Do we really know what a graviton is?
Clash Royale CLAN TAG#URR8PPP
up vote
6
down vote
favorite
Just a random, baseless question I'm throwing out there; but how do we know that we haven't discovered the graviton? How do we know we haven't just labeled it as something else? i.e. how do we know for instance the Higgs boson isn't a graviton? If we found it, and it wasn't like what was predicted, would we know to label it as a graviton?
particle-physics gravity quantum-gravity carrier-particles
edited Aug 20 at 6:26
Qmechanic♦
96.3k121631016
asked Aug 20 at 0:41
tox123
320115
add a comment |Â
up vote
6
down vote
favorite
Just a random, baseless question I'm throwing out there; but how do we know that we haven't discovered the graviton? How do we know we haven't just labeled it as something else? i.e. how do we know for instance the Higgs boson isn't a graviton? If we found it, and it wasn't like what was predicted, would we know to label it as a graviton?
particle-physics gravity quantum-gravity carrier-particles
edited Aug 20 at 6:26
Qmechanic♦
96.3k121631016
asked Aug 20 at 0:41
tox123
320115
1
Saying that we haven't discovered the graviton is like saying we haven't discovered the photon in 1850. This sentence means that "we have not yet detected quantum aspects of the gravitational wave".
– pathintegral
Aug 20 at 0:55
6
It has not been proven that gravity is quantum. There may be no gravitons at all.
– safesphere
Aug 20 at 5:03
add a comment |Â
up vote
6
down vote
favorite
up vote
6
down vote
favorite
Just a random, baseless question I'm throwing out there; but how do we know that we haven't discovered the graviton? How do we know we haven't just labeled it as something else? i.e. how do we know for instance the Higgs boson isn't a graviton? If we found it, and it wasn't like what was predicted, would we know to label it as a graviton?
particle-physics gravity quantum-gravity carrier-particles
edited Aug 20 at 6:26
Qmechanic♦
96.3k121631016
asked Aug 20 at 0:41
tox123
320115
Just a random, baseless question I'm throwing out there; but how do we know that we haven't discovered the graviton? How do we know we haven't just labeled it as something else? i.e. how do we know for instance the Higgs boson isn't a graviton? If we found it, and it wasn't like what was predicted, would we know to label it as a graviton?
particle-physics gravity quantum-gravity carrier-particles
edited Aug 20 at 6:26
Qmechanic♦
96.3k121631016
asked Aug 20 at 0:41
tox123
320115
edited Aug 20 at 6:26
Qmechanic♦
96.3k121631016
edited Aug 20 at 6:26
Qmechanic♦
96.3k121631016
edited Aug 20 at 6:26
Qmechanic♦
96.3k121631016
96.3k121631016
asked Aug 20 at 0:41
tox123
320115
asked Aug 20 at 0:41
tox123
320115
asked Aug 20 at 0:41
tox123
320115
320115
1
Saying that we haven't discovered the graviton is like saying we haven't discovered the photon in 1850. This sentence means that "we have not yet detected quantum aspects of the gravitational wave".
– pathintegral
Aug 20 at 0:55
6
It has not been proven that gravity is quantum. There may be no gravitons at all.
– safesphere
Aug 20 at 5:03
add a comment |Â
1
Saying that we haven't discovered the graviton is like saying we haven't discovered the photon in 1850. This sentence means that "we have not yet detected quantum aspects of the gravitational wave".
– pathintegral
Aug 20 at 0:55
6
It has not been proven that gravity is quantum. There may be no gravitons at all.
– safesphere
Aug 20 at 5:03
1
1
Saying that we haven't discovered the graviton is like saying we haven't discovered the photon in 1850. This sentence means that "we have not yet detected quantum aspects of the gravitational wave".
– pathintegral
Aug 20 at 0:55
Saying that we haven't discovered the graviton is like saying we haven't discovered the photon in 1850. This sentence means that "we have not yet detected quantum aspects of the gravitational wave".
– pathintegral
Aug 20 at 0:55
6
6
It has not been proven that gravity is quantum. There may be no gravitons at all.
– safesphere
Aug 20 at 5:03
It has not been proven that gravity is quantum. There may be no gravitons at all.
– safesphere
Aug 20 at 5:03
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
15
down vote
accepted
The properties of the graviton include:
- it has spin 2
- it is massless (so the force it carries is long range)
- it couples to the stress-energy tensor, which basically means everything should be able to emit and absorb gravitons
- it has zero electric charge and zero color charge
These are extremely distinctive properties, so it's really unlikely that we've already seen the graviton and not noticed. For example, the Higgs has spin 0 and it is massive.
In fact, since the graviton is massless and can be produced by anything, we hypothetically produce tons of them all the time; you produce them whenever you move. The issue is not that we've seen it and not noticed, but that a graviton is too feeble to be seen at all.
answered Aug 20 at 0:53
knzhou
32.9k895165
1
It also has zero isospin charge (unlike the Higgs). More generally, it has no non-trivial internal charges, because the metric has no internal indices.
– AccidentalFourierTransform
Aug 20 at 1:12
Neutrino almost fits the bill, but it has spin 1/2 instead of 2. Would a composite of four neutrinos work?
– John Dvorak
Aug 20 at 10:53
@JohnDvorak the Weinberg Witten Theorem rules out composite gravitons in a local QFT
– CStarAlgebra
Aug 20 at 11:28
@JohnDvorak Neutorinos have masses.
– user1803551
Aug 20 at 12:40
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
15
down vote
accepted
The properties of the graviton include:
- it has spin 2
- it is massless (so the force it carries is long range)
- it couples to the stress-energy tensor, which basically means everything should be able to emit and absorb gravitons
- it has zero electric charge and zero color charge
These are extremely distinctive properties, so it's really unlikely that we've already seen the graviton and not noticed. For example, the Higgs has spin 0 and it is massive.
In fact, since the graviton is massless and can be produced by anything, we hypothetically produce tons of them all the time; you produce them whenever you move. The issue is not that we've seen it and not noticed, but that a graviton is too feeble to be seen at all.
answered Aug 20 at 0:53
knzhou
32.9k895165
1
It also has zero isospin charge (unlike the Higgs). More generally, it has no non-trivial internal charges, because the metric has no internal indices.
– AccidentalFourierTransform
Aug 20 at 1:12
Neutrino almost fits the bill, but it has spin 1/2 instead of 2. Would a composite of four neutrinos work?
– John Dvorak
Aug 20 at 10:53
@JohnDvorak the Weinberg Witten Theorem rules out composite gravitons in a local QFT
– CStarAlgebra
Aug 20 at 11:28
@JohnDvorak Neutorinos have masses.
– user1803551
Aug 20 at 12:40
add a comment |Â
up vote
15
down vote
accepted
The properties of the graviton include:
- it has spin 2
- it is massless (so the force it carries is long range)
- it couples to the stress-energy tensor, which basically means everything should be able to emit and absorb gravitons
- it has zero electric charge and zero color charge
These are extremely distinctive properties, so it's really unlikely that we've already seen the graviton and not noticed. For example, the Higgs has spin 0 and it is massive.
In fact, since the graviton is massless and can be produced by anything, we hypothetically produce tons of them all the time; you produce them whenever you move. The issue is not that we've seen it and not noticed, but that a graviton is too feeble to be seen at all.
answered Aug 20 at 0:53
knzhou
32.9k895165
1
It also has zero isospin charge (unlike the Higgs). More generally, it has no non-trivial internal charges, because the metric has no internal indices.
– AccidentalFourierTransform
Aug 20 at 1:12
Neutrino almost fits the bill, but it has spin 1/2 instead of 2. Would a composite of four neutrinos work?
– John Dvorak
Aug 20 at 10:53
@JohnDvorak the Weinberg Witten Theorem rules out composite gravitons in a local QFT
– CStarAlgebra
Aug 20 at 11:28
@JohnDvorak Neutorinos have masses.
– user1803551
Aug 20 at 12:40
add a comment |Â
up vote
15
down vote
accepted
up vote
15
down vote
accepted
The properties of the graviton include:
- it has spin 2
- it is massless (so the force it carries is long range)
- it couples to the stress-energy tensor, which basically means everything should be able to emit and absorb gravitons
- it has zero electric charge and zero color charge
These are extremely distinctive properties, so it's really unlikely that we've already seen the graviton and not noticed. For example, the Higgs has spin 0 and it is massive.
In fact, since the graviton is massless and can be produced by anything, we hypothetically produce tons of them all the time; you produce them whenever you move. The issue is not that we've seen it and not noticed, but that a graviton is too feeble to be seen at all.
answered Aug 20 at 0:53
knzhou
32.9k895165
The properties of the graviton include:
- it has spin 2
- it is massless (so the force it carries is long range)
- it couples to the stress-energy tensor, which basically means everything should be able to emit and absorb gravitons
- it has zero electric charge and zero color charge
These are extremely distinctive properties, so it's really unlikely that we've already seen the graviton and not noticed. For example, the Higgs has spin 0 and it is massive.
In fact, since the graviton is massless and can be produced by anything, we hypothetically produce tons of them all the time; you produce them whenever you move. The issue is not that we've seen it and not noticed, but that a graviton is too feeble to be seen at all.
answered Aug 20 at 0:53
knzhou
32.9k895165
answered Aug 20 at 0:53
knzhou
32.9k895165
answered Aug 20 at 0:53
knzhou
32.9k895165
answered Aug 20 at 0:53
knzhou
32.9k895165
32.9k895165
1
It also has zero isospin charge (unlike the Higgs). More generally, it has no non-trivial internal charges, because the metric has no internal indices.
– AccidentalFourierTransform
Aug 20 at 1:12
Neutrino almost fits the bill, but it has spin 1/2 instead of 2. Would a composite of four neutrinos work?
– John Dvorak
Aug 20 at 10:53
@JohnDvorak the Weinberg Witten Theorem rules out composite gravitons in a local QFT
– CStarAlgebra
Aug 20 at 11:28
@JohnDvorak Neutorinos have masses.
– user1803551
Aug 20 at 12:40
add a comment |Â
1
It also has zero isospin charge (unlike the Higgs). More generally, it has no non-trivial internal charges, because the metric has no internal indices.
– AccidentalFourierTransform
Aug 20 at 1:12
Neutrino almost fits the bill, but it has spin 1/2 instead of 2. Would a composite of four neutrinos work?
– John Dvorak
Aug 20 at 10:53
@JohnDvorak the Weinberg Witten Theorem rules out composite gravitons in a local QFT
– CStarAlgebra
Aug 20 at 11:28
@JohnDvorak Neutorinos have masses.
– user1803551
Aug 20 at 12:40
1
1
It also has zero isospin charge (unlike the Higgs). More generally, it has no non-trivial internal charges, because the metric has no internal indices.
– AccidentalFourierTransform
Aug 20 at 1:12
It also has zero isospin charge (unlike the Higgs). More generally, it has no non-trivial internal charges, because the metric has no internal indices.
– AccidentalFourierTransform
Aug 20 at 1:12
Neutrino almost fits the bill, but it has spin 1/2 instead of 2. Would a composite of four neutrinos work?
– John Dvorak
Aug 20 at 10:53
Neutrino almost fits the bill, but it has spin 1/2 instead of 2. Would a composite of four neutrinos work?
– John Dvorak
Aug 20 at 10:53
@JohnDvorak the Weinberg Witten Theorem rules out composite gravitons in a local QFT
– CStarAlgebra
Aug 20 at 11:28
@JohnDvorak the Weinberg Witten Theorem rules out composite gravitons in a local QFT
– CStarAlgebra
Aug 20 at 11:28
@JohnDvorak Neutorinos have masses.
– user1803551
Aug 20 at 12:40
@JohnDvorak Neutorinos have masses.
– user1803551
Aug 20 at 12:40
add a comment |Â
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f423690%2fdo-we-really-know-what-a-graviton-is%23new-answer', 'question_page');
);
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
1
Saying that we haven't discovered the graviton is like saying we haven't discovered the photon in 1850. This sentence means that "we have not yet detected quantum aspects of the gravitational wave".
– pathintegral
Aug 20 at 0:55
6
It has not been proven that gravity is quantum. There may be no gravitons at all.
– safesphere
Aug 20 at 5:03