Why is there zero gravity in space? By Michelle Thaller

Michelle Thaller: Joshua, you ask a really great question, “Why is there no gravity in space?” I bet you’ve seen pictures of the astronauts up in the space station and they’re floating around as if there’s no gravity at all. This is actually a really interesting misconception about what’s going on with the astronauts. And it gets to one of my favorite questions in all of astronomy, and that is: what is an orbit? What’s happening when astronauts are orbiting the Earth? And why does it appear like there’s no gravity in space?

So, to talk about why this is kind of a misconception, the astronauts are about 200 miles above the surface of the Earth in the space station; the space station orbits around us about once every 90 minutes. It’s not that they’re so far away from the Earth that there’s no gravity—in fact, if you built a skyscraper that was 200 miles tall and you were up on one of those top floors you might weigh a tiny little bit less, but you probably weigh at least about 80 percent what you normally would. You’re really not that much farther away from the Earth. So it’s not that they’re weightless because they’re in space and far away from the Earth, they’re actually close enough to the Earth to feel the gravitational pull of the Earth itself. So what’s going on? Why are they floating around?

Well, this is what an orbit really is. We have to get spacecraft going very, very fast to put them into orbit. That’s why we put them on rockets. Rockets launch spacecraft and get them going very, very fast, and if you’re in orbit where the space station is, you’re traveling at about 17,000 miles an hour.

Now, what happens to those astronauts is that they’re going very, very fast but they’re actually freely falling towards the Earth. The Earth has gravity, and that gravity is pulling them down just the same as what would happen as if you dropped a ball. If you dropped a ball it would fall to the floor. The same thing is happening to the astronauts; they are falling towards the surface of the Earth.

But here’s a cool thing: they’re going so fast they keep missing the Earth as they fall. And that’s the definition of an orbit.

Now think about it this way: I talked about dropping a ball and the ball just falls straight down; what would happen if I put the ball in a little cannon and shot it out? The ball would start to drop towards the Earth the minute it left the cannon, but the cannon has given it some velocity, and so the ball might go a hundred yards, right? It might actually go a hundred yards before it fell because the cannon gave it that velocity.

Now, let’s take an even bigger cannon, let’s take a huge cannon that can shoot things many, many miles. So you shoot the ball out, the ball is still falling freely towards the Earth all the time, but now it goes farther because you’ve given it more velocity. And maybe with a really big cannon, you can shoot a ball a hundred miles.

What about with a rocket? With a rocket, you could get something going so fast, up to 17,000 miles an hour, that as it fell freely towards Earth, Earth would keep curving away under it and it would keep missing it.

That’s what an orbit is, and that’s why you need a rocket to get into orbit. You need to get yourself going so fast that, as you fall back towards Earth, you keep missing it.

So the astronauts are not weightless because there’s no gravity in space; the astronauts are falling the same way a skydiver is falling freely through space, it’s just that they’re going so fast they keep missing the Earth.

They are all the time falling towards the Earth going fast enough that they keep missing it.

Everything that’s in orbit around anything else is doing the same thing. Right now you and I are falling freely towards the sun, but the Earth is moving, actually at about 30,000 miles an hour, and we keep missing the sun as we go around it, and that means we’re in orbit around the sun.

The moon is in orbit around the Earth. It’s falling towards the Earth, it’s just traveling so fast it keeps missing it. You’ve asked an excellent question. Everything in space that is orbiting is freely falling under gravity, it’s just going too fast to ever hit anything.

http://bigthink.com/videos/michelle-thaller-why-is-there-zero-gravity-in-space?utm_source=Daily+Newsletter&utm_campaign=e9898486a6-EMAIL_CAMPAIGN_2018_06_07&utm_medium=email&utm_term=0_45b26faecc-e9898486a6-43656993

The Two Options: A Christian’s View…… submitted by Dr. Thomas Mathai

So What is the Something That Must Have Always Existed?

There are only two options if we’re following the logic given in the cosmological argument.

  • Either the universe has always existed or
  • Something outside the universe has always existed

Scientific evidence shows us that the universe hasn’t always existed.

Here are some of the evidences that support that the universe did begin at a certain point of time:

1.  The Second Law of Thermodynamics

The Second Law of Thermodynamics states that the amount of usable energy in a closed system, like in the case of the universe, is decreasing.

In other words, the amount of usable energy is dying out just like the batteries die in your flashlight.

If a closed system like the universe is in fact running out of energy, then the universe can’t be eternal because a finite amount of energy could never have brought the universe through an eternity of time.

2.  The Universe is Expanding

In 1929, Edwin Hubble, made a discovery that the universe is expanding.

Once scientists understood that the universe was expanding, they realized that it would have been smaller in the past.

At some point historically, the entire universe would have been a single point.

This point is what many people refer to as the Big Bang, which is the point when our universe began to exist.

3.  The Cosmic Background Radiation

Physics.org describes the Cosmic Background Radiation as, “The left-over heat from the fireball of the Big Bang in which the Universe was born 13.7 billion years ago.”

While the age of the earth is speculation by scientists, most do agree that the Cosmic Background Radiation does point to a finite universe that has a specific age.

So to recap, here’s the cosmological argument which offers proof for the existence of God:

Who Created God?

Atheists usually say that if we follow the logic in the argument, then God must have had a creator too.

I used to bring up this objection to those who believed in God when I was an atheist.

However, the cosmological argument only states that everything that came into existence must have a cause.

God didn’t come into existence, He always was, is, and will forever be.

The cosmological argument points to the first cause of the universe as Someone that has always existed.

That is a part of the argument.

The argument points that there must be something that did not have a cause.

But Wait, Maybe that Eternal Creator isn’t God

Most atheists, if they concede that yes, there must be an eternal first cause to the universe, then they’ll say that we don’t know what it is.

They’ll says that science is still making new discoveries every day.

Therefore, they’ll say that there could be other life forms out there that we don’t know about yet, and maybe they are the ones that created the universe.

READ  How is God Glorified When People Don’t Respond to the Gospel?

God vs. Aliens (other life forms)

The bottom line is that there is no concrete evidence that other life forms exist.

You can tell me about the climate of Mars, or about Kepler-186f, and I’ll again say that there’s no concrete evidence that other life forms exist on those planets or anywhere else.

On the other hand, the evidence for the Christian God is much more concrete.

Why?

When we look at how Christianity spread after the death and resurrection of Jesus, we notice something that’s both fascinating and unique.

This unique thing is that the apostles and early followers of Jesus weren’t just martyred for their faith, most of them were tortured first before they were killed.

This is documented in historical books that are written by authors outside of the Bible, authors such as Josephus and Tertullian.

The reason that the torture and death of the first followers of Jesus is so significant, is because they were tortured for saying that they had witnessed the risen Christ.

You might be thinking, “So what? Hundreds of people die for their beliefs everyday.”

But hold on for a just a minute, there’s a huge difference.

The 12 apostles of Jesus

The first followers of Jesus were tortured and martyred for saying that they saw Jesus resurrected

Hundreds of people die everyday because they believe that their religion is true.

However, nobody is willing to die for a false testimony.

Did you notice the difference between these two?

If the apostles and early Christians were lying about seeing the risen Christ, then as soon as they would’ve experienced persecution and torture, then surely they would have changed their false testimony.

They would have said, “Sorry, we’re lying about seeing the risen Christ.  Please stop torturing us and let us go.”

But none of them withdrew their testimonies, they were tortured until death, and they maintained that they had seen the resurrected Jesus.

Why would so many people be willing to do die for a false testimony?

Do you know anyone that’s willing to die for giving a false testimony in court?

The answer is no.

That’s why this is one of the most compelling evidences for Christianity being an accurate belief system.

Wait, a Universe From Nothing is Possible, Says Stephen Hawking, Lawrence Krauss and Others

Sometimes atheists will bring up M-theory, or the multiverse, citing that it’s possible for a universe to be created from nothing.

M-theory is a theory that says that there’s either an infinite or finite amount of universes.

Since there are so many universes, then one of them must be fine-tuned to sustain life.

In Stephen Hawking’s book, The Grand Design, Hawking Writes, “Because there is a law of gravity, the universe can and will create itself out of nothing.

Both Hawking and Lawrence Krauss propose that it’s theoretically possible for the universe to have come from nothing using M-theory, string theory, and quantum physics to do away with God as being the creator.

However, there are major flaws to M-theory, and there are a number of respected physicists who point out these flaws.

Some physicists have gone as far as saying that M-theory isn’t even a science, it’s a pseudoscience.

Problems With M-Theory and a Multiverse

1.  M-theory requires the law of gravity and gravity is not “nothing.”  It’s “something.”

Any supporters of M-theory need to alter the definition of the word “nothing” to support their view.

Nothing is no-thing, it’s the state of non-being.

Scientific laws describe what happens under certain conditions and they need something to work on.

You can be sure that gravity isn’t nothing, it’s something.

2.  There is no evidence for a multiverse existing.

There isn’t much to be said here.  If there was evidence to support this theory, there wouldn’t be such a debate.

There is no observable evidence for an infinite, or even a finite number of universes existing.

3.  When physicists talk about “nothing”, they are talking about a quantum vacuum.  But there’s a problem.

A quantum vacuum is not nothing.

A quantum vacuum does have the properties of “something” as Dr. Alexander Vilenkin points out in this video.

If you’re interested in reading more about M-theory, the multiverse, and related topics, I recommend you check out this article by Focus.org, or this article by Professor John Lennox.

What Would the Universe Look like without God?

A universe without God wouldn’t exist, and you wouldn’t exist either if there was no God.

the Lord is the one who made us

This is my belief and personal conviction.

I used to think otherwise when I was an atheist, but now, I have peace knowing that I have a relationship with God, the creator of heaven and earth.

I shared with you my beliefs and I’d love to hear about yours.

Do you believe in God? Why or why not?

Universe shouldn’t exist, CERN physicists conclude

(We are told the universe was created by Big Bang. The Big Bang created equal amount of matter and antimatter, which should have destroyed each other and created energy. Obviously it did not happen, matter survived and it created universe. Theoretically universe should not exist. Recent experiments by CERN could not solve this puzzle. Will this lead to questioning the Big Bang Theory itself? Interesting article to read. f.sheikh )

A super-precise measurement shows proton and antiproton have identical magnetic properties, writes Cathal O’Connell.

One of the great mysteries of modern physics is why antimatter did not destroy the universe at the beginning of time.

To explain it, physicists suppose there must be some difference between matter and antimatter – apart from electric charge. Whatever that difference is, it’s not in their magnetism, it seems.

Physicists at CERN in Switzerland have made the most precise measurement ever of the magnetic moment of an anti-proton – a number that measures how a particle reacts to magnetic force – and found it to be exactly the same as that of the proton but with opposite sign. The work is described in Nature.

“All of our observations find a complete symmetry between matter and antimatter, which is why the universe should not actually exist,” says Christian Smorra, a physicist at CERN’s Baryon–Antibaryon Symmetry Experiment (BASE) collaboration. “An asymmetry must exist here somewhere but we simply do not understand where the difference is.”

Antimatter is notoriously unstable – any contact with regular matter and it annihilates in a burst of pure energy that is the most efficient reaction known to physics. That’s why it was chosen as the fuel to power the starship Enterprise in Star Trek.

The standard model predicts the Big Bang should have produced equal amounts of matter and antimatter – but that’s a combustive mixture that would have annihilated itself, leaving nothing behind to make galaxies or planets or people.

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To explain the mystery, physicists have been playing spot the difference between matter and antimatter – searching for some discrepancy that might explain why matter came to dominate.

So far they’ve performed extremely precise measurements for all sort of properties: mass, electric charge and so on, but no difference has yet been found.

Last year, scientists at CERN’s Antihydrogen Laser PHysics Apparatus (ALPHA) experiment probed an atom of anti-hydrogen with light for the first time, again finding no difference when compared with an atom of hydrogen.

But one property was known only to middling accuracy compared to the others – the magnetic moment of the antiproton.

Ten years ago, Stefan Ulmer and his team at BASE collaboration set themselves the task of trying to measure it.

First they had to develop a way to directly measure the magnetic moment of the regular proton. They did this by trapping individual protons in a magnetic field, and driving quantum jumps in its spin using another magnetic field. This measurement was itself a groundbreaking achievement reported in Nature in 2014.

Next, they had to perform the same measurement on antiprotons – a task made doubly difficult by the fact that antiprotons will immediately annihilate on contact with any matter.

To do it, the team used the coldest and longest-lived antimatter ever created.

After creating the antiprotons in 2015, the team were able to store them for more than a year inside a special chamberabout the size and shape of a can of Pringles.

Since no physical container can hold antimatter, physicists use magnetic and electric fields to contain the material in devices called Penning traps.

Usually the antimatter lifetime is limited by imperfections in the traps – little instabilities allow the antimatter to leak through.

But by using a combination of two traps, the BASE team made the most perfect antimatter chamber ever – holding the antiprotons for 405 days.

This stable storage allowed them to run their magnetic moment measurement on the antiprotons. The result gave a value for the antiproton magnetic moment of −2.7928473441 μN. (μN is a constant called the nuclear magneton.) Apart from the minus sign, this is identical to the previous measurement for the proton.

The new measurement is precise to nine significant digits, the equivalent of measuring the circumference of the Earth to within a few centimeters, and 350 times more precise than any previous measurement.

“This result is the culmination of many years of continuous research and development, and the successful completion of one of the most difficult measurements ever performed in a Penning trap instrument,” says Ulmer.

The universe’s greatest game of spot the difference goes on. The next hotly anticipated experiment is over at ALPHA, where CERN scientists are studying the effect of gravity of antimatter – trying to answer the question of whether antimatter might fall ‘up’.

https://cosmosmagazine.com/physics/universe-shouldn-t-exist-cern-physicists-conclude

Cathal 2016.png?ixlib=rails 2.1
CATHAL O’CONNELL is a science writer based in Melbourne.

Does God Exist?

  1.  

    Editorial Note:

    This thread was initiated in email loop by Syed Imtiaz Bokhari after reading an article in daily New York Times.            Syed Nayyar Bokhari provided a video from Facebook providing reasons in favor of Existence of God.                                   For serious discussion, this thread has been established in TFUSA website.

    nSalik {Noor Salik}

    “Does God exist? – Neil deGrasse Tyson and Michio Kaku Debate” on YouTube

    On Oct 24, 2017 11:13 AM, “Nayyar Bokhari” <> wrote:

    On Friday, October 20, 2017 10:32 AM, Bokhari Imtiaz
    Hi members, I downloaded this article from today’s NYT.
     Unknown Unknowns: Three Inquiries into Religion” philosopher Tim Crane is an atheist.
    James Ryerson reviewed this book and presented his comments in a very balanced and rational way. It is worth reading give us another perspective by an atheist philosopher on religion and its genesis.   
    Having surveyed religious traditions across the world and throughout history, he sees religion, at its core, as a set of “culturally prescribed practices” that aim to help people access “superhuman powers” in the hope of “realizing human goods” and avoiding bad things, typically “in conditions and situations they cannot control and with problems that they cannot solve.
    This seems to me is the crux of the religion, since ages people find solace in religion when confronted with problems in life to ward off calamities. To me it is a psychological remedy people looking for and it propel them to a comfort zones they created for them. It is still permeates all religions and people strongly belief in this cultural remedy, science has contrary view. Once they adhere to this philosophy their existential anxieties marginalized. 
    Worries about things like the meaning of life and the problem of evil are peripheral. “If religion could not promise the help of superhuman powers,” he concludes, “then religion would not exist.”
    With some my comments enjoy the article, expecting some feedback.
    Unknown Unknowns: Three Inquiries into Religion
    OCT. 20, 2017
    The philosopher Tim Crane is an atheist. Though educated in a Catholic environment, he has come to believe that nothing exists beyond the world of everyday experience and scientific explanation — nothing transcendent. Some people look around and think,this can’t be all there is. Crane is not one of those people. That he avows atheism, as opposed to agnosticism, does not strike him as presumptuous or arrogant. He has considered the relevant evidence and arguments as best he can and drawn the most reasonable-seeming conclusion. What more is a thinker supposed to do? He is convinced religious believers are wrong.
    But his qualm is not with them. As he explains in his lucid and thoughtful book THE MEANING OF BELIEF: Religion From an Atheist’s Point of View (Harvard University, $24.95), he is more troubled by some of his fellow atheists — specifically, those who campaign against religion as an irrational vestige of primitive thought outmoded by modern science. A notable feature of this campaign, Crane observes, has been its general failure to change the minds of religious people. Maybe those people are just foolish. Or maybe, as Crane is inclined to think, they do not recognize themselves or their beliefs in the picture of religion under attack. The atheists miss their target because they are aiming elsewhere. And because they fail to understand what religion is, they lack a suitably “realistic and feasible way to relate” to people of faith — which is to say, most people.
    In a spirit of reconciliation, Crane proposes to paint a more accurate picture of religion for his fellow unbelievers. Religion is an immense, sprawling and variegated affair. Any attempt to define it, however comprehensive, will omit some aspects and most attempts to define it, however crude, will capture something. The name of the game is what you see as central. Crane resists the notion, common to combative atheists, that the core of religion is an archaic cosmology (beliefs about things like the origin of the universe and supernatural agents) grafted onto a moral code. If you conceive of religion this way, as bad science plus arbitrary injunctions, of course you will think it should be replaced by good science and rational ethics.
    For Crane, the religious worldview is better understood as the combination of two attitudes. First: a sense of the transcendent, of an unseen moral order to the universe, often known as God. Second: an identification with a community that tries to “make sense of the world” by attempting to bring its members into alignment with this moral order through a tradition of narratives and rituals. Crane concedes there is a cosmology here; a belief in the transcendent is “a claim about the universe.” He also grants that religion, like science, is trying to explain things. But the kind of explanation and the kind of cosmology offered by religion, which does not “expect all aspects of the world to be intelligible,” are nothing like those of science, which strives to eliminate mystery.
    The atheist and evolutionary biologist Richard Dawkins has suggested that the idea of God is a “hypothesis” about a supernatural agent, ventured as a possible account of perplexing natural phenomena. Crane disagrees. The god of actual religious people — the source of the unseen orders that imbues everything with significance — is both vaguer and more nuanced than that. Science takes “complex or confusing things” and tries to explain them in terms of “simpler or clearer things.” God is not simple or clearReligion isn’t supposed to be a neat explanation of causal forces. It’s supposed to be a difficult explanation of the meaning of life. This explanation, Crane contends, is destined to be forever incomplete, always a struggle to fathom, not because it is missing some key facts, but because it involves “attempts to encounter” the transcendent.
    Crane himself thinks there is no transcendent reality, but he knows there can be no proof of this. Given the ineluctable enigma of existence, he believes religion can be a rational, “intelligible human reaction to the mystery of the world.”
    This picture of religion would no doubt strike the sociologist Christian Smith as “too cognitive, cerebral, intellectualist.” In his substantial, richly informed book RELIGION: What It Is, How It Works, and Why It Matters (Princeton University, $35), Smith offers a social scientific theory that disputes the notion, advanced by titans of social thought like Clifford Geertz and Max Weber, that religion is a cultural meaning system. “Religion is not at heart a set of replies to existential questions,” Smith writes, “even if it often involves this.”
    For Smith, the paradigmatic expression of religion is something like praying to God to cure your wife’s cancer, or beseeching a cloud spirit to bring rain to your withering crops.Having surveyed religious traditions across the world and throughout history, he sees religion, at its core, as a set of “culturally prescribed practices” that aim to help people access “superhuman powers” in the hope of “realizing human goods” and avoiding bad things, typically “in conditions and situations they cannot control and with problems that they cannot solve.” Smith is quick to acknowledge that this is not all religion provides, nor the sole reason people practice religion. But he maintains it is the “central” reason. And unlike other things religion does, like providing an identity (which a profession can also do) or seeking existential meaning (which philosophy can also do), it is “unique to religion.”
    A methodological hazard of discussing religion at this level of abstraction is the need, as Crane says, “to generalize the views of billions of people.” Smith hopes to avoid this difficulty by focusing less on subjective religious belief and more on public religious practices, which are “more or less objective.” This has allowed him, he believes, to focus on what religion is.He distinguishes this from what religion can do, its “secondary outgrowths” (things like fostering identity, meaning, and community and so on). Though these derivative features are “often crucial” for the personal experience and institutional strength of religion, they do not constitute its “ultimate raison d’être.”
    Smith’s is a theoretical work, but he provides ample illustrations of his theory, including religious traditions that might at first seem like counterexamples, such as American Protestant evangelicalism, which stresses the importance of beliefs and attitudes over rituals and customs. In all cases, he finds formalized calls for heavenly assistance, often involving this-worldly concerns like financial security and family health, to be central. Worries about things like the meaning of life and the problem of evil are peripheral. “If religion could not promise the help of superhuman powers,” he concludes, “then religion would not exist.”
    At some point in the distant past, of course, religion did not exist. The story of its emergence in the universe, and the significance of this story for our understanding of the nature of religion, are the subject of THE NEW COSMIC STORY: Inside Our Awakening Universe (Yale University, $25), by the theologianJohn F. Haught. Like Crane and Smith, he takes a “generalized approach” to religion; focusing on what all such traditions have in common. Unlike Crane and Smith, he sees religion as something whose journey, like that of the rest of the universe described by modern science, is “unfinished,” and hence whose nature must be understood, in part, in terms of where it may be headed.
    Haught describes religion as the “anticipation of a rightness that is now mostly out of range.” This formulation resembles Crane’s, with its transcendent moral order both everywhere present and agonizingly beyond reach. But Haught, a man of faith, disagrees with Crane that religion’s truths will necessarily remain so remote. Ever since the Big Bang, we have seen the emergence of matter, then life, then conscious life — and then, most notably, in Haught’s estimation, the human consciousnessof “interior striving” that finds its zenith in our “spiritual adventures.”
    Who knows what advances in religion the next stage of the universe’s evolution will bring? Thanks to modern science, Haught argues, we know “the cosmic story is far from over” and can look “patiently and expectantly ahead for a possible meaning to it all.” Should such a cosmic gift come to pass, it would amount to a salvation of the physical world, not a deliverance from it — a kind of redemption perhaps even an atheist could live with.
    James Ryerson is a senior staff editor for The Times’s Op-Ed page