Thony Christie on Hevelius

Scutum constellation in the Uranographia

If you have any interest in the his­tory of astro­nomy you should be fol­low­ing The Renaissance Mathematicus blog and this post, The last great naked eye astro­nomer, is a per­fect example of why. This is a post about Johannes Hevelius who has to be one of the most fam­ous unheard of astro­nomers ever.

That doesn’t make sense I know. There are a lot of people who haven’t heard of Hevelius, but if you have heard of Hevelius, then the idea that people haven’t heard of him seems non­sense because his work is every­where in astronomy.

Scutum constellation in the Uranographia

Scutum in the Uranographia by Hevelius. Source: Wikipedia.

Everyone’s happy that most con­stel­la­tions are ancient, but what is less well-known is that not every star was in a con­stel­la­tion. There were gaps between con­stel­la­tions filled with faint and bor­ing stars. These were called αμορφοι amorphoi or unformed stars by the Greeks. This is no good if you want to do sci­ence, because things like comets don’t stick to the inter­est­ing parts of the sky. That’s why map­ping was so import­ant in the Renaissance. In the case of Hevelius, his maps were so use­ful that he formed seven con­stel­la­tions that stay with us to this day.

I’ll admit con­stel­la­tions like Lacerta or Vulpecula aren’t fam­ous con­stel­la­tions, but he was work­ing with the haps between con­stel­la­tions. The fact that his charts were made of con­stel­la­tions vis­ible in Europe shows he was work­ing in a highly com­pet­it­ive space.

It’s easy to take this kind of work for gran­ted. The out­put can be seen as an uncon­tested fact, but Thony’s post put’s Hevelius’s work into the con­text of its time includ­ing the often intense sci­entific rivalry between astro­nomer defend­ing per­sonal and national status.

The also shows that while with hind­sight it seems obvi­ous that tele­scopes would bring more accur­ate meas­ure­ments, at any given time in his­tory it’s not always obvi­ous that new tech­no­logy is The Next Big Thing, it could be a dis­trac­tion or Expensive Dead End.

What’s the difference between archaeology and grave-robbing?

HMS Victory sinking by Peter Monamy
HMS Victory sinking by Peter Monamy

Loss of HMS Victory, 4 October 1744 by Peter Monamy

The HMS Victory (not that one) is set to be recovered accord­ing to the BBC and many other sites. You could say speed. Archaeology is an enorm­ously inef­fi­cient of rob­bing graves. These days archae­olo­gists can take years to study one bar­row (an earth mound mark­ing a burial) while in the 18th cen­tury aris­to­crats used to go on pic­nics and have the work­men open up one or two in an after­noon for gold.

There is a deeper reason.

Archaeologists are so slow because they want to say some­thing about the people who live there. There’s a great Paul Bahn line: Archaeology is not about find­ing things, it’s about find­ing things out. Obviously find­ing things out is easier if you find arte­facts with people and that’s why sud­den dis­asters are great from an archae­olo­gical point of view.

It doesn’t stop a dis­aster site effect­ively being a grave. If you’re genu­inely inter­ested in find­ing out about people, it’s would be odd if you didn’t give a damn about their grave. Digging up a site is effect­ively des­troy­ing it.* If you’re going to do that you’ll want to go slowly and make sure that the story you can tell about this person’s life is a bet­ter memorial than the one he or she already has.

The news stor­ies this week­end are all about find­ing the ship, along with a brief men­tion of the up to £500 mil­lion value of gold on board. What they don’t men­tion is that the UK gov­ern­ment has sanc­tioned the recov­ery in exchange for 20% of that. Is the gov­ern­ment more inter­ested in the treas­ure, or has it developed a keen interest in archae­ology so that, as Lord Lingfield says: “We hope it will give a unique insight into the world of the mid-18th cen­tury Royal Navy.

The answer can be found in this story from October 2011 in the Daily Mail.

Odyssey said yes­ter­day the UK gov­ern­ment was ‘des­per­ately look­ing for new sources of income’ and was urging it to find more British wrecks. It is also invest­ig­at­ing HMS Sussex, lost off Gibraltar with 10 tons of gold in 1694, and HMS Victory, a pre­cursor to Nelson’s flagship.

There are thou­sands of deser­ted medi­eval vil­lages in the UK. In the 21st cen­tury the biggest defence any buri­als in them have have against feed­ing bankers is that the fin­an­cial pay­off of crack­ing them open is too low.

*Not hyper­bolae. It’s recog­nised by pro­fes­sional archae­olo­gists then if you dig up some­thing it’s not going to be there for someone else to dig. +Kris Hirst col­lects quotes on her site, and a great one from Kent Flannery is: “Archeology is the only branch of anthro­po­logy where we kill our inform­ants in the pro­cess of study­ing them.

A post that ori­gin­ally appeared on Google+.

One small slip for man, one giant mistake for space heritage?

Jim Lovell reading a newspaper story about the Apollo 13 mission

There’s a check­list from the Apollo XIII mis­sion owned(?) by Jim Lovell. It’s an inter­est­ing puzzle from an astro-heritage point of view and some­thing I’ve not given any thought to at all. In fact there’s two puzzles. One is legal own­er­ship and the other is what her­it­age value does it have and neither ques­tion is con­nec­ted much. The only con­nec­tion I see is that if there is no her­it­age value then people won’t get worked up too much about the ownership.

Jim Lovell reading a newspaper story about the Apollo 13 mission

Jim Lovell dis­cov­ers he got back to Earth safely thanks to the Honolulu Star-Bulletin. Photo: NASA.

I get the impres­sion NASA would have been within their rights to claim own­er­ship, but if they allowed astro­nauts to keep memen­tos, then that’s their mis­take. I’m sur­prised that a check­list with cru­cial cal­cu­la­tions was dis­carded from a failed mis­sion, but I don’t know the exact cir­cum­stances of how Jim Lovell got to keep it, but it seems NASA wasn’t that her­it­age aware at the time.

At the same time I don’t know what her­it­age value it has. Heritage value isn’t the same as his­tor­ical or archae­olo­gical value. While the cal­cu­la­tions are his­tor­ic­ally import­ant, is the paper that holds them neces­sary to under­stand the his­tory of the trip?

What I can see is that there’s a big emo­tional hit with the arte­fact. Seeing the authen­tic arte­fact puts you vicari­ously in a pos­i­tion of being in deep trouble in deep space. The emo­tional value is noth­ing to be sneered at. It’s part of being human and it’s going to play a part in dis­cus­sions whether you dir­ectly address it or not. A sens­ible con­clu­sion is going to have to deal with the emo­tional and exper­i­en­tial side of the checklist.

For those who think the answer is obvi­ous, this is tax-payer fun­ded mater­ial there­fore the tax-payer owns it, here’s another puzzle. Suppose an Apollo astro­naut gets paid to endorse Moon Juice a new fizzy sugar-laden drink. The only reason he is get­ting the job is because tax-payers fun­ded him to go to the moon. Does that mean that the tax-payers should get the fee and not the astro­naut? It’s not an exact ana­logy, this is a mater­ial arte­fact. Yet if it’s an arte­fact that was going to be dis­carded by NASA it wrong for an astro­naut to own it, or is it a bet­ter solu­tion that nobody owns it? Should Mitchell’s cam­era have been left on the Moon where no one could access it?

I don’t see an obvi­ous answer that sat­is­fies every­one. Another good piece by +Amy Shira Teitel.

A post that ori­gin­ally appeared on Google+.

Cervix watching


Emily Baldwin @astroemz on Twitter is going in for a loop excision next week to remove pre-cancerous cells from her cer­vix. As she says it’s a routine oper­a­tion, but it’s only routine for the pro­fes­sion­als. It’s not routine for her so she is under­stand­ably nervous. She’s blog­ging on what hap­pens to help raise aware­ness of the import­ance of cer­vical smears under the twit­ter hashtag #cer­vix­watch.

I think this is one of those situ­ations where put­ting thoughts into writ­ing can help. I had a routine oper­a­tion to remove a kind of can­cer that Emily will never get, and some­times it’s wor­ry­ing. The raw stat­ist­ics are that almost every­one has no trouble, so you can feel silly for being anxious. Still, I woke up one night in a small puddle of my own blood I was a bit con­cerned. After think­ing about how to write this up I real­ised I’d be even more wor­ried if I’d woken up in a puddle of someone else’s blood. This kind of detach­ment made it easier to cope with waiting.

It’s easier to be detached when some­thing is over too. I think put­ting inform­a­tion online before the out­come is known is brave. It’s a per­sonal exper­i­ence and con­fess­ing fears can make you feel more vul­ner­able. I don’t ima­gine it’s a huge help that the cells might be pre-cancerous, mean­ing it’s not actu­ally can­cer. The c-word is still there but because it’s pre– you could feel fool­ish for wor­ry­ing about it. Oddly I’m told it’s a com­mon thing among can­cer patients to feel guilty because you know other people have had it worse. In Emily’s blog I see some­thing sim­ilar. She doesn’t want to over­play the situ­ation, but she’s still per­fectly entitled to be anxious and some of her post explains why.

In my case other people def­in­itely have had it worse than me. The sad­dest memory I have is from the wait­ing room when I had chemo­ther­apy. There weren’t enough seats, so the polite thing to do was to stand and let the people with can­cer sit down. There were a lot of people there in a much worse way than me and they didn’t all have can­cer. I felt tired in my muscles all the time, like I’d been swim­ming all day, but I wasn’t as run down as some of the carers, so I stood up to give one of them a seat. It was heart­break­ing to see how shattered they were look­ing after someone they loved. Many of them were clearly in dire need of a rest, and for some of them it was never going to get any better.

Compared to that a bit of embar­rass­ment and worry is a bar­gain. If you’re female and you’re squeam­ish at the thought of smear tests or think you really shouldn’t make a fuss about some­thing like that, then you should fol­low Emily’s blog over the next few weeks to see if it’s really worth risk­ing dying of embarrassment.

…and as a follow-up she now has her exper­i­ence online.

A post that ori­gin­ally appeared on Google+.

Snapseed review

The same Greenhouse at Kew after Snapseed

I’ve had a quick play with Snapseed for Mac. Below is a neut­ral photo of a green­house at Kew expor­ted from Aperture, and one after a couple of minutes of editing.

Greenhouse at Kew, neutral version

Greenhouse at Kew, neut­ral version.

Snapseed works with a mod­i­fied form of Nik’s UPoint inter­face. You can make global changes, but on some fea­tures you can make masked adjust­ments. Here I put a point on the left of the sky in a blue part. I pulled the size to make it a big area, but when I did the clouds were auto­mat­ic­ally masked off, so it was only going to be the blue parts of the area that were affected. There’s handy red high­light­ing as you do this to show where your effect will apply. I reduced bright­ness and increased sat­ur­a­tion, then duplic­ated the point and moved the duplic­ate to the other side if the blue sky so that all the area was covered.

Snapseed at work

Snapseed at work.

There are other ways of doing the same thing in other photo apps, but this is usu­ally a pain­less way of select­ing an area. It works well for com­plex shapes, like if you want to select flower­heads in a shot. My ver­sion of PhotoShop Elements is out-of-date so I don’t know how good the smart select­ors are in that now, but the ver­sions I have used have been much harder to do the same thing with.

It’d be great if you could do that with all the effects, but you can’t. The range of point options is lim­ited to bright­ness, con­trast and sat­ur­a­tion. If you want a lot of con­trol then it’s $99 for Viveza or Color Efex. The rest of Snapseed’s effects are global. I applied the Structure+ effect to bring out details in the stones and clouds. That’s a scal­able effect, so if you think I’ve gone over the top you could pull a slider down to ease off.

That’s all I did because then it looks like a bug kicked in and I couldn’t apply any more effects like Vignette or Drama. In this case it might be a bless­ing but it’ll annoy me if that’s per­sist­ent. Looking at the res­ult I think I’d want to push it back in to Aperture to blur the sky a little. I could do some­thing sim­ilar to remove struc­ture in Snapseed by adding a point and turn­ing down the con­trast a little. If there hadn’t been the bug.

The same Greenhouse at Kew after Snapseed

The same Greenhouse at Kew after Snapseed.

I keep think­ing about buy­ing Viveza, HDR Efex or Color Efex, or the bulk suite, but I keep get­ting put off because whenever I look the price in Europe is much higher than from the US store, even after allow­ing for VAT. The only excep­tion was a recent sale where things were up to 50% off. A $10 instruc­tion video was indeed 50% off, but the sav­ings on the soft­ware were bring­ing down the prices to US levels, which doesn’t feel like a sav­ing. This adds an extra span­ner to Nik mar­ket­ing machine, because this does a lot of what I want from Viveza or Color Efex. Ok, I don’t get the Sunrise Glow fil­ter, but how often would I use it? I like to sleep in. The last thing I want to do is make people think I’m will­ing to get up at the crack of dawn to pho­to­graph some­thing. I’d get even less use out of the “Cross-processed on a rainy Tuesday” fil­ter and so on. Have Nik lost a sale, or have they worked out that tools, excel­lent as they are, are aimed at the pro mar­ket and they need some­thing dif­fer­ent to prise money out of the hobby market?

It is expens­ive to com­pared to a lot of the photo fil­ter apps in the MacStore, but if you don’t have any app and you don’t need fine con­trol like Color Efex or Viveza then it’s a good buy. If you’re happy shuff­ling pho­tos between an iPad and a Mac and you already have Snapseed, then it’s not worth the pur­chase. Altering your pho­tos by touch feels nicer.

A post that ori­gin­ally appeared on Google+.

HDR and Reality

The Lovell Telescope at Jodrell Bank
A com­ment on this link HDR: Love it or or Leave it? pos­ted by +Matt Shalvatis.
The Lovell Telescope at Jodrell Bank

The Lovell Telescope at Jodrell Bank

This has been on my ‘to-blog-about’ list for years. On the one side there’s the artistic effect, which you can debate. I get the impres­sion HDR is a per­sonal taste, so telling people it’s the right or wrong way seems point­less to me. In my view my early HDR stuff was poor. In par­tic­u­lar it was often over-saturated so I could see what was hap­pen­ing (I have odd col­our vis­ion). These days if I can can do some­thing I want without HDR I will, and I find adjust­ing the white and black points is often enough for what I want, but when it isn’t a light touch in Photomatix can make a big and subtle difference

The other side is that it can have prac­tical uses in some­thing like archae­ology. I have seen too many pho­tos of pitch-black church interi­ors. HDR can provide a much bet­ter impres­sion of what the human eye sees than the lim­ited dynamic range of a cam­era because you can expose the shot for a wider range of light and shadow. The altern­at­ive is to bring a massive light­ing rig along with you, and that’s not practical.

I know some people think this is bad because it’s manip­u­lat­ing the pho­to­graph and there­fore not a ‘true record’. They’re right it isn’t ‘true’. But the auto func­tion on a cam­era isn’t neut­ral. It makes its own judge­ments on what the set­tings should be. The dif­fer­ence is that these set­tings are often hid­den from the user when they’re made, so it’s harder to see what assump­tions are being built in. Just because you can’t see the manip­u­la­tion of set­tings hap­pen­ing doesn’t mean it isn’t happening.

I don’t ever see the same angst about real­ity in archae­olo­gical illus­tra­tion though. I think a lot of archae­olo­gists will laugh if you say the cam­era never lies, but I think there’s a bias to believ­ing that cam­eras can be neut­ral. Maybe with pho­tos look­ing so much closer to real­ity we sub­con­sciously insist devi­ations from real­ity are flaws not art.

A post that ori­gin­ally appeared on Google+.