Friday, June 24, 2005

Blowing up a comet for the 4th of July


At around 06:52 – Lisbon Time - (or 05:52 UTC/GMT) the 4th of July, NASA's Deep Impact Mission is going to send an impactor to blow a hole in the "Tempel 1" comet.

The impactor is just a piece of metal with, more or less, the same size and shape of a small table.

Perhaps, in the future, people will look at this mission as the first trying to "explode" a comet, routine procedure to save the earth from catastrophic encounters (a subject science-fiction as visited several times, just remember the movie pictures: "Deep Impact" and "Armageddon”).

Since the internal structure of the comets is not know, there is no clear idea about what is going to happen and if the event would be seen from Earth (with a telescope).

Several other probes, beside “Deep Impact”, will try to collect info during the collision. The Hubble Space Telescope will take a snapshot.

There are not going to use explosives, but do not be fooled by that; with the velocity involved, and since the kinetic energy is proportional to de SQUARE of the velocity (i.e. each time you double the velocity, you multiply the energy by 4) the shock is going to be quite "explosive" (as everybody who as read "The Moon is an Harsh Mistress", my Robert A. Heinlein favorite book, know).

The velocity of impact is about 37 100 Km/h (30 times the speed of sound in the Earth surface). With 364 kg the impactor will reach to comet with almost 2E10 Joules of energy, the equivalent of around 5 tons of TNT.

Probably I will joint nuclio [ link: http://www.nuclio.pt ] to follow the event using a ESA satellite link (C-band?) . (Programs also available ay the internet)

The timetable (ESA TV):

*** 4 July

07:15 CEST (05:15 UTC/GMT) (06:15 Lisbon)
ESA TV live event (approx 60 minutes) based on NASA-TV plus studio interviews and inserts. with links to ESO, MPI Lindau (Rosetta), ESA/ ESAC (XMM/Newton) and ESA/ESOC (mission operations).

07:52 CEST (05:52 UTC/GMT) (06:52 Lisbon)
***** IMPACT *****

09:30 CEST (07:30 UTC/GMT) (08:30 Lisbon)
ESA TV update on European observations (approx 20 minutes).

10:00 CEST (08:00 UTC/GMT) (09:00 Lisbon)
NASA media briefing – live rebroadcast by ESA TV (approx 30 minutes).

18:00 CEST (16:00 UTC/GMT) (17:00 Lisbon)
ESA TV update with first Hubble image (black and white) (approx 20 minutes).

20:00 CEST (18:00 UTC/GMT) (19:00 Lisbon)
NASA media briefing – live rebroadcast by ESA TV (approx 30 minutes).

*** 5 July

06:00 CEST (04:00 UTC/GMT) (05:00 Lisbon)
ESA TV update with first ESO colour images

More links:

http://www.esa.int/SPECIALS/Rosetta/index.html

http://www.nasa.gov/mission_pages/deepimpact/main/index.html

ESA TV (Internet downlink guide):

http://television.esa.int

and see also "Things to watch" in the upper left corner of this blog.

UPDATE: (location)

http://maps.google.com/maps?q=lisbon+portugal&ll=38.778563,-9.114425&spn=0.005300,0.007124&t=k&hl=en

http://www.mapquest.com/maps/map.adp?latlongtype=decimal&latitude=38.77856&longitude=-9.11442

UPDATE2 – 28th of June: (picture on the top of this post) The comet from Hubble Space Telescope, in a picture taken in the 27th of June.

On the right we can see a natural burst from the comet. The result of the 4 o July impact may as well be like that.

http://www.nasa.gov/mission_pages/deepimpact/multimedia/tempel1-hst-062705.html

Monday, June 20, 2005

June 21 - Demonstration in Lisbon against software patents

Tomorrow (June 21) we will have a demonstration against "software patents" in Lisbon.

In my other blog [ http://lasers-na-selva.blogspot.com/2005/06/contra-as-patentes-de-software.html ] I have pictures of the place and a link to a map of the area.

Thursday, June 16, 2005

Sunday, June 12, 2005

How to save money and work in a birthday party?

bday1

bday2

How to same money and work in a birthday party?

Just find more three friends or relatives that have the birthday in a given week. Celebrate all the 4 birthdays in the weekend with a big party.

For the birthday cake, just and put the name of each person in a corner, with candles. Everybody blows the candles at the same time.

Friday, June 10, 2005

Things (my slide rule)

slide rule (tri-log)

This is a picture of my slide rule. It is a "Aristo trig-log", because it has 3 logarithm scales (plus 3 INVERSE logarithms scales). In my last year at high scool and in my first two years at the University I became very proficient in using slide rules for all sort of computations and the slide rule shown was quite precise.

My favorite slide rule, however, was a "multi-log" (5+5 log scales). With half the size of this tri-log it was not so precise, but it was more powerful and, besides, it fitted well in my coat pocket.

Around 1975 electronic calculators became very cheap and, around 1977, I made some money tutoring high school students and I bought a programmable Texas Calculator. I never used any of my slide rules again.

I lost some familiarity with numbers, and some inside, but I gain a lot of significant figures.

Wednesday, June 08, 2005

A Cool Picture

Hokkaido University  (Hokkaido Island / Sapporo City / Japan)



Now that the weather is becoming hotter by the day (at least in the Northern Hemisphere...) I am showing a cool picture. It was taken by Professor Hideki Shimamura in the campus of the Hokkaido University, in Sapporo, Japan.

To have an idea of the place where the picture was taken, click in the following link:

http://www.mapquest.com/maps/map.adp?latlongtype=decimal&latitude=43.08222&longitude=141.33917

(zoom in and out as you like)

The last time I have been to Hokkaido I didn't have a GPS yet. Because of that I have use maps to find the location, so this is just a rough approximation, perhaps with 1 Km of error.

Monday, June 06, 2005

Things (my rolleiflex)

rolleiflex



This use to be my father favorite camera. I try to keep it functional, but I do not use it often, because is clumsy and because I have to go special stores to buy the film and, latter, to process it (the film is not cheap, 5 times more expensive that the usual film for cameras).

It's a Twin Lens Reflex (TLR) Rolleiflex, probably the most famous camera - ever.

Twins means that we have a set of lens to record the image in the film, and a duplicate set of lens to produce the same image in the "visor" - OK parallax is a (solvable) problem.

That’s why we see the “8 shaped” objective in the front. In reality it’s the 2 twin objectives side by side.

This machine uses 6cm x 6 cm film, with 56mm X 56 mm negatives, witch compares to the 35 mm film, widely used today, with a 36mm x 24mm negative. The increased area of the negative allows a better quality of the photo (if all other parameters are equal). This makes the difference, for example, if you enlarge the picture in order to frame and hang it on the wall. It also compensates, somehow, the lack of zoom lens.

more info:

http://www.mir.com.my/rb/photography/companies/rollei/rolleiflex/

http://www.stutterheim.nl/rollei/faq.html