From boud w astro.uni.torun.pl Tue Feb 17 23:51:47 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Tue, 17 Feb 2004 23:51:47 +0100 (CET) Subject: wewnetrzny grant UMK Message-ID: hi Andrzej (Kus), Apparently we need to spend 5kPLN of an internal UMK grant money/application and decide by tomorrow? IMHO this would be best spent on improving the computing facilities in the student room in KRA. If formally speaking this should be for a research project, that's no problem - the whole existence of the internet means that students can get a taste of research and be motivated to study questions of which the answers are not yet known. As the students get to learn how to program, find theoretical information and observational data, and analyse it in ways they understand, they also will start contributing to research (hopefully). i meant to have a look at the computers with Roman before the new semester started, i didn't realise it had already started. i remember some students claiming not many of the terminals/computers were working properly, but i didn't get around to checking specifically. ** It could certainly not hurt to buy another computer, which we can put as cosmic topology research - or for Bartek and my dark matter projects - but which i can set up for secondary usage by the students who i'm sure can always use more cpu and disk space. ** Maybe also a DAT drive + a few dozen DAT tapes (to last several years) for backups so that all the students can have a decent amount of backed up disk space. KA&A seems to have more or less good student support but we clearly are pushing the limits with the larger numbers of students. pozd boud From michalf w ncac.torun.pl Tue Feb 24 13:09:55 2004 From: michalf w ncac.torun.pl (Michal Frackowiak) Date: Tue, 24 Feb 2004 13:09:55 +0100 Subject: festiwal nauki In-Reply-To: <200402240952.KAA14422@galileo.astro.uni.torun.pl> References: <200402240952.KAA14422@galileo.astro.uni.torun.pl> Message-ID: <403B3F13.9000603@ncac.torun.pl> przepraszam, z co to znaczy: "Wed?ug papieru wydrukowanego przez organizatorów oficjalnych: [...] /Micha? Fra;ckowiak/ - dlaczego kosmologia jest skonczona" czy to oznacza, ze jestem wciagniety na liste prezenterow, o czym za bardzo wczesniej nie wiedzialem, na dodatek z tematem, ktory mowi mniej wiecej tyle: "jestem ignorantem w dobie rozwoju nauki, gdy ten rozwoj jest szybszy niz kiedykolwiek"? (to tak, jakby kilka lat temu powiedziec, ze internet jest skonczony) a wiec o co tu naprawde chodzi? pozdr - zaniepokojony michal Andrzej Marecki wrote: >>http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004 >> >>Please correct, update, modify... >> >> > > From boud w astro.uni.torun.pl Tue Feb 24 13:45:08 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Tue, 24 Feb 2004 13:45:08 +0100 (CET) Subject: festiwal nauki In-Reply-To: <403B3F13.9000603@ncac.torun.pl> References: <200402240952.KAA14422@galileo.astro.uni.torun.pl> <403B3F13.9000603@ncac.torun.pl> Message-ID: witam, On Tue, 24 Feb 2004, Michal Frackowiak wrote: > przepraszam, z co to znaczy: > > "Wed?ug papieru wydrukowanego przez organizatorów oficjalnych: [...] > /Micha? Fra;ckowiak/ - dlaczego kosmologia jest skonczona" > > czy to oznacza, ze jestem wciagniety na liste prezenterow, o czym za > bardzo wczesniej nie wiedzialem, http://www.astro.uni.torun.pl/sympa/cosmo-torun/2003-12/msg00001.html http://www.astro.uni.torun.pl/sympa/cosmo-torun/2003-12/msg00002.html > na dodatek z tematem, ktory mowi mniej > wiecej tyle: "jestem ignorantem w dobie rozwoju nauki, gdy ten rozwoj > jest szybszy niz kiedykolwiek"? (to tak, jakby kilka lat temu > powiedziec, ze internet jest skonczony) Przepraszam, próbowałem poprawić co jest części ofycjalna i przenosiłem do dolu strony. Tytuł ,,dlaczego kosmologia jest skonczona" jest tylko moja propozycja prowokacyjna ;) - nie była pisana na ofycjalna papier. Ale chyba teraz jest administrator, który zdesperowanie ty szuka żeby podpisać że akceptujesz 150 złoty. Ja nic nie znałem o tym - wszystko zosta więcej komplikowany i polityczny kiedy jest pieniądze :(. > a wiec o co tu naprawde chodzi? Byli dwa mejli - możesz uczestniczyć lub nie jak chcesz, i możesz zmienić tytuł twoja prezentacja jak chcesz! Stylu organizacyjny komitarz Festiwał Nauki ewidentnie nie jest moj stylu lub stylu TLUGa! I chyba wykładowców, którze dają sam prelekcji, są płacone 600 złoty (dla my jest 600/4 = 150) - jest też chyba powód dlaczego jest cieżki biurokracji zamiast dyskusji otwartych... Does this help? pozd boud > Andrzej Marecki wrote: > > >>http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004 > >> > >>Please correct, update, modify... From michalf w ncac.torun.pl Tue Feb 24 14:09:07 2004 From: michalf w ncac.torun.pl (Michal Frackowiak) Date: Tue, 24 Feb 2004 14:09:07 +0100 Subject: festiwal nauki In-Reply-To: References: <200402240952.KAA14422@galileo.astro.uni.torun.pl> <403B3F13.9000603@ncac.torun.pl> Message-ID: <403B4CF3.3050603@ncac.torun.pl> Boud! this is certainly NOT A GOOD WAY OF MAKING PEOPLE INVOLVED. what I mean is that you have sent an email to cosmo-torun mailing list asking: " Prosze^ poprawiuj ten stron! http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004" are we obliged to look at every page you create with your wiki pages? if I did not edit/looked at this page it would mean I am not interested in the Festival. but suddenly my name appeared there. I have not signed anything nor agreed to take part in it nor confirmed anything (although I remember some short "oral talk" about the festival and _possibility_ of open discussion). do you have any email from me that says sth else? or en entry at your twiki I have edited concerning the Festival? I do not want to be offensive but does not seem to me like a good way. > Byli dwa mejli - możesz uczestniczyć lub nie jak chcesz, i możesz > zmienić tytuł twoja prezentacja jak chcesz! I did not want to have a cosmological presentation at the Festival and did not changed my mind. why have you not asked more directly? I do not read cosmo-torun that often. lucky me I looked this time. regards - michal Boud Roukema wrote: >witam, > >On Tue, 24 Feb 2004, Michal Frackowiak wrote: > > > >>przepraszam, z co to znaczy: >> >>"Wed?ug papieru wydrukowanego przez organizatorów oficjalnych: [...] >>/Micha? Fra;ckowiak/ - dlaczego kosmologia jest skonczona" >> >>czy to oznacza, ze jestem wciagniety na liste prezenterow, o czym za >>bardzo wczesniej nie wiedzialem, >> >> > >http://www.astro.uni.torun.pl/sympa/cosmo-torun/2003-12/msg00001.html >http://www.astro.uni.torun.pl/sympa/cosmo-torun/2003-12/msg00002.html > > > >>na dodatek z tematem, ktory mowi mniej >>wiecej tyle: "jestem ignorantem w dobie rozwoju nauki, gdy ten rozwoj >>jest szybszy niz kiedykolwiek"? (to tak, jakby kilka lat temu >>powiedziec, ze internet jest skonczony) >> >> > >Przepraszam, próbowałem poprawić co jest części ofycjalna i przenosiłem >do dolu strony. > >Tytuł ,,dlaczego kosmologia jest skonczona" jest tylko moja propozycja >prowokacyjna ;) - nie była pisana na ofycjalna papier. Ale chyba teraz >jest administrator, który zdesperowanie ty szuka żeby podpisać że >akceptujesz 150 złoty. Ja nic nie znałem o tym - wszystko zosta >więcej komplikowany i polityczny kiedy jest pieniądze :(. > > > >>a wiec o co tu naprawde chodzi? >> >> > >Byli dwa mejli - możesz uczestniczyć lub nie jak chcesz, i możesz >zmienić tytuł twoja prezentacja jak chcesz! > >Stylu organizacyjny komitarz Festiwał Nauki ewidentnie nie jest moj stylu >lub stylu TLUGa! I chyba wykładowców, którze dają sam prelekcji, są >płacone 600 złoty (dla my jest 600/4 = 150) - jest też chyba powód dlaczego >jest cieżki biurokracji zamiast dyskusji otwartych... > >Does this help? > >pozd >boud > > Boud! this is certainly NOT A GOOD WAY OF MAKING PEOPLE INVOLVED. From boud w astro.uni.torun.pl Tue Feb 24 14:31:44 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Tue, 24 Feb 2004 14:31:44 +0100 (CET) Subject: festiwal nauki In-Reply-To: <403B4CF3.3050603@ncac.torun.pl> References: <200402240952.KAA14422@galileo.astro.uni.torun.pl> <403B3F13.9000603@ncac.torun.pl> <403B4CF3.3050603@ncac.torun.pl> Message-ID: On Tue, 24 Feb 2004, Michal Frackowiak wrote: > Boud! this is certainly NOT A GOOD WAY OF MAKING PEOPLE INVOLVED. what I > mean is that you have sent an email to cosmo-torun mailing list asking: > > " Prosze^ poprawiuj ten stron! > http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004" > > are we obliged to look at every page you create with your wiki pages? if No, you're not obliged. > I did not edit/looked at this page it would mean I am not interested in > the Festival. but suddenly my name appeared there. I have not signed > anything nor agreed to take part in it nor confirmed anything (although > I remember some short "oral talk" about the festival and _possibility_ > of open discussion). > do you have any email from me that says sth else? or en entry at your > twiki I have edited concerning the Festival? No. > I do not want to be offensive but does not seem to me like a good way. > > > Byli dwa mejli - możesz uczestniczyć lub nie jak chcesz, i możesz > > zmienić tytuł twoja prezentacja jak chcesz! > > > I did not want to have a cosmological presentation at the Festival and > did not changed my mind. why have you not asked more directly? I do not > read cosmo-torun that often. lucky me I looked this time. OK, you're no longer listed on the page. So i don't see where the problem is. If you don't wish to participate, then you don't! The point is that we have several feedback mechanisms: negative feedback for correcting errors and positive feedback for focussing on what people agree on. i'll send a message to the Festiwal Nauki organisers so that they remove your name from any printed stuff - hopefully they're not so silly that they start printing propaganda two months before the event. pozd boud From michalf w ncac.torun.pl Tue Feb 24 14:28:58 2004 From: michalf w ncac.torun.pl (Michal Frackowiak) Date: Tue, 24 Feb 2004 14:28:58 +0100 Subject: festiwal nauki In-Reply-To: References: <200402240952.KAA14422@galileo.astro.uni.torun.pl> <403B3F13.9000603@ncac.torun.pl> <403B4CF3.3050603@ncac.torun.pl> Message-ID: <403B519A.9050705@ncac.torun.pl> ok, thanx!!! Boud Roukema wrote: >On Tue, 24 Feb 2004, Michal Frackowiak wrote: > > > >>Boud! this is certainly NOT A GOOD WAY OF MAKING PEOPLE INVOLVED. what I >>mean is that you have sent an email to cosmo-torun mailing list asking: >> >>" Prosze^ poprawiuj ten stron! >>http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004" >> >>are we obliged to look at every page you create with your wiki pages? if >> >> > >No, you're not obliged. > > > >>I did not edit/looked at this page it would mean I am not interested in >>the Festival. but suddenly my name appeared there. I have not signed >>anything nor agreed to take part in it nor confirmed anything (although >>I remember some short "oral talk" about the festival and _possibility_ >>of open discussion). >>do you have any email from me that says sth else? or en entry at your >>twiki I have edited concerning the Festival? >> >> > >No. > > > >>I do not want to be offensive but does not seem to me like a good way. >> >> >> >>>Byli dwa mejli - możesz uczestniczyć lub nie jak chcesz, i możesz >>>zmienić tytuł twoja prezentacja jak chcesz! >>> >>> >>I did not want to have a cosmological presentation at the Festival and >>did not changed my mind. why have you not asked more directly? I do not >>read cosmo-torun that often. lucky me I looked this time. >> >> > >OK, you're no longer listed on the page. > >So i don't see where the problem is. If you don't wish to participate, >then you don't! > >The point is that we have several feedback mechanisms: negative >feedback for correcting errors and positive feedback for focussing >on what people agree on. > >i'll send a message to the Festiwal Nauki organisers so that they >remove your name from any printed stuff - hopefully they're not so silly >that they start printing propaganda two months before the event. > >pozd >boud > > > >------------------------------------------------------------------------ > >LISTNAME: cosmo-torun >HELP: send an email to sympa w astro.uni.torun.pl with "help" >WEB ARCHIVE: http://www.astro.uni.torun.pl/sympa/cosmo-torun/ >UNSUBSCRIBE: email to sympa w astro.uni.torun.pl with "unsubscribe cosmo-torun" > > > > From boud w astro.uni.torun.pl Tue Feb 24 14:39:59 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Tue, 24 Feb 2004 14:39:59 +0100 (CET) Subject: poprawienie do listy uczestnikow ,,Wszechswiat: globalisci vs antyglobalisci" Message-ID: Witam, Jak rozumiem, nasze propozycja dla dyskusji panelowej o temat kosmologii byli akceptowany dla Festiwału Nauki: http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004 Proszę do mąlego poprawki: Pisaliśmy że Michał Frąckowiak chce uczestniczyć, ale prawdziwie on nie chce uczestniczyć. Proszę usunuj swoj nazwa od listy uczestników na baz danych Festiwału. Pozdrawiam serdecznie Boud Roukema (Centrum Astronomii UMK) From Bartosz.Lew w astri.uni.torun.pl Tue Feb 24 17:33:23 2004 From: Bartosz.Lew w astri.uni.torun.pl (Bartosz Lew) Date: Tue, 24 Feb 2004 17:33:23 +0100 (CET) Subject: CMB energy In-Reply-To: Message-ID: CMBR is almost perfectly well described by u(\ni) d\ni function - the plack function which is the spectral energy density described with the only parameter - temperature. Expansion changes the overall CMBR energy (as we see it) like (1+z)^4 which comes from 4'th power T relation when we integrate u(\ni) d(\ni) (to get Stefan boltzmann law) ( and there is stright relation between temperature of boson gaz with it's enery - alghough coefficients are different in classic and ultra relativistic regime). Bosons are particles which participe positivly to universe's density and pressure thus they only make expansion slower, hence IMHO it's incorrect to say that "it takes some energy to expand the Universe..." nor that the expansion is derived by it's contents. In fact we don't know why BB happened. In fact we don't even know if it happened. (although the expansion rate is altered by the contents in various ways). Recalling the energy density doesn't help much for the question since there still remains 1+z factor left to explain. It's the question why photons suffer from redshift? And is the fact that different observers see, say two identical photons (each of them observes his own photon) as two different photons actually a manifestation of violation of energy conservation principle? I've been thinking about this problem yesterday and what I concluded is... shocking simple. :) IMHO The correct answer is: Nothing happened to that energy. It's still there (unless photons gets older or other crap like that), the only thing that changed is that we no longer see hot photons because, as we've been tought in high school, we're floating away from everything else according to the hubble law. (So the answer is essentialy in the question ;) The "doppler effect" which can easily be derived from SR transformaiton formulas causes that we see everythig red. The only difference from the situation described above with observers looking at identical photons (and yet seeing them in different colors) and complication I see here is that it is not possible to find a recerence frame in which we will see the whole CMB photons at different temperature - color etc. This is of course because it's the space that expands and there is nothing we can do about it, so changing reference frame won't help in understanding that it is just our obserwational effect not a true energy theft by some more less unidentified process. But still I belive that this reddening can be ballanced once when Universe start to collapse. I hope that helps. regards bartek On Mon, 23 Feb 2004, Jarek Rzepecki wrote: > Hi all, > CMB photons are red-shifted due to Universe expansion -> this means that > the whole CMB energy gets smaller... where does it go? > pozdrawiam > Jarek > > From jarekr w ncac.torun.pl Tue Feb 24 18:34:38 2004 From: jarekr w ncac.torun.pl (Jarek Rzepecki) Date: Tue, 24 Feb 2004 18:34:38 +0100 (CET) Subject: CMB energy In-Reply-To: References: Message-ID: On Tue, 24 Feb 2004, Bartosz Lew wrote: > The correct answer is: Nothing happened to that energy. It's still there > (unless photons gets older or other crap like that), the only thing that > changed is that we no longer see hot photons because, as we've been tought > in high school, we're floating away from everything else according to the hubble law. > (So the answer is essentialy in the question ;) > The "doppler effect" which can easily be derived from SR transformaiton > formulas causes that we see everythig red. The only difference from the > situation described above with observers looking at identical photons (and > yet seeing them in different colors) and > complication I see here is that it is not possible to find a recerence frame > in which we will see the whole CMB photons at different temperature - color > etc. This is of course because it's the space that expands and there is nothing > we can do about it, so changing reference frame won't help in understanding > that it is just our obserwational effect not a true energy theft by some > more less unidentified process. But still I belive that this reddening can > be ballanced once when Universe start to collapse. Well I think that the problem is closer to the question: Why photons getting out of potential well suffer from red-shift - where their energy go in that case? then to the Doppler... From Bartosz.Lew w astri.uni.torun.pl Tue Feb 24 19:14:15 2004 From: Bartosz.Lew w astri.uni.torun.pl (Bartosz Lew) Date: Tue, 24 Feb 2004 19:14:15 +0100 (CET) Subject: CMB energy In-Reply-To: Message-ID: On Tue, 24 Feb 2004, Jarek Rzepecki wrote: > > > On Tue, 24 Feb 2004, Bartosz Lew wrote: > > > The correct answer is: Nothing happened to that energy. It's still there > > (unless photons gets older or other crap like that), the only thing that > > changed is that we no longer see hot photons because, as we've been tought > > in high school, we're floating away from everything else according to the hubble law. > > (So the answer is essentialy in the question ;) > > The "doppler effect" which can easily be derived from SR transformaiton > > formulas causes that we see everythig red. The only difference from the > > situation described above with observers looking at identical photons (and > > yet seeing them in different colors) and > > complication I see here is that it is not possible to find a recerence frame > > in which we will see the whole CMB photons at different temperature - color > > etc. This is of course because it's the space that expands and there is nothing > > we can do about it, so changing reference frame won't help in understanding > > that it is just our obserwational effect not a true energy theft by some > > more less unidentified process. But still I belive that this reddening can > > be ballanced once when Universe start to collapse. > > Well I think that the problem is closer to the question: Why photons > getting out of potential well suffer from red-shift - where their energy > go in that case? then to the Doppler... > > well, your question, as I understood it, was about what's with the energy that seems to be missing because of the redshift. So I disagree. The cosmological redshift isn't caused by gravitational effects - i.e. gravitational reddening, but by combined effect of time dilatation and lenght change which comes from transformation from one reference frame to another - and together we call it "a doppler effect". Sahs Wolfe effect is a minor one here, and fully understood in terms of GR predisitons. However I do realise that my explanation is a bit outstretched, because SR do not allow space to change in time, or at least doesn't say anything about that. But on the other hand a single photon, or any other particle (eg. proton, neutrino) can't (or can ? - I think not :) feel it travels trough space that is actually expanding. If it did, we all would grow in time, atoms would have become greater etc. So eventually it makes no difference weather space is expandind or observer is receeding, except the problem I said before >> ******************************************************************************* Bartosz Lew e-mail: blew w astri.uni.torun.pl blew w astro.uni.torun.pl Centrum Astronomii UMK TORUN, POLAND www: http://adjani.astro.uni.torun.pl/~blew ******************************************************************************* From boud w astro.uni.torun.pl Tue Feb 24 21:40:26 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Tue, 24 Feb 2004 21:40:26 +0100 (CET) Subject: CMB energy In-Reply-To: References: Message-ID: On Tue, 24 Feb 2004, Jarek Rzepecki wrote: > Well I think that the problem is closer to the question: Why photons > getting out of potential well suffer from red-shift - where their energy > go in that case? then to the Doppler... When you throw a frictionless ball up in the air at initial vertical velocity v_0, it starts off with kinetic energy 0.5 m v_0^2 . So why does the ball lose (kinetic) energy as it goes up? Why does 0.5 m v^2 get smaller? Where does the energy go? From amr w astro.uni.torun.pl Wed Feb 18 10:00:16 2004 From: amr w astro.uni.torun.pl (Andrzej Marecki) Date: Wed, 18 Feb 2004 10:00:16 +0100 (MET) Subject: wewnetrzny grant UMK In-Reply-To: Message-ID: <200402180900.KAA08872@galileo.astro.uni.torun.pl> According to Boud: > Apparently we need to spend 5kPLN of an internal UMK grant There is no such limit! I called the rectorate - no formal limits. But... of course you can't apply for 1Mzł :) They say that the modest requirement is of the _order_ of 10kzł. In practical terms this means: if you apply for 5-10 kzł, there's a good chance you'll get through. > money/application and decide by tomorrow? The deadline is 21st Feb. AM From michalf w ncac.torun.pl Wed Feb 25 09:07:51 2004 From: michalf w ncac.torun.pl (Michal Frackowiak) Date: Wed, 25 Feb 2004 09:07:51 +0100 Subject: CMB energy In-Reply-To: References: Message-ID: <403C57D7.7060302@ncac.torun.pl> Bartosz Lew wrote: >On Tue, 24 Feb 2004, Jarek Rzepecki wrote: > > > >>On Tue, 24 Feb 2004, Bartosz Lew wrote: >> >> >> >>>The correct answer is: Nothing happened to that energy. >>> That is not the correct answer. A single photon loses its energy. >>>It's still there >>>(unless photons gets older or other crap like that), the only thing that >>>changed is that we no longer see hot photons because, as we've been tought >>>in high school, we're floating away from everything else according to the hubble law. >>>(So the answer is essentialy in the question ;) >>>The "doppler effect" which can easily be derived from SR transformaiton >>>formulas causes that we see everythig red. >>> SR do not apply to cosmology in this case as I believe. >>>The only difference from the >>>situation described above with observers looking at identical photons (and >>>yet seeing them in different colors) and >>>complication I see here is that it is not possible to find a recerence frame >>>in which we will see the whole CMB photons at different temperature - color >>>etc. This is of course because it's the space that expands and there is nothing >>>we can do about it, so changing reference frame won't help in understanding >>>that it is just our obserwational effect not a true energy theft by some >>>more less unidentified process. But still I belive that this reddening can >>>be ballanced once when Universe start to collapse. >>> >>> > >well, your question, as I understood it, was about what's with the energy >that seems to be missing because of the redshift. >So I disagree. The cosmological redshift >isn't caused by gravitational effects - i.e. gravitational reddening, but by >combined effect of time dilatation and lenght change which comes from >transformation from one reference frame to another - and together we call it >"a doppler effect". > > O really? I always thought calling photon reddening a "doppler effect" is the most naive one. A agree it comes from the transformation..... but it is far more complicated. If fact the problem as I see it is: photon field energy + energy of the gravitational field is conserved (when only those 2 fields are present). Have you never solved Friedmann's equations? Come back to the source, to the lagrangian density for the tensor grav. theory (Riemann tensors etc.) - I believe a conservation rule can be obtained at this level. As I remember the energy of the photon field (as well as any other form of the energy) is (depending on its equation of state) transfered between the grav. field and this particular field. Why do you think photon field is trying to slow down the expansion??? Because of this interaction. My answer is: do not treat photons as separate objects for the photon field is not an isolated system - the photon field interacts with the grav. field. If GR does not give you the answer - that would be a problem. >Sahs Wolfe effect is a minor one here, and fully understood in terms of GR >predisitons. > >However I do realise that my explanation is a bit outstretched, because SR >do not allow space to change in time, or at least doesn't say anything about >that. > Forget about SR in cosmology!!!!!!!!!!!!!!!!!!! >But on the other hand a single photon, or any other particle (eg. >proton, neutrino) can't (or can ? - I think not :) feel it travels trough >space that is actually expanding. > have you attended prof Rudak's lectures on cosmology? >If it did, we all would grow in time, atoms would >have become greater etc. So eventually it makes no difference weather space >is expandind or observer is receeding, except the problem I said before >> > > > we do not grow in time because subatomic, atomic (electromagnetic) and even gravitational interaction on small scales are MUCH STRONGER than the effect of space expansion. GR is not a "perfect" and "final" theory. But for sure all the modern cosmology (Friedmann's cosmology) is based on it. Search for the answer in GR. regards - michal From jarekr w ncac.torun.pl Wed Feb 25 09:57:41 2004 From: jarekr w ncac.torun.pl (Jarek Rzepecki) Date: Wed, 25 Feb 2004 09:57:41 +0100 (CET) Subject: CMB energy In-Reply-To: References: Message-ID: > When you throw a frictionless ball up in the air at initial vertical > velocity v_0, it starts off with kinetic energy 0.5 m v_0^2 . > > So why does the ball lose (kinetic) energy as it goes up? Why does > 0.5 m v^2 get smaller? Where does the energy go? Well, sure but how can one definne potential energy for a photon? From boud w astro.uni.torun.pl Wed Feb 18 13:26:18 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Wed, 18 Feb 2004 13:26:18 +0100 (CET) Subject: UMK grants by Sat 21 Feb for Wydzial Fizyki Message-ID: For UMK grant applications http://www.uni.torun.pl/badania/finansowanie/granty/umk/ From boud w astro.uni.torun.pl Wed Feb 18 17:41:56 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Wed, 18 Feb 2004 17:41:56 +0100 (CET) Subject: wewnetrzny grant UMK In-Reply-To: References: Message-ID: hi everyone, Attached are two equivalent copies of the draft application (pdf to help a certain person who uses micro$oft ;) Any substantial comments, criticisms? (Or trivial ones?) Given that it's for pedagogical purposes, i haven't put anything about a specific "research project". i put my title as "dr" since i presume i don't officially have "hab" until the central committee confirms it. i can expect the bureaucrats may complain that the format is slightly changed, but that's their fault for using micro$oft. They're here to support us, we're not here to work for them doing trivia. pozd boud -------------- następna część --------- Binarny załącznik wiadomości został usunięty... Nazwa: g.ps Typ: application/postscript Rozmiar: 132162 bytes Opis: UMK grant application postscript 132kb Adres: -------------- następna część --------- Binarny załącznik wiadomości został usunięty... Nazwa: grant04.pdf Typ: application/pdf Rozmiar: 160237 bytes Opis: UMK grant application pdf 160kb Adres: From amr w astro.uni.torun.pl Fri Feb 20 09:58:06 2004 From: amr w astro.uni.torun.pl (Andrzej Marecki) Date: Fri, 20 Feb 2004 09:58:06 +0100 (MET) Subject: Cosmo parameters according to VSA Message-ID: <200402200858.JAA26723@galileo.astro.uni.torun.pl> Paper: astro-ph/0402466 Title: Cosmological parameter estimation using Very Small Array data out to l=1500 Authors: Rafael Rebolo, Richard A. Battye, Pedro Carreira, Kieran Cleary, et al. We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other CMB data and external priors. Within the flat $\Lambda$CDM model, we find that the inclusion of high resolution data from the VSA modifies the limits on the cosmological parameters as compared to those suggested by WMAP alone, while still remaining compatible with their estimates. [...] From jarekr w ncac.torun.pl Mon Feb 23 14:26:35 2004 From: jarekr w ncac.torun.pl (Jarek Rzepecki) Date: Mon, 23 Feb 2004 14:26:35 +0100 (CET) Subject: CMB energy Message-ID: Hi all, CMB photons are red-shifted due to Universe expansion -> this means that the whole CMB energy gets smaller... where does it go? pozdrawiam Jarek From boud w astro.uni.torun.pl Mon Feb 23 14:41:06 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Mon, 23 Feb 2004 14:41:06 +0100 (CET) Subject: festiwal nauki Message-ID: hi - i updated the Festiwal Nauki page: http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004 Please correct, update, modify... i guess it's now obvious why there was silly bureaucracy - there's money (150 zl) paid to official speakers (and if i understood the small print, "students" cannot be paid, though doktoranci are OK) - this is not a "grassroots" festival by scientists... Missing info: how much time do we have? One hour? Two hours? And is this time schedule definitely fixed? Staszek Krawczyk and A Strobel seem to be the official contacts so i'm cc-ing them here. boud From boud w astro.uni.torun.pl Mon Feb 23 15:54:33 2004 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Mon, 23 Feb 2004 15:54:33 +0100 (CET) Subject: CMB energy In-Reply-To: References: Message-ID: On Mon, 23 Feb 2004, Jarek Rzepecki wrote: > Hi all, > CMB photons are red-shifted due to Universe expansion -> this means that > the whole CMB energy gets smaller... where does it go? > pozdrawiam > Jarek http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/CosmoFAQ -> http://www.astro.ubc.ca/people/scott/faq_email.html There's an FAQ on this but i'm not totally happy with it. > The photons that are observed in CMB observations have presumably been > traveling through space undisturbed since sometime after the big > bang. But thay have apparently lost energy in the process, as their > wavelength has changed. Where did this energy go? Did it go into the > gravitational field? > > Submitted by jamont at visto.com 4/00 > > I'm surprised I haven't been asked this before, since it's such a good > question! > > There are several different ways of looking at this. One answer would > be that the energy goes into the gravitational potential energy of the > whole Universe. Really this should be energy density, or energy within some fixed comoving volume. > Another answer is that it takes energy to expand the > Universe, and that this "work" comes out of the contents which are > expanding. e.g. pp34, 35 Liddle 2000 polski > Yet another answer is that the cooling of the CMB as the Universe > expands is part of a simple relativisitic solution which describes the > entire Universe, using the theoretical basis of General Relativity, > which is a well tested theory of gravity. And if part of that solution > appears to violate energy conservation, then tough! i would add the special relativistic point of view - energy is not an absolute quantity. On scales where curvature is small (much less than a horizon radius), SR (STW) is valid. The amount of energy depends on which reference frame you use. If you stick to one inertial frame, you can think of photons *not* losing any energy. E.g. Think of a UV photon which was emitted from a high redshift galaxy X when (in constant cosmological time) the first amoebae evolved on Earth and is today absorbed on the Earth. In the reference from of galaxy X, just using SR and not GR, the Earth is moving at extremely high velocity away from galaxy X. So when the UV photon is absorbed, the calculation for what physically happens should be made between a UV photon moving at c, and a spectrometer moving at, e.g. 0.9c. If we take an alternative inertial frame, where the Earth is at rest, then of course the energy of the photon in this frame is much lower - just standard SR. boud From amr w astro.uni.torun.pl Tue Feb 24 10:52:17 2004 From: amr w astro.uni.torun.pl (Andrzej Marecki) Date: Tue, 24 Feb 2004 10:52:17 +0100 (MET) Subject: festiwal nauki In-Reply-To: Message-ID: <200402240952.KAA14422@galileo.astro.uni.torun.pl> > http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/FestiwalNauki2004 > > Please correct, update, modify... Corrected... a.