Thread: 100 hour day?

I recently read something I didn't understand from a respected scientist.

He said Homo sapiens could not have evolved on earth if the eart-day were 100 hours long (as opposed to 24 hours long), but he didn't explaine why, and I've been scratching my head since.

Can anyone imaigine why he would have made this statement?

Who is the respected scientist? Can you provide a link to what he said?

This is just off the top of my head but it could be due to the fact the Earth's magnetic field is related to the rate of rotation, if the day was 100 hours long (not 24) the slower rate of rotation would lead to a smaller magnetic field, so there would be less protection from cosmic rays, solar wind etc, leaving conditions too harsh for life to evolve... (This could be bollocks but as I say, just my first initial thought on reading your post).

Originally Posted by WhyGuy

He said Homo sapiens could not have evolved on earth if the eart-day were 100 hours long (as opposed to 24 hours long), but he didn't explaine why, and I've been scratching my head since.

I've seen studies showing that we actually prefer a 25 hour cycle, based on what cycle people naturally revert to when there are no clocks and no cues about day and night.

100 hours could also cause those dudes to die hard during the night.
fire rising out of woods usually cannot stay 50 hours long, and some animals are going to eat those dudes

Originally Posted by cosmictraveler

Who is the respected scientist? Can you provide a link to what he said?

Jaques Vallee

He said

If the day was 100 hours long instead of 24, mankind as we know it could not have evolved or survived at all.

http://www.jacquesvallee.net/bookdocs/arguments.pdf

OK, yeah. Pages 8 and 9.
All he is saying there that if the conditions life evolved under were different then the life forms would have evolved differently.
It is a simple truism that does nothing to support his "fringe" idea that UFOs are from other dimensions.

As a point of interest it is surprising how many award winning scientists adopt totally crank ideas about things not related to their own narrow area of expertise. There used to be a list on the internet of Nobel Prize winners who went crank, I do not know if it is still available.

I think the key phrase is "mankind as we know it". Of course if you increased the length of the day by 4x it would effect how a creature evolves to survive. Homos Longassdayus would probably have better night vision to deal with 50 hours of dark, or may even hibernate for a couple of days. You would definitely have a more extreme temperature swing. I hate to see mid July in Texas with 50 hours of baking sunshine.

If days were 100 hours long our eating habits (and digestive processes) would be vastly different.
Imagine waking up having slept for (two of our) days: how hungry would you be?
On top of that, (supposing we were suited to a 100-hour day) we'd be physiologically different: fatigue levels, metabolic rate...

It's likely that if even the smallest of things were different, life would have taken a different evolutionary path and come up with something other than Homo Sapiens as its most intelligent species.

~ Just understanding the subject is a dyslectic's nightmare.. When I saw this post thread, I immediately got it wrong..
It was too easy for me to jump in the wrong direction. I saw 100 hours as a change to the way we measure time.. The existing Day becoming a devided into 100 not 24. WRONG.. This is about the FACT that this evolutionary process would have to have been very different if the day was so long as the Day night period was 100 hours long.. Earths rotational velocity.. Yes we may not have evolved from the swamp.. Too hot, too cold.. Different.

I would say the most considerable thing is if everyday is 100 hours long, those creatures are all dead already. earth has Not enough rpm, not enough magnetic field to protect creatures from deadly sun radiation.

I think the biggest effect would be much hotter days and colder nights.

Now that it's clear to me that we are talking of a slower rotation velocity.. I make this view known..
Life of any kind might not have evolved here at all.
I have some understanding of how much the temperature would change over a 50 hour night and 50 hour day..
I imagine a lot of rain and cloud cover as extra heat would evaporate and to refreeze when the night arrives..
or a Venus type of harshness we are wanting to avoid.. Not only would we not be here..
Nothing would have emerged from the swamps of primitive Earth..

It's all about magnetic field. Coz creatures can still live in hot temperature or long our sunshine like ever night and ever day happened at South Pole and North Pole. But
radiation from sun Will turn every inch of earth into nuclear waste land

Originally Posted by mozarc

It's all about magnetic field. Coz creatures can still live in hot temperature or long our sunshine like ever night and ever day happened at South Pole and North Pole. But radiation from sun Will turn every inch of earth into nuclear waste land

Three points:

1.The long nights/long days at the North and South poles are moderated by the more normal variations at other longitudes, and no part of the planet has the extreme variations in temps over a relatively short period that would be the result of a 100 hr day in the lower latitudes.

2. The forms of life that do now live in these extremes originally evolved in much less extreme environments and by slow adaptation spread into the extreme regions. With a 100 hr day, lifeforms would have to deal with the extremes from the get go.

3. As far as I can tell from Jaques Vallee's statement, "as we know it" is a key phrase. In other words, life that evolved and was adapted to a 100 hr day would be much different than the life we see on our planet. If any intelligent life form were to arise on such a world it would bear no resemblance to present humans. H eis not arguing that life itself could not evolve on such a world, just that evolution on such a world would not lead to anything resembling us.