Scusate se pubblico doppio questo post ma pare che blogspot abbia deciso di dare i numeri con le date. Continua infatti a ricacciarlo indietro di un mese per quanto io mi ostini a cambiare la data.
Incollo sotto i commenti che erano già stati inseriti.
------------------------
Avendo ormai raggiunto mia figlia la maggior età, credevo di essermi lasciato alle spalle il periodo delle imbarazzanti domande che hanno come incipit "perché", a favore di altre, forse non meno imbarazzanti, ma a cui un genitore si sente solitamente più preparato a rispondere e che, magari con timore, si prepara to deal with for years.
So the other night at dinner I was duly prepared to answer questions on love, peace in the universe, the exhaustion of stocks of petroleum and well also on sex, with little children when I innocently asked if I that there is other intelligent life in the universe and if you believe in the possibility of time travel?
I put up on how "mature father (but not too much) in front of naive daughter (but not too much) and I reply in order:
A) You think there is other intelligent life in the universe (and I quote pompously Margherita Hack)
B) I do not think you can travel in time.
I relax, down with the guard (on the other hand tonight I will not answer Questions about love, sex and universal peace) e. .. SBAMMMMM ... I get the knockout blow.
"Why do not you think the theories of Stephen Hawking?"
falters, stammered something like "Stephen who?" I try to catch me on the ropes but the little ones, seem possible to knock out does not give up.
"but Stephen Hawking talking about physics ... and do not know who is Hawking?" (Angelic voice accusatory)
From the angle I can help my partner "is not that a physical disability issues that is also involved in astronomy" (you can not imagine how many resources have a dance teacher) . Luckily the maid plays the gong with the excuse to take orders and I take this opportunity to rearrange ideas.
clear who you are talking about the debate focuses on two points
1-Stephen Hawking (as I understand it) does not exclude the existence of other life in the universe. Does not exclude that the universe has seen other intelligent life beyond our own. Believes it unlikely that intelligent life may exist at the same time in this universe. Not impossible but highly unlikely. Even more, it is unlikely, and there would be more appropriate to say, impossible, that these life forms could ever meet.
So far I get it. I can not share at all (but I'm just a poor father, he a great physicist ..) but I understand ...
2 - Stephen Hawking says he is convinced that we can travel in time, but only forward. To prove it is inspired by the famous example of astronauts leaving for a trip at relativistic speeds. Upon their return to Earth to discover that those who stayed past the time is faster and a father who left a young child, she discovers that now this is older than him.
Now my daughter tells me about a thought experiment proposed in a CNN documentary, and inspired by this idea of \u200b\u200bHawking. If you build a train that could travel at near the speed of light and a railroad which circumnavigates the globe, the passengers on that train could travel, For example, for a week, starting from point A, turning several times around the earth, falling back to point A and see that in reality on the ground some years have passed. This is actually a time machine.
And here my mind reels before the paradox. Although he knew the broad outline of the paradoxes of relativity and also that it proposes a truly escapes me.
Speed \u200b\u200bis relative to the observer. So if it is true that the train is moving relative to the earth at a speed close to that of light, it is also true for observers on the train, the earth is moving at that speed while the train rather than to stop them.
a result ... because the passage of time should slow down just for them? If the observers on the ground see the train slow down time, because there should not be the same effect for those off the train, look out the window events?
Who helps me to reaffirm my (benign) parental authority?
For those interested in the articles by Stephen Hawking, I can find some on his website:
http://www.hawking.org.uk/
------------ ----------
4 comments:
- ataru1976 said ...
-
Fair sure that your daughter has only 18 years?
not that you are to have traveled in the train and now your daughter is in her thirties?
O_O Maybe I'll be unlucky, but the people I know (even more than eighteen years old) I know just talking about the big brother and I, who do not watch it, I never know what to say.
Regarding your question, I think that to understand the experiment, you should place outside of both systems: the train is traveling around BC, not the earth. So
time on the train is accelerated compared to that on Earth.
I hope I was clear and had not shot too many heresies ... - February 25, 2011 19:59
- allison said ...
-
it is the twin paradox, a seeming contradiction to special relativity. In reality, those who get on the train not only moves at the speed of light. but accelerates to reach this speed. This acceleration means that the symmetry breaking.
- February 25, 2011 20:27
- Orsovolante said ...
.jpg "Orsovolante")
-
I am convinced that you are right but ...
@ ataru because the train traveling near C and the earth not? What is the observer's frame of reference? If he were sitting on a photon from the Sun even the earth travels around C
@ Allison
It also speeds up the land for those who are on the train ... it is true that those who are on the train "change" accelerated frame of reference and then return to the Earth decelerating (ok, it is always in physics acceleration :-)) ... probably in this passage from one reference system to another that's the catch I'm missing. PS my
figlia ha appena compiuto 19 anni... temo qualche volta abbia guardato il GF ma il bello è che fa studi classici.
In ogni caso tendo a riporre nei giovani molta più fiducia di quanto vedo fare da molti adulti e questa cosa è anche causa di molte discussioni con i miei colleghi e conoscenti in genere. - 25 febbraio 2011 21:19
- Orsovolante ha detto...
-
@Allison
Non ricordavo il nome del paradosso... quello dei gemelli e la tua dritta è quella giusta. In effetti bisogna tenere conto n0on di due ma di tre sistemi inerziali.
Per adesso sto leggendo la soluzione su wiki, poi, se sopravvivono abbastanza neuroni, provo a cercare qualcosa di più scientifico (ma la vedo dura :-) ) - 25 febbraio 2011 21:30
0 comments:
Post a Comment