Talk:Sputnik 1

An event mentioned in this article is an October 4 selected anniversary.

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100 km is not equal 150 miles -- Vassili Nikolaev

Very true. I'll take whichever was listed first in the page's history and adjust the other. — Toby 11:10 Oct 10, 2002 (UTC)

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I've cut "had a size about that of a basketball" because it assumes the reader has knowledge of what a basketball is (and the basketball article doesn't actually say how big one is until a page down or so). Far too many things on Wikipedia assume the reader is familiar with US culture. -- Tarquin 13:55 Feb 22, 2003 (UTC)

Hmmmm ... On the other hand, US culture is so widely known (in order not to offend my US friends, I'm resisting the temptation to say "so damn widely known") that most people probably do know how big a basketball is, certainly most people who can read English and access a computer to visit Wikipedia with. And "about the size of a basketball" is clear and easily understood, where "a diameter of 27.6cm" (or whatever size it was) is less so.

Perhaps we could say "about the size of a soccer ball" instead. (Tannin hears Mintguy coming, sees big stick, runs for cover.)

perhaps just give a diameter, maybe the reader will rather think of it as a small pumpkin or a large melon. Susan Mason

let's give a diameter and link it to an orders of magnitude page. Those pages then give a variety of comparisons. Readers are invited to own a ruler. ;-) -- Tarquin 17:15 Feb 22, 2003 (UTC) (remember that we may also one day produce paper versions of Wikipedia, which may go to places where US culture does not reach. Tarquin Goes to wash his mouth out for using the words "US" and "culture" together... ;-) )

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The article seems to be full of inconsistencies, it states that Sputnik 1 burned upon reentry on Jan 3 1958, then it states that it's orbit started to decay starting on Jan 4 1958 and then stayed in this declining orbit for almost a year and in Dec 9 1958 it was orbiting 600 km above the earth instead of the original 947 km. Then it says Sputnik 1 fell back to earth Jan 4 1958. So one case states reentry on Jan 3, and another on Jan 4 1958. The third one states that on Jan 4 1958 Sputnik's orbit merely started decaying and has no further reference on when it actually crashed. When trying to find several sites for sources I got conflicting reports as well, so far these are the 4 I have found.

-incinerated upon reentry Jan 3 1958

-incinerated upon reentry Jan 4 1958

-on Jan 4 1958 Sputnik's orbit started to decay (reached 600 km alltitude on Dec 9 1958 but no further mention of it's faith)

-incinerated upon reentry after 844 days in space

It seems the several sites on the Sputnik can't be trusted for information on the Sputnik 1, how de we proceed to get the right answers in the article, I'm yet a amateur wikipedian and not sure about the procedures on these matters. --Jimius 16:20, 2 Sep 2004 (UTC)

Re: the weight/mass issue, as far as I have been taught in my A-Level Physics course, Sputnik still had a weight. It just provides the centripetal force for the orbit rather than pulling the satellite to the ground. It seems to me that this comment is just plain wrong... Drw25 21:03, 14 Oct 2004 (UTC)

but isn't the equation for centripetal force f= m(v²/r? that doesn't include weight only mass. (ok so physics is really not my area)Geni 23:01, 14 Oct 2004 (UTC)

Indeed - the force in question (F) is the weight of the satellite, which provides the centripetal force. Drw25 15:30, 15 Oct 2004 (UTC)

If we look at Weight it defeines weight as "the force exerted upon an object by virtue of its position in a gravitational field". The force in the equation is the centripetal force (which is why it should be writen F_centripetal)Geni 16:17, 15 Oct 2004 (UTC)

But a satellite is still in the gravitational field of the earth and consequently a force still acts:

The gravitational attraction between two bodies (ie. weight of one body in the other's gravitational field) is given by the equation mg=GMm/(r^2) where m and M are the masses of the two bodies, G is the gravitational constant and r is the distance between the two bodies - if you put numbers into these equations, it's pretty clear that the weight of a satellite is very significant at its radius orbit. This force provides the centripetal force for the orbit to occur. The centripetal force is not present because circular motion occurs, the circular motion occurs because the centripetal force is present. Centripetal force is a cause, not a consequence. Drw25 17:42, 15 Oct 2004 (UTC)

but doesn't that equation assume that the two objects are statick? the sputnik was in free fall.