Cosmological models that describe how the universe has evolved are getting quite good at describing the process from “recombination” (i.e. the time when the CMB was produced) up to now. The CMB reveals local fluctuations and, with the right amount of dark matter stirred in, the models can explain how galaxy/galaxy clusters start forming.

However, where did the density fluctuations come from in the first place? The very early ‘stuff’ of the universe was in a state that current main-stream physics cannot handle. Clearly it did not expand uniformly but created almost a ‘foam-like’ distribution of matter.

Current thoughts are that quantum fluctuations did exist in the very early universe (i.e. before inflation) and these became the seeds of the density variations. When inflation happened, quantum variations in the primordial ‘stuff’ expanded so rapidly that they became ‘frozen in’ as permanent regions of density variation.

Implicit in the proposal of smoothness

I feel that if this is true, this should lead to a universe where matter is distributed uniformly across space

is the assumption of an equilibrium, a thermodynamic equilibrium is how smoothness is created in matter as we know it. In order for such an equilibrium to exist all the space time points of the tiny universe immediately after the the Big Bang should be able to interact with each other. This is not true because in the model special relativity still holds and there are parts of the universe that do not have access to others, due to the light cones.

Despite the above argument, the Cosmic Microwave Background data show remarkable uniformity from the time that the photons decoupled from the hadronic soup.


at the level of 10^-8 the universe showed uniformity that could not have been achieved if General Relativity and Special Relativity, foundation stones of the Big Bang model, hold.

Looking at the details of the map in such definition one sees the blobs and depletions which led to the currently granular nature of the observable universe.


To explain the inconsistency, an effective quantization model for gravity was introduced for the first times after the Big Bang, before 10^-32 seconds . The inflaton with its quantum mechanical indeterminancy is not constrained by the particle definitions and the velocity of light, and thus it could churn the early universe into a homogeneous soup, the quantum mechanical fluctuations giving the observed inhomogeneity over the largely homogeneous early universe.

Yet most matter is clumped up into stars and planets, with areas of nothing in between. What could have led to such an irregular universe?

Inflation has been continuing ever since 10^-32 seconds , space expanding as the Big Bang models currently, and this expansion has distanced the clumps generated by the quantum effects of the inflaton into what is currently a clumpy universe.





BRIAN GREENE: And if that’s not strange enough, the direction you move makes a difference, too. Watch what happens when the alien turns around and bikes toward Earth. The alien’s new “now slice” is angled to…toward the future, and so it includes events that won’t happen on Earth for 200 years: perhaps our friend’s great-great-great granddaughter teleporting from Paris to New York. Once we know that your now can be what I consider the past, or your now can be what I consider the future, and your now is every bit as valid as my now, then we learn that the past must be real, the future must be real. They could be your now. That means past, present, future…all equally real; they all exist.

The alien, 10 billion light years away from us, can only see our region of the universe as it was 10 billion years ago, which did not include our solar system yet. However, he could look over here, right now and legitimately say that the future of this region of the universe, for the next 10 billion years is already written. Whether or not it includes earthlings will take him another 10 billion years to find out. We are seeing the region of the universe that now presumably contains this alien as it was 10 billion years ago, and its future for the next 10 billion years has already been written. Whether or not it includes an alien will take us another 10 billion years to learn. Even if this alien, at the “present” time, hops in his spaceship and accelerates up to almost the speed of light, it will take him another 10 billion years to get here (although it could be only seconds for him) and another 10 billion years of history will have gone by during his trip, which did not yet exist at the time he started his trip. Or, if we want to consider an alien from 10 billion years ago (who we could now “see”) who would do the same thing, he would be just now arriving and during his trip, the past 10 billion years of history would have transpired in this region of the universe, as well as in his home region of the universe. (We could watch his journey and it would only take a few seconds of our time to “see” him go from his home to our home.) These comments assume, as Brian Greene does, that we are using a Frame of Reference in which an earthling or an alien is at rest. But one of the tenets of Special Relativity is that only those conclusions that are frame invariant are reflective of reality. Coordinate times and distances are frame dependent and do not comport with reality.

It’s just like in the Twin Paradox where both twins “see” time dilation in the other one’s clock and different frames will define different amounts of time dilation to the two clocks but it’s only when they return that all frames agree on the difference in time accumulated on the two clocks. Brian Greene is talking only about coordinate times on distant clocks as defined by different Frames of Reference. Of course they are going to be different but this has nothing to do with whether any future has already been written.

The Andromeda Paradox emphasises that the hyperplane called “now” is just a coordinate-based labelling of events. “Future” and “past” are meaningful only insofar as they refer to an observer’s light cones.

This, at present, is more of a philosophical question because the statement, ‘time exists’ is axiomatic with regards to physics. It seems that we need it so as to preserve causality but at the same time we don’t understand it’s presence. I like to visualize time as a membrane on which all events are allowed to flow only radially outward. A sort of heuristic boat on a lake scenario, in which the water (time) allows the boat (object) to move across the lake (space). As you go cross the lake in your boat the ripples radiate radially outward through time and space and the water isn’t being created in front of the boat as it moves across the lake, it already exists there.

Also, something sort of fun I like to think about with regard to time travel and how it is probably not possible therefore time can not be malleable.
Disclaimer: You will most likely have to read this a few times to get what I am trying to say.

Let us assume that the possibility to travel backward through time exists, then at some later time, say in 100 years from now we will actually be able to travel back in time. Also, we must stipulate that if we did travel backward in time we would be able to interact with the space at that time. And lastly, we must stipulate that time does not branch (i.e. no infinite universes theory). So, if time travel is possible then what is to say that right now is not the future’s past? That is to say that someone from the future has traveled back to now. Our present time would then be the future’s past. Because time travel is possible would mean that our present time is not the probable ‘leading edge’ of time because anyone from the future could go back to any point in time. Actually, our present time would be the least probable candidate for being the ‘leading edge’ of time (Assuming all points in time have equal “weight”).

Now since it is most probable to believe that we are existing in the past of some future time and our recorded history shows no evidence of anyone from the future traveling back in time, then their are only a couple possibilities.

Time travel is not possible, people who have traveled back in time have not been recorded into our documented history, or we are the ‘leading edge’ of time. Since there is no evidence in our historical record that someone has traveled back to then and that we are unlikely the leading edge of time, I propose that the ability to time travel is highly unlikely. Therefore time is not malleable.

Has a very distant event in our personal past and outside our personal past light cone, already happened?

Since there is no such thing as a universal simultaneousness, everyone’s personal ‘now’ cuts right through many other’s definitions of ‘past’ and ‘future’, so what exactly would a Universe look like if we’d assume the future hasn’t already happened? How would a Universal ‘now’ progress spatially if it has to deal with everyone’s definition of it?

Or, what I was referring to with the first sentence, what would a Universe look like if everyone’s past only already occurred, if it has moved within their personal past light cones? How would the Universe’s ‘coming to existence’ progress spatially, if everyone’s measurements only makes it real? When we look at the moon, all we are allowed to know is that it was there 1.3 seconds ago…

It’s at least a lot easier to think of the future as already being out there, like some four dimensional object that we live in, with the illusion of moving through it. Like Greg’s rather dogmatic explanation here.

Dr. Greene illustrated how space and time are connected by comparing the space time of the universe to a loaf of bread. Each slice of the bread was a “now” of a different section of the universe. He demonstrated how an alien on the other side of the galaxy going away from earth “now” would include our future.

Once we know that your now can be what I consider the past, or your now can be what I consider the future, and your now is every bit as valid as my now, then we learn that the past must be real, the future must be real. They could be your now. That means past, present, future…all equally real; they all exist.

Just as we think of all of space as being “out there,” we should think of all of time as being “out there” too. Everything that has ever happened or will happen, it all exists, from Leonardo da Vinci laying the final brushstroke on the Mona Lisa; to the signing of the Declaration of Independence; to your first day of school; to events that, from our perspective, are yet to happen, like the first humans landing on Mars.

Just the way an entire movie exists on celluloid, think of all moments of time as already existing too. The difference is that in the movies, a projector lights up or selects each frame as it goes by, but in the laws of physics, there is no evidence of something like a projector light that selects one moment over another. Our brains may create this impression, but in reality, what we all experience as the flow of time really may be nothing more than an illusion.

This means I’m already dead in someone else’s “now”. If the alien is traveling close to speed of light toward you, he is actually freeze in time in your time frame, you’ll be progressing until you are dead in normal speed, then the alien will wake up and find you dead.

Me: I heard Jamal from 90th street watched that tape last week and this mornin’ he woke up dead!

You: How the hell do you wake up dead?

Me: Cause’ you’re alive when you go to sleep.

You: So you’re telling me you can go to bed dead and wake up alive?

Me: You can’t go to bed dead! That shit would’ve been redundant.

You: No it would’nt cause’ you can go to bed and not be dead, and you can die and not be in the bed.

Me: But you are in the bed. That’s how you wake up dead in the first place fool!

You: Damn! that’s some quantum shit right there man! You should be teaching classes!







Apa itu Dark Matter ?

Sebelum saya membahas tentang dark matter & dark energy, saya ingin menekankan bahwa apa yang akan saya jabarkan di sini adalah simplifikasi dari konsep yang sebenarnya. Untuk mengetahui secara detail dan menyeluruh, Anda perlu membaca lebih lanjut jurnal ilmiah serta hasil penelitian terbaru berkaitan dengan substansi ini

Sebelum saya menjabarkan lebih jauh, saya ingin sedikit menceritakan kedua pendekatan dalam fisika. Dalam upaya mengungkap tabir misteri alam semesta, para ilmuwan fisika menggunakan 2 pendekatan, yang pertama pendekatan observational/pengamatan (experimental physics) dan yang kedua adalah pendekatan secara teoritis (theoretical physics). Dalam upaya mendapatkan jawaban tersebut, kedua pendekatan ini saling melengkapi dan saling mengoreksi satu sama lain.

Pada awalnya para ilmuwan beranggapan bahwa seluruh materi dan energi yang tersusun dari proton, neutron, dan elektron mencakup semua substansi yang ada di jagat raya ini. Akan tetapi berdasarkan pengamatan terhadap benda-benda langit (astronomical observation), ternyata ada bentuk materi dan energi yang kasat mata namun berperan besar terhadap berbagai fenomena fisika yang terjadi di seluruh alam semesta. Materi dan energi itulah yang kemudian diberi nama Dark Matter dan Dark Energy.


Perkembangan teori tentang dark matter ini berjalan berdasarkan proses observasi dan pendekatan matematis yang sangat panjang, penuh dengan koreksi, sanggahan, kemudian diperkuat kembali, hingga menjadi hipotesa kuat sampai dengan saat ini. Proses dari perkembangan teori ini bisa Anda lihat di timeline cosmological theories. Untuk mempermudah, Anda bisa langsung lihat dan perdalam materinya sejak Edwin Hubble pada tahun 1924 mengetahui bahwa alam semesta ini terdiri dari begitu banyak galaksi.

Untuk mempermudah pemahaman tentang dark matter, saya akan mencoba merangkum dan menyederhanakan semua hasil observasi dan pendekatan matematis terhadap sejarah terbentuknya konsep ini, sebagai berikut:

Singkat cerita…

Secara teoritis, diketahui bahwa total force yang dibutuhkan untuk memicu Big Bang adalah dengan besaran tertentu (katakanlah sebesar X). Sedangkan secara observational, jumlah force yang bisa dideteksi ternyata tidak sebesar X, melainkan lebih kecil dari X, katakanlah sebesar Y.
Berarti secara teoritis ada suatu force yang “menghambat” ekspansi laju X menjadi sebesar Y, force itulah yang kita namakan sebagai gravitasi, dan secara matematis sederhana ditulis sebagai M = X-Y.

Kemudian secara observational, para ahli astrofisika kembali menemukan fakta unik, bahwa ternyata total force gravitasi di alam semesta ini tidak sejumlah M, tapi lebih kecil dari itu, kali ini ilmuwan menyepakati dengan sebutan m (m huruf kecil).

Selisih antara M besar dengan m kecil (M-m) atau (delta M = △M) inilah yang disebut dengan DARK MATTER.
Dark matter ini berperan besar dalam interaksinya dengan gravitasi di seluruh jagat raya serta bertanggung jawab terhadap keteraturan dari kecepatan rotasi yang (hampir) konstan dari seluruh galaxy di alam semesta.

Dark matter ini disebut dark karena dia tidak dapat berinteraksi dengan electromagnetic fields (cahaya). Sifat inilah yang menyebabkan dark matter tidak dapat dilihat oleh kita. Kemudian materi ini disebut matter, karena sifat satu-satunya yang bisa kita ketahui adalah bahwa materi ini bisa mempengaruhi gravitasi.

Sejauh ini telah banyak dilakukan upaya untuk mendeteksi adanya dark matter, tetapi hasilnya belum memuaskan. Terlepas dari sifatnya yang belum bisa kita observasi, tidak lantas kita bisa mengatakan bahwa materi ini tidak ada. Karena pada dasarnya tetaplah ada materi yang berinteraksi dengan gravitasi dan bertanggung jawab terhadap mekanisme interaksi materi di semua galaxy di jagat raya ini sehingga seluruh materi di dalam galaxy berotasi secara (hampir) konstan—sedangkan Dark Matter hanyalah masalah penamaan terhadap materi ini.
Jadi memang secara observasi dark matter ini belum bisa dibuktikan, tapi sejauh ini para ilmuwan memiliki inferential evidence yang sangat kuat bahwa substansi ini hampir pasti benar-benar ada.



Kecepatan pengembangan alam semesta yang diukur saat ini adalah 74.3 ± 2.1 km/s / megaparsec.
Mengapa kecepatan mengembangnya ditambahi “per megaparsec” ?
Karena untuk setiap megaparsec jarak dari pengamat, kecepatan expansi alam semesta bertambah 74.3 ± 2.1 km/detik
1 megaparsec = 1 juta parsec
1 parsec = 3,26 tahun cahaya atau 31 triliun km.

Apa Gravitasi Mempengaruhi Waktu? Bagaimana dengan kecepatan?
waktu berjalan lebih cepat diketinggian, apalagi di angkasa. Kalau mau lebih muda beberapa detik tinggal di dasar laut, semakin dekat ke pusat gravitasi waktu berjalan lebih lambat. Cerita mengenai lebih muda di angkasa adalah jika mampu bepergian melebihi kecepatan cahaya sehingga memundurkan waktu, maka pulangnya bisa lebih muda.
beda cerita Di ISS waktu berjalan lebih lambat daripada di bumi, karena ISS juga bergerak sangat cepat, ingat ada efek Special Relativity dan General Relativity juga yang mempengaruhi Time Dilation.

Sementara perbedaan waktu di ISS bukan karena gravitasi, tapi karena kecepatan mengorbit ISS itu sendiri yang amat sangat cepat dibandingkan rotasi bumi. Kecepatan rotasi bumi sekitar 1.666 KM/H (keliling equator dibagi 24 jam), sedangkan kecepatan ISS sendiri 28.164 KM/H. Makanya crew di ISS mengelilingi bumi satu putaran setiap 90 menit di ISS, berarti kan mereka bisa melihat matahari terbit dan matahari terbenam setiap 45 menit



Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people. – Carl Sagan

Ada apa sebelum universe? Jawabannya ada bigbang-Pertanyaan selanjutnya ada apa sebelum Big-Bang? “Sebelum BigBang ada kegelapan (Darkness), anda juga bisa menyebutnya Nothing, tapi dalam pengertian baru, dimana Nothing bukanlah sebuah kondisi “Kosong” atau “Hampa”, tapi sebuah kondisi ketidakstabilan materi dimana interaksi yang terjadi pada level itu adalah chaos, science terutama particle physic menyebutnya quantum mechanic.

Quantum mechanic adalah sebuah theory yang sanggup menjelaskan alam semesta pada level subatomic, pertanyaan apa yang terjadi sebelum bigbang bisa didekati dengan quantum mechanic, dalam buku yang ditulis dengan elegant oleh Lawrence M Krauss “The Universe From Nothing” dijelaskan bahwa, pertanyaan mengapa sesuatu yang ada lebih baik dari pada sesuatu yang tidak ada, karena sesuatu yang ada bisa diamati, diteliti, kemudian diuji coba melalui experiment. Dan proses uji coba ini telah berlangsung sejak 500th terakhir sejak era copernicus.

Ide tentang alam semesta (Universe) telah menjadi imaginasi tertinggi dari manusia sejak lama, dimana dimasa lalu manusia percaya bahwa alam semesta ini diciptakan oleh sesuatu kekuatan besar yang tak terdeteksi, tak terjangkau bahkan oleh nalar manusia, concept ini dikenal dengan nama “GOD”, tuhanlah yang bertanggungjawab menciptakan alam semesta ini, dan tidak ada keraguan dalam koncep itu.

Pertanyaan yang bisa diajukan adalah, mengapa konsep “tuhan” tidak bisa dipertanyakan?” alasan yang paling sederhana adalah karena konsep itu sudah final, harga mati dan manusia sebagi mahluk yang lemah akalnya tidak diperkenankan untuk mempertanyakan konsep itu, apapun dan dimanapun kondisinya, dan bagi siapapun yang dengan berani mempertanyakan konsep itu maka akan siap denga konsekwensi yang paling mengerikan dari otoritas agama yang mengclaim sebagai wakil tuhan diatas planet ini.

Dalam sejarah perkembangan kesadaran manusia, mereka yang memcoba mempertanyakan konsep itu harus berhadapan dengan “kematian”, Giordano Bruno seorang ilmuan, philosopher italia 1548-1600 harus mati secara mengenaskan karena mencoba memberikan perspektif baru atas dunia tempat species manusia hidup.

Artinya agama yang sejak lama mencoba mendominasi pikiran manusia atas realitas yang complex, dan tidak membiarkan pikiran-pikiran alternatif muncul dari manusia merdeka seperti G.Bruno untuk menjelaskan bagaimana sebenarnya alam semesta dan realitasya bekerja.

Gagalnya agama dalam menjawab pertanyaan-pertanyaan fundamental seperti dari mana semua materi ini berasal, atau mengapa bumi itu bulat dan tidak kotak?”atau mengapa manusia memiliki kemampuan menganalisa, membangun dan sekaligus menghancurkan tidak sanggup dijawab secara menyakinkan oleh agama. Kemudian science lahir dari manusia-manusia Curios seperti Copernicus, yang mencoba memberikan penjelasan logis dan membantah theory ptolemy yang menyebutkan bahwa bumi adalah pusat dari alam semesta, yang terbukti dikemudian hari memang keliru, bumi bukanlah pusat dari alam semesta, dan bumi juga bukan pusat dari tata surya.

Artinya apa yang dipahami oleh manusia dimasa lalu, terutama mereka yang nongkrong dibarisan otoritas agama, salah, dan bisa anda bayangkan ada berapa juta manusia yang sudah terlanjur percaya dengan theory-theory yang disodorkan oleh agama, terutama otoritas gereja saat itu. Jutaan manusia telah tertipu, jutaan manusia telah percaya pada sesuatu yang keliru dan bagi saya itu adalah pelajaran yang sangat berharga bagi kemanusiaan.

Science tidak mengclaim mengetahui segalanya, science juga bukan hanya soal kepastian (Certain), tapi pada level paling fundamental science justru adalah ketidakpastian (Uncertain) dan disanalah menariknya science, mencoba menjelaskan sesuatu yang “Unknown” menjadi “Known”, dimana 500th yang lalu manusia percaya matahari bekerja mengelilingi bumi, namun setelah science lahir “kepercayaan” itu kemudian direvisi sesuai dengan kenyataan yang sesunguhnya. Inilah science, bekerja berdasarkan methode yang ketat, jelas dan harus melewati experiment, tanpa itu tidak ada yang namanya science.

Seorang teman mengirimkan tulisan menarik kepada saya, yang judulnya “RUNTUHNYA PEMUJA SAINTIK, TAPAL BATAS SAINS — ada apa sebelum universe ?–

Secara umum tulisan ini cukup menarik dan “akurat” dalam argument, namun menjadi runtuh ketika kawan ini mencoba memasukkan variabel Qur’an dalam menjelaskan bagaimana alam semesta bekerja, apa yang terjadi sebelum bigbang, karena pertanyaan”ada apa sebelum universe”saya kira kurang akurat.

Terakhir, untuk menutup catatan singkat ini, saya ingin menampilkan quote singkat dari seorang Ilmuan yang bertanggung jawab melahirkan Quantum Mechanic, Warner Heisenberg, “Bukan hanya Quantum Mechanic itu weird, dalam pikiran kita, tapi weird dalam Imaginasi terjauh yang pernah dijangkau oleh manusia”, ini terjemahan bebas dari saya.