Science Forums Biology Forum Molecular Biology Forum Physics Chemistry Forum Time and entropy
 User Name Remember Me? Password

 Physics Forum Physics Forum. Discuss and ask physics questions, kinematics and other physics problems.

# Time and entropy

## Time and entropy - Physics Forum

### Time and entropy - Physics Forum. Discuss and ask physics questions, kinematics and other physics problems.

#1
02-10-2006, 01:10 PM
 Don1 Guest Posts: n/a
Time and entropy

What is the relationship between time and entropy?

Why is entropy considered as a running down; toward a heat death of the
energy contained in the sun, stars, and planets?

Why can't energy be increasing?

Don

#2
02-10-2006, 02:33 PM
 Sam Wormley Guest Posts: n/a
Time and entropy

Don1 wrote:

The total mass-energy of the universe was fixed in the big bang.

#3
02-10-2006, 06:58 PM
 Don1 Guest Posts: n/a
Time and entropy

Sam Wormley wrote:

What's unfixing it? Why can't entropy remain the same, or be decreasing?

#4
02-10-2006, 07:05 PM
 PD Guest Posts: n/a
Time and entropy

Don1 wrote:

There isn't a fixed one, other than as time increases, then the *total*
entropy of the universe increases.

Heat death is not the *lowering* of energy, it's the homogenizing of
energy. The only reason we can do anything at all (motors, chemistry,
biology) is that energy is more concentrated in some places than in
others. It's the controlled gating of that energy from concentrated
spots to less concentrated spots that results in work, heat flow,
chemical processes.

I suppose it could be, but it doesn't seem to be, experimentally.
That's why we took note of energy as an interesting quantity that seems
to remain constant, and why we guessed that it is conserved.

#5
02-10-2006, 10:28 PM
 Sam Wormley Guest Posts: n/a
Time and entropy

Don1 wrote:

Entropy is a measure of the disorder of a system and is defined
by equations in this link
[Only registered users see links. ]

The mass-energy of a system can remain constant while
the entropy can change.
#6
02-11-2006, 01:13 AM
 Steve Pope Guest Posts: n/a
Time and entropy

Don1 <[Only registered users see links. ]> wrote:

They're certainly gaining potential energy since the universe
is expanding. I believe total mass plus energy is conserved --
something to do with the universe cooling.

Steve
#7
02-11-2006, 03:57 AM
 Allan Murray Guest Posts: n/a
Time and entropy

It wasn't my high school teaching (or university, that matter)
that made me beleive that gravity (only) attracts. I don't know what
planet you are living on. But it (so far) seems to be an experimentally
observable fact.

Allan Murray
[Only registered users see links. ]

I bet they still think that quantifying

#8
02-11-2006, 05:08 AM
 Allan Murray Guest Posts: n/a
Time and entropy

Because:

"Energy spontaneously tends to flow only from being concentrated in one
place
to becoming diffused or dispersed and spread out."

See Prof. Frank Lambert's website for a good (modern) explanation
[Only registered users see links. ]

Allan Murray
[Only registered users see links. ]

"Don1" <[Only registered users see links. ]> wrote in message

#9
02-19-2006, 02:47 AM
 Two Guest Posts: n/a
Time and entropy

"Don1" <[Only registered users see links. ]> wrote in message

The local universe is expanding at the speed of light, FAPP. It is
impossible for something to exceed (go faster than) the rate at which space
is being created. All things are involved in this expansion but are
'measured' locally without consulting the rate of change. It's called Time's
Arrow.

Imagine seeing the local universe from a position which saw all things
happening in the context of expansion; entropy as we consider it would not
be relevant.

Never mind the breaking glass returning to its original state metaphors. Way
too macro to be pertinent.

#10
02-19-2006, 02:49 AM
 Two Guest Posts: n/a
Time and entropy

"Sam Wormley" <[Only registered users see links. ]> wrote in message
news:Ur8Hf.767758\$_o.193853@attbi_s71...

Keep in mind the necessary artificiality of the 'system' to make the
equations work.

 Tags entropy , time

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home General Science Forums     Biology Forum     New Member Introductions Forum     Chemistry Forum         Organic Chemistry Forum     Physics Forum     General Science Questions and Layperson Board         Science and Religion Forum         Zoology Forum     Environmental Sciences and Issues General Forum     Chit Chat         Science and Lab Jokes     Article Discussion     Molecular Biology News and Announcements         Conferences , Symposiums and Meetings         Molecular Station Suggestion Forum         Instructions for Posting, Help, and Frequently Asked Questions     Science News and Views         Molecular Biology Lectures and Videos     Science Careers         Post-doctoral         Medical School         Ph.D Doctor of Philosophy         Science Jobs Forum Molecular Research Topics Forum     PCR - Polymerase Chain Reaction Forum         Real-Time PCR and Quantitative PCR Forum     Bioinformatics         BioStatistics Forum     Molecular Biology Techniques         Molecular Cloning Forum         Electrophoretic Mobility Shift Assay Forum         Agarose Gel Electrophoresis Forum         BioPhysics Forum         Gene Therapy     Cell Biology and Cell Culture         Apoptosis, Autophagy, and Necrosis Forum         Flow Cytometry Forum         Transfection Forum         Confocal - Microscopy Imaging Techniques         Immunology and Host-Pathogen Interactions         Signalling Biology         Stem Cell Forum     Basic Lab Protocols and Techniques         SDS-PAGE Gel Electrophoresis Forum     DNA Techniques         DNA Extraction Forum         cDNA Forum     Epigenetics Forum: DNA Methylation, Histone and Chromatin Study         ChIP Chromatin Immunoprecipitation Forum     Protein Science         Antibody Forum             Immunoprecipitation Forum         Western Blot Forum         Protein Crystallography Forum         Recombinant Protein Forum         ELISA Assay Forum         Protein Forum     Proteomics Forum         Peptide Forum         Mass Spectrometry Forum         2-D Gel Electrophoresis Forum     Omics and Genomics Forum         Microarrays Forum         Genomics Forum     RNA Techniques Forum         RNAi and SiRNA Forum     Histology Forum         Immunohistochemistry Forum         Immunocytochemistry Forum         Electron Microscopy Forum         Immunofluorescence Forum     Protocols and Methods Forum     Molecular Biology Articles and Protocols     Animal and Molecular Model Systems         Drosophila Forum         Yeast Forum         Zebrafish Forum         Botany Forum         C Elegans Forum         Arabidopsis and Plant Biology         Microbiology Forum         Knockout Mouse Forum     Chromatography Forum Products and Vendor Discussion     Molecular Biology Products and Vendors         Bad Product/Service? Post Here         Lab Equipment Discussion and Reviews Regional Molecular Biology Discussion     Forum Chemie     Forum Biologie     Forum Biologia     Forum Chimica     Forum Physik     Forum De Chimie     Forum De Physique     Forum Chemia     中国人分子的生物学论坛 Chinese     Greek Molecular Biology Forums     分子生物学のフォーラム Japanese     ميدان فارسى. Persian Molecular Biology     [أربيك] علم ساحة- Arabic     Forum de Biologie Moleculaire     Forum Biologia Molecolare     Forum die Molekularbiologie     Foro Biologia Molecular

 Similar Threads Thread Thread Starter Forum Replies Last Post jollyrogership@yahoo.com Physics Forum 64 03-31-2012 10:24 AM drelliot@gmail.com Physics Forum 0 08-29-2006 06:32 AM drelliot@gmail.com Physics Forum 1 07-06-2006 05:19 PM Yrael Physics Forum 3 09-12-2005 03:11 AM

All times are GMT. The time now is 09:40 PM.

 Contact Us - Molecular Biology - Archive - Privacy Statement - Top