Monday, September 22, 2014

UFOs in Portsmouth?

I'm quoted in the Portsmouth News and the Daily Mail this week commenting on a UFO (unidentified flying object) seen in Portsmouth. I sent my comments in an email to Portsmouth News reporter. What was printed in the story was this: 


' Given that the pictures show a dark object against a daytime sky it's clearly not an astronomical object. Many "UFO sightings" are actually the planet Venus, but this one can't be that.  
The distances in space are so vast that it's just not possible for aliens to be visiting Earth, so any interpretation suggesting this is an alien spacecraft is clearly wrong. '


So what were these statements based on? Here's some more extended explanation I sent to the reporter about the vastness of space: 

The nearest star is more than 3 light years away - meaning it would take more than 3 years to make the trip even at the speed of light. Most stars which are visible in the night sky are within about 1000 light years of Earth. That's considered close on astronomical scales, and that's a distance which takes 1000 years to travel even at the speed of light. 

 Most people don't understand just how fast the speed of light is. If they look at the length of one of their arms, light travels that length in 1 nano second (1 billionth of a second). It travels the distance between the Earth and the Moon (which took the Apollo astronauts 3 days to cover) in just over 1 second, and reaches the outer edge of our Solar System in about 5 hours (a spacecraft has been on its way there from Earth since 2006 and is only just arriving). 

 Light travels at about 10 million times faster than the typical speed a jumbo jet. 

 In order to make a spacecraft travel even close to the speed of light would take vast quantities of energy - many many many times more than any energy source we are aware of (including carrying entire stars along with you to power your spacecraft). 

Supposing you could accelerate your spacecraft fast enough - then any collision between such an object and even a microscopic piece speck of rock in space would cause it to explode. 

 Physics really tells us that interstellar travel is just not possible, despite how much fun the stories and films about it are. 

Here's the picture of the #pompeyufo people were sharing online. I still think it looks like a cloud based on this picture! 
People might (and do) object to these statements about it not being physically possible for aliens to visit Earth. In Science Fiction new physics is invented to get around the problems. The most famous example is warp drive (e.g. in Star Trek) which gets around this by warping space time so that the distance between two places is made much smaller. My problem with invoking this is that we might as well then invoke magic. We can imagine ways to bend our current knowledge of physics to get around the speed limit of light, but it doesn't mean it's actually going to be possible. The energy source is I think the biggest stumbling block - it's not like we just need to find something with a bit more energy than rocket fuel, it's something with billions and billions of times more energy, and which doesn't immediately disintegrate us at the same time! 

 If you are keen on aliens, the positive news about the size of the Universe is that there are so many stars in the Universe I find it implausible to believe we're the only life in it, but the sad thing is that the distances between stars, let alone between galaxies are so vast, that I also find it implausible to believe that any civilisation would/will ever be able to work out a way to travel between them. 

And if they did I think the last thing they would do is to buzz Portsmouth, UK and then disappear without trace. 

I still think it's a cloud. 

Update 24th Sept: I was wrong about it being a cloud - the whole thing was faked as a publicity stunt for a SciFi event happening this weekend in Portsmouth. 




Wednesday, July 16, 2014

Feynman and my "Beautiful Stars" quote….

My blog name was inspired by a quote from Feynman.
Poets say science takes away from the beauty of the stars - mere globs of gas atoms. I too can see the stars on a desert night, and feel them. But do I see less or more? - Feynman
From this it is perhaps obvious that I own his Lectures in Physics. I also own (and memorably read during a summer I spent working at the Planetarium at the Maryland Science Center in Baltimore) "The Please of Finding things Out", by Feynman.

I recall reading about his "adventures" with women - definitely not my favourite part of that book. I actually have a strong  (and hopefully accurate!) memory of sitting on a wall in the Inner Harbour in Baltimore reading about him choosing to study Portguese because the class had more pretty women than the Spanish class. When I think about it now it's obvious he wouldn't have seen me (as a then 19 year old reading his book) as a physicist, and that does make me uncomfortable.

Honestly, I don't have a lot to add to the recent online controversy over Feyman as a sexual predator. Other people have written much more thoughtful and eloquent posts than I could, and I have not looked into this personally. You might like to read these two blogs:

Richard Feynman, sexism and changing perceptions of a scientific icon - originally on Scientific American Blogs, now reposted by the author on their personal blog. 

The Problem with Feynman, Galileo's Pendulum

However it's made me sufficiently uncomfortable to want to change the quote on my personal blog. Funny thing is I was recently reading Dava Sobel's book on Copernicus: "A more perfect heaven", and noticed that Copernicus has been recorded as having a similar sentiment. I took the book back to the library already, so don't have the exact version in that text, but I found the below (from here) which is similar in sentiment:
The strongest affection and utmost zeal should, I think, promote the studies concerned with the most beautiful objects. This is the discipline that deals with the universe's divine revolutions, the stars' motions, sizes, distances, risings and settings . . . for what is more beautiful than heaven? - Nicolas Copernicus

So I have a new quote.  I like it better.

Factors which affect the physical science career interest of female students.

 I recently read this paper about the interest level of girls in physical sciences and was fascinated by the conclusion. They tested the impact of five different experiences on the level of interest (US) high school girls expressed in physical sciences careers. 


 The experiences were: 

* Single-sex class
* Women scientist guest speaker
* Female teacher
* Discussion of the work of women scientists
* Discussion of the underrepresentation of women in STEM

 They found that by quite a margin the biggest impact was found by girls having had the last experience (with a mild effect from the second to last). The first three were found to have no significant impact (although female teachers were found to be more likely to run the last two experiences). 



 Anyway I thought it was neat to see this kind of evidence based analysis of the effect of different experiences, so I wanted to share. 

(Full disclose I knew Zahra Hazari when we were both working at CfA in Boston and attended science education group meetings there) 



Friday, June 6, 2014

Talking about Colliding Galaxies on the Sky at Night


I was lucky enough to be invited to participate in filming for this month's Sky at Night. The theme of the show is Impacts, and I was invited to talk with Chris Lintott about colliding galaxies.

We filmed in Oxford in a back room at the Natural History Museum. It was a really fun experience for me, and fascinating to hang around and watch them film other segments for the show around the museum.

HST image of merging galaxies Arp274


The show will air on BBC4 this Sunday 8th June, at 10pm, and be repeated three further times on BBC. It will also be available to download via the BBC iPlayer. For more details on how to watch visit the BBC Website for Sky at Night: Impacts

Forty Years of Women at Wadham

I had a lovely experience as an undergraduate at Oxford University, and my college was Wadham College (founded by Dorothy Wadham in 1610). Wadham was proud of having been amongst he first Oxford colleges to admit women in 1974, and this year is celebrating 40 years of women at Wadham.

I was invited to participate in these celebrations, and you might spot me profiled among the women on the news item about Forty Years of Women at Wadham.

There's a page of Wadham Women's Voices , with an entry from me about studying Physics at Wadham in 1997-2000 (shockingly - for me - not too long after the halfway point of the history of women at Wadham).

As I was in touch with the alumni office, they also invited me to do a longer interview about my involvement with the Galaxy Zoo project, which is led out of the Oxford Physics Department. I guess they couldn't resist the pun: Masters of the Galaxies.

They also took this nice photo of me in the Wadham back quad during my visit.



Sadly Physics at Wadham is still struggling to attract women, with none listed in the recent yearbook I was sent. I hope 20 years from now I'll be able to tell a different story.

Saturday, February 15, 2014

Happy 450th Birthday to Galileo

Today, Feb 15th 2014 is 450 years since the birth of Galileo Galilei.

By chance, last week I had the opportunity to visit the house Galileo lived in in the last years of his life near Arcetri Observatory in Florence.

I was actually visiting the Observatory where I had been invited to give a seminar.


Here's the explanation (in English) of the historic nature of the site. 


From the roof of the observatory you can see across the valley to the Villa il Gioiello where Galileo lived from 1631-1642. It's the yellowish building just left of centre.

Simone Bianchi was my host at Arcetri, and was kind enough to offer to take me over to the house. The house is not regularly open to the public, and the details of its future use are still being debated. 

A famous number by the front door. 



Here's an 18th century monument to Galileo from when the house was first becoming famous.


A plaque above the door from the time the University of Florence bought the house. The house has been under renovation for some time and is currently very nicely kept (but almost completely empty). 


Here's me in the room which is believed to have been Galileo's study during the time he was working on the proofs of his last book "Discourse and Mathematical Demonstrations Relating to Two New Sciences"


Here's the view from the upper balcony. This level was through to house the household staff at the time of Galileo. 


The walk between the observatory and the house was partly along a beautiful planet walk installed by the observatory. They host regular public tours when visitors can explore this walk, as well as the historic telescope and other instruments on the site (although unfortunately not the Galileo house). 


It was a nice visit, and has inspired me to re-read Dava Sobel's "Galileo's Daughter" which is about his time in this house, and well worth a read. 

Wednesday, February 12, 2014

British Astronomers

I had cause to Google "British Astronomers" yesterday, and was so horrified by the result I felt I needed to post it. Actually once I think about it it's not a surprise at all, but the raw numbers still shocked me.

The top line is a list (with images) of the results "most mentioned on the web". I did a screen shot of that below.

It's William Herschel, Patrick Moore, Isaac Newton, Edmond Halley, John Flamsteed, Caroline Herschel, George Airy, John Herschel, James Bradley (?), Arthur Stanley Eddington, Jeremiah Horrocks, Nevil Maskelyne, John Adams (?), Fred Hoyle, Richard van der Riet Woolley (?), Frank Watson Dyson (?), William Parsons, Martin Rees, Harold Spencer Jones (?) and Jocelyn Bell.



Only two out of the 20 (10%) are alive, only two (10%) are women.

I put question marks above on names which were not immediately recognisable to me (this I take as my failing not Google's, but I was curious why they're there). It turns out that most of them are former Astronomer Royals whose wikipedia article begins "XX is an English Astronomer who was Astronomer Royal from XX-XX". John Adams I should have known - he's the person who (a the same time as but independently of Le Verrier) predicted the existence of Neptune from deviations in Uranus's orbit.

Is it time to add some more recent British astronomers to the list? Perhaps some more women (where is Cecilia Payne-Gaposhkin in this?). It seems we can help to do this by editing Wikipedia which is a good thing to do anyway.

Curiously Googling either "English Astronomers" or "American Astronomers" does not return the series of images ("Italian Astronomers" does - but missing Galileo!).