares.

In that perfect eclipse, you can look at the sun with the naked eye and it’s
beautiful and humbling. Like the day suddenly turns into a night for a few
minutes.

The TV series “Heroes” was all about this eclipse. It’s a fun show if you
enjoy this kind of things.

~~~
titzer
I witnessed the 2017 total solar eclipse in person. Very eery feeling. It's
worth noting that you should still not look at the sun during a total eclipse
as the corona is still bright enough to do damage, and your pupils are
dilated.

------
dmalvarado
Since we seem to have a good discussion here, there's something I've always
wanted to know.

If I understand correctly, the universe is approximately 13.8 billion years
old. As is mentioned frequently when staring at deep space, we are looking at
the universe not as it is, but as it was, since it takes so long for the light
to travel to us. Some objects in the Hubble Deep Field are over 9 billion
years old, and some within 1 billion years of the beginning of the universe.

My question, as best I am able to ask it, is assuming the big bang theory is
true, how can it be that we on Earth can be looking at something
simultaneously so old and so far away? If everything originated from the same
point, how can it be that we pick an object in the sky and say "that is what
the object looked like 12 billion years ago"? Doesn't it beg the question,
"well then where were we 12 billion years ago?" As in, how can we be here,
observing something close to the beginning of time? Didn't both objects start
at the same place?

I hope that makes sense.. Articles and videos much appreciated

~~~
btilly
Well, let's try to explain general relativity, shall we?

First of all, the universe is expanding. A good visual is to paint stuff on
the surface of a balloon. Everything on the balloon started off close
together. But as the balloon expands, things on the surface of that ballon get
farther apart. So it is with the universe.

Where did this happen? Everywhere, and nowhere. The balloon is an analogy for
the structure of the universe. The balloon exists in a 3-D world at a time and
place. But all notions of time and place are defined within the structure of
the universe. So I'm describing what happened everywhere. All places used to
be close. And now they are not.

Now the Big Bang theory is this. If you play that tape backwards, everything
that we can see was once _really_ close together. But still had all the same
stuff. So the universe was a hot, dense place. Then it began expanding, and
got large and cool and fairly empty.

So if everything used to be close, why does light only now reach us from
somewhere that wasn't that far away originally? Well look at light as being
like an ant crawling on the surface of the balloon. At first your journey
doesn't look far, but the balloon starts expanding and the trip gets longer.
You keep traveling and it gets longer still. That's exactly the plight of
light from the early universe.

Did that help?

~~~
fosk
I have a very naive question: if everything expands, why aren’t planets also
expanding and why isn’t any molecular structure expanding as well? In other
words, what does expand the universe yet prevents the planets (and us) from
also expanding with it?

~~~
SolarNet
Because this expansion is so infinitesimal on that scale as to be negligible.
It's about 7%/Gyr, or a billion years for an unbound structure's "space" to
grow by 7%. Or about 70 picometers (10^-12) per meter every year. Or in other
words, about a water molecule per meter every _four_ years.

At that rate nearly every other force (from chemical bonds to gravity) prevent
anything but the largest cosmological structures (like galaxies) from being
effected. They simply continue with their system as they always have, and the
extra space shows up as distance between galaxies.

~~~
lifeformed
> Or in other words, about a water molecule per meter every four years.

That still sounds measurable though. Has there been any multiyear experiments
that try to measure something like that?

~~~
SolarNet
How? Gravity will make all such changes impossible to measure except at
galactic scales.

Again any "new space" doesn't stick around where it was created. The atomic
forces, chemical forces, and gravity maintain the system distances we are used
to.

------
gen3
The sheer scale on these photos is amazing. Seeing galaxies strewn around like
marbles is very humbling.

I hope there are more plans for deep space photos. I wonder what a telescope
on the other side of the moon could capture.

~~~
gwern
And frightening. Such photos really bring home the Great Silence. All of those
specks which are entire galaxies, and not the single slightest sign of
intelligent life anywhere, ever. The marbles roll on just as they have for
billions and billions of years and will go on rolling for billions to come,
dead pieces of inert matter tracing out their gravitational trajectories and
burning as predicted.

~~~
krapp
>All of those specks which are entire galaxies, and not the single slightest
sign of intelligent life anywhere, ever.

You say that as if we could tell with any certainty, at that scale. There
could be interstellar civilizations spanning several of those galaxies and
uncountable intelligent civilizations that simply never pursued space travel
or the constant accelerated curve of energy consumption and colonization we
assume they would, only because we ourselves would.

We wouldn't know, we don't even really know what we're looking for, and the
universe is so vast that even if we did, we'd be all but certain to blink and
miss it.

~~~
bluGill
It isn't even clear that the pursuit of colonization we want to pursue is even
possible. It takes a lot of energy to do those things and there are limits to
how much we can safely use. We are already worried about global warming
despite not having a colony to support.

------
doctoboggan
I remember the first time I saw the deep field image. It blew my mind then and
still does today. I had no idea it was a controversial experiment at the time.

~~~
iamkroot
I don't think anything else that I've seen or read has properly conveyed the
scale of the universe the way these images do. They did and still do stagger
my imagination.

------
thaumasiotes
> For 100 hours, between Dec. 18 and 28, Hubble stared at a patch of sky near
> the Big Dipper’s handle that was only about 1/30th as wide as the full moon.
> In total, the telescope took 342 pictures of the region, each of which was
> exposed for between 25 and 45 minutes.

How did this work? 342 pictures at 25 minutes each is already well over 100
hours. At 45 minutes, it'd be 256 hours.

~~~
ISL
Indeed, the math doesn't pencil out.

I don't know, but I'd hazard a guess that the image is 100 hr deep on multiple
tiles.

The dataset spans 10 days, which is 240 hr.

~~~
MiguelHudnandez
The telescope's orbital period and the relative positions of the earth and the
sun will affect how the exposures are scheduled.

I went looking for more detailed information -- It appears they are open
enough with the data that you can see exactly how the exposures were taken.
Assuming what I found is right and that someone could make sense of the data.
There are postscript files listing activity for each of the 10 days, but I am
not exactly sure what we're looking at.

[https://www.stsci.edu/ftp/science/hdf/project/project.html](https://www.stsci.edu/ftp/science/hdf/project/project.html)

~~~
Darkphibre
Here you go:

[https://www.stsci.edu/ftp/science/hdf/project/scheduling.htm...](https://www.stsci.edu/ftp/science/hdf/project/scheduling.html)

Observations run from 352:16 to 362:19.

Filter Nexp hours

F300W 100 48.93

F450W 62 36.52

F606W 77 34.94

F814W 49 34.86

------
guerrilla
I don't know of anything more awesome (in the literal sense of the word) than
these photos. It makes my wonder just how densely packed (ignoring variation
in distance) the area is. What will we see when we start looking between those
dark spots? What if there's literally something in every direction...

~~~
gizmo686
Before our modern understanding of cosmology, a serious question astromers
asked is "why is the night sky dark". If there truly were stars/galaxies in
every direction you would expect the entire night sky to be bright, as no
matter which way you looked you would see a star; and the combined light of
all of those stars should illuminate the sky.

As it turns out, empty space isn't dark, but rather illuminated by the cosmic
microwave background. This suggests that the space between us and this
boundary in space from when photons started to be able to move mostly freely
is mostly empty. Otherwise this backround would either be over-shadowed by
stars, or obscured by whatever stuff was obscuring said stars.

Of course, it is important to keep in mind the speed of light implications.

~~~
philiplu
For more on this, see Olbers’ paradox -
[https://en.wikipedia.org/wiki/Olbers%27_paradox](https://en.wikipedia.org/wiki/Olbers%27_paradox)

~~~
drran
But, Hubble demonstrates that every line of sight is actually ends on surface
of a star or an object, so what is your point?

~~~
gizmo686
When did Hubble demonstrate that? What the experiment in the article showed is
that seemingly empty regions contained stars. If you want to claim that every
1 dimensional line of sight ends on an object, then you need to explain how
the cosmic microwave background manages to reach us. Unless, of course, you
count quark-gluon plasma as an object; in which case we do pretty much hit a
wall in every direction.

~~~
drran
It looks like your naked sight is much better than Hubble telescope.
Congratulations!

~~~
cambalache
You should read a basic Astronomy book and dont make a fool of yourself here

~~~
drran
You mean, I should _write_ a book, right?

------
nojvek
Isn’t it great the the starlink junk doesn’t photobomb Hubble?

It’s amazing we have a giant telescope outside the planet. We know so much
about the universe because of Hubble and friends.

When I was young I truly believed in heaven and hell as some distant planets.
Then learning about Hubble, cosmic radiation and the fact that we can see
millions of lightyears away which is an incomprehensible distance and the fact
that our vision is limited by speed of light that seems super slow relative to
those distances.

I really had a paradigm shift. Heaven and hell are probably good ideas but
don’t actually physically exist. Took me a while to digest that. If they were
actually there, we’d have seen them by now.

I have a lot of respect for Astronomy.

~~~
vlasev
Just a nitpick: Hubble is at a much higher altitude than Starlink and as such
would never be interfered with.

------
whoisjuan
[http://archive.is/5cgaD](http://archive.is/5cgaD)

~~~
archon810
Thank you. It's incredibly obnoxious when a website says I have 3 free
articles left to read this month and 10s later pops up a non-dismissable pop-
up that forces registration.

------
joncp
For me, those images are a sliver of the Total Perspective Vortex. The more I
try to comprehend them the more blown away I am by them.

------
baxtr
_> “With this achievement, the estimated number of galaxies in the universe
had multiplied enormously — to 50 billion, five times more than previously
expected,”_

This numbers is sheer incredible. Each of them contains 50 billion stars. How
come some think we’re alone in this universe?

EDIT: yeah, I know speed of light and all... it’s just a stupid fantasy that
is fueled by these numbers

~~~
Ma8ee
I have this nagging thought that maybe intelligent life really is a
coincidence of a grand cosmic scale. Maybe we really really are all alone in
this galaxy and among many others. What an incredible opportunity we are
given, and how we squander it with our bickering.

~~~
mensetmanusman
Lol, would love to know the thought process of someone that bothered to
downvote you.

 _if you don’t believe aliens exist, you are wronggggg!!!_

~~~
Ma8ee
Yeah, that one surprised me too.

------
tigen
“With this achievement, the estimated number of galaxies in the universe had
multiplied enormously — to 50 billion, five times more than previously
expected,”

It seems that current estimates for this are higher, such as 100 billion in a
2020 article I saw. Anyone have an authoritative scientific source for the
best current estimates?

50 billion galaxies (or 100) somehow doesn't actually seem so many.
Considering that's on the same scale as the number of people on our tiny space
rock. Yes each one has billions of stars inside, but still, we're talking
about the entire universe.

Somehow, intuition suggests there must be more "stuff" beyond our observable
universe.

~~~
keithnz
I agree....

here's [https://phys.org/news/2017-01-universe-trillion-
galaxies.htm...](https://phys.org/news/2017-01-universe-trillion-
galaxies.html) where it's 2 trillion. Which is 1 galaxy for every dollar in
the US Coronovirus stimulus package or 256 galaxies per person. Which makes it
also feel like an approachable number for the amount of galaxies in the
universe.

------
noisy_boy
I was looking at the Hubble eXtreme Deep Field photo and in there locked on a
galaxy that was just a dot and imagined that out of the billions of stars and
trillions of planets in that dot, there could be life on a planet with a
variety and richness and vast history that is unfathomable to us. Us and them,
two dots unbelievably far away yet parallelly flowing through time. I think
the only reason Space doesn't generate a lot more interest than it draws now
is because it is truly mind boggling.

------
hn_throwaway_99
I have a sense that the article is presenting things in a more dramatic way
than how it really occurred:

> So, with his job perhaps on the line, Williams went off, put together a
> small team of post-docs, and did exactly as he’d planned. For 100 hours,
> between Dec. 18 and 28, Hubble stared at a patch of sky near the Big
> Dipper’s handle that was only about 1/30th as wide as the full moon. In
> total, the telescope took 342 pictures of the region, each of which was
> exposed for between 25 and 45 minutes. The images were processed and
> combined, then colored, and 17 days later, released to the public.

I mean, each image was only exposed for 25-45 minutes. If the full hundred
hours was such a huge risk, why not take, like, 5-10 photos first to see if
you get much of anything? Seems like they would have been able to know pretty
early on whether it was going to be worth it.

~~~
spenczar5
If they found nothing in the first 5-10 images, what do you imagine they would
do? Telescope scheduling is a very tricky business, not one that lets you
change courses too quickly.

~~~
MiroF
Schedule the 5-10 mins, then schedule again for later.

~~~
barkingcat
The amount of programming and orbital changes needed for this is not feasible.

For the hubble to point at something, I'd imagine it needed to station-keep
and burn some hydrazine.

If you did infinite numbers of 5-10 min studies, you'd burn right out of the
fuel store of a spacecraft before you'd get anything done.

From what I hear, hubble telescope times are scoped out, planned out a year or
several years in advance - the telescopes and scientific instruments need to
be programmed, the spacecraft needed to be moved/pivoted to aim at the right
part of space, communications times needs to be booked with receivers/ground
stations across the entire Deep Space Network so you can receive the data.

It's nontrivial - if you booked 5-10 min at a time you'd have wasted your most
precious resource.

[https://eyes.nasa.gov/dsn/dsn.html](https://eyes.nasa.gov/dsn/dsn.html)

~~~
vlasev
Hubble points via gyroscopes, not thrusters! But they are slow, so that's part
of why you need to schedule things well. YouTube video explaining how it
points:
[https://www.youtube.com/watch?v=qEZI9DxIQss](https://www.youtube.com/watch?v=qEZI9DxIQss)

Also, I don't think it needs to change orbital parameters at all for its
operation. Station-keeping yea, but I don't think it needs to burn more fuel
because of pointing at things.

------
samcal

      We learned new words for things. The decade changed.
      
      The first few pictures came back blurred, and I felt ashamed
      For all the cheerful engineers, my father and his tribe.
      The second time,
      The optics jibed. We saw to the edge of all there is—
      
      So brutal and alive it seemed to comprehend us back.
    

\- excerpt from Tracy K. Smith's "My God, It's Full of Stars" [1]

Smith's father worked on the Hubble telescope, and she would be named US Poet
Laureate in 2017. I highly recommend reading her poetic account of this
photograph :)

[1]: [https://www.poetryfoundation.org/poems/55519/my-god-its-
full...](https://www.poetryfoundation.org/poems/55519/my-god-its-full-of-
stars)

------
szymonsidor
I stared at nothing. I stared at absolutely nothing and it was everything that
I thought it could be.

------
elboru
Probably it’s a perspective issue, but galaxies look relatively close to each
other, is that the case?

I mean they look relatively close compared to their size, in contrast our
solar system’s bodies are really far away from each other (of course
relatively).

~~~
nabla9
Average distance between galaxies is 10-100 times the diameter of the average
galaxies.

Andromeda for naked eye is a smudge six time bigger than the moon (3.0 degrees
across).

~~~
depressedpanda
I found it hard to believe that Andromeda would be six times larger in the
night sky than the moon, so I searched online and discovered this article
showing what the galaxy would look like if it were brighter:
[https://petapixel.com/2014/12/08/photos-night-sky-look-
like-...](https://petapixel.com/2014/12/08/photos-night-sky-look-like-
andromeda-galaxy-brighter/)

Wow. TIL.

~~~
Ono-Sendai
You can see it with the naked eye in a very dark place. It looks like a big
brighter smudged area, a little off the plane of the milky way. And it does
appear a lot bigger than the moon.

------
brutt
See also:
[https://en.wikipedia.org/wiki/Tolman_surface_brightness_test](https://en.wikipedia.org/wiki/Tolman_surface_brightness_test)

------
iliaznk
I'm sorry, I haven't read the article, maybe it's explained there, but as far
as I understand by 100 hours they mean that the telescope was sitting there
for 100 hours exposed open like a camera, right? How come the image is so
sharp then? Wouldn't all those galaxies be constantly moving and end up
blurred in a photo?

~~~
ben_w
Hubble is in space. They just pointed it somewhere and said “don’t move”
(well, multiple times and stacked, but the effect is the same). The galaxies
themselves are so far away their own motion is way less than a single pixel.

~~~
iliaznk
Good point. But still, I think, if it really was exposed for 100 hours the
photo wouldn't be as sharp.

~~~
vlasev
Since it's done by stacking 30-45 min exposures, it would be sharp. All you
have to do is align the images well.

------
aaron695
So Bob was right, because Bob was right.

Good learning opportunity here.

We shouldn't think to hard whether he was right or why though.

------
aaroninsf
Curious how strongly apparent size correlates to youth.

I am guessing that especially in the extreme deep field,

the distant couple-pixel dots correspond to the back of the room i.e. the
oldest/most distant galaxies,

so this is in some real if crude sense looking through a core sample of
cosmological time?

------
MichaelMoser123
Will you reach a limit if you come up with a telescope ten times as big -
where is the real limit? Is that an exciting question? I think there is a bit
of rhetorics involved at interpeting the result of this experiment.

~~~
vlasev
You can pretty much make a telescope as large as you'd like, depending on your
technological level. Hypothetically, you can use gravitational lensing to make
a telescope via the sun! It's rather unfeasible at our current level of
rocketry, but in time, maybe! Article:
[https://blogs.scientificamerican.com/observations/using-
the-...](https://blogs.scientificamerican.com/observations/using-the-sun-as-a-
cosmic-telescope/)

You can also use Earth's atmosphere as a lens too! It's an amazing video:
[https://www.youtube.com/watch?v=jgOTZe07eHA](https://www.youtube.com/watch?v=jgOTZe07eHA)

Going even crazier, I can imagine we could some day use a massive black hole
as a giant telescope.

------
suzzer99
I've had a framed poster of the Hubble Deep Field on my wall since the late
90s. I see it every day when I wake up. It's the only wall-art I own that I
know I'll never swap out for something else.

------
jaquers
Get around "sign up if you wanna read" modal w/
window.bc.jQuery.fancybox.close(); jQuery('.fancybox-
lock,body,html').css({overflow:'scroll'})

~~~
beastman82
how do I use this

------
kiloreven
I find it really sweet that the author of the article illustrates the
perspective of our place in the universe as her father is known for just the
same rhing :D

------
Waterluvian
It seems counter to the fundamentals of science culture that the director just
kind of gets 10% of the time without need for approval.

Can anyone cast some light on this?

~~~
munificent
You can look at it as _the process of becoming director_ is itself approval
for those kind of discetionary choices. When an organization works well, it
entrusts power to those who have the judgement to use it well.

If someone needs to get ten different kinds of approvals, are they really a
"director" for most meaningful senses of the word?

------
nickgrosvenor
Best article I've read in a long long time.

------
annoyingnoob
Ha! I just ordered a custom skate deck with these images on the bottom.

------
ngcc_hk
Such a brave soul.

------
johnnymonster
Paywall links need to be downvoted

